DARPA funds developing Quantized Inertia into breakthrough space propulsion

DARPA is giving $1.3 million for a four-year study of quantized inertia (QI) for possible breakthrough space propulsion.

The QI theory predicts that objects can be pushed by differences in the intensity of so-called Unruh radiation in space, similar to the way in which a ship can be pushed towards a dock because there are more waves hitting it from the seaward side.

The theory has already predicted galaxy rotation without dark matter, and the fact that if a system is accelerated enough – such as a spinning disc or light bouncing between mirrors – the Unruh waves it sees can be influenced by a shield. Therefore, if a damper is placed above the object, it should produce a new kind of upwards thrust.

Chemical rockets are very expensive because of the explosive propellant they need, so this new kind of thruster would be much cheaper and safer as it would only need a source of electrical power to accelerate the core of a thruster.

The research is being funded through DARPA’s Nascent Light-Matter Interactions (NLM) programme, which aims to improve the fundamental understanding of how to control the interaction of light and engineered materials.

It will see Dr McCulloch collaborating with experimental scientists from the Technische Universität Dresden in Germany, and the University of Alcala in Spain.

Over the first 18 months, the Plymouth team will seek to develop a fully predictive theoretical model of how matter interacts with light (Unruh radiation) using the quantized inertia model. This will provide a new predictive tool for light-matter interactions.

A series of experiments will then be conducted in Germany and Spain to test whether the thrust is specifically due to quantized inertia, and whether it can be enhanced significantly.

284 thoughts on “DARPA funds developing Quantized Inertia into breakthrough space propulsion”

  1. Say you construct a 10m long coilgun with a block fixed to it to it in front of the muzzle, with the entire structure on freely rolling wheels. if you were a to accelerate a piston down that coil gun under low acceleration so as not to cause the structure to roll backward with recoil, and allow that piston to impact your fixed block, would the structure shift forward? That is what QI is effectively stating should be possible, only with radiation in a box.

  2. Chemical rockets are very expensive because of the explosive propellant they need”. Chemical rockets are expensive only because they are not reusable. The propellant alone is comparatively very cheap. https://www.theverge.com/…/spacex-reusable-rocket-refurbishment-repair-design-cost… Dec 24, 2015 – It costs $60 million to make the Falcon 9, and $200,000 to fuel it, according to SpaceX CEO Elon Musk.

  3. Chemical rockets are very expensive because of the explosive propellant they need””.Chemical rockets are expensive only because they are not reusable. The propellant alone is comparatively very cheap.https://www.theverge.com/…/spacex-reusable-rocket-refurbishment-repair-design-cost…Dec 24″” 2015 – It costs $60 million to make the Falcon 9 and $200000 to fuel it”” according to SpaceX CEO Elon Musk.”””

  4. The true promise of the emdrive is (in addition to being useful for station keeping) would be for interstellar flight. Chemical rockets are woefully inadequate.

  5. But now SpaceX has shown us that they ARE reusable. fly that Falcon 9 a hunderd times and its only 800,000 / launch

  6. It’s not just the difficulty of managing high temperature combustion. It’s also that the energy content of the fuel is low compared to the energy necessary to get out of our gravity well. This drives the need for extreme weight savings, in order to get high mass ratios. If chemical fuels had ten times the energy, or Earth a much shallower gravity well, rockets would be cheap to build.

  7. Siamsam: The huge expense of chemical rockets comes from having to build a machine capable of managing, & surviving, the explosive propellant. As an analogy: Elon Musk has found electric car engines need less engineering in this sense (no explosions, fewer moving parts, less wear & tear). The saving with electrically-powered launchers would be far better.

  8. The true promise of the emdrive is (in addition to being useful for station keeping) would be for interstellar flight. Chemical rockets are woefully inadequate.

  9. But now SpaceX has shown us that they ARE reusable. fly that Falcon 9 a hunderd times and its only 800000 / launch

  10. It’s not just the difficulty of managing high temperature combustion. It’s also that the energy content of the fuel is low compared to the energy necessary to get out of our gravity well.This drives the need for extreme weight savings in order to get high mass ratios. If chemical fuels had ten times the energy or Earth a much shallower gravity well rockets would be cheap to build.

  11. Siamsam: The huge expense of chemical rockets comes from having to build a machine capable of managing & surviving the explosive propellant. As an analogy: Elon Musk has found electric car engines need less engineering in this sense (no explosions fewer moving parts less wear & tear). The saving with electrically-powered launchers would be far better.

  12. Hello Mike. What do you think about the latest developments on the Emdrive? Seems like some fairly professional replications will declare their results negative. This has put the discussion on some formerly lively places like NASA Spaceflight forum into a sad, moody state. I understand your theory predicts some thrust but it should be weaker than most proponents of the Emdrive expected, probably now making some of the experimenters to declare it an artifact, are they giving up too soon?

  13. Good luck to them and to Mike, who seems to be around. It’s not by playing safe and by the rules that things change. And if it doesn’t pan out, at least we’ll know more. There are far worse things to waste public money on. Specially if this is something with so much potential ROI.

  14. If they can fly it ten times the components are reliable. To get it up to 100 they need to be resistant to fatigue problems too. I would not be shocked if that carbon fiber tank has issues after multiple flights it’s really pushing the edge for current art.

  15. Assuming it actually works which I view as a rather long shot at this point.Without some kind of radical physics breakthrough (manned) interstellar travel would still be possible but the infrastructure demands would be immense we couldn’t do it until we were approaching being a K-2 civilization.

  16. Hello Mike. What do you think about the latest developments on the Emdrive?Seems like some fairly professional replications will declare their results negative.This has put the discussion on some formerly lively places like NASA Spaceflight forum into a sad moody state.I understand your theory predicts some thrust but it should be weaker than most proponents of the Emdrive expected probably now making some of the experimenters to declare it an artifact are they giving up too soon?

  17. Good luck to them and to Mike who seems to be around.It’s not by playing safe and by the rules that things change.And if it doesn’t pan out at least we’ll know more. There are far worse things to waste public money on. Specially if this is something with so much potential ROI.

  18. faster than c? only if you know how to build a hyperdrive motivator, understand how to align warp coils, deploy stargates or compute jump drive coordinates!

  19. Posting this again, my earlier comment will probably surface afterwards… Doing this faces the “Far Centaurus” problem: You leave on a 2500 year trip, and a century later some idiot comes up with a ship that’s more than 4% faster, and beats you there. It’s a long recognized issue in the literature of manned interstellar flight. I seriously doubt anybody is going to launch a manned interstellar fight before the ships have gotten fast enough, and progress has stalled enough, that they’d be reasonably confident of reaching the destination before a better ship launched later. Exceptions, of course, for “Holy spit, the sun is going to explode!”, and people colonizing outbound comets and launching them on hyperbolic trajectories just to get away from here, not arrive first someplace else. I expect the first manned ship, barring major physics breakthroughs, to use mass beam propulsion on this end of the trip, and nuclear or magnetic braking against the destination’s solar wind, at the other end. Thus, huge infrastructure requirements for the mass beamer.

  20. Sounds interesting for getting around the neighborhood. But Unruh is limited to “c”. Makes for a long trip to the next town (star), or county (say, Perseus). Develope it – yes, very good. Any hope of going faster?

  21. If they crack that problem, (Assuming the haven’t already, which wouldn’t shock me.) we’d never hear about it. The proliferation problems would be terrifying, at least fission triggers make nuclear bombs easy to track.

  22. Or, we had pure fusion detonation without the drawback of fission triggers to propel an Orion type launch vehicle. Someone pulls-off a direct ignition of fusion, will bring other issues to the table.

  23. Put two ocean going tankers side-by-side for a lightering; and, run the experiment in calm wind with nothing more than a heavy chop present. Will find they will tend to close upon the other.

  24. If I have a say in how my tax money is spent, by all means test every theory for reactionless drives we can. Even if they do not pan out we may get blessed by the god of serendipity and discover one that does work and opens access to the stars. In the meantime, by all means let’s spend the money on the best systems we can build now that will open up the solar system to us. Laser propulsion, nuclear plasma, heck an Orion drive craft built on the dark side of the moon with 1000 crew members if we can. Whatever it takes to get us off this ball of mud. Possibly the new Space Force will provide the resources considering a Navy ship or Air Force planes are just targets from orbit.

  25. Does the physics work out for conventional (i.e. reaction-mass effected) rocket propulsion to get Humans to other stars within their lifetimes? Even assuming reasonable stretching of that lifetime thru hibernation, genetic adaptations, genetic-damage repair and other “active” systems? Say… 2,500 years, with hibernation. And the genetic angles. Say… harnessing most-efficient but not magic nucleonics Say… tho’ dreamy, cannot use antimatter rationally. What’s left? Both fission and fusion remain good candidates, “fuels” are sources of energy and potential reaction-mass stores. If we go with radioactives that emit energetic charged particles for one type of thrust, that have capture-able fission or fusion energies at modestly impressive efficiencies (greater than 70%), … and so on … The Tsiolkovsky Rocket Equation still rules. ΔV = Vₑ ln( Mᵢ/Mᵩ ), no matter what. Vₑ = 9.81 × ISP. Mᵢ is initial mass of rocket. Mᵩ is final mass, after exhausting a bunch of reaction mass at Vₑ. To get to a nearby (say “within 25 light years”) star system (of which there are 176 systems, excluding all below-brown-dwarfs which we obviously haven’t detected, but also which include at least 26 and probably over 125 systems with planets), AND STOP THERE (I believe an important criterion!), we have what… a 2500 year budget? D = ½at₁² + vt₂ Where t₁ is the acceleration phase, and t₂ is the ‘drifting along’ phase. Hard to say where the break is, until we can quantify the emission-rate of reaction mass. But let’s say “1% per year of original mass”. Sure, its a rabbit-out-of-the-hat guess, but its not unreasonable. t₁ = 70 years t₂ = ½(2500) – 70 t₂ = 1180 years Vₑ = 33% of 1 MeV for single-charged fission nucleons Z ≈ 120. Vₑ ≈ 727,000 m/s per nucleon a(t) = F / M(t) where mass changes as reaction mass is used up. Calculus! Nonetheless, one can approximate that mean( a(t) ) is approximately (1 ⊕ ¹⁄₀.3) ÷ 2 or 2.16× the Mᵢ initial mass calculation. So… using ‘A’ ins

  26. If they can fly it ten times, the components are reliable. To get it up to 100, they need to be resistant to fatigue problems, too. I would not be shocked if that carbon fiber tank has issues after multiple flights, it’s really pushing the edge for current art.

  27. Assuming it actually works, which I view as a rather long shot at this point. Without some kind of radical physics breakthrough, (manned) interstellar travel would still be possible, but the infrastructure demands would be immense, we couldn’t do it until we were approaching being a K-2 civilization.

  28. faster than c? only if you know how to build a hyperdrive motivator understand how to align warp coils deploy stargates or compute jump drive coordinates!

  29. Posting this again my earlier comment will probably surface afterwards…Doing this faces the Far Centaurus”” problem: You leave on a 2500 year trip”” and a century later some idiot comes up with a ship that’s more than 4{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} faster and beats you there. It’s a long recognized issue in the literature of manned interstellar flight.I seriously doubt anybody is going to launch a manned interstellar fight before the ships have gotten fast enough and progress has stalled enough that they’d be reasonably confident of reaching the destination before a better ship launched later.Exceptions of course”” for “”””Holy spit”””” the sun is going to explode!”””””” and people colonizing outbound comets and launching them on hyperbolic trajectories just to get away from here not arrive first someplace else.I expect the first manned ship barring major physics breakthroughs to use mass beam propulsion on this end of the trip and nuclear or magnetic braking against the destination’s solar wind at the other end. Thus”” huge infrastructure requirements for the mass beamer.”””

  30. Sounds interesting for getting around the neighborhood. But Unruh is limited to c””. Makes for a long trip to the next town (star)”” or county (say Perseus). Develope it – yes”” very good. Any hope of going faster?”””

  31. If they crack that problem (Assuming the haven’t already which wouldn’t shock me.) we’d never hear about it. The proliferation problems would be terrifying at least fission triggers make nuclear bombs easy to track.

  32. Or we had pure fusion detonation without the drawback of fission triggers to propel an Orion type launch vehicle. Someone pulls-off a direct ignition of fusion will bring other issues to the table.

  33. Put two ocean going tankers side-by-side for a lightering; and run the experiment in calm wind with nothing more than a heavy chop present. Will find they will tend to close upon the other.

  34. If I have a say in how my tax money is spent by all means test every theory for reactionless drives we can. Even if they do not pan out we may get blessed by the god of serendipity and discover one that does work and opens access to the stars.In the meantime by all means let’s spend the money on the best systems we can build now that will open up the solar system to us. Laser propulsion nuclear plasma heck an Orion drive craft built on the dark side of the moon with 1000 crew members if we can. Whatever it takes to get us off this ball of mud. Possibly the new Space Force will provide the resources considering a Navy ship or Air Force planes are just targets from orbit.

  35. Does the physics work out for conventional (i.e. reaction-mass effected) rocket propulsion to get Humans to other stars within their lifetimes? Even assuming reasonable stretching of that lifetime thru hibernation genetic adaptations genetic-damage repair and other active”” systems?Say… 2″”500 years with hibernation. And the genetic angles. Say… harnessing most-efficient but not magic nucleonicsSay… tho’ dreamy cannot use antimatter rationally. What’s left? Both fission and fusion remain good candidates”” “”””fuels”””” are sources of energy and potential reaction-mass stores. If we go with radioactives that emit energetic charged particles for one type of thrust”” that have capture-able fission or fusion energies at modestly impressive efficiencies (greater than 70{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12}) … and so on … The Tsiolkovsky Rocket Equation still rules. ΔV = Vₑ ln( Mᵢ/Mᵩ ) no matter what. Vₑ = 9.81 × ISP. Mᵢ is initial mass of rocket. Mᵩ is final mass”” after exhausting a bunch of reaction mass at Vₑ.To get to a nearby (say “”””within 25 light years””””) star system (of which there are 176 systems”” excluding all below-brown-dwarfs which we obviously haven’t detected but also which include at least 26 and probably over 125 systems with planets) AND STOP THERE (I believe an important criterion!) we have what… a 2500 year budget?D = ½at₁² + vt₂Where t₁ is the acceleration phase and t₂ is the ‘drifting along’ phase. Hard to say where the break is”” until we can quantify the emission-rate of reaction mass. But let’s say “”””1{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} per year of original mass””””. Sure”” its a rabbit-out-of-the-hat guess but its not unreasonable. t₁ = 70 yearst₂ = ½(2500) – 70t₂ = 1180 yearsVₑ = 33{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of 1 MeV for single-charged fission nucleons Z ≈ 120.Vₑ ≈ 727000 m/s per”

  36. What? even going at a small but consequent fraction of c would be a monumental achievement. It basically means that the stars won’t be closed off for humanity forever, as we currently believe they are. Also, any similar propellentless propulsion scheme, extracting energy from the quantum vacuum would have even bigger implications for the future of energy generation and its prospects for long term civilization.

  37. The theory has already predicted galaxy rotation without dark matter…””Oh no! Someone committed Establishment Grant Whore Science Heresy by challenging the dark matter dogma! Bring out the firing squad!”””

  38. What? even going at a small but consequent fraction of c would be a monumental achievement.It basically means that the stars won’t be closed off for humanity forever as we currently believe they are.Also any similar propellentless propulsion scheme extracting energy from the quantum vacuum would have even bigger implications for the future of energy generation and its prospects for long term civilization.

  39. Dunno… I think the future is more mundane: alpha particle repulsion. There are two interesting cases: alpha reflection and anisotropic alpha capture. As a thought experiment, consider a pinhead covered with a film of some alpha emitter such as radium oxide. Alphas — fully charged helium nuclei — don’t go very far, a few µm in metals, before they’re absorbed. In a vacuum tho, they’ll go the distance. Never break down either. Inert little zingers. So, our pinhead is sitting in free-space emitting alphas in all directions. Looking up a few choice facts and converting them into kinetics: 222.0175777 = AMU for 222Rn gas (decay product of 226Ra radiation) 226.0254098 = AMU for 226Ra 4.007832100 = difference 4.002603254 = ⁴He gas rest mass (but remember, includes electron) 0.005228846 = difference between helium-at-rest and ejected alpha … divide by 1,000 g/kg and divide by 6.022×10²³ particles per mole 8.68291×10⁻³⁰ = mass difference per radium→radon+alpha radiative decay … times 299,792,458² (speed of light in E=mc²) 7.80381×10⁻¹³ = joules difference per radiation decay … divide by 1.6×10⁻¹⁹ J/eV 4,877,379 = eV difference. Now remove the electrons… – 511,000 → electron 1 – 511,000 → electron 2 3,855,000 = eV of the naked alpha … V = √( 2E / m ) 13,624,000 = velocity of each about 4 MeV alpha 4.5% speed of light (c) … times 6.64663×10⁻²⁷ alpha mass 9.06×10⁻²⁰ ‘mv’ impulse per nucleon 54,532 newton-seconds per mole of alphas (or radium, fully decayed) 13,624,000 N-s per kg of alphas. … times 4 ÷ 226 He : Ra ratio… … divided by 9.81 N/kg for ISP 24,580 ISP of radium, naked stuff. Wasn’t that fun? The point is that films of radium will have an appreciable ISP just from the “naked surface” (which I’ve totally ignored the hemispheric emission pattern and the derating for that). But more to the point, one can decelerate the alphas with a sufficiently large electric field gradient (say about 5 million volts), which would prevent collecting them, but w

  40. So it costs “nothing” to recondition and recertify them after each flight? Who knew! Even commercial aircraft — the veritable paragons of reliability — have to have significant engine checks every few hundred flight hours, and non-invasive X-ray structural tests every 1,000 flight hours. Costs a bundle. Its all quite hidden from The Public’s eyesight (that’s what every airport’s far flung airfield-full-of-big-hangers is all about). One (me) might imagine that the recertification of a reusable rocket is going to be substantially more invasive, time consuming. As more flights are done, process metrics will accumulate showing just which parts ought to be preëmptively replaced due to their much-increased likelihood of in-flight failure. Oh, as the design(s) mature, better parts, more robust parts will be designed and vetted. Yet it remains: there is DEFINITELY a “tension” between keeping the Rocket Stuff really light weight and its mission durability. And multi-mission survivability. Just saying, GoatGuy

  41. I guess the problem (as identified by the maths) is that no matter what, it takes an appreciable multiple of the payload worth of reaction-mass to attain a velocity high enough that the trip doesn’t take dozens or hundreds of millennia. Braking notwithstanding. And yes, the “Holy snot! The sun is about to Nova!” point is well taken. I don’t think we’ll be worrying about that for another half dozen billion years; perhaps sooner it’ll become a Red Giant and vaporize Earth anyway. In 3 billion. A way’s off. GoatGuy

  42. No , Randall Mills believe in dark matter and claim he make it in his lab and call it ” hydrino “. also Randall Mills hate quantum mechanics with a passion , it is very unfair to compare McCulloch to Randall Mills.

  43. … and its also good for FREE energy … or nearly free. Any device which delivers a force F for some power input P at a conversion ratio of F = kP … (where k is in newtons per watt), will in turn be an above-unity free-energy device when the V of the thing is greater than 1/k. If “the thing” is a spacecraft, then 2/k is the criterion, as it also encapsulates all the energy necessary to get it up to 1/k meters per second. At V = 2/k, the spacecraft will have a kinetic energy exceeding ALL the thruster’s input energy to get it to that velocity. Just saying. Free energy. Is good. GoatGuy

  44. There are THREE interesting limits that one must really keep in mind whilst reading such intriguing articles. № 1: the reflected electromagnetic radiation limit Basically, if one were to have a perfect mirror, and impinge upon it light (or radio waves, or any EMF), reflecting entirely normal to the surface (i.e “back at the sender”), then the amount of force the mirror would experience is: F = 2 E/c dt Force = energy (joules) divided by speed of light in same units. and F = 2 P/c Force is 2 times impinged power, divided by c = 299,792,458. That’s at one side. № 2: Zero. Somewhere between ZERO and № 1’s result, is the FORCE we might expect, for reactionless thrusting. № 3: something LARGER than № 1. This is where things get interesting. “Standard physics” holds that unless one is actually pushing (or pulling) against something having an inertial mass, the MOST one might hope for is № 1. Anything greater than № 1 — by standard physics — requires exerting force on, and in return ‘feeling’ an opposite force from traction against a mass. Your car, for instance, would get nowhere obviously, if it were suspended from cables, the tires unable to push against the road (proxy or the Whole Earth). Yet, when your car pushes against the road, the road in turn pushes against the tires, and the car’n’occupants feel both accelerative and deceleration forces. Analogously, for both jet aircraft and now no-longer-sexy “jetboats”, instead of having something of near-infinite mass to push against, the receiver of the push is a fluid. Air and exhaust gas for jet planes, and water for jet boats. BECAUSE the actual fluid is far less massive than The Earth, whether air or water, it picks up appreciable velocity (i.e. kinetic energy) relative to its rest state. (I wish for italics here…) This in turn saps the producer-of-the-force (the jet engine or jet-boat motor) of some of its output energy. But in return, thrust is still realized from the fluid medium. B

  45. It my sound a bit dyspepsic, but din’t Randall Mills (of “Blacklight Snake Oil Free’n’Cheap Energy”) also claim the same? And the never-ending (but now gratefully all but invisible) freewheeling purveyors of [i]“conical helix theory”[/i]? Just saying. Seems like the Solutions to Cosmic Irregularities crop up. Like crop circles. All the time. GoatGuy

  46. I would like to see some more work done/reported on fission pumped excimer (e.g. KrF, Ar2) lasers. With the extremely short rise-times possible with “bursts” of fission (i.e. prompt like a TRIGA) it is possible to dump GJs of energy into a lasing gas in a device of major dimension on the order of meter(s). Could be formed by bundling uranium bearing glass tubes of whatever minimum diameter such that tube bowing doesn’t much obstruct the line of sight between the mirrors (turn the stimulated emission into heat). Uranium could be a constituent of the glass or deposited by vapor deposition. Maybe most of the power would be generated in a surrounding zone with the laser cavity in the central ‘glory hole’ – whatever. Even if only 0.5% of the fission energy came out as UV stimulated emission you’d still have a 5MJ laser pulse (greater than NIF) for a 1GW burst. That would heat a 500kg glass reactor 2300 deg-C if it weren’t cooled/purged during the shot using the lasing gas. Look at that – just replaced NIF with a fission reactor and doubled it’s power.

  47. The theory has already predicted galaxy rotation without dark matter…” Oh no! Someone committed Establishment Grant Whore Science Heresy by challenging the dark matter dogma! Bring out the firing squad!

  48. Dunno… I think the future is more mundane: alpha particle repulsion. There are two interesting cases: alpha reflection and anisotropic alpha capture. As a thought experiment consider a pinhead covered with a film of some alpha emitter such as radium oxide. Alphas — fully charged helium nuclei — don’t go very far a few µm in metals before they’re absorbed. In a vacuum tho they’ll go the distance. Never break down either. Inert little zingers. So our pinhead is sitting in free-space emitting alphas in all directions.Looking up a few choice facts and converting them into kinetics:222.0175777 = AMU for 222Rn gas (decay product of 226Ra radiation)226.0254098 = AMU for 226Ra4.007832100 = difference4.002603254 = ⁴He gas rest mass (but remember includes electron)0.005228846 = difference between helium-at-rest and ejected alpha… divide by 1000 g/kg and divide by 6.022×10²³ particles per mole8.68291×10⁻³⁰ = mass difference per radium→radon+alpha radiative decay… times 299792458² (speed of light in E=mc²)7.80381×10⁻¹³ = joules difference per radiation decay… divide by 1.6×10⁻¹⁹ J/eV4877379 = eV difference. Now remove the electrons…- 511000 → electron 1- 511000 → electron 23855000 = eV of the naked alpha… V = √( 2E / m )13624000 = velocity of each about 4 MeV alpha4.5{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} speed of light (c)… times 6.64663×10⁻²⁷ alpha mass9.06×10⁻²⁰ ‘mv’ impulse per nucleon54532 newton-seconds per mole of alphas (or radium fully decayed)13624000 N-s per kg of alphas.… times 4 ÷ 226 He : Ra ratio…… divided by 9.81 N/kg for ISP24580 ISP of radium naked stuff.Wasn’t that fun? The point is that films of radium will have an appreciable ISP just from the aked surface”” (which I’ve totally ignored the hemispheric emission pattern and the derating for that). But more to the point”” one can decelerate the alphas with a sufficiently large e”

  49. So it costs othing”” to recondition and recertify them after each flight? Who knew! Even commercial aircraft — the veritable paragons of reliability — have to have significant engine checks every few hundred flight hours”” and non-invasive X-ray structural tests every 1000 flight hours. Costs a bundle. Its all quite hidden from The Public’s eyesight (that’s what every airport’s far flung airfield-full-of-big-hangers is all about). One (me) might imagine that the recertification of a reusable rocket is going to be substantially more invasive time consuming. As more flights are done process metrics will accumulate showing just which parts ought to be preëmptively replaced due to their much-increased likelihood of in-flight failure. Oh as the design(s) mature better parts”” more robust parts will be designed and vetted. Yet it remains: there is DEFINITELY a “”””tension”””” between keeping the Rocket Stuff really light weight and its mission durability. And multi-mission survivability. Just saying””””GoatGuy”””””””

  50. I guess the problem (as identified by the maths) is that no matter what it takes an appreciable multiple of the payload worth of reaction-mass to attain a velocity high enough that the trip doesn’t take dozens or hundreds of millennia. Braking notwithstanding. And yes the Holy snot! The sun is about to Nova!”” point is well taken. I don’t think we’ll be worrying about that for another half dozen billion years; perhaps sooner it’ll become a Red Giant and vaporize Earth anyway. In 3 billion.A way’s off. GoatGuy”””

  51. No Randall Mills believe in dark matter and claim he make it in his lab and call it hydrino “”. also Randall Mills hate quantum mechanics with a passion “””” it is very unfair to compare McCulloch to Randall Mills.”””

  52. … and its also good for FREE energy … or nearly free. Any device which delivers a force F for some power input P at a conversion ratio of F = kP … (where k is in newtons per watt) will in turn be an above-unity free-energy device when the V of the thing is greater than 1/k. If the thing”” is a spacecraft”” then 2/k is the criterion as it also encapsulates all the energy necessary to get it up to 1/k meters per second. At V = 2/k”” the spacecraft will have a kinetic energy exceeding ALL the thruster’s input energy to get it to that velocity. Just saying.Free energy.Is good.GoatGuy”””””””

  53. There are THREE interesting limits that one must really keep in mind whilst reading such intriguing articles. № 1: the reflected electromagnetic radiation limitBasically if one were to have a perfect mirror and impinge upon it light (or radio waves or any EMF) reflecting entirely normal to the surface (i.e back at the sender””)”” then the amount of force the mirror would experience is:F = 2 E/c dt Force = energy (joules) divided by speed of light in same units.andF = 2 P/c Force is 2 times impinged power divided by c = 299792458.That’s at one side. № 2: Zero.Somewhere between ZERO and № 1’s result is the FORCE we might expect”” for reactionless thrusting.№ 3: something LARGER than № 1.This is where things get interesting. “”””Standard physics”””” holds that unless one is actually pushing (or pulling) against something having an inertial mass”” the MOST one might hope for is № 1. Anything greater than № 1 — by standard physics — requires exerting force on and in return ‘feeling’ an opposite force from traction against a mass. Your car for instance would get nowhere obviously if it were suspended from cables the tires unable to push against the road (proxy or the Whole Earth). Yet when your car pushes against the road the road in turn pushes against the tires and the car’n’occupants feel both accelerative and deceleration forces. Analogously”” for both jet aircraft and now no-longer-sexy “”””jetboats”””””” instead of having something of near-infinite mass to push against the receiver of the push is a fluid. Air and exhaust gas for jet planes and water for jet boats. BECAUSE the actual fluid is far less massive than The Earth whether air or water it picks up appreciable velocity (i.e. kinetic energy) relative to its rest state. (I wish for italics here…) This in turn saps the producer-of-the-force (the jet engine or jet-boat motor) of some of its output energy. But in return thrust is still realized fr”

  54. It my sound a bit dyspepsic but din’t Randall Mills (of Blacklight Snake Oil Free’n’Cheap Energy””) also claim the same? And the never-ending (but now gratefully all but invisible) freewheeling purveyors of [i]“conical helix theory”[/i]?Just saying.Seems like the Solutions to Cosmic Irregularities crop up.Like crop circles.All the time.GoatGuy”””””””

  55. I would like to see some more work done/reported on fission pumped excimer (e.g. KrF Ar2) lasers. With the extremely short rise-times possible with bursts”” of fission (i.e. prompt like a TRIGA) it is possible to dump GJs of energy into a lasing gas in a device of major dimension on the order of meter(s). Could be formed by bundling uranium bearing glass tubes of whatever minimum diameter such that tube bowing doesn’t much obstruct the line of sight between the mirrors (turn the stimulated emission into heat). Uranium could be a constituent of the glass or deposited by vapor deposition. Maybe most of the power would be generated in a surrounding zone with the laser cavity in the central ‘glory hole’ – whatever. Even if only 0.5{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of the fission energy came out as UV stimulated emission you’d still have a 5MJ laser pulse (greater than NIF) for a 1GW burst. That would heat a 500kg glass reactor 2300 deg-C if it weren’t cooled/purged during the shot using the lasing gas. Look at that – just replaced NIF with a fission reactor and doubled it’s power.”””

  56. Going WAY into the speculative zone, I wonder if it would be possible to push against spacetime itself. It’s supposedly quite rigid (otherwise warp drives would be much easier). I’m not sure if it can be considered to have mass of its own (and if so, how much), but in effect you’d be pushing against the huge rest mass of distant stars. Kind of like pushing against Earth via a steel rod, if you imagine Earth representing the distant stars, and the rod representing spacetime. Related to that – or perhaps equivalent – might we be able to construct some sort of gravity wave drive? Basically the gravitational equivalent of a photon rocket. Who knows, it might work better.. Obviously, both options are far beyond current technology, if not current physics. And I’m sure they’ll require massive amounts of energy, as any other interstellar drive.

  57. Going WAY into the speculative zone I wonder if it would be possible to push against spacetime itself. It’s supposedly quite rigid (otherwise warp drives would be much easier). I’m not sure if it can be considered to have mass of its own (and if so how much) but in effect you’d be pushing against the huge rest mass of distant stars. Kind of like pushing against Earth via a steel rod if you imagine Earth representing the distant stars and the rod representing spacetime.Related to that – or perhaps equivalent – might we be able to construct some sort of gravity wave drive? Basically the gravitational equivalent of a photon rocket. Who knows it might work better..Obviously both options are far beyond current technology if not current physics. And I’m sure they’ll require massive amounts of energy as any other interstellar drive.

  58. Insofar as anyone in Physics has been able to determine, gravity is a MONOPOLAR field, and with relativity, is (ironically) simplified as a bending of space-time. But the bending is always [i]“pointing”[/i] into the normal (math) of a mass; Again, its like counting thing less-than-zero. You can have any positive quantity of “stuff” in the REAL world. 1 elephant, 2 coconuts, 3 pebbles, 4 sewing pins, 5 sesame seeds, 6 bits of lint, 7 … and so on. One can even philosophically have ZERO things. No elepants, no coconuts, no pebbles. But in the REAL (not math or imagined) world, one cannot have fewer than zero things of a kind. You can’t have negative 4 parakeets, or minus 12 camels. You of course can be owed 12 camels by Habib, or owed 4 parakeets by the Aviary Store owner. But that is not the same as HAVING negative numbers of camels and parakeets respectively. Gravity is like that. Can’t have “negative mass” (but can have zero!) Can’t have “repulsive gravity” (but can have zero!) Also as forces go, having no complimentary force (such as electric fields having the compliment ‘magnetism’) … which just saying probably sets off alarms in all physicists here … but not having a conjugated pair of forces, gravity also doesn’t appear to have anything except the presence of mass, to “turn it on” and off. Like the two main macroscopic forces (electromagnetism and gravity), gravity is thought to be well conserved with a strength of 1/D² (gravitational attraction varies as the square of distance), and a simple linear scale related to absolute value of M (the mass of an attractor) and m (the mass of the attractee.) F = G₀Mm/D² Experiments have confirmed that the force of gravity propagates at the speed of time (‘c’); there are no known ways to ‘bend’ gravitation force, to focus it, to diverge it, to increase it without increasing mass, or to decrease it similarly. It is isotropic perfectly (uniform in all directions). It seems to have a few relativistic m

  59. Beryllium spheres I can get you by the gross. Watch the dust though.Dilithium crystals are a bit harder to come by.

  60. Insofar as anyone in Physics has been able to determine gravity is a MONOPOLAR field and with relativity is (ironically) simplified as a bending of space-time. But the bending is always [i]“pointing”[/i] into the normal (math) of a mass; Again its like counting thing less-than-zero. You can have any positive quantity of stuff”” in the REAL world. 1 elephant”” 2 coconuts 3 pebbles 4 sewing pins 5 sesame seeds 6 bits of lint 7 … and so on. One can even philosophically have ZERO things. No elepants no coconuts no pebbles. But in the REAL (not math or imagined) world one cannot have fewer than zero things of a kind. You can’t have negative 4 parakeets or minus 12 camels. You of course can be owed 12 camels by Habib”” or owed 4 parakeets by the Aviary Store owner. But that is not the same as HAVING negative numbers of camels and parakeets respectively. Gravity is like that. Can’t have “”””negative mass”””” (but can have zero!)Can’t have “”””repulsive gravity”””” (but can have zero!)Also as forces go”” having no complimentary force (such as electric fields having the compliment ‘magnetism’) … which just saying probably sets off alarms in all physicists here … but not having a conjugated pair of forces gravity also doesn’t appear to have anything except the presence of mass”” to “”””turn it on”””” and off. Like the two main macroscopic forces (electromagnetism and gravity)”” gravity is thought to be well conserved with a strength of 1/D² (gravitational attraction varies as the square of distance) and a simple linear scale related to absolute value of M (the mass of an attractor) and m (the mass of the attractee.)F = G₀Mm/D²Experiments have confirmed that the force of gravity propagates at the speed of time (‘c’); there are no known ways to ‘bend’ gravitation force to focus it to diverge it to increase it without increasing mass”” or to decrease it similarly. It is isotropic perfectly (uniform in all directions). It seems to”

  61. According to the big NSF EMdrive thread, recent conference reports are suggesting EMdrive work is in trouble. One report suggested some force reports could be entirely explained due to experimental setup/noise, several drive replication efforts reported null thrust, including an update from Tajmar who was the first big null reporter. There is still ongoing concern over experiment design/replication efforts however even from the null report crowd (instrumentation design is difficult to formalize/standardize due to differences in facilities/sensors/budget, and the tiny thrusts they are chasing), so the case isn’t completely closed yet. Also, by some possible scaling ideas, the cost cliff to step up to higher power for a more definitive thrust result is onerous in money/equipment/safety/licensing terms (high power RF is not human friendly). But a US Navy team reported a null result at the conference, though is still pursing it. The chinese and those aligned with the chinese drive design concepts are thinking they need to move to frustrum-esque shapes that are more asymmetric and/or easier to make based on their ideas regarding the RF mode and the shape. There’s strange things going on as well, such as positive result holders only willing to lend out their drives to others who report a non-null result from their experiment rig (one could say this is an attempt at quality control of the instrumentation before lending a “known working” drive, but the language used is doing no one any favors).

  62. Beryllium spheres I can get you, by the gross. Watch the dust, though. Dilithium crystals are a bit harder to come by.

  63. Hi PiperIt is an urban legend.You can search:Popular physics myth is all at seaDoes the ghostly Casimir effect really cause ships to attract each other?”” (4 May 2006 | Nature)Regards.”””

  64. According to the big NSF EMdrive thread recent conference reports are suggesting EMdrive work is in trouble. One report suggested some force reports could be entirely explained due to experimental setup/noise several drive replication efforts reported null thrust including an update from Tajmar who was the first big null reporter. There is still ongoing concern over experiment design/replication efforts however even from the null report crowd (instrumentation design is difficult to formalize/standardize due to differences in facilities/sensors/budget and the tiny thrusts they are chasing) so the case isn’t completely closed yet. Also by some possible scaling ideas the cost cliff to step up to higher power for a more definitive thrust result is onerous in money/equipment/safety/licensing terms (high power RF is not human friendly). But a US Navy team reported a null result at the conference though is still pursing it. The chinese and those aligned with the chinese drive design concepts are thinking they need to move to frustrum-esque shapes that are more asymmetric and/or easier to make based on their ideas regarding the RF mode and the shape. There’s strange things going on as well such as positive result holders only willing to lend out their drives to others who report a non-null result from their experiment rig (one could say this is an attempt at quality control of the instrumentation before lending a known working”” drive”””” but the language used is doing no one any favors).”””

  65. I like fission fragment rockets. I’d start out using it for station keeping on satellites; All you need are some small panels either on gimbles, or with controllable shutters. (Perhaps the first usable alloy for this purpose should be called “Cavorite”?) Ultimately, maybe a dusty plasma reactor based system, using Thorium as the fuel. Nice thing about Thorium is that you don’t need to worry about your fuel going critical, so you can store it compactly. The problems with storing a significant amount of U235 on a spacecraft are non-trivial. None of these systems are going to have high acceleration, though.

  66. Hi Piper, It is an urban legend. You can search: “Popular physics myth is all at sea Does the ghostly Casimir effect really cause ships to attract each other?” (4 May 2006 | Nature) Regards.

  67. I like fission fragment rockets. I’d start out using it for station keeping on satellites; All you need are some small panels either on gimbles or with controllable shutters. (Perhaps the first usable alloy for this purpose should be called Cavorite””?) Ultimately”” maybe a dusty plasma reactor based system using Thorium as the fuel. Nice thing about Thorium is that you don’t need to worry about your fuel going critical so you can store it compactly. The problems with storing a significant amount of U235 on a spacecraft are non-trivial.None of these systems are going to have high acceleration”” though.”””

  68. T`hiyliym/Psalms: 99:8: YOU answered them, O YaHVeH our Elohiym: YOU were an EL that forgave them, though YOU took vengeance of their inventions. Yeshayah: 2:8: Their land also is full of idols; they worship the work of their own hands, that which their own fingers have made:

  69. T`hiyliym/Psalms: 99:8: YOU answered them O YaHVeH our Elohiym: YOU were an EL that forgave them though YOU took vengeance of their inventions.Yeshayah: 2:8: Their land also is full of idols; they worship the work of their own hands that which their own fingers have made:

  70. I may be completely in la la land, but have you guys looked into Thomas Townsend Brown’s work? Or read that book by Paul LaViolette (Secrets of Antigravity Propulsion)? Or the Paul Hill (NASA scientist) book (Unconventional Flying Objects)? This stuff went black more than half a century ago. But it’s been, and presumably is being, done; e.g.: “Ben Rich passed away in 1995 and before he passed away, he dropped a number of bombshells. This took place at Wright-Patterson AFB back in 1993. He gave a slide presentation there and also at the UCLA School of Engineering Alumni speech – he gave on March 23, 1993. At the very end of his presentation, in both of these venues, he completed his slides with the following quote: `The U. S. Air Force has just given us a contract to take E. T. back home.’ “He also mentioned, “We already have the means to travel among the stars, but these technologies are locked up in black projects and it would take an act of God to ever get them out to benefit humanity… …anything you can imagine we already know how to do. “And he also mentioned at the UCLA speech, `It is time to end all secrecy on this as it no longer poses a national security threat and to make the technology available for use in the private sector.’ That’s exactly what we’re talking about here. “He was telling us about a whole level of aircraft, of spacecraft, of advanced propulsion systems that are so far advanced. He even mentioned technologies that are 50 years beyond even what we could possibly dream of. Now, when you hear that coming from the Director of the Skunk Works, I think it is important to really take that to heart. This gentleman knew something and he was trying to tell us something. And I think this is the space program that none of us have a clue about in the civilian sector. This is what Ben Rich was trying to tell us about.”

  71. I may be completely in la la land but have you guys looked into Thomas Townsend Brown’s work? Or read that book by Paul LaViolette (Secrets of Antigravity Propulsion)? Or the Paul Hill (NASA scientist) book (Unconventional Flying Objects)? This stuff went black more than half a century ago. But it’s been and presumably is being done; e.g.: “Ben Rich passed away in 1995 and before he passed away he dropped a number of bombshells. This took place at Wright-Patterson AFB back in 1993. He gave a slide presentation there and also at the UCLA School of Engineering Alumni speech – he gave on March 23 1993. At the very end of his presentation in both of these venues he completed his slides with the following quote: `The U. S. Air Force has just given us a contract to take E. T. back home.’He also mentioned”” “”We already have the means to travel among the stars”””” but these technologies are locked up in black projects and it would take an act of God to ever get them out to benefit humanity… …anything you can imagine we already know how to do.””””And he also mentioned at the UCLA speech”””” `It is time to end all secrecy on this as it no longer poses a national security threat and to make the technology available for use in the private sector.’ That’s exactly what we’re talking about here.””””He was telling us about a whole level of aircraft”” of spacecraft of advanced propulsion systems that are so far advanced. He even mentioned technologies that are 50 years beyond even what we could possibly dream of. Now when you hear that coming from the Director of the Skunk Works”” I think it is important to really take that to heart. This gentleman knew something and he was trying to tell us something. And I think this is the space program that none of us have a clue about in the civilian sector. This is what Ben Rich was trying to tell us about.””””””””

  72. What the bleeep!? Are you off your meds again Phil? Sorry to disparage you but if that’s your best response to this posting then please just go away and leave this group alone. Please.

  73. When they get a test rig that produces macroscopic, i.e. newton-level or more, levels of thrust (and, hence, can’t easily be the result of test defects) or produces measurable acceleration on an actual spacecraft, come back and I’ll believe you. Until then, it’s just theoretical games.

  74. What the bleeep!? Are you off your meds again Phil?Sorry to disparage you but if that’s your best response to this posting then please just go away and leave this group alone. Please.

  75. When they get a test rig that produces macroscopic i.e. newton-level or more levels of thrust (and hence can’t easily be the result of test defects) or produces measurable acceleration on an actual spacecraft come back and I’ll believe you. Until then it’s just theoretical games.

  76. I like the radium alpha emitter rocket idea. Though if you start with a much lighter element you’d get a much bigger ISP. As it is you’re left with say a 50% radium craft only getting a delta v of 170 000 m/s. Which is better than I can manage on a push bike, but not really interstellar. Now Be 8 decays completely into 2 alpha particles. With the same alpha particle energy (there are reasons behind this I think) that this is 13,624,000 N-s per kg of fuel, an ISP of 1.4 million. Pity the half life is an impossible to deal with 6.7(17)×10−17 s

  77. I like the radium alpha emitter rocket idea.Though if you start with a much lighter element you’d get a much bigger ISP. As it is you’re left with say a 50{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} radium craft only getting a delta v of 170 000 m/s.Which is better than I can manage on a push bike but not really interstellar.Now Be 8 decays completely into 2 alpha particles. With the same alpha particle energy (there are reasons behind this I think) that this is 13624000 N-s per kg of fuel an ISP of 1.4 million.Pity the half life is an impossible to deal with 6.7(17)×10−17 s”

  78. It looks like a closed system to me. Doesn’t the damper have to be outside of the system to make this work?

  79. I like the radium alpha emitter rocket idea. Though if you start with a much lighter element you’d get a much bigger ISP. As it is you’re left with say a 50% radium craft only getting a delta v of 170 000 m/s. Which is better than I can manage on a push bike, but not really interstellar. Now Be 8 decays completely into 2 alpha particles. With the same alpha particle energy (there are reasons behind this I think) that this is 13,624,000 N-s per kg of fuel, an ISP of 1.4 million. Pity the half life is an impossible to deal with 6.7(17)×10−17 s

  80. I like the radium alpha emitter rocket idea.Though if you start with a much lighter element you’d get a much bigger ISP. As it is you’re left with say a 50{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} radium craft only getting a delta v of 170 000 m/s.Which is better than I can manage on a push bike but not really interstellar.Now Be 8 decays completely into 2 alpha particles. With the same alpha particle energy (there are reasons behind this I think) that this is 13624000 N-s per kg of fuel an ISP of 1.4 million.Pity the half life is an impossible to deal with 6.7(17)×10−17 s”

  81. I like the radium alpha emitter rocket idea.

    Though if you start with a much lighter element you’d get a much bigger ISP. As it is you’re left with say a 50% radium craft only getting a delta v of 170 000 m/s.

    Which is better than I can manage on a push bike, but not really interstellar.

    Now Be 8 decays completely into 2 alpha particles. With the same alpha particle energy (there are reasons behind this I think) that this is 13,624,000 N-s per kg of fuel, an ISP of 1.4 million.

    Pity the half life is an impossible to deal with 6.7(17)×10−17 s

  82. What the bleeep!? Are you off your meds again Phil? Sorry to disparage you but if that’s your best response to this posting then please just go away and leave this group alone. Please.

  83. What the bleeep!? Are you off your meds again Phil?Sorry to disparage you but if that’s your best response to this posting then please just go away and leave this group alone. Please.

  84. When they get a test rig that produces macroscopic, i.e. newton-level or more, levels of thrust (and, hence, can’t easily be the result of test defects) or produces measurable acceleration on an actual spacecraft, come back and I’ll believe you. Until then, it’s just theoretical games.

  85. When they get a test rig that produces macroscopic i.e. newton-level or more levels of thrust (and hence can’t easily be the result of test defects) or produces measurable acceleration on an actual spacecraft come back and I’ll believe you. Until then it’s just theoretical games.

  86. I may be completely in la la land, but have you guys looked into Thomas Townsend Brown’s work? Or read that book by Paul LaViolette (Secrets of Antigravity Propulsion)? Or the Paul Hill (NASA scientist) book (Unconventional Flying Objects)? This stuff went black more than half a century ago. But it’s been, and presumably is being, done; e.g.: “Ben Rich passed away in 1995 and before he passed away, he dropped a number of bombshells. This took place at Wright-Patterson AFB back in 1993. He gave a slide presentation there and also at the UCLA School of Engineering Alumni speech – he gave on March 23, 1993. At the very end of his presentation, in both of these venues, he completed his slides with the following quote: `The U. S. Air Force has just given us a contract to take E. T. back home.’ “He also mentioned, “We already have the means to travel among the stars, but these technologies are locked up in black projects and it would take an act of God to ever get them out to benefit humanity… …anything you can imagine we already know how to do. “And he also mentioned at the UCLA speech, `It is time to end all secrecy on this as it no longer poses a national security threat and to make the technology available for use in the private sector.’ That’s exactly what we’re talking about here. “He was telling us about a whole level of aircraft, of spacecraft, of advanced propulsion systems that are so far advanced. He even mentioned technologies that are 50 years beyond even what we could possibly dream of. Now, when you hear that coming from the Director of the Skunk Works, I think it is important to really take that to heart. This gentleman knew something and he was trying to tell us something. And I think this is the space program that none of us have a clue about in the civilian sector. This is what Ben Rich was trying to tell us about.”

  87. I may be completely in la la land but have you guys looked into Thomas Townsend Brown’s work? Or read that book by Paul LaViolette (Secrets of Antigravity Propulsion)? Or the Paul Hill (NASA scientist) book (Unconventional Flying Objects)? This stuff went black more than half a century ago. But it’s been and presumably is being done; e.g.: “Ben Rich passed away in 1995 and before he passed away he dropped a number of bombshells. This took place at Wright-Patterson AFB back in 1993. He gave a slide presentation there and also at the UCLA School of Engineering Alumni speech – he gave on March 23 1993. At the very end of his presentation in both of these venues he completed his slides with the following quote: `The U. S. Air Force has just given us a contract to take E. T. back home.’He also mentioned”” “”We already have the means to travel among the stars”””” but these technologies are locked up in black projects and it would take an act of God to ever get them out to benefit humanity… …anything you can imagine we already know how to do.””””And he also mentioned at the UCLA speech”””” `It is time to end all secrecy on this as it no longer poses a national security threat and to make the technology available for use in the private sector.’ That’s exactly what we’re talking about here.””””He was telling us about a whole level of aircraft”” of spacecraft of advanced propulsion systems that are so far advanced. He even mentioned technologies that are 50 years beyond even what we could possibly dream of. Now when you hear that coming from the Director of the Skunk Works”” I think it is important to really take that to heart. This gentleman knew something and he was trying to tell us something. And I think this is the space program that none of us have a clue about in the civilian sector. This is what Ben Rich was trying to tell us about.””””””””

  88. T`hiyliym/Psalms: 99:8: YOU answered them, O YaHVeH our Elohiym: YOU were an EL that forgave them, though YOU took vengeance of their inventions. Yeshayah: 2:8: Their land also is full of idols; they worship the work of their own hands, that which their own fingers have made:

  89. T`hiyliym/Psalms: 99:8: YOU answered them O YaHVeH our Elohiym: YOU were an EL that forgave them though YOU took vengeance of their inventions.Yeshayah: 2:8: Their land also is full of idols; they worship the work of their own hands that which their own fingers have made:

  90. What the bleeep!? Are you off your meds again Phil?

    Sorry to disparage you but if that’s your best response to this posting then please just go away and leave this group alone. Please.

  91. When they get a test rig that produces macroscopic, i.e. newton-level or more, levels of thrust (and, hence, can’t easily be the result of test defects) or produces measurable acceleration on an actual spacecraft, come back and I’ll believe you. Until then, it’s just theoretical games.

  92. I like fission fragment rockets. I’d start out using it for station keeping on satellites; All you need are some small panels either on gimbles, or with controllable shutters. (Perhaps the first usable alloy for this purpose should be called “Cavorite”?) Ultimately, maybe a dusty plasma reactor based system, using Thorium as the fuel. Nice thing about Thorium is that you don’t need to worry about your fuel going critical, so you can store it compactly. The problems with storing a significant amount of U235 on a spacecraft are non-trivial. None of these systems are going to have high acceleration, though.

  93. I like fission fragment rockets. I’d start out using it for station keeping on satellites; All you need are some small panels either on gimbles or with controllable shutters. (Perhaps the first usable alloy for this purpose should be called Cavorite””?) Ultimately”” maybe a dusty plasma reactor based system using Thorium as the fuel. Nice thing about Thorium is that you don’t need to worry about your fuel going critical so you can store it compactly. The problems with storing a significant amount of U235 on a spacecraft are non-trivial.None of these systems are going to have high acceleration”” though.”””

  94. Hi Piper, It is an urban legend. You can search: “Popular physics myth is all at sea Does the ghostly Casimir effect really cause ships to attract each other?” (4 May 2006 | Nature) Regards.

  95. Hi PiperIt is an urban legend.You can search:Popular physics myth is all at seaDoes the ghostly Casimir effect really cause ships to attract each other?”” (4 May 2006 | Nature)Regards.”””

  96. I may be completely in la la land, but have you guys looked into Thomas Townsend Brown’s work? Or read that book by Paul LaViolette (Secrets of Antigravity Propulsion)? Or the Paul Hill (NASA scientist) book (Unconventional Flying Objects)? This stuff went black more than half a century ago. But it’s been, and presumably is being, done; e.g.: “Ben Rich passed away in 1995 and before he passed away, he dropped a number of bombshells. This took place at Wright-Patterson AFB back in 1993. He gave a slide presentation there and also at the UCLA School of Engineering Alumni speech – he gave on March 23, 1993. At the very end of his presentation, in both of these venues, he completed his slides with the following quote: `The U. S. Air Force has just given us a contract to take E. T. back home.’

    “He also mentioned, “We already have the means to travel among the stars, but these technologies are locked up in black projects and it would take an act of God to ever get them out to benefit humanity… …anything you can imagine we already know how to do.

    “And he also mentioned at the UCLA speech, `It is time to end all secrecy on this as it no longer poses a national security threat and to make the technology available for use in the private sector.’ That’s exactly what we’re talking about here.

    “He was telling us about a whole level of aircraft, of spacecraft, of advanced propulsion systems that are so far advanced. He even mentioned technologies that are 50 years beyond even what we could possibly dream of. Now, when you hear that coming from the Director of the Skunk Works, I think it is important to really take that to heart. This gentleman knew something and he was trying to tell us something. And I think this is the space program that none of us have a clue about in the civilian sector. This is what Ben Rich was trying to tell us about.”

  97. According to the big NSF EMdrive thread, recent conference reports are suggesting EMdrive work is in trouble. One report suggested some force reports could be entirely explained due to experimental setup/noise, several drive replication efforts reported null thrust, including an update from Tajmar who was the first big null reporter. There is still ongoing concern over experiment design/replication efforts however even from the null report crowd (instrumentation design is difficult to formalize/standardize due to differences in facilities/sensors/budget, and the tiny thrusts they are chasing), so the case isn’t completely closed yet. Also, by some possible scaling ideas, the cost cliff to step up to higher power for a more definitive thrust result is onerous in money/equipment/safety/licensing terms (high power RF is not human friendly). But a US Navy team reported a null result at the conference, though is still pursing it. The chinese and those aligned with the chinese drive design concepts are thinking they need to move to frustrum-esque shapes that are more asymmetric and/or easier to make based on their ideas regarding the RF mode and the shape. There’s strange things going on as well, such as positive result holders only willing to lend out their drives to others who report a non-null result from their experiment rig (one could say this is an attempt at quality control of the instrumentation before lending a “known working” drive, but the language used is doing no one any favors).

  98. According to the big NSF EMdrive thread recent conference reports are suggesting EMdrive work is in trouble. One report suggested some force reports could be entirely explained due to experimental setup/noise several drive replication efforts reported null thrust including an update from Tajmar who was the first big null reporter. There is still ongoing concern over experiment design/replication efforts however even from the null report crowd (instrumentation design is difficult to formalize/standardize due to differences in facilities/sensors/budget and the tiny thrusts they are chasing) so the case isn’t completely closed yet. Also by some possible scaling ideas the cost cliff to step up to higher power for a more definitive thrust result is onerous in money/equipment/safety/licensing terms (high power RF is not human friendly). But a US Navy team reported a null result at the conference though is still pursing it. The chinese and those aligned with the chinese drive design concepts are thinking they need to move to frustrum-esque shapes that are more asymmetric and/or easier to make based on their ideas regarding the RF mode and the shape. There’s strange things going on as well such as positive result holders only willing to lend out their drives to others who report a non-null result from their experiment rig (one could say this is an attempt at quality control of the instrumentation before lending a known working”” drive”””” but the language used is doing no one any favors).”””

  99. T`hiyliym/Psalms: 99:8: YOU answered them, O YaHVeH our Elohiym: YOU were an EL that forgave them, though YOU took vengeance of their inventions.

    Yeshayah: 2:8: Their land also is full of idols; they worship the work of their own hands, that which their own fingers have made:

  100. Beryllium spheres I can get you, by the gross. Watch the dust, though. Dilithium crystals are a bit harder to come by.

  101. Beryllium spheres I can get you by the gross. Watch the dust though.Dilithium crystals are a bit harder to come by.

  102. I like fission fragment rockets. I’d start out using it for station keeping on satellites; All you need are some small panels either on gimbles, or with controllable shutters. (Perhaps the first usable alloy for this purpose should be called “Cavorite”?)

    Ultimately, maybe a dusty plasma reactor based system, using Thorium as the fuel. Nice thing about Thorium is that you don’t need to worry about your fuel going critical, so you can store it compactly. The problems with storing a significant amount of U235 on a spacecraft are non-trivial.

    None of these systems are going to have high acceleration, though.

  103. Insofar as anyone in Physics has been able to determine, gravity is a MONOPOLAR field, and with relativity, is (ironically) simplified as a bending of space-time. But the bending is always [i]“pointing”[/i] into the normal (math) of a mass; Again, its like counting thing less-than-zero. You can have any positive quantity of “stuff” in the REAL world. 1 elephant, 2 coconuts, 3 pebbles, 4 sewing pins, 5 sesame seeds, 6 bits of lint, 7 … and so on. One can even philosophically have ZERO things. No elepants, no coconuts, no pebbles. But in the REAL (not math or imagined) world, one cannot have fewer than zero things of a kind. You can’t have negative 4 parakeets, or minus 12 camels. You of course can be owed 12 camels by Habib, or owed 4 parakeets by the Aviary Store owner. But that is not the same as HAVING negative numbers of camels and parakeets respectively. Gravity is like that. Can’t have “negative mass” (but can have zero!) Can’t have “repulsive gravity” (but can have zero!) Also as forces go, having no complimentary force (such as electric fields having the compliment ‘magnetism’) … which just saying probably sets off alarms in all physicists here … but not having a conjugated pair of forces, gravity also doesn’t appear to have anything except the presence of mass, to “turn it on” and off. Like the two main macroscopic forces (electromagnetism and gravity), gravity is thought to be well conserved with a strength of 1/D² (gravitational attraction varies as the square of distance), and a simple linear scale related to absolute value of M (the mass of an attractor) and m (the mass of the attractee.) F = G₀Mm/D² Experiments have confirmed that the force of gravity propagates at the speed of time (‘c’); there are no known ways to ‘bend’ gravitation force, to focus it, to diverge it, to increase it without increasing mass, or to decrease it similarly. It is isotropic perfectly (uniform in all directions). It seems to have a few relativistic m

  104. Insofar as anyone in Physics has been able to determine gravity is a MONOPOLAR field and with relativity is (ironically) simplified as a bending of space-time. But the bending is always [i]“pointing”[/i] into the normal (math) of a mass; Again its like counting thing less-than-zero. You can have any positive quantity of stuff”” in the REAL world. 1 elephant”” 2 coconuts 3 pebbles 4 sewing pins 5 sesame seeds 6 bits of lint 7 … and so on. One can even philosophically have ZERO things. No elepants no coconuts no pebbles. But in the REAL (not math or imagined) world one cannot have fewer than zero things of a kind. You can’t have negative 4 parakeets or minus 12 camels. You of course can be owed 12 camels by Habib”” or owed 4 parakeets by the Aviary Store owner. But that is not the same as HAVING negative numbers of camels and parakeets respectively. Gravity is like that. Can’t have “”””negative mass”””” (but can have zero!)Can’t have “”””repulsive gravity”””” (but can have zero!)Also as forces go”” having no complimentary force (such as electric fields having the compliment ‘magnetism’) … which just saying probably sets off alarms in all physicists here … but not having a conjugated pair of forces gravity also doesn’t appear to have anything except the presence of mass”” to “”””turn it on”””” and off. Like the two main macroscopic forces (electromagnetism and gravity)”” gravity is thought to be well conserved with a strength of 1/D² (gravitational attraction varies as the square of distance) and a simple linear scale related to absolute value of M (the mass of an attractor) and m (the mass of the attractee.)F = G₀Mm/D²Experiments have confirmed that the force of gravity propagates at the speed of time (‘c’); there are no known ways to ‘bend’ gravitation force to focus it to diverge it to increase it without increasing mass”” or to decrease it similarly. It is isotropic perfectly (uniform in all directions). It seems to”

  105. Going WAY into the speculative zone, I wonder if it would be possible to push against spacetime itself. It’s supposedly quite rigid (otherwise warp drives would be much easier). I’m not sure if it can be considered to have mass of its own (and if so, how much), but in effect you’d be pushing against the huge rest mass of distant stars. Kind of like pushing against Earth via a steel rod, if you imagine Earth representing the distant stars, and the rod representing spacetime. Related to that – or perhaps equivalent – might we be able to construct some sort of gravity wave drive? Basically the gravitational equivalent of a photon rocket. Who knows, it might work better.. Obviously, both options are far beyond current technology, if not current physics. And I’m sure they’ll require massive amounts of energy, as any other interstellar drive.

  106. Going WAY into the speculative zone I wonder if it would be possible to push against spacetime itself. It’s supposedly quite rigid (otherwise warp drives would be much easier). I’m not sure if it can be considered to have mass of its own (and if so how much) but in effect you’d be pushing against the huge rest mass of distant stars. Kind of like pushing against Earth via a steel rod if you imagine Earth representing the distant stars and the rod representing spacetime.Related to that – or perhaps equivalent – might we be able to construct some sort of gravity wave drive? Basically the gravitational equivalent of a photon rocket. Who knows it might work better..Obviously both options are far beyond current technology if not current physics. And I’m sure they’ll require massive amounts of energy as any other interstellar drive.

  107. Hi Piper,

    It is an urban legend.

    You can search:

    “Popular physics myth is all at sea
    Does the ghostly Casimir effect really cause ships to attract each other?” (4 May 2006 | Nature)

    Regards.

  108. Dunno… I think the future is more mundane: alpha particle repulsion. There are two interesting cases: alpha reflection and anisotropic alpha capture. As a thought experiment, consider a pinhead covered with a film of some alpha emitter such as radium oxide. Alphas — fully charged helium nuclei — don’t go very far, a few µm in metals, before they’re absorbed. In a vacuum tho, they’ll go the distance. Never break down either. Inert little zingers. So, our pinhead is sitting in free-space emitting alphas in all directions. Looking up a few choice facts and converting them into kinetics: 222.0175777 = AMU for 222Rn gas (decay product of 226Ra radiation) 226.0254098 = AMU for 226Ra 4.007832100 = difference 4.002603254 = ⁴He gas rest mass (but remember, includes electron) 0.005228846 = difference between helium-at-rest and ejected alpha … divide by 1,000 g/kg and divide by 6.022×10²³ particles per mole 8.68291×10⁻³⁰ = mass difference per radium→radon+alpha radiative decay … times 299,792,458² (speed of light in E=mc²) 7.80381×10⁻¹³ = joules difference per radiation decay … divide by 1.6×10⁻¹⁹ J/eV 4,877,379 = eV difference. Now remove the electrons… – 511,000 → electron 1 – 511,000 → electron 2 3,855,000 = eV of the naked alpha … V = √( 2E / m ) 13,624,000 = velocity of each about 4 MeV alpha 4.5% speed of light (c) … times 6.64663×10⁻²⁷ alpha mass 9.06×10⁻²⁰ ‘mv’ impulse per nucleon 54,532 newton-seconds per mole of alphas (or radium, fully decayed) 13,624,000 N-s per kg of alphas. … times 4 ÷ 226 He : Ra ratio… … divided by 9.81 N/kg for ISP 24,580 ISP of radium, naked stuff. Wasn’t that fun? The point is that films of radium will have an appreciable ISP just from the “naked surface” (which I’ve totally ignored the hemispheric emission pattern and the derating for that). But more to the point, one can decelerate the alphas with a sufficiently large electric field gradient (say about 5 million volts), which would prevent collecting them, but w

  109. Dunno… I think the future is more mundane: alpha particle repulsion. There are two interesting cases: alpha reflection and anisotropic alpha capture. As a thought experiment consider a pinhead covered with a film of some alpha emitter such as radium oxide. Alphas — fully charged helium nuclei — don’t go very far a few µm in metals before they’re absorbed. In a vacuum tho they’ll go the distance. Never break down either. Inert little zingers. So our pinhead is sitting in free-space emitting alphas in all directions.Looking up a few choice facts and converting them into kinetics:222.0175777 = AMU for 222Rn gas (decay product of 226Ra radiation)226.0254098 = AMU for 226Ra4.007832100 = difference4.002603254 = ⁴He gas rest mass (but remember includes electron)0.005228846 = difference between helium-at-rest and ejected alpha… divide by 1000 g/kg and divide by 6.022×10²³ particles per mole8.68291×10⁻³⁰ = mass difference per radium→radon+alpha radiative decay… times 299792458² (speed of light in E=mc²)7.80381×10⁻¹³ = joules difference per radiation decay… divide by 1.6×10⁻¹⁹ J/eV4877379 = eV difference. Now remove the electrons…- 511000 → electron 1- 511000 → electron 23855000 = eV of the naked alpha… V = √( 2E / m )13624000 = velocity of each about 4 MeV alpha4.5{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} speed of light (c)… times 6.64663×10⁻²⁷ alpha mass9.06×10⁻²⁰ ‘mv’ impulse per nucleon54532 newton-seconds per mole of alphas (or radium fully decayed)13624000 N-s per kg of alphas.… times 4 ÷ 226 He : Ra ratio…… divided by 9.81 N/kg for ISP24580 ISP of radium naked stuff.Wasn’t that fun? The point is that films of radium will have an appreciable ISP just from the aked surface”” (which I’ve totally ignored the hemispheric emission pattern and the derating for that). But more to the point”” one can decelerate the alphas with a sufficiently large e”

  110. So it costs “nothing” to recondition and recertify them after each flight? Who knew! Even commercial aircraft — the veritable paragons of reliability — have to have significant engine checks every few hundred flight hours, and non-invasive X-ray structural tests every 1,000 flight hours. Costs a bundle. Its all quite hidden from The Public’s eyesight (that’s what every airport’s far flung airfield-full-of-big-hangers is all about). One (me) might imagine that the recertification of a reusable rocket is going to be substantially more invasive, time consuming. As more flights are done, process metrics will accumulate showing just which parts ought to be preëmptively replaced due to their much-increased likelihood of in-flight failure. Oh, as the design(s) mature, better parts, more robust parts will be designed and vetted. Yet it remains: there is DEFINITELY a “tension” between keeping the Rocket Stuff really light weight and its mission durability. And multi-mission survivability. Just saying, GoatGuy

  111. So it costs othing”” to recondition and recertify them after each flight? Who knew! Even commercial aircraft — the veritable paragons of reliability — have to have significant engine checks every few hundred flight hours”” and non-invasive X-ray structural tests every 1000 flight hours. Costs a bundle. Its all quite hidden from The Public’s eyesight (that’s what every airport’s far flung airfield-full-of-big-hangers is all about). One (me) might imagine that the recertification of a reusable rocket is going to be substantially more invasive time consuming. As more flights are done process metrics will accumulate showing just which parts ought to be preëmptively replaced due to their much-increased likelihood of in-flight failure. Oh as the design(s) mature better parts”” more robust parts will be designed and vetted. Yet it remains: there is DEFINITELY a “”””tension”””” between keeping the Rocket Stuff really light weight and its mission durability. And multi-mission survivability. Just saying””””GoatGuy”””””””

  112. I guess the problem (as identified by the maths) is that no matter what, it takes an appreciable multiple of the payload worth of reaction-mass to attain a velocity high enough that the trip doesn’t take dozens or hundreds of millennia. Braking notwithstanding. And yes, the “Holy snot! The sun is about to Nova!” point is well taken. I don’t think we’ll be worrying about that for another half dozen billion years; perhaps sooner it’ll become a Red Giant and vaporize Earth anyway. In 3 billion. A way’s off. GoatGuy

  113. I guess the problem (as identified by the maths) is that no matter what it takes an appreciable multiple of the payload worth of reaction-mass to attain a velocity high enough that the trip doesn’t take dozens or hundreds of millennia. Braking notwithstanding. And yes the Holy snot! The sun is about to Nova!”” point is well taken. I don’t think we’ll be worrying about that for another half dozen billion years; perhaps sooner it’ll become a Red Giant and vaporize Earth anyway. In 3 billion.A way’s off. GoatGuy”””

  114. No , Randall Mills believe in dark matter and claim he make it in his lab and call it ” hydrino “. also Randall Mills hate quantum mechanics with a passion , it is very unfair to compare McCulloch to Randall Mills.

  115. No Randall Mills believe in dark matter and claim he make it in his lab and call it hydrino “”. also Randall Mills hate quantum mechanics with a passion “””” it is very unfair to compare McCulloch to Randall Mills.”””

  116. … and its also good for FREE energy … or nearly free. Any device which delivers a force F for some power input P at a conversion ratio of F = kP … (where k is in newtons per watt), will in turn be an above-unity free-energy device when the V of the thing is greater than 1/k. If “the thing” is a spacecraft, then 2/k is the criterion, as it also encapsulates all the energy necessary to get it up to 1/k meters per second. At V = 2/k, the spacecraft will have a kinetic energy exceeding ALL the thruster’s input energy to get it to that velocity. Just saying. Free energy. Is good. GoatGuy

  117. … and its also good for FREE energy … or nearly free. Any device which delivers a force F for some power input P at a conversion ratio of F = kP … (where k is in newtons per watt) will in turn be an above-unity free-energy device when the V of the thing is greater than 1/k. If the thing”” is a spacecraft”” then 2/k is the criterion as it also encapsulates all the energy necessary to get it up to 1/k meters per second. At V = 2/k”” the spacecraft will have a kinetic energy exceeding ALL the thruster’s input energy to get it to that velocity. Just saying.Free energy.Is good.GoatGuy”””””””

  118. There are THREE interesting limits that one must really keep in mind whilst reading such intriguing articles. № 1: the reflected electromagnetic radiation limit Basically, if one were to have a perfect mirror, and impinge upon it light (or radio waves, or any EMF), reflecting entirely normal to the surface (i.e “back at the sender”), then the amount of force the mirror would experience is: F = 2 E/c dt Force = energy (joules) divided by speed of light in same units. and F = 2 P/c Force is 2 times impinged power, divided by c = 299,792,458. That’s at one side. № 2: Zero. Somewhere between ZERO and № 1’s result, is the FORCE we might expect, for reactionless thrusting. № 3: something LARGER than № 1. This is where things get interesting. “Standard physics” holds that unless one is actually pushing (or pulling) against something having an inertial mass, the MOST one might hope for is № 1. Anything greater than № 1 — by standard physics — requires exerting force on, and in return ‘feeling’ an opposite force from traction against a mass. Your car, for instance, would get nowhere obviously, if it were suspended from cables, the tires unable to push against the road (proxy or the Whole Earth). Yet, when your car pushes against the road, the road in turn pushes against the tires, and the car’n’occupants feel both accelerative and deceleration forces. Analogously, for both jet aircraft and now no-longer-sexy “jetboats”, instead of having something of near-infinite mass to push against, the receiver of the push is a fluid. Air and exhaust gas for jet planes, and water for jet boats. BECAUSE the actual fluid is far less massive than The Earth, whether air or water, it picks up appreciable velocity (i.e. kinetic energy) relative to its rest state. (I wish for italics here…) This in turn saps the producer-of-the-force (the jet engine or jet-boat motor) of some of its output energy. But in return, thrust is still realized from the fluid medium. B

  119. There are THREE interesting limits that one must really keep in mind whilst reading such intriguing articles. № 1: the reflected electromagnetic radiation limitBasically if one were to have a perfect mirror and impinge upon it light (or radio waves or any EMF) reflecting entirely normal to the surface (i.e back at the sender””)”” then the amount of force the mirror would experience is:F = 2 E/c dt Force = energy (joules) divided by speed of light in same units.andF = 2 P/c Force is 2 times impinged power divided by c = 299792458.That’s at one side. № 2: Zero.Somewhere between ZERO and № 1’s result is the FORCE we might expect”” for reactionless thrusting.№ 3: something LARGER than № 1.This is where things get interesting. “”””Standard physics”””” holds that unless one is actually pushing (or pulling) against something having an inertial mass”” the MOST one might hope for is № 1. Anything greater than № 1 — by standard physics — requires exerting force on and in return ‘feeling’ an opposite force from traction against a mass. Your car for instance would get nowhere obviously if it were suspended from cables the tires unable to push against the road (proxy or the Whole Earth). Yet when your car pushes against the road the road in turn pushes against the tires and the car’n’occupants feel both accelerative and deceleration forces. Analogously”” for both jet aircraft and now no-longer-sexy “”””jetboats”””””” instead of having something of near-infinite mass to push against the receiver of the push is a fluid. Air and exhaust gas for jet planes and water for jet boats. BECAUSE the actual fluid is far less massive than The Earth whether air or water it picks up appreciable velocity (i.e. kinetic energy) relative to its rest state. (I wish for italics here…) This in turn saps the producer-of-the-force (the jet engine or jet-boat motor) of some of its output energy. But in return thrust is still realized fr”

  120. It my sound a bit dyspepsic, but din’t Randall Mills (of “Blacklight Snake Oil Free’n’Cheap Energy”) also claim the same? And the never-ending (but now gratefully all but invisible) freewheeling purveyors of [i]“conical helix theory”[/i]? Just saying. Seems like the Solutions to Cosmic Irregularities crop up. Like crop circles. All the time. GoatGuy

  121. It my sound a bit dyspepsic but din’t Randall Mills (of Blacklight Snake Oil Free’n’Cheap Energy””) also claim the same? And the never-ending (but now gratefully all but invisible) freewheeling purveyors of [i]“conical helix theory”[/i]?Just saying.Seems like the Solutions to Cosmic Irregularities crop up.Like crop circles.All the time.GoatGuy”””””””

  122. I would like to see some more work done/reported on fission pumped excimer (e.g. KrF, Ar2) lasers. With the extremely short rise-times possible with “bursts” of fission (i.e. prompt like a TRIGA) it is possible to dump GJs of energy into a lasing gas in a device of major dimension on the order of meter(s). Could be formed by bundling uranium bearing glass tubes of whatever minimum diameter such that tube bowing doesn’t much obstruct the line of sight between the mirrors (turn the stimulated emission into heat). Uranium could be a constituent of the glass or deposited by vapor deposition. Maybe most of the power would be generated in a surrounding zone with the laser cavity in the central ‘glory hole’ – whatever. Even if only 0.5% of the fission energy came out as UV stimulated emission you’d still have a 5MJ laser pulse (greater than NIF) for a 1GW burst. That would heat a 500kg glass reactor 2300 deg-C if it weren’t cooled/purged during the shot using the lasing gas. Look at that – just replaced NIF with a fission reactor and doubled it’s power.

  123. I would like to see some more work done/reported on fission pumped excimer (e.g. KrF Ar2) lasers. With the extremely short rise-times possible with bursts”” of fission (i.e. prompt like a TRIGA) it is possible to dump GJs of energy into a lasing gas in a device of major dimension on the order of meter(s). Could be formed by bundling uranium bearing glass tubes of whatever minimum diameter such that tube bowing doesn’t much obstruct the line of sight between the mirrors (turn the stimulated emission into heat). Uranium could be a constituent of the glass or deposited by vapor deposition. Maybe most of the power would be generated in a surrounding zone with the laser cavity in the central ‘glory hole’ – whatever. Even if only 0.5{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of the fission energy came out as UV stimulated emission you’d still have a 5MJ laser pulse (greater than NIF) for a 1GW burst. That would heat a 500kg glass reactor 2300 deg-C if it weren’t cooled/purged during the shot using the lasing gas. Look at that – just replaced NIF with a fission reactor and doubled it’s power.”””

  124. The theory has already predicted galaxy rotation without dark matter…” Oh no! Someone committed Establishment Grant Whore Science Heresy by challenging the dark matter dogma! Bring out the firing squad!

  125. The theory has already predicted galaxy rotation without dark matter…””Oh no! Someone committed Establishment Grant Whore Science Heresy by challenging the dark matter dogma! Bring out the firing squad!”””

  126. What? even going at a small but consequent fraction of c would be a monumental achievement. It basically means that the stars won’t be closed off for humanity forever, as we currently believe they are. Also, any similar propellentless propulsion scheme, extracting energy from the quantum vacuum would have even bigger implications for the future of energy generation and its prospects for long term civilization.

  127. What? even going at a small but consequent fraction of c would be a monumental achievement.It basically means that the stars won’t be closed off for humanity forever as we currently believe they are.Also any similar propellentless propulsion scheme extracting energy from the quantum vacuum would have even bigger implications for the future of energy generation and its prospects for long term civilization.

  128. faster than c? only if you know how to build a hyperdrive motivator, understand how to align warp coils, deploy stargates or compute jump drive coordinates!

  129. faster than c? only if you know how to build a hyperdrive motivator understand how to align warp coils deploy stargates or compute jump drive coordinates!

  130. According to the big NSF EMdrive thread, recent conference reports are suggesting EMdrive work is in trouble. One report suggested some force reports could be entirely explained due to experimental setup/noise, several drive replication efforts reported null thrust, including an update from Tajmar who was the first big null reporter.

    There is still ongoing concern over experiment design/replication efforts however even from the null report crowd (instrumentation design is difficult to formalize/standardize due to differences in facilities/sensors/budget, and the tiny thrusts they are chasing), so the case isn’t completely closed yet. Also, by some possible scaling ideas, the cost cliff to step up to higher power for a more definitive thrust result is onerous in money/equipment/safety/licensing terms (high power RF is not human friendly).

    But a US Navy team reported a null result at the conference, though is still pursing it. The chinese and those aligned with the chinese drive design concepts are thinking they need to move to frustrum-esque shapes that are more asymmetric and/or easier to make based on their ideas regarding the RF mode and the shape. There’s strange things going on as well, such as positive result holders only willing to lend out their drives to others who report a non-null result from their experiment rig (one could say this is an attempt at quality control of the instrumentation before lending a “known working” drive, but the language used is doing no one any favors).

  131. Posting this again, my earlier comment will probably surface afterwards… Doing this faces the “Far Centaurus” problem: You leave on a 2500 year trip, and a century later some idiot comes up with a ship that’s more than 4% faster, and beats you there. It’s a long recognized issue in the literature of manned interstellar flight. I seriously doubt anybody is going to launch a manned interstellar fight before the ships have gotten fast enough, and progress has stalled enough, that they’d be reasonably confident of reaching the destination before a better ship launched later. Exceptions, of course, for “Holy spit, the sun is going to explode!”, and people colonizing outbound comets and launching them on hyperbolic trajectories just to get away from here, not arrive first someplace else. I expect the first manned ship, barring major physics breakthroughs, to use mass beam propulsion on this end of the trip, and nuclear or magnetic braking against the destination’s solar wind, at the other end. Thus, huge infrastructure requirements for the mass beamer.

  132. Posting this again my earlier comment will probably surface afterwards…Doing this faces the Far Centaurus”” problem: You leave on a 2500 year trip”” and a century later some idiot comes up with a ship that’s more than 4{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} faster and beats you there. It’s a long recognized issue in the literature of manned interstellar flight.I seriously doubt anybody is going to launch a manned interstellar fight before the ships have gotten fast enough and progress has stalled enough that they’d be reasonably confident of reaching the destination before a better ship launched later.Exceptions of course”” for “”””Holy spit”””” the sun is going to explode!”””””” and people colonizing outbound comets and launching them on hyperbolic trajectories just to get away from here not arrive first someplace else.I expect the first manned ship barring major physics breakthroughs to use mass beam propulsion on this end of the trip and nuclear or magnetic braking against the destination’s solar wind at the other end. Thus”” huge infrastructure requirements for the mass beamer.”””

  133. Sounds interesting for getting around the neighborhood. But Unruh is limited to “c”. Makes for a long trip to the next town (star), or county (say, Perseus). Develope it – yes, very good. Any hope of going faster?

  134. Sounds interesting for getting around the neighborhood. But Unruh is limited to c””. Makes for a long trip to the next town (star)”” or county (say Perseus). Develope it – yes”” very good. Any hope of going faster?”””

  135. If they crack that problem, (Assuming the haven’t already, which wouldn’t shock me.) we’d never hear about it. The proliferation problems would be terrifying, at least fission triggers make nuclear bombs easy to track.

  136. If they crack that problem (Assuming the haven’t already which wouldn’t shock me.) we’d never hear about it. The proliferation problems would be terrifying at least fission triggers make nuclear bombs easy to track.

  137. Or, we had pure fusion detonation without the drawback of fission triggers to propel an Orion type launch vehicle. Someone pulls-off a direct ignition of fusion, will bring other issues to the table.

  138. Or we had pure fusion detonation without the drawback of fission triggers to propel an Orion type launch vehicle. Someone pulls-off a direct ignition of fusion will bring other issues to the table.

  139. Put two ocean going tankers side-by-side for a lightering; and, run the experiment in calm wind with nothing more than a heavy chop present. Will find they will tend to close upon the other.

  140. Put two ocean going tankers side-by-side for a lightering; and run the experiment in calm wind with nothing more than a heavy chop present. Will find they will tend to close upon the other.

  141. If I have a say in how my tax money is spent, by all means test every theory for reactionless drives we can. Even if they do not pan out we may get blessed by the god of serendipity and discover one that does work and opens access to the stars. In the meantime, by all means let’s spend the money on the best systems we can build now that will open up the solar system to us. Laser propulsion, nuclear plasma, heck an Orion drive craft built on the dark side of the moon with 1000 crew members if we can. Whatever it takes to get us off this ball of mud. Possibly the new Space Force will provide the resources considering a Navy ship or Air Force planes are just targets from orbit.

  142. Does the physics work out for conventional (i.e. reaction-mass effected) rocket propulsion to get Humans to other stars within their lifetimes? Even assuming reasonable stretching of that lifetime thru hibernation, genetic adaptations, genetic-damage repair and other “active” systems? Say… 2,500 years, with hibernation. And the genetic angles. Say… harnessing most-efficient but not magic nucleonics Say… tho’ dreamy, cannot use antimatter rationally. What’s left? Both fission and fusion remain good candidates, “fuels” are sources of energy and potential reaction-mass stores. If we go with radioactives that emit energetic charged particles for one type of thrust, that have capture-able fission or fusion energies at modestly impressive efficiencies (greater than 70%), … and so on … The Tsiolkovsky Rocket Equation still rules. ΔV = Vₑ ln( Mᵢ/Mᵩ ), no matter what. Vₑ = 9.81 × ISP. Mᵢ is initial mass of rocket. Mᵩ is final mass, after exhausting a bunch of reaction mass at Vₑ. To get to a nearby (say “within 25 light years”) star system (of which there are 176 systems, excluding all below-brown-dwarfs which we obviously haven’t detected, but also which include at least 26 and probably over 125 systems with planets), AND STOP THERE (I believe an important criterion!), we have what… a 2500 year budget? D = ½at₁² + vt₂ Where t₁ is the acceleration phase, and t₂ is the ‘drifting along’ phase. Hard to say where the break is, until we can quantify the emission-rate of reaction mass. But let’s say “1% per year of original mass”. Sure, its a rabbit-out-of-the-hat guess, but its not unreasonable. t₁ = 70 years t₂ = ½(2500) – 70 t₂ = 1180 years Vₑ = 33% of 1 MeV for single-charged fission nucleons Z ≈ 120. Vₑ ≈ 727,000 m/s per nucleon a(t) = F / M(t) where mass changes as reaction mass is used up. Calculus! Nonetheless, one can approximate that mean( a(t) ) is approximately (1 ⊕ ¹⁄₀.3) ÷ 2 or 2.16× the Mᵢ initial mass calculation. So… using ‘A’ ins

  143. If I have a say in how my tax money is spent by all means test every theory for reactionless drives we can. Even if they do not pan out we may get blessed by the god of serendipity and discover one that does work and opens access to the stars.In the meantime by all means let’s spend the money on the best systems we can build now that will open up the solar system to us. Laser propulsion nuclear plasma heck an Orion drive craft built on the dark side of the moon with 1000 crew members if we can. Whatever it takes to get us off this ball of mud. Possibly the new Space Force will provide the resources considering a Navy ship or Air Force planes are just targets from orbit.

  144. Does the physics work out for conventional (i.e. reaction-mass effected) rocket propulsion to get Humans to other stars within their lifetimes? Even assuming reasonable stretching of that lifetime thru hibernation genetic adaptations genetic-damage repair and other active”” systems?Say… 2″”500 years with hibernation. And the genetic angles. Say… harnessing most-efficient but not magic nucleonicsSay… tho’ dreamy cannot use antimatter rationally. What’s left? Both fission and fusion remain good candidates”” “”””fuels”””” are sources of energy and potential reaction-mass stores. If we go with radioactives that emit energetic charged particles for one type of thrust”” that have capture-able fission or fusion energies at modestly impressive efficiencies (greater than 70{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12}) … and so on … The Tsiolkovsky Rocket Equation still rules. ΔV = Vₑ ln( Mᵢ/Mᵩ ) no matter what. Vₑ = 9.81 × ISP. Mᵢ is initial mass of rocket. Mᵩ is final mass”” after exhausting a bunch of reaction mass at Vₑ.To get to a nearby (say “”””within 25 light years””””) star system (of which there are 176 systems”” excluding all below-brown-dwarfs which we obviously haven’t detected but also which include at least 26 and probably over 125 systems with planets) AND STOP THERE (I believe an important criterion!) we have what… a 2500 year budget?D = ½at₁² + vt₂Where t₁ is the acceleration phase and t₂ is the ‘drifting along’ phase. Hard to say where the break is”” until we can quantify the emission-rate of reaction mass. But let’s say “”””1{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} per year of original mass””””. Sure”” its a rabbit-out-of-the-hat guess but its not unreasonable. t₁ = 70 yearst₂ = ½(2500) – 70t₂ = 1180 yearsVₑ = 33{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of 1 MeV for single-charged fission nucleons Z ≈ 120.Vₑ ≈ 727000 m/s per”

  145. If they can fly it ten times, the components are reliable. To get it up to 100, they need to be resistant to fatigue problems, too. I would not be shocked if that carbon fiber tank has issues after multiple flights, it’s really pushing the edge for current art.

  146. If they can fly it ten times the components are reliable. To get it up to 100 they need to be resistant to fatigue problems too. I would not be shocked if that carbon fiber tank has issues after multiple flights it’s really pushing the edge for current art.

  147. Assuming it actually works, which I view as a rather long shot at this point. Without some kind of radical physics breakthrough, (manned) interstellar travel would still be possible, but the infrastructure demands would be immense, we couldn’t do it until we were approaching being a K-2 civilization.

  148. Assuming it actually works which I view as a rather long shot at this point.Without some kind of radical physics breakthrough (manned) interstellar travel would still be possible but the infrastructure demands would be immense we couldn’t do it until we were approaching being a K-2 civilization.

  149. Hello Mike. What do you think about the latest developments on the Emdrive? Seems like some fairly professional replications will declare their results negative. This has put the discussion on some formerly lively places like NASA Spaceflight forum into a sad, moody state. I understand your theory predicts some thrust but it should be weaker than most proponents of the Emdrive expected, probably now making some of the experimenters to declare it an artifact, are they giving up too soon?

  150. Hello Mike. What do you think about the latest developments on the Emdrive?Seems like some fairly professional replications will declare their results negative.This has put the discussion on some formerly lively places like NASA Spaceflight forum into a sad moody state.I understand your theory predicts some thrust but it should be weaker than most proponents of the Emdrive expected probably now making some of the experimenters to declare it an artifact are they giving up too soon?

  151. Good luck to them and to Mike, who seems to be around. It’s not by playing safe and by the rules that things change. And if it doesn’t pan out, at least we’ll know more. There are far worse things to waste public money on. Specially if this is something with so much potential ROI.

  152. Good luck to them and to Mike who seems to be around.It’s not by playing safe and by the rules that things change.And if it doesn’t pan out at least we’ll know more. There are far worse things to waste public money on. Specially if this is something with so much potential ROI.

  153. The true promise of the emdrive is (in addition to being useful for station keeping) would be for interstellar flight. Chemical rockets are woefully inadequate.

  154. The true promise of the emdrive is (in addition to being useful for station keeping) would be for interstellar flight. Chemical rockets are woefully inadequate.

  155. But now SpaceX has shown us that they ARE reusable. fly that Falcon 9 a hunderd times and its only 800,000 / launch

  156. But now SpaceX has shown us that they ARE reusable. fly that Falcon 9 a hunderd times and its only 800000 / launch

  157. Insofar as anyone in Physics has been able to determine, gravity is a MONOPOLAR field, and with relativity, is (ironically) simplified as a bending of space-time. But the bending is always [i]“pointing”[/i] into the normal (math) of a mass; Again, its like counting thing less-than-zero.

    You can have any positive quantity of “stuff” in the REAL world. 1 elephant, 2 coconuts, 3 pebbles, 4 sewing pins, 5 sesame seeds, 6 bits of lint, 7 … and so on.

    One can even philosophically have ZERO things. No elepants, no coconuts, no pebbles.

    But in the REAL (not math or imagined) world, one cannot have fewer than zero things of a kind. You can’t have negative 4 parakeets, or minus 12 camels. You of course can be owed 12 camels by Habib, or owed 4 parakeets by the Aviary Store owner. But that is not the same as HAVING negative numbers of camels and parakeets respectively.

    Gravity is like that.

    Can’t have “negative mass” (but can have zero!)
    Can’t have “repulsive gravity” (but can have zero!)

    Also as forces go, having no complimentary force (such as electric fields having the compliment ‘magnetism’) … which just saying probably sets off alarms in all physicists here … but not having a conjugated pair of forces, gravity also doesn’t appear to have anything except the presence of mass, to “turn it on” and off.

    Like the two main macroscopic forces (electromagnetism and gravity), gravity is thought to be well conserved with a strength of 1/D² (gravitational attraction varies as the square of distance), and a simple linear scale related to absolute value of M (the mass of an attractor) and m (the mass of the attractee.)

    F = G₀Mm/D²

    Experiments have confirmed that the force of gravity propagates at the speed of time (‘c’); there are no known ways to ‘bend’ gravitation force, to focus it, to diverge it, to increase it without increasing mass, or to decrease it similarly. It is isotropic perfectly (uniform in all directions). It seems to have a few relativistic math “gotchas”, but they too are simple and well behaved on all time scales.

    So… no gravity waves that can be macroscopically “felt” without having neutron-star or black-hole rotating binaries. And since we can’t exactly either conjure these up as needed, or if in hand, can’t comport them about because of their mass, well … etc.

    If you like, it is OK to think of the “stuff of spacetime” as a fabric; its also fine to abstract it as having a very high density, but specifically and exclusively of virtual energy. The Dirac equations point to jaw-dropping amounts of energy lodged in every cubic proton’s worth of spacetime. Its accessibility so far has been closed.

    Just saying,
    GoatGuy

  158. It’s not just the difficulty of managing high temperature combustion. It’s also that the energy content of the fuel is low compared to the energy necessary to get out of our gravity well. This drives the need for extreme weight savings, in order to get high mass ratios. If chemical fuels had ten times the energy, or Earth a much shallower gravity well, rockets would be cheap to build.

  159. It’s not just the difficulty of managing high temperature combustion. It’s also that the energy content of the fuel is low compared to the energy necessary to get out of our gravity well.This drives the need for extreme weight savings in order to get high mass ratios. If chemical fuels had ten times the energy or Earth a much shallower gravity well rockets would be cheap to build.

  160. Siamsam: The huge expense of chemical rockets comes from having to build a machine capable of managing, & surviving, the explosive propellant. As an analogy: Elon Musk has found electric car engines need less engineering in this sense (no explosions, fewer moving parts, less wear & tear). The saving with electrically-powered launchers would be far better.

  161. Siamsam: The huge expense of chemical rockets comes from having to build a machine capable of managing & surviving the explosive propellant. As an analogy: Elon Musk has found electric car engines need less engineering in this sense (no explosions fewer moving parts less wear & tear). The saving with electrically-powered launchers would be far better.

  162. Going WAY into the speculative zone, I wonder if it would be possible to push against spacetime itself. It’s supposedly quite rigid (otherwise warp drives would be much easier). I’m not sure if it can be considered to have mass of its own (and if so, how much), but in effect you’d be pushing against the huge rest mass of distant stars. Kind of like pushing against Earth via a steel rod, if you imagine Earth representing the distant stars, and the rod representing spacetime.

    Related to that – or perhaps equivalent – might we be able to construct some sort of gravity wave drive? Basically the gravitational equivalent of a photon rocket. Who knows, it might work better..

    Obviously, both options are far beyond current technology, if not current physics. And I’m sure they’ll require massive amounts of energy, as any other interstellar drive.

  163. Chemical rockets are very expensive because of the explosive propellant they need”. Chemical rockets are expensive only because they are not reusable. The propellant alone is comparatively very cheap. https://www.theverge.com/…/spacex-reusable-rocket-refurbishment-repair-design-cost… Dec 24, 2015 – It costs $60 million to make the Falcon 9, and $200,000 to fuel it, according to SpaceX CEO Elon Musk.

  164. Chemical rockets are very expensive because of the explosive propellant they need””.Chemical rockets are expensive only because they are not reusable. The propellant alone is comparatively very cheap.https://www.theverge.com/…/spacex-reusable-rocket-refurbishment-repair-design-cost…Dec 24″” 2015 – It costs $60 million to make the Falcon 9 and $200000 to fuel it”” according to SpaceX CEO Elon Musk.”””

  165. Dunno… I think the future is more mundane: alpha particle repulsion. There are two interesting cases: alpha reflection and anisotropic alpha capture.

    As a thought experiment, consider a pinhead covered with a film of some alpha emitter such as radium oxide. Alphas — fully charged helium nuclei — don’t go very far, a few µm in metals, before they’re absorbed. In a vacuum tho, they’ll go the distance. Never break down either. Inert little zingers.

    So, our pinhead is sitting in free-space emitting alphas in all directions.

    Looking up a few choice facts and converting them into kinetics:

    222.0175777 = AMU for 222Rn gas (decay product of 226Ra radiation)
    226.0254098 = AMU for 226Ra

    4.007832100 = difference
    4.002603254 = ⁴He gas rest mass (but remember, includes electron)

    0.005228846 = difference between helium-at-rest and ejected alpha
    … divide by 1,000 g/kg and divide by 6.022×10²³ particles per mole

    8.68291×10⁻³⁰ = mass difference per radium→radon+alpha radiative decay
    … times 299,792,458² (speed of light in E=mc²)

    7.80381×10⁻¹³ = joules difference per radiation decay
    … divide by 1.6×10⁻¹⁹ J/eV

    4,877,379 = eV difference. Now remove the electrons…
    – 511,000 → electron 1
    – 511,000 → electron 2

    3,855,000 = eV of the naked alpha
    … V = √( 2E / m )

    13,624,000 = velocity of each about 4 MeV alpha
    4.5% speed of light (c)
    … times 6.64663×10⁻²⁷ alpha mass

    9.06×10⁻²⁰ ‘mv’ impulse per nucleon
    54,532 newton-seconds per mole of alphas (or radium, fully decayed)
    13,624,000 N-s per kg of alphas.
    … times 4 ÷ 226 He : Ra ratio…
    … divided by 9.81 N/kg for ISP

    24,580 ISP of radium, naked stuff.

    Wasn’t that fun? The point is that films of radium will have an appreciable ISP just from the “naked surface” (which I’ve totally ignored the hemispheric emission pattern and the derating for that). But more to the point, one can decelerate the alphas with a sufficiently large electric field gradient (say about 5 million volts), which would prevent collecting them, but would definitely vector them the opposite direction “for free”. At least doubling the thrust. Maybe more.

    its the other theory of getting useful work directly from nuclear decay.
    Could work for fusion too, I guess.
    Especially if there are a lot of charged particles

    GoatGuy

  166. So it costs “nothing” to recondition and recertify them after each flight? Who knew!

    Even commercial aircraft — the veritable paragons of reliability — have to have significant engine checks every few hundred flight hours, and non-invasive X-ray structural tests every 1,000 flight hours. Costs a bundle. Its all quite hidden from The Public’s eyesight (that’s what every airport’s far flung airfield-full-of-big-hangers is all about).

    One (me) might imagine that the recertification of a reusable rocket is going to be substantially more invasive, time consuming. As more flights are done, process metrics will accumulate showing just which parts ought to be preëmptively replaced due to their much-increased likelihood of in-flight failure. Oh, as the design(s) mature, better parts, more robust parts will be designed and vetted.

    Yet it remains: there is DEFINITELY a “tension” between keeping the Rocket Stuff really light weight and its mission durability. And multi-mission survivability.

    Just saying,
    GoatGuy

  167. I guess the problem (as identified by the maths) is that no matter what, it takes an appreciable multiple of the payload worth of reaction-mass to attain a velocity high enough that the trip doesn’t take dozens or hundreds of millennia. Braking notwithstanding.

    And yes, the “Holy snot! The sun is about to Nova!” point is well taken. I don’t think we’ll be worrying about that for another half dozen billion years; perhaps sooner it’ll become a Red Giant and vaporize Earth anyway. In 3 billion.

    A way’s off.

    GoatGuy

  168. No , Randall Mills believe in dark matter and claim he make it in his lab and call it ” hydrino “. also Randall Mills hate quantum mechanics with a passion , it is very unfair to compare McCulloch to Randall Mills.

  169. … and its also good for FREE energy … or nearly free. Any device which delivers a force F for some power input P at a conversion ratio of F = kP … (where k is in newtons per watt), will in turn be an above-unity free-energy device when the V of the thing is greater than 1/k. If “the thing” is a spacecraft, then 2/k is the criterion, as it also encapsulates all the energy necessary to get it up to 1/k meters per second. At V = 2/k, the spacecraft will have a kinetic energy exceeding ALL the thruster’s input energy to get it to that velocity.

    Just saying.
    Free energy.
    Is good.

    GoatGuy

  170. There are THREE interesting limits that one must really keep in mind whilst reading such intriguing articles.

    № 1: the reflected electromagnetic radiation limit

    Basically, if one were to have a perfect mirror, and impinge upon it light (or radio waves, or any EMF), reflecting entirely normal to the surface (i.e “back at the sender”), then the amount of force the mirror would experience is:

    F = 2 E/c dt Force = energy (joules) divided by speed of light in same units.

    and

    F = 2 P/c Force is 2 times impinged power, divided by c = 299,792,458.

    That’s at one side.

    № 2: Zero.

    Somewhere between ZERO and № 1’s result, is the FORCE we might expect, for reactionless thrusting.

    № 3: something LARGER than № 1.

    This is where things get interesting.

    “Standard physics” holds that unless one is actually pushing (or pulling) against something having an inertial mass, the MOST one might hope for is № 1. Anything greater than № 1 — by standard physics — requires exerting force on, and in return ‘feeling’ an opposite force from traction against a mass.

    Your car, for instance, would get nowhere obviously, if it were suspended from cables, the tires unable to push against the road (proxy or the Whole Earth). Yet, when your car pushes against the road, the road in turn pushes against the tires, and the car’n’occupants feel both accelerative and deceleration forces.

    Analogously, for both jet aircraft and now no-longer-sexy “jetboats”, instead of having something of near-infinite mass to push against, the receiver of the push is a fluid. Air and exhaust gas for jet planes, and water for jet boats.

    BECAUSE the actual fluid is far less massive than The Earth, whether air or water, it picks up appreciable velocity (i.e. kinetic energy) relative to its rest state. (I wish for italics here…) This in turn saps the producer-of-the-force (the jet engine or jet-boat motor) of some of its output energy. But in return, thrust is still realized from the fluid medium.

    But the point is, that the energy system defined as “energy-in → propulsive force out” is very tightly defined by the concept of exerting force on a pair of entities… the testbed (“self”) and the propelled reaction mass. Be that air, water, ions, chickpeas or superconducting magnetic bits.
    ______

    Where this whole [i]“Unruh Radiation”[/i] schema goes off the rails is that it carefully coöpts some of the basic Laws of Physics and their equations into supporting the idea that Inertia is a field force (tensor), not a scalar one. In the end, tho’ it is FAR above my pay grade to describe in detail, my own pretty-good math analysis doesn’t agree with the conclusion, Drs Woodward, Mach and everyone else notwithstanding.

    Lets hope I’m wrong.
    And the Stars will be Our Destination. (Heinline, paraphrased)

    GoatGuy

  171. It my sound a bit dyspepsic, but din’t Randall Mills (of “Blacklight Snake Oil Free’n’Cheap Energy”) also claim the same? And the never-ending (but now gratefully all but invisible) freewheeling purveyors of [i]“conical helix theory”[/i]?

    Just saying.
    Seems like the Solutions to Cosmic Irregularities crop up.
    Like crop circles.
    All the time.

    GoatGuy

  172. I would like to see some more work done/reported on fission pumped excimer (e.g. KrF, Ar2) lasers. With the extremely short rise-times possible with “bursts” of fission (i.e. prompt like a TRIGA) it is possible to dump GJs of energy into a lasing gas in a device of major dimension on the order of meter(s). Could be formed by bundling uranium bearing glass tubes of whatever minimum diameter such that tube bowing doesn’t much obstruct the line of sight between the mirrors (turn the stimulated emission into heat). Uranium could be a constituent of the glass or deposited by vapor deposition. Maybe most of the power would be generated in a surrounding zone with the laser cavity in the central ‘glory hole’ – whatever. Even if only 0.5% of the fission energy came out as UV stimulated emission you’d still have a 5MJ laser pulse (greater than NIF) for a 1GW burst. That would heat a 500kg glass reactor 2300 deg-C if it weren’t cooled/purged during the shot using the lasing gas.

    Look at that – just replaced NIF with a fission reactor and doubled it’s power.

  173. “The theory has already predicted galaxy rotation without dark matter…”

    Oh no! Someone committed Establishment Grant Whore Science Heresy by challenging the dark matter dogma!

    Bring out the firing squad!

  174. What? even going at a small but consequent fraction of c would be a monumental achievement.

    It basically means that the stars won’t be closed off for humanity forever, as we currently believe they are.

    Also, any similar propellentless propulsion scheme, extracting energy from the quantum vacuum would have even bigger implications for the future of energy generation and its prospects for long term civilization.

  175. Posting this again, my earlier comment will probably surface afterwards…

    Doing this faces the “Far Centaurus” problem: You leave on a 2500 year trip, and a century later some idiot comes up with a ship that’s more than 4% faster, and beats you there. It’s a long recognized issue in the literature of manned interstellar flight.

    I seriously doubt anybody is going to launch a manned interstellar fight before the ships have gotten fast enough, and progress has stalled enough, that they’d be reasonably confident of reaching the destination before a better ship launched later.

    Exceptions, of course, for “Holy spit, the sun is going to explode!”, and people colonizing outbound comets and launching them on hyperbolic trajectories just to get away from here, not arrive first someplace else.

    I expect the first manned ship, barring major physics breakthroughs, to use mass beam propulsion on this end of the trip, and nuclear or magnetic braking against the destination’s solar wind, at the other end. Thus, huge infrastructure requirements for the mass beamer.

  176. Sounds interesting for getting around the neighborhood. But Unruh is limited to “c”. Makes for a long trip to the next town (star), or county (say, Perseus). Develope it – yes, very good. Any hope of going faster?

  177. If they crack that problem, (Assuming the haven’t already, which wouldn’t shock me.) we’d never hear about it. The proliferation problems would be terrifying, at least fission triggers make nuclear bombs easy to track.

  178. Or, we had pure fusion detonation without the drawback of fission triggers to propel an Orion type launch vehicle. Someone pulls-off a direct ignition of fusion, will bring other issues to the table.

  179. Put two ocean going tankers side-by-side for a lightering; and, run the experiment in calm wind with nothing more than a heavy chop present. Will find they will tend to close upon the other.

  180. If I have a say in how my tax money is spent, by all means test every theory for reactionless drives we can. Even if they do not pan out we may get blessed by the god of serendipity and discover one that does work and opens access to the stars.

    In the meantime, by all means let’s spend the money on the best systems we can build now that will open up the solar system to us. Laser propulsion, nuclear plasma, heck an Orion drive craft built on the dark side of the moon with 1000 crew members if we can. Whatever it takes to get us off this ball of mud. Possibly the new Space Force will provide the resources considering a Navy ship or Air Force planes are just targets from orbit.

  181. Does the physics work out for conventional (i.e. reaction-mass effected) rocket propulsion to get Humans to other stars within their lifetimes? Even assuming reasonable stretching of that lifetime thru hibernation, genetic adaptations, genetic-damage repair and other “active” systems?

    Say… 2,500 years, with hibernation. And the genetic angles.
    Say… harnessing most-efficient but not magic nucleonics
    Say… tho’ dreamy, cannot use antimatter rationally.

    What’s left? Both fission and fusion remain good candidates, “fuels” are sources of energy and potential reaction-mass stores. If we go with radioactives that emit energetic charged particles for one type of thrust, that have capture-able fission or fusion energies at modestly impressive efficiencies (greater than 70%), … and so on …

    The Tsiolkovsky Rocket Equation still rules.

    ΔV = Vₑ ln( Mᵢ/Mᵩ ),

    no matter what. Vₑ = 9.81 × ISP. Mᵢ is initial mass of rocket. Mᵩ is final mass, after exhausting a bunch of reaction mass at Vₑ.

    To get to a nearby (say “within 25 light years”) star system (of which there are 176 systems, excluding all below-brown-dwarfs which we obviously haven’t detected, but also which include at least 26 and probably over 125 systems with planets), AND STOP THERE (I believe an important criterion!), we have what… a 2500 year budget?

    D = ½at₁² + vt₂

    Where t₁ is the acceleration phase, and t₂ is the ‘drifting along’ phase. Hard to say where the break is, until we can quantify the emission-rate of reaction mass. But let’s say “1% per year of original mass”. Sure, its a rabbit-out-of-the-hat guess, but its not unreasonable.

    t₁ = 70 years

    t₂ = ½(2500) – 70
    t₂ = 1180 years

    Vₑ = 33% of 1 MeV for single-charged fission nucleons Z ≈ 120.
    Vₑ ≈ 727,000 m/s per nucleon

    a(t) = F / M(t) where mass changes as reaction mass is used up. Calculus!

    Nonetheless, one can approximate that mean( a(t) ) is approximately (1 ⊕ ¹⁄₀.3) ÷ 2 or 2.16× the Mᵢ initial mass calculation. So… using ‘A’ instead of a(t):

    A = 2.16 × F/Mᵢ

    F is going to be harder… 1% of reaction mass per year. 90% of ship mass is reaction mass? Why not!
    So… that works out to 207 newtons of thrust, raw.

    A = 2.16 × 207 ÷ 1,000,000 kg
    A = 0.000484 m/s²
    t₂ = 1150 years
    V = At = 991,000 m/s

    composite distance = 3.92 light years (at turn-around, deceleration point)
    total distance ≈ 8 light years.

    Well, how about that. IT IS ALMOST POSSIBLE … with life extension methods and really efficient conventional thrusting. “Conventional” meaning not requiring Unruh radiation and magic.

    Just saying,
    GoatGuy

  182. If they can fly it ten times, the components are reliable. To get it up to 100, they need to be resistant to fatigue problems, too. I would not be shocked if that carbon fiber tank has issues after multiple flights, it’s really pushing the edge for current art.

  183. Assuming it actually works, which I view as a rather long shot at this point.

    Without some kind of radical physics breakthrough, (manned) interstellar travel would still be possible, but the infrastructure demands would be immense, we couldn’t do it until we were approaching being a K-2 civilization.

  184. Hello Mike. What do you think about the latest developments on the Emdrive?

    Seems like some fairly professional replications will declare their results negative.

    This has put the discussion on some formerly lively places like NASA Spaceflight forum into a sad, moody state.

    I understand your theory predicts some thrust but it should be weaker than most proponents of the Emdrive expected, probably now making some of the experimenters to declare it an artifact, are they giving up too soon?

  185. Good luck to them and to Mike, who seems to be around.

    It’s not by playing safe and by the rules that things change.

    And if it doesn’t pan out, at least we’ll know more. There are far worse things to waste public money on. Specially if this is something with so much potential ROI.

  186. It’s not just the difficulty of managing high temperature combustion. It’s also that the energy content of the fuel is low compared to the energy necessary to get out of our gravity well.

    This drives the need for extreme weight savings, in order to get high mass ratios. If chemical fuels had ten times the energy, or Earth a much shallower gravity well, rockets would be cheap to build.

  187. Siamsam: The huge expense of chemical rockets comes from having to build a machine capable of managing, & surviving, the explosive propellant. As an analogy: Elon Musk has found electric car engines need less engineering in this sense (no explosions, fewer moving parts, less wear & tear). The saving with electrically-powered launchers would be far better.

  188. “Chemical rockets are very expensive because of the explosive propellant they need”.

    Chemical rockets are expensive only because they are not reusable. The propellant alone is comparatively very cheap.

    https://www.theverge.com/…/spacex-reusable-rocket-refurbishment-repair-design-cost…
    Dec 24, 2015 – It costs $60 million to make the Falcon 9, and $200,000 to fuel it, according to SpaceX CEO Elon Musk.

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