In a Universe ruled by the harsh and unyielding laws of Physics, it’s often tempting to dream of mechanisms which defy these rigid restrictions. Although over the past hundred years we have made astounding progress in uncovering ways to work within these restrictions — including splitting and fusing atoms to liberate immense amounts of energy — there are those who dream of making reality a bit more magical. The concept of asymmetrical electrostatic propulsion is a major player here, with the EmDrive the infamous example. More recently [Dr. Charles Buhler] proposed trying it again, as part of his company Exodus Propulsion Technologies.
The problem with such propellantless space propulsion proposals is that they violate the core what we know about the physical rules, such as the conclusion by Newton that for any action there has to be an opposite reaction. If you induce an electrostatic field or whatever in some kind of device, you’d expect any kind of force (‘thrust’) this creates to act in all directions equally, ergo for thrust to exist, it has to push on something in the other direction. Rocket and ion engines (thrusters) solve this by using propellant that create the reaction mass.
The EmDrive was firmly disproven 2021 by [M. Tajmar] and colleagues in their paper titled High-accuracy thrust measurements of the EMDrive and elimination of false-positive effects as published in CEAS Space Journal, which had the researchers isolate the EmDrive from all possible outside influences. Since the reported thrust was on the level of a merest fraction of a Newton, even the impact from lighting in a room and body heat from the researchers can throw off the results, not to mention the heat developed from a microwave emitter as used in the EmDrive.
Meanwhile True Believers flock to the ‘Alt Propulsion Engineering Conference’ (APEC), as no self-respecting conference or scientific paper will accept such wishful claims. In the case of [Buhler], he claims that their new-and-improved EmDrive shows a force of 10 mN in a ‘stacked system’, yet no credible paper on the experiments can be found other than APEC presentations. Until their prototype is tested the way the EmDrive was tested by [M. Tajmar] et al., it seems fair to assume that the rules of physics as we know them today remain firmly intact.
I think this tech will eventually find some sort of way to emit pulsed, rotating fields that act like standing waves and allows the net thrust to be observed. Like an RF “smoke ring” antenna blowing out the engine cavity…
So basically a very inefficient photon drive. These drives work by having tiny, barely-measurable accidental thermal effects or magnetic effects upon the test apparatus/Earth’s magnetic field. They would do very poorly in open space. The fact that the null device (a big resistor wired in to simulate the load) still produces thrust in many of these tests (not this specific one, but several emdrive tests) is fairly damning.
Maybe this one is different… But conservation of momentum is pretty ironclad. If it does work, then congratulations, you’ve accidentally also discovered the most destructive gadget known to man.
https://www.projectrho.com/public_html/rocket/reactionlessdrive.php#id–EmDrive
its a matter of show me the thrust, extrordinary claims…etc. every reactionless drive has failed when asked to scale the thrust above the noise threshold of the instruments.
It’s propellantless, not reactionless. And there are tests that show above noise levels.
then show me the thrust. seen this with em, canne, mach effect/mega drive and most recently the thrown-in-space quantized inertia drive. wheres the vroom vroom?
The data is there for you to find if you really are interested. You could actually call Charles Buhler and discuss the data with him if you choose.
That would be a photon rocket. 300mj for on N of thrust.
It’s still not reactionless, which is the claim here.
Also, ‘pulsed rotating standing waves’ is not physics.
What does “300mj for on N of thrust.” mean?
You mean 300 MW (megawatts) for one Newton of thrust?
Reminiscent of the old Kzinti saying: “A reaction drive’s efficiency as a weapon is in direct proportion to its efficiency as a drive.”
Kudos for the Ringworld reference.
Referencing an earlier short story of the first contact.
watts and joules are not units of the same thing. Joules are a unit of energy, watts are a unit of power (energy/time)
mj = megajoules
in watts, this is 300 megawatt-seconds.
I suspect that this: “300mj for on N of thrust.” should have been expressed as “ What does “300mj for one newton-second of thrust.”
csw
mJ is actually milli-joules.
MJ is mega-joules, in standard units.
Quantum Physics versus Macrophysics or the Exhaust of Quantum Particles versus the Exhaust of Matter Chunks. How can that be misconstrued?
It’s actually more like 1 milliwatt for 1 milli Newton of thrust in latest tests. Its way beyond a photon rocket.
Yay! Let’s hear it for the laws of physics! I spent almost 50 years looking for a chink in their armour and every time you think you’ve found a wInner it just requires a bit deeper analysis to figure out that you’ve been fooling yourself. As the saying goes, if it looks too be too good to be true…..
What is so dangerous about a character like Buhler is he gives good kids bad ideas.
Oh Ed – You sounded like Dirty Harry then!
Remember when everyone thought heavier than air flight was impossible?
Birds have been around for a long time. Their existence and flight ability proves that heavier than air flight is possible.
“for humans”
No, because no one (with any scientific understanding of the problem) ever did.
A bumblebee is heavier than air. It flies.
Everyone?
What a silly argument…
Progress is progress, the numbers will show us what’s true or not. Of course, I personally assume that our understanding of actual physics is rudimentary at best, and in the coming decades we’ll find that we were fundamentally wrong about more than one accepted “truth.”
We already know we’re wrong about many fundamental truths.
For example, we already know relativity and quantum mechanics are not correct – they’ re just more correct than their predecessor.
And the problem with the idea that we’re wrong about fundamental truths is that whatever replaces it must still give the same answer where we’ve confirmed by observation – the classical limit.
So reactionless drives are still not going to be possible.
That’s just character assassination. Buhler has a long and distinguished scientific career including at NASA. I would believe him over a critic who spent all of 5 minutes reading an article.
Marketing people do a good job in making people believe what will sell more, that’s all. Science is not hard, but not every person likes to use it. I mean… isn’t the free energy concept more compelling than the equations used to disprove it?
The cynic in me is thinking “The concept of someone getting rich off of selling people on the idea of free energy is more compelling than the concept of free energy.”
In this age of “science deniers”, I find myself asking fairly often, “what exactly are you calling ‘science’?” I think that “they” think this makes me a “science denier”.
people who use the term “science deniers” are just as ignorant about sciences as the ones they are calling out with the term. cant we just call the pandemic a massive fustercluck on all fronts and let it be? theres a vaccine, take it, dont, i dont care. old news. science is not scripture. not to mention at any given time you can rifle through papers on a large number of competing theories that all contradict eachother worse than the bible. even in the hard sciences like physics. “trust the science”, thats not how science works.
“Science is not scripture” sounds like the spiel of someone happy to let a round of mumps run its course through the local population of school kids.
““Science is not scripture” sounds like the spiel of someone happy to let a round of mumps run its course through the local population of school kids.”
Amen………. :)
Science is not a “god”, science is the investigation of the world around us, real and imagined, to figure out how it works and applies to all of us. Some ideas for investigation lead to false trails. Some lead to inspiration for others to pursue. Some stay a dream till someone finds the path. Science is not settled, it changes to the right or wrong. What is settled in the hard mind that says you cannot do that
except that would be stupid.
Then stop acting like it’s scripture.
When they say ‘trust the science’ they mean ‘trust the science _reporting_’.
‘Trust the science reporting’ is just insane. Flat no.
Assume you have deep knowledge of a technical subject (any subject).
Recall the last time you heard TV reporting about that subject.
Was it in any way good or accurate?
Now poll your STEM friends. Same question.
Media bats 000 at technical and science reporting.
Amazing really, you’d think after all these decades, they’d get something right by accident.
J-schools require no non-remedial math or science to graduate. They take middle school math/science for a third time. Barely get Cs. Graduate.
It’s not just the media: understanding things *conceptually* is a different skillset than being able to work in a STEM field, because the concepts themselves are unimportant to the actual results. Doesn’t matter if you understand where centrifugal acceleration comes from in a non-inertial frame, you’ll measure it just the same.
If you haven’t been paying attention, science is actually quite difficult, and we’re essentially babies who’ve learned to roll around on the floor as a means of locomotion. Anyone who says science is not hard has undeniable misunderstandings and biases in what they constitute science to the point you’re only a step above astrology. Some things people laud as science, even as far as cosmology, aren’t even close.
it can work, it will just cost 300 megawatts per newton.
one of these days i will work out the delta v of the flashlight on my desk.
With a near perfect reflector in the right geometry… Small! Very very small.
Trivial to work out. Using a notional 100-gram flashlight with 30 kJ of stored energy (an 18650 lithium cell), you’ll get 30e3 J / 300e6 J/N.s = 0.1 mN.s impulse. On 100 g mass, that will give you a deltaV of 1 mm/s.
Easy with a rational set of units. May god help you if you try to figure that out in slug-seconds or pound-force per pound mass – seconds or whatever.
‘…their current devices, which Buhler told The Debrief “weigh somewhere between 30-40 grams on their own” without the attached test equipment, were producing enough thrust to counteract the full force of one Earth gravity’
That’s quite a massive improvement over the milligees they were reporting before! This is either the breakthrough of the century…
or they’re just dumping enough power into the device that its surface ablates.
>> “were producing enough thrust to counteract the (30-40 grams) of one Earth gravity”
On the plus side, this should be easy to debunk, because a 35gram force is easy to measure, it’s the weight of about 4 one-euro coins.
If they’re for real, they get a Nobel, but if they’re con artists, they’ve broken the first rule of swindle-ology – they made a specific, easily measurable, claim.
Trust me, every time you say “well this’ll be easy to debunk” you’ll be *amazed* at the lengths people will leap through to justify a presupposed result.
They’ve already jumped through hoops in their own head for all the times it *didn’t* work for them, too, so they’ve had plenty of practice.
Have you never worked in a lab? You usually have a goal of what you’re trying to do, and you often have to develop the protocol and it is an experience and intuition based trial and error process. Usually you have more ways not to make a lightbulb than you do finished lightbulbs by the time you’re finished. I wouldn’t say it’s mental gymnastics, but the way it works. I’m not saying anything or condoning the research on this specific case, just talking about how doing this kind of work goes.
These aren’t real labs – they have a strong economic bias to be correct. As in, they say “hey I’m getting result X this is amazing!” a real lab says “uh, no, I tried to reproduce it and you made this mistake” and they’ll say “oh no that wasn’t a mistake you actually need to coat the device in a superconductor and sprinkle unicorn dust and that cancels the quantum vacuum fairy.”
Hell, even in independent labs people will go to crazy lengths to satisfy their original opinions, so it’s not like this is surprising.
The problem with understanding the crank stuff is that a lot of the time the problem is that the first person that they conned is *themselves*.
Hey, why you dumping on him?
Others out there are talking about “gravity waves” and “God particles” and nobody’s dumping on them.
Probably because both of those things you are referring to have been both proved mathematically, and with empirical objective evidence. They both were also proposed many decades ago, but the sometimes frustratingly slow process of actual scientific methodology has proven them both to be true through rigorous evidence based investigation.
i might be on a different wavelength here but it seems like modern physics *is* full of junk ideas, contradictions, and oversold results. everything from dark matter and dark energy to quantum teleportation and spooky action at a distance from quantum entanglement.
the difference is that at least the scientists at the core of it (but not always their PR departments!) are usually pretty upfront about their limitations. everyone in the field knows dark matter / dark energy is the least satisfying explanation. and the spooky quantum experiments, if you read the paper, it’s pretty clear why the effect is too rareified to be of any significant import. people keep blah-blah-blahing about quantum computing but just as quickly people are pointing out classical computer algorithms to achieve the same results just as efficiently.
in other words, people *are* dumping on them and most often it’s the scientists who are conducting the experiments are dumping on themselves. it really is a marveous thing, the genuine struggle with reality’s reluctance to be known
“everyone in the field knows dark matter / dark energy is the least satisfying explanation.”
No, everyone knows that the *model being used* is not a satisfying explanation because it’s not *intended to be*. It’s like if you said “let’s assume the Earth is a sphere” and then measure things *relative* to that model – the deviations then allow you to figure out the true shape.
The difficulty and frustration is that the “ultrasimple approximation” works too well. It’d be like if the Earth was *actually* a ball to a part in a million or something.
“and the spooky quantum experiments”
There are no “spooky quantum experiments.” Entanglement is trivial to describe mathematically/physically, the difficulty is trying to understand it in common terms, which is pointless because one available answer is always “you don’t have to understand it in common terms at all.” You don’t need “the particle collapses into a state instantaneously” if the concept of “a particle” was never real to begin with.
It’s the “god d*** particle” since they knew where to look, but were frustrated with not having the right equipment to find it. A book publisher took liberty in doing a little language sanitizing.
Anyone remember Steorn?
Yeah. I was in the program. They proved how to extract energy from magnets. I have the files
at the time i saw comments saying it was the best designed website they had ever seen. their highest accomplishment apparently.
https://web.archive.org/web/20130805200459/http://www.steorn.com/about/
In the mid 1970’s, ‘Pyramid Power’ was going to solve all of our energy needs…
50 years later and the Rubes are still getting robbed.
But the razor blades stay sharp.
Rubbish. Razor blades dont get dull sitting on your bathroom counter they get dull as you use them. Putting a dull blade under a pyramid isn’t going to resharpen it.
What’s old is new again. I leave you the “Dean Drive”
https://patents.google.com/patent/US2886976
They literally just proved propellantless propulsion.. I have the news article on my phone.
In 2021, a man claimed he could violate the laws of physics and use a wind-powered vehicle to go downwind faster than the wind itself.
https://hackaday.com/2021/07/02/10-000-physics-wager-settles-the-debate-on-sailing-downwind-faster-than-the-wind/#more-485133
There was a lot of hand-waving, a lot of smoke and mirrors, and even some math. A physicist bet him $10,000, and paid up when he was convinced he had lost.
So, as late as 2021, you could still fool some of the physicists some of the time. Maybe you still can.
Kusenko’s a cosmologist. It was a publicity stunt. No one sane who thought about it for a second would’ve had a problem with the idea.
(how do I know it was a publicity stunt? cuz if you think physicists randomly have $10k lying around, you don’t know many physicists)
Here is a few simple premises:
1. Wind blowing across the earth has kinetic energy.
2. To slow the wind relative to the earth, you must remove some of that kinetic energy.
3. It is possible to build a device that slows down the wind relative to the earth. (A wall, sail, circular fan, etc)
4. You can design the device to even work when the device is moving the same speed as the wind or faster than the wind. (A car driving the same speed as the wind with a fan blowing backwards to slow the wind down).
5. It is possible to build a device that extracts the wind’s kinetic energy and converts it to useful action/power. (Wind mills)
Those are all true statements, right?
If you combine them all together, you get a device that extracts useful energy from the wind by slowing it down relative to the earth even if the device is moving with the wind. Then just use the energy to power a motor to make the device go faster.
Everything is all just fine here until the final two sentences. I will address the last sentence only, specifically, saying “use the energy to power a motor to make the device go faster” is like saying “use a motor to run a generator to make enough electricity to make the motor go faster.”
Incorrect analogy – that would involve the creation of energy, which is not possible. What’s described simply utilizes the kinetic energy of the wind in a different fashion. This is more like extracting energy from a wider area and concentrating it, like a solar heater – solar energy on Earth’s surface lacks the necessary watts per square meter to boil water, but it can easily boil it if you concentrate it.
““use the energy to power a motor to make the device go faster” is like saying “use a motor to run a generator to make enough electricity to make the motor go faster.””
No, it’s not, because depending on your frame of reference you’re either pulling energy from the *wind* and using it to push against the *ground*, or pulling energy from the *ground* and using it to push against the *air*. Doesn’t matter which way you view it. You’re still just pulling energy from a constant speed differential.
The “but if you’re moving the same speed as the wind there’s no wind” completely misses the point – in *every* frame of reference, there’s a speed differential between the two media (the ground and the air), and you can *always* extract power from two media moving at different speeds. Everything else is just an engineering challenge.
i think you’re misstating the experiment? no one claimed to violate the laws of physics. and the machine was able to go downwind faster than the wind. and, if i understand, the man with the fast downwind machine won the bet — the naysayer agreed to pay up.
the question is just whether it’s possible to extract energy from the differential in speed between the wind and the ground while your machine is itself moving. and i think the answer is obviously yes and, as has been said, the rest is all just engineering.
the energy extraction depends on the linkage between the wind and the ground (i.e., between the propeller and the wheels), not the linkage between the propeller and the chassis.
Just attach the magical words “NASA” and “Dr.” and presto, your wild-ass theory is as solid as the rock of Gibraltar. You should check Quora where Einstein is out-Einstein-ed 100 times a day and the moon landings never happened. In general if those two words are in the first sentence the entire article is bunk.
That said, there IS a way to milk energy from the vacuum and it’s been empirically proven (the Casimir effect) but it isn’t worth exploiting it, at least with our current technology. It’s like pulverizing a hundred ton of rocks to get a pint of water. The very quantity of “vacuum energy” is a subject of a heated debate where some indirect measurements differ from other methods by 30 orders of magnitude.
“That said, there IS a way to milk energy from the vacuum and it’s been empirically proven (the Casimir effect)”
You mean experimental, not empirical.
But the Casimir effect is a convenient way of imagining how the quantum zero point could result in real effects, but the actual experimentally observed effect doesn’t actually depend on the quantum vacuum at all. The quantum vacuum discussion is a way of showing what the Casimir force *must approach* in the strong-interaction limit.
In other words, if you *conceptualize* the vacuum as real, you can calculate certain forces very easily and quickly. But it’s conceptual – the existence of the forces doesn’t imply the vacuum as real, you introduced the vacuum as real to make the calculation easier.
Yes, I know this sounds different than what’s said online, but in most of those cases they’re trying to convey a different idea, and in other cases they’re probably wrong. Casimir’s original paper is a recalculation of Casimir & Polder’s earlier result, and that earlier result has *zero reference* to the vacuum whatsoever. It’s just straightforward perturbation theory.
If the Casimir effect proved the vacuum zero point was real, there’d be no way to derive the Casimir effect *without* it, and obviously Casimir & Polder did originally (for molecules) and Schwinger did later (for the infinite conducting plane case).
So why is there so much confusion? Because when you say “quantum vacuum” everyone assumes you’re talking about some single, universal thing. But it’s not! The “quantum vacuum” of Casimir’s toy model is not a fundamental vacuum, because it’s a toy model. In other words, Casimir’s vacuum is a *mathematical* tool – it’s not the same thing as the vacuum of, say, a Standard Model calculation.
The article is factually wrong. Tajmar did not “firmly disprove” the Emdrive. He merely could not reproduce the work in his lab but that’s not very surprising for a variety of reasons.
No, he very clearly showed that the previous results were due to defects in the other experiments. As in, he could make their thrust appear/disappear and showed the reason for it.
No, he showed only that’s what he thinks happened. I don’t trust Tajmars lab.
I don’t appreciate the tone of this article. It shows arrogance and ignorance. No one ever has or ever will “break the laws of physics” but plenty of scientists have broken the dogma or what accepted models say. I expect that might happen in this field someday whether this invention does or not. We don’t know everything and very likely the physics 100 years from now will be different from our current understanding. A propellantless propulsion system would not “break the laws of physics” but only break a naive characterization of Newton’s laws.
What’s the difference between Conservation of Momentum and Inertia? Why does the former prove the latter can’t work?
Einstein proved that mass can become energy (E=MC2), but the equation works in the other direction too. Energy can become mass. And then you could have that mass ejected in a particular direction and get thrust. It would all be consistent with Newton’s laws. It kind of depends on how you define “propellantless drive” – if you mean that the drive does not have any stored propellant and instead converts pure energy into mass (which technically becomes a propellant ), then such a drive is possible and would not violate the laws of physics.
Except that’s not what the EmDrive purports to do.
The 15 kiloton bomb be dropped on Hiroshima converted less that one gram of matter to energy. So you’re gonna need astronomical amounts of energy to produce even the smallest whiff of mass.
Yeah, all the wiggity-wiggity “do this and Einstein says you get thrust” all result in fundamentally exactly the same math as a photon rocket, and we don’t make bottle rockets out of flashlights.
I saw a video two days ago. Some NASA guy who wants to try again. Remember Arthur Clarke’s truism “For Every Expert there is an Equal and Opposite Expert”.
Good science is indistinguishable from magic
Only to the ignorant. But that’s repairable. Desired, even.
What’s the difference between Conservation of Momentum and Inertia?
Swimming in water is also propellantless, so we just need to find dark mater in space
The density of dark matter in space isn’t significantly different (by orders of magnitude, that is) than the density of normal matter, and your ability to interact with normal matter is orders of magnitude higher. (It’s even worse than that since dark matter shouldn’t be nearly as uniform as gas density).
In other words, swimming using dark matter would be *less* effective than trying to swim through the interstellar medium. Good luck with that.
No, you have to propel water in the opposite direction to move when you swim.
Laser driven propulsion is also propellantless! wtf
True, for some types of “laser driven” and certain definitions of “propellant”.
Why dont they just focus on making a CRT thruster? Boil electrons and accelerate them in the direction you want to thrust.
That’s an excellent way of turning your whole spacecraft into an x-ray source, when those electrons come screaming back to your now-positive-charged hull. Oh, and by the way, nulling out any momentum transfer.
Actually the overall idea isn’t crazy, just… entirely backwards. You want to accelerate the ions, not the electrons, since they’re way heavier. Which is how ion thrusters work – and then you spit out electrons as well to neutralize the exhaust.
Yes, I was leaving that as an exercise for Sean to work out.
It’s a darned shame it’s so energetically expensive to produce ions. Xenon or mercury are pretty good, but have costs. Iodine good, but has issues. Krypton is OK. Argon is getting iffy for efficiency, but has the convenience of being pretty cheap.
I’m looking forward to seeing how the new heavy salt (ion) “green” propellants work out on orbit.
However, Charles Buhler might be on to something. This runs along the lines of the asymetrical capacitor line of thought. This traces its origins back to the Biefiel Brown experiments. Buhler has been doing his experiments in a total vacuum ruling out ionized wind effects.
While projects like this may seem to violate the known laws of Physics, it’s those of us who ignore such facts that make the most progress. Heavier-than-air flight was somehow an impossibility at one time. So was space travel. Even recently, the idea of dropping a rover gently on Mars using some crazy thing called a ‘Sky Crane’ was ridiculous. Personally, I thought for sure that was going to fail. I was wrong. Twice.
It might be fun to debunk junk science, but it’s always wise to give an interesting idea a second look.
I came here for the thought provoking comments. Ty.
Why is it on most “tech” sites I always see 2-4 people replying dozens of times to shoot down every single comment that either disagrees with the article, them or both? It’s almost like some groups in society today cannot accept any opinions or beliefs other than their own and SJW style spend all their waking time trying to make sure only OBE opinion (which they call a FACT) is ever heard.
There’s protestors shouting down the other side or speaker so they can’t talk, for example. Then there’s “News” sites (on both sides) that are obviously majorly partisan to the point they might as well be called propaganda sites. The only time they agree is to attack the very idea of a 3rd alternative. What a waste of time/vote… Yeah, we love YOUR system!
I don’t know about this drive, speaking as an Electronic Engineer. Maybe Newton thinking about an apple isn’t the end all be all of physics forever, but I do know people who think there’s no possible fast way across the galaxy and/or universe just because we primitive Earthlings haven’t managed to do it yet (at least openly) is pretty darn narrow thinking. People were burned at the stake for suggesting contradicting views of the universe. That didn’t mean they were wrong. Personally, I try to keep an open mind about a Universe that might well be a holographic projection/illusion in the first place.
Wake up Neo.
There is another propellantless space propulsion available now that:
• Does not violate any laws of physics.
• Is simple and relatively low-tech.
• Can be demonstrated in a classroom.
• Produces significant thrust.
How does it work and where is it?
How it works:
The system utilizes the normal behavior of gas/air molecules to produce thrust. Visualize a closed airtight container (like a 6-liter water bottle). Inside the container, there is gas/air at sea level pressure and temperature. At rest, the container will not move, but there are billions and billions of fast-moving molecules colliding with each other and the inner walls of the container.
For every collision, there is an equal and opposite counterforce, with no loss or creation of momentum. However, the direction of the molecules is randomized in every collision, resulting in symmetrical vector directions in all directions. Therefore, despite all the pushing against the inner surface of the container, the sum of the forces is equal in all directions (regardless of the shape of the container).
So, we have a container with a lot of internal pressure (14.7 pounds per square inch), but because of the natural tendency of colliding air molecules to randomize direction, a symmetry is created, resulting in an equal push in every direction.
How do we break the molecular symmetry to increase or decrease the push against one of the inner surfaces? There are several methods available (such as compression, turbines, electrohydrodynamics, among others), but the simplest method is a rotating propeller at one end of the airtight cylinder’s inner end (inner base).
When the propeller is activated, it collides with the freely moving gas/air molecules. With every collision, a force is exerted on the propeller, and as the propeller is attached to the cylinder by solid molecules, the force is exerted on the cylinder pushing it.
For every collision, each individual molecule receives an equal force that propels it in the opposite direction. If that molecule were to reach the opposite inner surface of the cylinder unmolested, the force exerted on the rear end would be equal to the force against the propeller, and the symmetry of forces would be retained.
However, as the molecule collides with billions of fast-moving molecules in random directions, some are diverted towards the inner circumference walls of the cylinder. In other words, we are stating that a moving propeller inside an airtight cylinder will push the cylinder from the inside.
A simple DIY experiment designed for the classroom that demonstrates the method can be seen here.
Where is it?
The fluid space drive was developed in Chile by Wjetech Spa, a company initially funded with startup funds granted by the Chilean Economic Development Agency in 2019. Wjetech was present at the FIDAE Space Summit 2024, where the method was presented to various participants.
Wjetech has developed a propellantless propulsion system for cubesats as its first product, which will be assembled for customers by regional aerospace companies.
More information can be found at wjetech.cl.
In your case I think this is a variation of the Dean Drive effect. I suspect there is enough torsion in the string the vibrations from the motor can react against to build the motion. Take away the string it’s hanging from and I think there will be no net motion in space.
I think we’ll find a way to block gravity before we come up with propellantless propulsion.
That was always a sticking point with me in science fiction. If you have the ability to control gravity to the point you can create 1G on a planar surface. Why can’t you just cancel it out or reflect it on one side of your space ship? If you’re flying around in a cube, and one side suddenly doesn’t feel any of the gravity present in the rest of the immediate universe, wouldn’t the ship start accelerating in the opposite direction?
Yeah, scifi stuff doesn’t handle that well. It’s actually not hard to work around. Basically what you’re saying is “if you can manipulate gravity, functionally you can push back against the rest of the universe” and that part doesn’t *have* to be true (I mean, c’mon, you’re making up physics, you can make it up however you want) – although who’s to say that’s not the way “impulse drives” work or something. But you could conceptually come up with an artificial gravity that basically requires a “start” and “stop” – so you imagine it gives a linear gravity potential between two regions and zero outside of it.
I mean, you could *create* something approximating that in general relativity, it’d just have the same “magic material” to cancel gravity out that you have in wormholes/warp drives/etc. If you want to avoid being able to use that “magic material” to do those other things you just come up with some technobabble stuff about how creating that material naturally arranges it into that “start”/”stop” configuration.
Kindof important to realize that all of the wormhole/warp drive/etc. goofball papers in GR result in them *starting* with the desired behavior and figuring out what configuration of energy is required to make it. Same deal here.
I wonder if needs a cold fusion power source to operate…
Coloumbs law Fe=Ke q1q2/r2 is 89 trillion Newton’s at 1 centimeter. That is just 1 volt and 1 Amp on 2 plates. Electrostatic generators goto 50,000 volts minimum so 1 million trillion pounds of pressure per square foot. Now increase the distance. At 10000 meters it’s still in the billions of pounds of thrust, now keep in mind that is just 2 charges. A device continually generating charge can go forward forever.
I believe it. I really Don’t care what critics who like to parrot known laws and rules with authority say. I care what the data says and in this case there have been thousands of experiments run over several years including in hard vacuum chambers. Yes, the force exists. Yes, It challenges our current understanding but data rules.
“yet no credible paper on the experiments can be found other than APEC presentations. Until their prototype is tested the way the EmDrive was tested by [M. Tajmar] et al., it seems fair to assume that the rules of physics as we know them today remain firmly intact.”
First, This is just argument from authority which is not valid in science. You might as well say if it’s presented at APEC it can’t be true whatever it is. That’s just bias. Second, it’s not an EmDrive. Third, there are problems with Tajmars lab. I don’t; trust their competence and even if his lab reports a negative test, that’s not proof such a tested device doesn’t work, just that Tajmars grad students couldn’t get it to work. Finally, forth, Nobody will ever break a law of physics however our understanding of what the laws really are may evolve with new knowledge and discoveries.