The 'Impossible' EM Drive Being Tested By NASA May Finally Be Explained (technologyreview.com) 532
MarkWhittington writes: The EmDrive, the so-called "impossible" space drive that uses no propellant, has roiled the aerospace world for the past several years ever since it was proposed by British aerospace engineer Robert Shawyer. In essence, the claim advanced by Shawyer and others is that if you bounced microwaves in a truncated cone, thrust would be produced out the open end. Most scientists have snorted at the idea, noting correctly that such a thing would violate physical laws. However, organizations as prestigious as NASA have replicated the same results, that prototypes of the EmDrive produces thrust. How does one reconcile the experimental results with the apparent scientific impossibility? MIT Technology Review suggested a reason why.
Quantized inertia? (Score:5, Insightful)
We'll eventually find out we really live in a simulation...
Re: Quantized inertia? (Score:2, Funny)
Oh goddamnit now they have to change the datatype on inertia...give it some more bits. Hope they have online ALTER
Re: Quantized inertia? (Score:5, Funny)
To be fair, assuming no race conditions, we'd never know if they took us offline. We could be running then stopping and running then stopping, and as long as the state was preserved, we'd never know (being part of that state).
"stop the world, I want to get off" just became a real thing...
Re: Quantized inertia? (Score:4, Insightful)
We could be running then stopping and running then stopping, and as long as the state was preserved, we'd never know (being part of that state).
If it turns out that time comes in discrete lumps, this is what is happening all the time anyway.
Re: Quantized inertia? (Score:5, Funny)
If both time and space are quantised to the extent that we're the simulation, there's some interesting corollaries to do with numerical instability [wikipedia.org] - basically that the computational steps in time have to be below a certain limit or spatial anomalies will occur, and vice versa.
And vice versa. :)
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If both time and space are quantised to the extent that we're the simulation, there's some interesting corollaries to do with numerical instability - basically that the computational steps in time have to be below a certain limit or spatial anomalies will occur, and vice versa.
You mean how like Newton works when you use him, and you find Einstein when you look for him? And when you deal with really high or low energy states that you'd need more resolution to model accurately, you need Bohr? Creepy ;)
Re: Quantized inertia? (Score:4, Insightful)
Or should we rather say it's happening EACH the time?
Re: Quantized inertia? (Score:3)
If it turns out that time comes in discrete lumps...
...it might have a prostate problem (FTFY).
Re: Quantized inertia? (Score:4)
To be fair, assuming no race conditions, we'd never know if they took us offline. We could be running then stopping and running then stopping, and as long as the state was preserved, we'd never know (being part of that state).
"stop the world, I want to get off" just became a real thing...
So basically what you're saying is when the world has a problem, turn it off and on again.
Re:Quantized inertia? (Score:5, Funny)
> We'll eventually find out we really live in a simulation...
And only the soul programs that have been save()d will be uploaded to the next life.
Re:Quantized inertia? (Score:5, Funny)
We'll eventually find out we really live in a simulation...
If you ever find yourself experiencing an uncontrollable urge to do something you wouldn't normally do, it's probably because you're being clicked-and-dragged.
Re:Quantized inertia? (Score:5, Funny)
I'm pretty sure I've been replaced with a simple shell script.
Re:Quantized inertia? (Score:5, Funny)
Re:Quantized inertia? (Score:4, Funny)
Exactly. And this is the explaination of the effect. As you probably know, at the same time when EmDrive has been invented, there were experiments to verify if our universe is a simulation. In these experiments they tried to find a regular structure in the observations (aka modelling grid). Knowing this fact, those who run this simulation stopped the process and made some changes in the engine, so now it woks on an irregular (stochastic) grid.
As a side effect of this, the process of modelling of microwaves bouncing in a truncated cone introduces some calculation errors that eventually leads to the movement of the cone itself.
Re: (Score:3, Interesting)
"There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here,
it will instantly disappear and be replaced by something even more bizarre and inexplicable.
There is another theory which states that this has already happened."
- Douglas Adams, The Restaurant at the End of the Universe
Re:Quantized inertia? (Score:5, Funny)
Re: (Score:2, Funny)
Re: Quantized inertia? (Score:3)
Re:Quantized inertia? (Score:5, Funny)
It also has a method such that when beings within one of the simulations start to figure out how the simulation works, it is immediately replaced with something more bizarre and inexplicable.
That's actually a quite decent explanation of quantum physics.
Re:Quantized inertia? (Score:5, Informative)
Thank Douglas Adams for that quote, not the AC...
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Careful. You're going to give Roko's Basilisk nightmares.
Re:Quantized inertia? (Score:5, Funny)
But of course we are living in a simulation. How else would you explain the apparently inborn feeling that there is a higher being or beings that controls the rules of the Universe, and observes us constantly even when we are alone or in the dark?
To quote Douglas Adams: "that's just perfectly normal paranoia. Everyone in the Universe has that.”
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What we know for sure is that if we live in a simulation, the programmer is one crazy dude.
That statement seems like the product of a sexist mind. An alternative phrasing that might get you further with the chicks, and may lead to some fascinating insights:
She dreams, therefore we are.
Great summary (Score:3, Insightful)
Great job lets not even try to attempt to summarize the article, instead lets post this like its a trailer for the 11 o'clock news!
Re:Great summary (Score:4, Interesting)
Given a variable speed of light and a different theory of momentum maybe it could all make sense.
Would you bother to even click on the link if that's all it leads to?
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I read the original article on the "Exceptionally Magic" drive way back. I have not bothered to read anything else since.
Re:Great summary (Score:5, Funny)
So it was literally the last thing that you read? You must have found it to be quite satisfying.
Re:Great summary (Score:4, Funny)
Thanks, Summary (Score:5, Insightful)
Re:Thanks, Summary (Score:5, Interesting)
Short version: photons seem to have inertial mass after all.
Re:Thanks, Summary (Score:4, Interesting)
Not at all that. From what I can read from the (equally bad) article, the claimed effect may be due to the (currently unobserved) Unruh effect. The Unruh effect is a hypothetical black body radiation observed by an accelerating observer. Basically, if you were accelerating in reference to a "stationary" observer, you observe yourself heating up (very, very slightly) while the "stationary" observer would not see this heat.
Re:Thanks, Summary (Score:5, Informative)
Have you read this part of the article?:
McCulloch’s theory [] makes two challenging assumptions. The first is that photons have inertial mass. The second is that the speed of light must change within the cavity.
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The first isn't very far-fetched. They definitely do have energy-derived mass as per E=mc^2, and this mass supposedly is indistinguishable from other forms of mass.
The other - we don't have solid proof either way, though the observations currently seem to go "against".
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The first isn't very far-fetched. They definitely do have energy-derived mass as per E=mc^2, and this mass supposedly is indistinguishable from other forms of mass.
No, they don't. Energy is not mass. That equation is actually incomplete: the full equation is E^2-p^2c^2=m^2c^4. For photons, E=pc, so their mass is zero.
Now, they can contribute to the invariant mass of a system, but that's different from the photons themselves being massive, which we're almost sure they aren't, to an extremely high precision.
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The article outright states (twice) that inertial mass is a required assumption of this theory.
I actually think the article was unusually good, in that it struck a balance between elementary and oversimplified, and hyper-obscure. However, it did bury the lede a bit -- it also has a variable speed of light within the cone as an assumption.
Re:Thanks, Summary (Score:5, Interesting)
Photons do not have rest mass, but they do carry both energy and momentum.
A photon imparts a force and thus may transfer momentum onto a reflecting mirror. The Mirror has mass and is thus subject to this quantized acceleration.
Also. The idea that the speed of light in a vacuum varies in a electromagnetic cavity is largely accepted as part of Quantum Electrodynamics.
This is closely related the Casimir force that developed between two uncharged metal plates. Empty space is filled with a continuum of virtual electromagnetic modes ( field fluctuation of every size). As the plates come together more and more long wave modes are excluded from the vacuum between the plates... but not "outside" , thus Vacuum between the plates is literally more empty, and the plates experience an attractive force. This is crazy.. but it had been actually measured.
Now....
In accelerating reference frames some of the virtual modes of the vacuum are converted into real modes this is the"Unruh radiation"... thus space looks like a heat bath when your are accelerating. it is not so clear how time in a heat bath becomes the generator of momentum, and inertial mass, unless General Relativity makes the Radiation bath An-isotropic ( not the same in all directions). thus the radiation pressure form the thermal radiation retards acceleration, acting exactly like inertial mass..... Hmmmm
so if you try to impart momentum on a small element embedded withing a larger cavity. The smallest change in momentum allowed is now a function of the size of the cavity , and lowest frequency mode that the cavity will support......
This is right out of an area in physics call Quantum Cavity Electrodynamics ( Google it).... Cool idea There may be something to it... Hell, Why it does NOT work may also be just as interesting. I like it! It been a long time since the Physics degree.
Amounts (Score:3)
The main trouble with all this talk is it doesn't mention amounts. One may be able to have all kinds of funny effects like Casimir and radiation behind the horizon and what not and it's interesting to figure out how momentum is conserved but to go from a measurable effect to 'let's use it for propulsion' is outright silly. The effect will be in the wrong ballpark and you'll be much better off by just using removing the back and using the actual microwaves for propulsion.
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TFA doesn't give exact numbers, but describes the magnitude of the hypothesized effect as in line with the observed acceleration of the EMDrive - Along with presenting at least two testable hypotheses that would support (or refute) the theory further.
Re:Amounts (Score:5, Interesting)
Only, I have to walk that back. It actually generates a good amount of thrust. Now I'm impressed.
Re:Amounts (Score:5, Informative)
To give a ballpark estimate(yield varies with about a factor 10), with a 5kw system you can lift 100g (one newton) on earth.
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One man's pull is another man's push. All parent post indicates is that the poster is demonstrably deficit in his understanding of relativity; he is hopelessly mired in his classical universe with its "objective observer".
The problem is in poster's head. His model of the universe lacks the fluidity necessary to a deep understanding of quantum mechanics, where the mind must be trained to jump with agility between incomplete and flawed models of Reality, staying poised on the knife edge of each one for only
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Likewise, Airplane wings don't produce lift because of the vacuum on the upper surface. They produce lift because the pressure on the lower surface is higher than the pressure on the upper surface so the wing is PUSHED up.
NASA calls this the Skipping stone theory [nasa.gov] aka, the Incorrect Theory #2
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Short version: photons seem to have inertial mass after all.
Slightly longer version: If the guy's model is a complete explanation of the measured thrust, then photons have inertial mass.
Very Serious Flaws (Score:5, Interesting)
Short version: photons seem to have inertial mass after all.
You cannot just rewrite fundamental physics to fix one issue without also looking at the implications of your theory for other predictions which is it likely to change. Worse it seems that nobody has tested these drives for the emission of charged particles. A far, far simpler explanation is that this drive works by electron emission. There are a variety of way this can work which all work in a vacuum but whic would unfortunately not work in space where you are electrically isolated and would eventually build up a counter charge and cause the thrust to reduce to zero over time. This all uses established fundamental physics so it would be nice to see this ruled out BEFORE coming up with crazy new physics. It might be less exciting but it is better science.
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Worse it seems that nobody has tested these drives for the emission of charged particles.
Well, yes but there are many other confounding factors too. Both NASA Eagleworks and Dresden have measured forces in the 10 micronewton range. Problem is that the null test at Dresden gave an even larger force.
20 micro newtons is TINY, and you somehow have to couple 700W into this thing without accidently coupling forces in magnetically or via thermal effects.
By way of example, You will feel 20 micronewtons of force is
Re:Very Serious Flaws (Score:4, Informative)
just build a small one, send it to space, turn the power on and see if it moves.
Re:Very Serious Flaws (Score:4, Interesting)
Actually, we would have removed a host of variables, and introduced virtually no new ones - it's *incredibly* difficult to apply electric power to something without it interacting electromagnetically with nearby objects, including your measurement apparatus. In orbit you've pushed the nearest objects many miles away, and need only really worry about interaction with the Earth's magnetic field. And orbital dynamics are well enough understood that measuring even small changes in velocity can be done extremely accurately.
>If this is ever going to be a serious drive we have to understand how it works.
Why? We use gravity all the time with no understanding of how it works. Most of early medicine worked fine without any understanding of how it works - even animals routinely ingest medicinal herbs and minerals when ill. Ditto metallurgy - people were forging ever stronger swords for centuries without the slightest real understanding of *how* their techniques made the metal stronger, they simply relied on trial and error to find new techniques that worked better.
Having a theoretical understanding of how something works allows you to optimize it far more rapidly, but if you have discovered an already useful phenomena, there's absolutely no reason not to harness it immediately - all you need is a practical understanding of how to create it, not a theory of the principles upon which it works.
As for an orbital test of an EM drive - the measured thrusts (if not due to experimental error) are more than sufficient to raise a simple probe to a much higher orbit over the course of, say, a year long test. And *nothing* else is going to have that effect without also raising the orbits of pretty much everything else as well - we have a huge control group of satellites already present. Even a few weeks would likely be enough to determine if the drive was actually generating thrust, and probably even if that thrust is too great to be explained by photon rocketry or ion-drive effects.
Now, you could certainly argue that the expense of putting such a test probe into orbit isn't justified by the current evidence, but frankly given the implications if it worked, I rather suspect that if you just built the damned thing, as small as possible, Elon Musk would be happy to deliver it to orbit for free using some of the excess capacity available on a typical launch. Or at worst, at the incremental cost of the additional fuel, etc required, which is what, in the $10-$100 per pound range?
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Why would it be a problem?
Maybe "the speed of light" is a misnomer, c is just a maximum speed defined by the universe, and photons travel at speeds that are extremely close to this cosmic speed limit. It would then be perfectly possible for them to have a tiny amount of mass. No laws break down (at least not in GR), you just have to replace Einstein's flashlights by hypothetical devices that transmit information slightly faster than light, with precisely the speed c.
Turns out "faster than light" is possible
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I agree that in principle the speed of light does not have to be the same as the limit speed and that they tend to be confused. Only even the tiniest mass of light particles would easily be measured and experiments have been made that are extremely sensitive to this 'nonzeroness' , mainly because they would strongly affect how electrostatic forces depend on distance. So the mass would have to be ridiculously small. ('ridiculous' differs orders of magnitude from 'extreme' ).
Simple and obvious, really (Score:3)
> If you bounced microwaves in a truncated cone, thrust would be produced out the open end. Most scientists have snorted at the idea
I can see why porcine scientists would snort with approval. After all, if you bounce refrigerators around in a truncated cone (nozzle), they'll produce thrust as they exit the narrow end. If you bounce toasters around, they'll produce thrust out the nozzle. Same with coffee makers. Therefore, if you bounce microwaves around a nozzle ...
tl;dr (Score:5, Informative)
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:tl;dr (Score:4, Funny)
The hypothetical Unruh effect (or sometimes Fulling–Davies–Unruh effect) is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none. In other words, the background appears to be warm from an accelerating reference frame; in layman's terms, a thermometer waved around in empty space, subtracting any other contribution to its temperature, will record a non-zero temperature.
That just blew my mind. It blew my mind so much that I can actually predict the future. I predict that I'm going to be in a bar one day, pretty snookered, and I'm going to be yelling about how, if you can hypothetically put me in a glass-encased vacuum at 0 degrees with a thermometer and an asbestos glove, I'll be holding the thermometer with the asbestos glove and waving it around like I'm trying to signal a passing ship and I'll look at the thing at it's going to read 0.1 degrees. But I won't know the name of what I'm describing, nor why it works. I'll bet a drink on it, though.
You mean it could be real? (Score:5, Insightful)
I was honestly expecting to find an explanation of some subtle source of experimental error that covered it, not a possible theory explaining why it (maybe) works. I'm really looking forward to experimental testing of the improvements predicted by the theory. Who knows? With a decent explanatory theory, it might even be possible to turn it into a practical thruster. That would be awesome.
Re:You mean it could be real? (Score:5, Insightful)
Even if it can't be scaled up, it would be fantastic!
I'm still worried it's a massive screwup that everybody repeated and nobody has found yet, but seems to be less and less likely. Still...
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There's only one thing to do... pack one of these things onto Elon's next rocket launch and see whether it can move itself around or not. The proof is in the pudding...
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About a year ago I remember reading that the control experiment also produced thrust....
http://phys.org/news/2015-07-s... [phys.org]
Has something changed since then?
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Reading the article, it would seem that the system cannot be "scaled up" -- at least in terms of the acceleration produced.
The article did say that adding a dielectric should increase thrust, if the theory is correct. It didn't say how much, though. On the other hand, perhaps experimental testing will allow refinement of the theory which generates other ideas for improvements. Or maybe it will never be practical as a thruster... but new physics is almost certain to lead to something useful.
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The jet engine isn't a good example. We needed more elaborate theories about compressible fluid flows -- and the computers needed to model them -- to get what we now call a "real" understanding of how jets work. But even without that, the basic physics of what goes on in a jet engine was very well understood before we started building them.
never was complicated (Score:2, Informative)
If you have multiple emitters into the chamber, angled toward a reflector, each emitter has a vector of momentum parallel to the axis of the motor, and another perpendicular to it. If the emitters are spaced properly, the perpendicular vectors will cancel, and the parallel components, summed, will be less than the momentum of the photons leaving the chamber through the "nozzle", giving a net forward thrust.
Re:never was complicated (Score:5, Informative)
The problem was that even with all you just said the thrust was higher than they expected. Hence the big issue with the drive and why people said it couldn't work. Yet it kept working in real world tests.
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You obviously didn't read the article with the talk of testing in 'qualified facilities'. It says specifically that six major groups have tested this:
"In 2012, a Chinese team said it had measured a thrust produced by its own version of the EmDrive. In 2014, an American scientist built an EmDrive and persuaded NASA to test it with positive results."
"And last year, NASA conducted its own tests in a vacuum to rule out movement of air as the origin of the force. NASA, too, confirmed that the EmDrive produces a
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If you have multiple emitters into the chamber, angled toward a reflector, each emitter has a vector of momentum parallel to the axis of the motor, and another perpendicular to it. If the emitters are spaced properly, the perpendicular vectors will cancel, and the parallel components, summed, will be less than the momentum of the photons leaving the chamber through the "nozzle", giving a net forward thrust.
That's not what's theorized is happening here. I could try to summarize, but you'd be better off reading the article.
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I don't think there's a nozzle.
Re:never was complicated (Score:5, Informative)
The summary of the article is very wrong, there is no nozzle. If it had a nozzle it would be easy to explain, anything with a nozzle will operate as a rocket regardless of the wavelength you produce (Newton's law about action/reaction) and laser/microwave drives with nozzles have been built, we already use ion drives after all.
This 'engine' is completely closed. It's basically a closed cone in which you send microwaves and somehow you get acceleration. In Newtonian physics this would make no sense because it's a closed system, there is no "action" on the outside (basically the sum of all vectors of force generated come out to 0). However there seems to be something happening at the quantum level (the sum of all vectors is not 0 perhaps because at some quantized level there are hypothetically 'rounding errors').
That turns out not to be the case (Score:5, Informative)
The amount of thrust they're seeing, even at microNewtons, is far higher than could be produced by the radiation pressure of simply emitting photons at those energy levels. If it wasn't, there wouldn't be all this fuss.
NASA measured an average of 91 microN with 17 W, or 5.3 microN/W. The Chinese measured 720 milliN at 2500 W - about 300 microN/W. By contrast, expected radiation pressure would be closer to 0.003 microN/W.
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You should strap it to a cat.
Re:never was complicated (Score:5, Insightful)
A theoretical physicist should go around all the time and say: According to Theory T, this should be impossible!
It's obviously burning Thetans. (Score:5, Funny)
FTFY summary (Score:5, Informative)
Most scientists have snorted at the idea, noting correctly that such a thing would violate observed physical laws.
The EM drive was discussed at length on other sites, and few posts were able to shine any light on the issue. Some items of note:
First, if your understanding of physics does *not* predict the Casimir effect [wikipedia.org], then you probably shouldn't be blithely dismissing the theory. The EM drive is based on a theory of physics that's more sophisticated than simple "momentum is conserved". It supposes an hypothesis that's different than what is currently accepted, but in a subtle way that is difficult to detect.
It's similar to relativity: most of our tests validate Newtonian physics, but you find relativity when you go looking for it.
Second, if you want to appeal to Noether's theorem [wikipedia.org], note that the theorem refers to smooth manifolds. If space is quantized, then Noether's theorem doesn't apply (despite being true). It's possible that Noether's theorem will break down at small scales. (If space is smooth, ie *not* quantized, then the true location of any particle is a [mathematical] real number with infinite entropy and it's action is non-computable. Not that having a non-computable universe is a problem, but...)
All in all, I get the impression that everyone commenting on the EM drive should probably keep quiet and let the experts sort it out.
I don't have any comment on either the theory or the experiment, but it's an interesting proposal.
From the Wikipedia page:
This is analyzed by Rothman and Boughn[32] who point out that the standard theory of radiation pressure is more complicated than the simplified analysis suggests.
Re:FTFY summary (Score:5, Informative)
The author's paper on the EM-drive is here: http://arxiv.org/abs/1604.0344... [arxiv.org]
I was interested to read that he claims his theory also explains galactic rotation without the need for dark matter, and it explains cosmic acceleration without the need for dark energy. Neither of those can be experimentally verified, so he's pretty excited to have an actual experiment to test his theories.
Part of the paper seems like nonsense (Score:5, Interesting)
Start with section 2. It treats photons as particles with some momentum m*v. I mean, what? That's just wrong. Photons are relativistic p = E/c and quantum mechanical, E = 2\pi hbar f.
I mean take a look at this:
"Normally, of course, photons are not supposed to have inertial mass in this way,
but here this is assumed. It is not clear what the size of this mass is, but it is
clear for example that light inside a mirrored box produces a kind of inertial mass
for the box. "
So in orthodox physics, photons are not supposed to have inertial mass, but also in orthodox physics light makes inertial mass and it's clear that it's so.
The second statement, about light inside a mirrored box, is so because of relativity and the assertion of the equivalence principle. Electromagnetic fields are part of the stress energy tensor (following Maxwell) which feeds into the source term of general relativity. So yes, there is some sort of inertial contribution, but in fact it can be computed pretty exactly, and it's extraordinarily tiny, and really mostly related to the energy density of the EM field.
So relativity sometimes, but not other times? WTF?
And if the non-standard theory that inertia comes from matter interacting with Unruh radiation, how exactly does that work with photons? Photons don't interact with photons. Zero cross section until the point that they are so energetic they can pop out electron/positron pairs from the vacuum, which is so far not an experimentally accessible regime.
Presumably the idea is that the Unruh radiation inside the cavity is quantized in a particular way different from free space, but wouldn't that mean that inertia of (presumably charged) particles inside that cavity would be altered? But he was talking about the non-sensical 'inertial mass' of the photons themselves. WTF?
I don't mind non-standard theories and their exploration at all, but it's necessary to be clear which standard axioms are being rejected and which others are preserved, and follow that consistently. I just saw very unclear physics.
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You can't approach these topics pounding a pulpit of 2nd year college physics.
Unbound photons might indeed have a rest mass, and not move at C (the speed of propagation of space-time ripples). Physicists are more careful than to say it must be zero by postulate, and so experiments have been done to set upper bound on photon rest mass such as observing the galactic potential vector and galactic plasma (so less than 3E-27 eV/C^2 by the way). Also worth mentioning that photons inside superconductors have n
Re:FTFY summary (Score:5, Interesting)
Second, if you want to appeal to Noether's theorem [wikipedia.org], note that the theorem refers to smooth manifolds. If space is quantized, then Noether's theorem doesn't apply (despite being true). It's possible that Noether's theorem will break down at small scales. (If space is smooth, ie *not* quantized, then the true location of any particle is a [mathematical] real number with infinite entropy and it's action is non-computable. Not that having a non-computable universe is a problem, but...)
Theres something about this that reminds me of Zenos paradoxes.
The Eleatics had the idea that they could logically prove that reality is nothing like anything we can imagine.
First, if you assume that space or time are discrete, you are led to paradox. So they can't be discrete.
Second, if you assume that space or time are continuous, you are led to paradox. So they can't be continuous.
So space and time can be neither continuous nor discrete, nor can they be both continuous and discrete.
What is left? Nothing we can imagine. There appears to be no other option than continuous or discrete.
Therefore time and space, reality, must be something unimaginable.
Yes, there were people thinking like this a very very long time ago.
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Yes, there were people thinking like this a very very long time ago.
do you think it's more interesting/impressive/etc that they managed to think of these things without the complex mathematics, or that we're able to think of them in terms of complex math?
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What paradox do you run into if space and time are discrete?
They go through a whole series of examples testing space being continuous, space being discrete, time being continuous, time being discrete, various combinations. Its really complicated and not something I'd go into detail here.
I'm just saying they used fairly sophisticated methods of reasoning to arrive at a fairly sophisticated and bewildering conclusion; that the underlying structure of space and time are nothing like anything we can conceive of.
Whether theres any flaw in the examples they give and the s
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a) The experts have no idea
b) It's always good for lay people to discuss and perhaps even find out more about this, perhaps they can learn or even educate or become the next Einstein
c) Most 'experts', especially the ones journalists quote, simply rely on Newtonian physics to explain things which is fine for most things in and around our solar system but not at either end of the scales
d) There are a number of valid theories these days about physics. There should be nothing "more sophisticated", for a physics
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Have had light exchanges with a physicist for years. When the EM drive came out I asked him in opinion on it. He snorted and laughed and assured me it was all measurement error and there is nothing to it. I asked him if he read the paper. He assured me he had not. When I pressed him how he could be so certain that it was complete junk science without ever having read the paper, he assured me that there was no need since it was impossible. He then assured me all his peers agreed with this position.
Ego is des
Something interesting (Score:2)
You might find this [princeton.edu] interesting.
Farnsworth (Score:3, Funny)
The ship stays where it is and the engines move the universe around it
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The ship stays where it is and the engines move the universe around it
Scotty: It never occurred to me to think of Space as the thing that was moving!
Mechanism (Score:2)
The universe has been swapped to off-line storage (Score:2)
But the universe won't notice the maintenance downtime to support development of universe 2.0.
Me.
We apologize for the inconvenience.
God.
Wavelength can't fit within the universe(?) (Score:2)
What does this statement mean?
Reading the reference http://arxivblog.com/?p=207 [arxivblog.com] didn't help me understand.
Turtleology (Score:5, Funny)
The lopsided nature of the cone causes the Ether Turtle's shell to become warmer than its belly. This difference is uncomfortable to reptiles and makes it shift around a bit, causing the turtle underneath to adjust to compensate, in turn triggering a similar re-shuffling of the turtle below it, and so on all the way down, causing the universe to shift position relative to the probe.
Finally, News for Nerds (Score:3)
What's that you say, an actual News for Nerds story? Bravo, Slashdot!
more like "lame man's terms" (Score:4, Informative)
I try, but as a non-physicist/non-mathematician, all I can really get out of this saga is:
1. Some guy builds and runs a funky apparatus in his lab/garage, and gets some strange results. He reports these excitedly to the world at large.
2. He's obviously smart but possibly deranged, since he claims that the apparatus violates the conservation of momentum, which is a classic crackpot move.
3. Any reputable scientists who have these results brought to their attention uniformly and immediately dismiss them as obvious crackpottery.
4. One night, while drunk, a small group of reputable scientists build the apparatus in their own lab, as a joke, and observe the same strange results.
5. Repeat steps 3-4 a bunch of times.
6. ???
7. Space probe to Alpha Centauri in my lifetime?
Engineering first, or science? (Score:3)
This "thing" shows the interesting interaction between the engineering community and the scientific community. This is why you should take scientist statements with a grain of salt.
Engineers: look, this works!
Scientists: that violates the laws of science and is impossible.
Engineers: who gives a sh*t what you think? Here's the data
Scientists: the data must be wrong
Engineers: you try it
Scientists: we have no f*cking idea what's happening, but it's happening
Engineers: f*cking pinheads
Scientists: oh, maybe this is what's happening
If you take scientists too seriously, you never get past step #1.
Re: They measured more "thrust" when turned off (Score:5, Informative)
Re: (Score:2)
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What should be most telling was that this "engine" produced more "thrust" when it was turned off than when it was turned on. That should tell you how stupid this thing is but everyone is so caught up in the "I want to believe" moment that they ignore all the warning signs.
I think you have demonstrated how stupid you are with that statement. They found thrust in the NULL experiment, not when it was off. The null experiment used a different shaped reflector that they felt would cancel out the acceleration. If they don't understand the theory of how the acceleration is created, then they could very well have failed to create a null experiment and instead created another shape that works as an EM drive. Once they understand how the trust in generated correctly then they can succ
Re: (Score:2, Informative)
Re: They measured more "thrust" when turned off (Score:3)
So you've recreated this experiment and proved this? Have you published your results to spare everyone the waste of time of further environments?
Re: Hoverboards (Score:5, Insightful)
No, it cannot mean any of that, because the amount of thrust provided is minimal. Even if you made the engine weightless(which you can't), you'd not be able to get enough thrust to lift anything off the ground.
The reason this is interesting for space is that in space, even tiny amounts of thirst are useful. Very slow acceleration is still fine, when you are not fighting planet like gravity: You just need to apply thrust for a long time, as opposed to what we do now, which is to turn on far more powerful drives for very short periods of time.
Re: Hoverboards (Score:5, Funny)
It's true that a lot of comets are made of ice, but still I don't see the connection...
Re: (Score:3)
You misspelled "Slurm"
Re: (Score:3, Funny)
The laws are more what you'd call "guidelines" than actual rules.
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Welcome aboard the Black Pearl, Miss Turner.
Re: (Score:3)
Well that's just silly. Why would the wormhole opening be traveling at the same speed as the ground, rather than at the speed of the wormhole generator? They're both completely arbitrary reference points after all, and if the generator can impart a relative velocity, then there's no reason you couldn't just stand still and generate a wormhole coming at you at 88mph, or 200, or whatever was convenient.
Plus, there's the little matter that, if it were actually employing a wormhole, *and* somehow shielding th