Cannae/EmDrive

[SomeGuy12]

Assuming that the experiment can be repeated by other researchers. So far, the EM-drive has too few positive results from too few teams to yet be a real challenge to theory.

Amusingly, this isn't quite true in every case. If one of those youtube nuts really had a method for perpetual motion and a method for working antigravity, and he strapped a perpetual motion generator to an "antigravity thruster" and launched it from his backyard. Well. As the thing hurtles into deep space at 1 G constant acceleration, we'd all owe the guy an apology, even if we were unable to replicate how he did it.

[vger]

Looks like gag order is still firmly in place. Too bad - i really appreciated getting information not filtrated by sensationalist media

The world really needs to find alternate ways of doing things.

We could end up never hearing about this thing again, for reasons that ultimately shouldn't matter. And then twenty years from now people will be talking about this the same way they do now about the "water-powered car."

[Vaporo]

Hmmm. Perhaps I should try building one myself. I just need an old microwave and some copper sheeting. It looks simple enough.

Anything new from Eagleworks?

[Nuke]

mach effect thrusters are even more approachable. all you really need is an rf power supply, some caps and some inductors.

[Albert VDS]

Yes, this thread is getting dug up again. Why? Because coming Monday Martin Tajmar will be present his test results on Emdrive on the 27th of July.

According to the following article hes well qualified for testing such things.

http://www.wired.co.uk/news/archive/2015-07/24/emdrive-space-drive-pluto-mission

[Dodgey]

I'm just going to fall asleep for a few years so I can just get the results on wheather or not it works. In any case good to see some more results finally coming out.

[spudman2]

I'm just going to fall asleep for a few years so I can just get the results on wheather or not it works. In any case good to see some more results finally coming out.

Take me with you.

[Scotius]

Heh. If this article is accurate, things might be going in the good direction.

[Frozen_Heart]

Hmmm. Perhaps I should try building one myself. I just need an old microwave and some copper sheeting. It looks simple enough.

Anything new from Eagleworks?

Messing with high powered microwaves is never a good idea. Unless you are qualified to mess with these things, plz don't touch them as they can be highly dangerous.

[Vaporo]

Ah! Finally! More results! I was starting to think that the government was going around cleansing the media of any new mention of the device.

It really is nice to get some more results. I really was considering trying to build my own just so that I could get some closure on the subject.

[vger]

Heh. If this article is accurate, things might be going in the good direction.

I dunno, the following quote...

Tajmar prefers his results not to be shared in advance, but told WIRED that his paper will not close the EmDrive story and that it merits further research.

...sounds negative to me. Maybe it's just not great wording, but I'm guessing the test results were less-than-stunning. At best, still inconclusive.

It's still nice to know that this didn't end up permanently vanishing into obscurity like I feared it would after the gag order.

[Albert VDS]

Maybe it's not so great wording.

[sal_vager]

Tajmar prefers his results not to be shared in advance, but told WIRED that his paper will not close the EmDrive story and that it merits further research.

This sounds like he couldn't figure it out.

[Dodgey]

Ah! Finally! More results! I was starting to think that the government was going around cleansing the media of any new mention of the device.

It really is nice to get some more results. I really was considering trying to build my own just so that I could get some closure on the subject.

If the effects were noticeable to the backyard scientist the wouldn't be this much controversy. All you will really notice are the effects of microwave radiation.

[magnemoe]

I dunno, the following quote...

...sounds negative to me. Maybe it's just not great wording, but I'm guessing the test results were less-than-stunning. At best, still inconclusive.

It's still nice to know that this didn't end up permanently vanishing into obscurity like I feared it would after the gag order.

its positive, closing the story is proving it does not work. The most probably case is also that it don't work.

More research indicate that they have data, does not sounds like an breakthrough but still good indications that it work.

[Aethon]

I wonder if K^2 or someone else in the physics department could explain the full ramifications to the Standard Model that a working EM drive poses. I'm sure it depends on what exactly makes it thrust, which will effect which side of the equations this all falls out on, so it may be to early to know, but I remember K^2 saying that a working EM drive is bad news for our understanding of physics.

I can understand some of the ways, but would like to hear from someone in the know.

Thnx.

[Aanker]

If it works. That's a big if. And if it works as some say it works.

The question could otherwise as well read, 'explain the ramifications to our understanding of physics if ghosts existed'.

[KSK]

Noether's theorem tells us that every conservation law arises from an underlying symmetry. Any reactionless drive which somehow violates conservation of momentum would therefore also imply a breakdown of translational symmetry. In other words, the laws of physics would change depending on position in space.

Which would make a mess of very large chunks of physics, if not all of physics.

[Technical Ben]

Heh. If this article is accurate, things might be going in the good direction.

An article, on the internet, accurate?

More chance of a perpetual... oh wait.

[vger]

I wonder if K^2 or someone else in the physics department could explain the full ramifications to the Standard Model that a working EM drive poses. I'm sure it depends on what exactly makes it thrust, which will effect which side of the equations this all falls out on, so it may be to early to know, but I remember K^2 saying that a working EM drive is bad news for our understanding of physics.

Not to mention possible bad news for the universe itself.

Which would make a mess of very large chunks of physics, if not all of physics.

The best chance it has is if there is some bizarre effect going on that we haven't seen before. But if that's the case, I can't see how we wouldn't have seen the phenomenon creeping up elsewhere.

[K^2]

I wonder if K^2 or someone else in the physics department could explain the full ramifications to the Standard Model that a working EM drive poses. I'm sure it depends on what exactly makes it thrust, which will effect which side of the equations this all falls out on, so it may be to early to know, but I remember K^2 saying that a working EM drive is bad news for our understanding of physics.

There are two different "if it works" scenarios here. If it provides thrust using some previously unseen interaction to transfer momentum, that'd merely be very bad. It'd mean we've missed something very big with the standard model.

If it actually violates conservation laws? It invalidates over 200 years of progress in physics. Needless to say SM could be just thrown into the garbage in its entirety. We'd be able to salvage Newton's laws as an approximation of typical behavior. That's about it. All of the physics following it, Lagrangian Mechanics, Classical Field Theory, Classical Electrodynamics, Thermodynamics, Relativity, Quantum Mechanics, Quantum Field Theory, Statistical Mechanics, and basically every branch of science they have spawned, rely either directly on conservation laws being true, or on symmetries that are fundamental to these conservation laws.

These are fundamental assumptions in absolutely every branch of physics. Violating them breaks everything beyond salvage.

[Technical Ben]

Even the pioneer probes extra momentum/speed got figured out recently. Right? If I remember correctly it was heat leaking from their nuclear power... if we can figure that out, and it's not some "magical" (word used lightly) physics breaking discovery, then we can here.

[SAI Peregrinus]

We'd be able to salvage Newton's laws as an approximation of typical behavior.

Not even necessarily true there, since it would mean they'd vary with position. So they might hold reasonably well now, but as Earth moves through space they'd probably eventually cease to apply even as approximations. Noether's theorem is pretty much pure math, so it won't be disproven, so if conservation of momentum were violated it would mean that the very idea of "universal physical laws" would have to be thrown out. Given how well our existing laws seem to work for the behavior observable by telescopes this seems incredibly unlikely, so it's effectively certain that the EmDrive can't be violating the conservation of momentum.

[CptRichardson]

The best chance it has is if there is some bizarre effect going on that we haven't seen before. But if that's the case, I can't see how we wouldn't have seen the phenomenon creeping up elsewhere.

Entirely possible that we HAVE and haven't recognized it. Dark matter ion drive maybe. Playing with virtual particles. Something else. Judging from the answer, it's a 'it works, but we still can't figure out why or come up with an experimental model to 100% prove why it works' scenario.

[PB666]

There are two different "if it works" scenarios here. If it provides thrust using some previously unseen interaction to transfer momentum, that'd merely be very bad. It'd mean we've missed something very big with the standard model.

If it actually violates conservation laws? It invalidates over 200 years of progress in physics. Needless to say SM could be just thrown into the garbage in its entirety. We'd be able to salvage Newton's laws as an approximation of typical behavior. That's about it. All of the physics following it, Lagrangian Mechanics, Classical Field Theory, Classical Electrodynamics, Thermodynamics, Relativity, Quantum Mechanics, Quantum Field Theory, Statistical Mechanics, and basically every branch of science they have spawned, rely either directly on conservation laws being true, or on symmetries that are fundamental to these conservation laws.

These are fundamental assumptions in absolutely every branch of physics. Violating them breaks everything beyond salvage.

I think that if it transfers momentum it is either because we dont understand

1. The scale variation in which quantum/classical divergence operate when pushed, the virtual particle effects

2. The full ramifications of Higgs and its so-called variants.

people who have claimed the standard model is complete have been somewhat premature. For example how the higgs field propogates through space.

I suspect the first is true, and when this drive is put into space i bet its thrust would be virtually the same as thrust given by any directed EM, ions in the vicinity will get a slight rise in back and sideward velocity, and the effect does not propogate on any particles more than 10m away. The most energetic would be those that passed within millimeters of the drive.

It wont violate conservation of momentum.

- - - Updated - - -

Entirely possible that we HAVE and haven't recognized it. Dark matter ion drive maybe. Playing with virtual particles. Something else. Judging from the answer, it's a 'it works, but we still can't figure out why or come up with an experimental model to 100% prove why it works' scenario.

Dark matter does not interact with EM, does not interact with electrons. On massive objects like the earth its effect is always relative minor. Its effect accumulates over the vast emptyness of space. if you can imagine a hihgly eccentric orbit, the sweep area per time is uniform, then at apogee those particles are traveling real slow, and thus they spend most of their time closer to their apogees, and a small amount of time whizzing through 'earths' and shortly out of the sokar system again.