[Bobboau]

but you are not extracting energy out of it, you are using it as a catylist to convert one form of energy into another, the system containing the thruster has the same total energy after it started moving as it did before. it's just now it has more kinetic and less electrical (as a general place holder for energy storage that get converted to electricity at some point in the process)

[Herra Tohtori]

Here's the thing: Conservation of energy is an approximation. It kind of doesn't hold absolutely, you can "borrow" energy for a while, but over a period of time things average out and the conservation of energy applies. On macroscopic scales, generally.

One such case would be Hawking radiation, where virtual particles end up spawning so that one falls into the event horizon and the other one escapes. The interesting thing is that energy over the entire event must conserve, so even though a particle "falls" into the event horizon, the end result is that the mass of the black hole decreases, while the energy of the universe outside event horizon increases by the amount of one particle (which transforms from virtual to real during the event).


To draw an analogy to the EM drive - assuming it really does work - the total energy must conserve. Looking at a situation where the drive is mounted on a small spacecraft - the spacecraft gains kinetic energy, and that must come from somewhere. One really interesting possibility is that this energy actually comes from vacuum energy - in other words, the thruster would generate a "bubble" of space behind it with energy density below the zero point energy of vacuum - which may not exactly be negative energy in the sense of requiring exotic matter and such, but it's functionally quite close to it. Especially if space-time geometry is dependent on the vacuum's energy state, which it probably is.


That would offer quite a tantalizing explanation to the warp field interferometer observations which apparently suggest that the EM drive actually does produce a space-time distortion of some variety.

In addition, if the apparent force is actually the result of some space-time anomaly, then it doesn't even break the conservation of momentum. In some ways, it could be considered artificial gravity.


I wonder if an accelerometer onboard a spacecraft with EM thrusters would actually measure acceleration, or not? Or would the measured acceleration depend on distance from the drive unit?

[Bobboau]

oh hey, what would happen if you bolted an em drive to the ground and powered it up? what would happen to small objects placed in their immediate vicinity?
if you bolted it vertically could you use it to train to battle Frieza?

[Scourge of Ages]

One really interesting possibility is that this energy actually comes from vacuum energy - in other words, the thruster would generate a "bubble" of space behind it with energy density below the zero point energy of vacuum - which may not exactly be negative energy in the sense of requiring exotic matter and such, but it's functionally quite close to it. Especially if space-time geometry is dependent on the vacuum's energy state, which it probably is.

That would offer quite a tantalizing explanation to the warp field interferometer observations which apparently suggest that the EM drive actually does produce a space-time distortion of some variety.

In addition, if the apparent force is actually the result of some space-time anomaly, then it doesn't even break the conservation of momentum. In some ways, it could be considered artificial gravity.

Give it to me straight, you guys: are we in Star Trek?

[karajorma]

I seem to once remember reading a theory that Star Trek is real and someone came back from the future to inspire Gene Roddenbury so as to ensure that their future would actually occur. It would explain why stuff he supposedly invented out of thin air seems to be possible when scientists try to do it later.

[headdie]

Here's the thing: Conservation of energy is an approximation. It kind of doesn't hold absolutely, you can "borrow" energy for a while, but over a period of time things average out and the conservation of energy applies. On macroscopic scales, generally.

One such case would be Hawking radiation, where virtual particles end up spawning so that one falls into the event horizon and the other one escapes. The interesting thing is that energy over the entire event must conserve, so even though a particle "falls" into the event horizon, the end result is that the mass of the black hole decreases, while the energy of the universe outside event horizon increases by the amount of one particle (which transforms from virtual to real during the event).


To draw an analogy to the EM drive - assuming it really does work - the total energy must conserve. Looking at a situation where the drive is mounted on a small spacecraft - the spacecraft gains kinetic energy, and that must come from somewhere. One really interesting possibility is that this energy actually comes from vacuum energy - in other words, the thruster would generate a "bubble" of space behind it with energy density below the zero point energy of vacuum - which may not exactly be negative energy in the sense of requiring exotic matter and such, but it's functionally quite close to it. Especially if space-time geometry is dependent on the vacuum's energy state, which it probably is.


That would offer quite a tantalizing explanation to the warp field interferometer observations which apparently suggest that the EM drive actually does produce a space-time distortion of some variety.

In addition, if the apparent force is actually the result of some space-time anomaly, then it doesn't even break the conservation of momentum. In some ways, it could be considered artificial gravity.


I wonder if an accelerometer onboard a spacecraft with EM thrusters would actually measure acceleration, or not? Or would the measured acceleration depend on distance from the drive unit?

So are we talking about a delay in the "balancing the books" so to speak in terms of the energy values which is generating the thrust?

I seem to once remember reading a theory that Star Trek is real and someone came back from the future to inspire Gene Roddenbury so as to ensure that their future would actually occur. It would explain why stuff he supposedly invented out of thin air seems to be possible when scientists try to do it later.

I also remember a quote which I cant place about science fiction driving science, I mean this EM + Vacuum drive seems a little close to a possible explanation of impulse drive

[The E]

In all this enthusiasm, please remember that this is still not a reliably confirmed result. Please check out this article by Ethan Siegel.

[Ghostavo]

To draw an analogy to the EM drive - assuming it really does work - the total energy must conserve. Looking at a situation where the drive is mounted on a small spacecraft - the spacecraft gains kinetic energy, and that must come from somewhere. One really interesting possibility is that this energy actually comes from vacuum energy - in other words, the thruster would generate a "bubble" of space behind it with energy density below the zero point energy of vacuum - which may not exactly be negative energy in the sense of requiring exotic matter and such, but it's functionally quite close to it. Especially if space-time geometry is dependent on the vacuum's energy state, which it probably is.

This has no chance of being related to a metastability event, right?

[watsisname]

In all this enthusiasm, please remember that this is still not a reliably confirmed result. Please check out this article by Ethan Siegel.

Yeah, this really can't be emphasized enough.

I'd really like for it to be true, but I won't believe it is true until it withstands a great deal more rigorous testing.  Ideally, have an independent group use it to change the orbit of a satellite, preferably in a predictable manner, and one incompatible with other causes of orbital evolution (tides, drag, and whatnot).  That would be extremely compelling; you cannot easily fake or misinterpret such a result, assuming its magnitude is large enough, which current claims of this drive's capability suggest it would be.  So, if this thing is legit, it should not take an inordinate amount of time to demonstrate it.  But it might take a fair amount of money.

[Herra Tohtori]

Yeah, it's a very good read.

It's still fun to fantasize, right? It's all fun and games, and we get to follow the story as it develops anyway.

So on the one hand, I'm still conscious of all the facts mentioned in the article, and I'm still sort of suspicious about the whole thing, but on the other hand...

[Bobboau]

we have not yet discovered new physics, we have discovered a hand full of faint anomalous results. But that article seems to be misrepresentative and is overly confident in it's own right. I mean just starting with the title, how do we know NASA hasn't just inadvertently invented a warp drive, so far the results are inconclusive but positive we don't know what this mass of copper is yet, it might be a really bad warp drive, or it might be a heavily over engineered paper weight , until more tests are done on it saying 'this isn't happening' is just as irresponsible as saying it is happening. there are only a handful of people in the world who will be able to really say anything about this device with any degree of authority, and that authority is entirely founded on their ability to say how other people can do this too, until that happens or until they say "yeah, upon further investigation turns out this didn't work" all the rest of us can really do is speculate.

...or build our own device and try to run the experiment our selves, assuming we have access to a high precision torque balance, a vacuum chamber, and we know how to mess with a magnetron without killing ourselves.

[Luis Dias]

Would be funny if Elon Musk took those schematics and replicated the experiment successfully.

[Bobboau]

and then licesnsed the technology and we ended up with flying Teslas.

[perihelion]

I'd hit it.

[Cyborg17]

The Forbes article makes a few points that are flawed. 

The upper limits for test force in these experiments is actually above three standard deviations of the limits.  This could perhaps be a problem with one lab producing the results, but if three labs can reproduce similar results, then the likelihood that the it is the measuring device falls even further.  An anomalous occurrence above two standard deviations is surprising when it happens but is understood to occasionally occur.  An anomalous occurrence above three standard deviations is pretty significant and would be even more so when similar problems are shared by three different labs (which are also performing null experiments).   (Forgive me if I understand standard deviation incorrectly.  I actually really dislike statistics.)

The reliability of the equipment can also be verified by setting up experiments where known forces are involved to test the equipment.  Furthermore, we just mentioned how many orders of magnitude greater these forces are to traditional EM propulsion, even if the measurement is inaccurate, it's significance is not reduced.

The writer fairly points out the original creator has made bold claims in the past.  However, this is not salient in the face of three independent labs.  Even a complete crackpot could get lucky, and the original creator doesn't sound like a crackpot.  He also displays a lack of understanding of the devices in question: he mentions that their outputs aren't directly related without mentioning that they are made of different materials, as has been known from many other sources.

Additionally, many so called laws are frequently bent or broken in science because their exceptions are based upon truths that are just as fundamental.  It's true, you can't measure both position and momentum of particles with arbitrary accuracy, but that's only true if you measure one particle. If you measure many particles whose positions and momenta fall under a bell curve, then you can measure the mean of both and then therefore know both things for some particles (when both happen to occur in the same particle). 

The rule is bent.  And it make sense: our existential reality is based on us living in this weird universe that doesn't behave to our eyes like the quantum world does because of the loopholes we live in.  Things classical physics and chemistry work because we live in a world of loopholes. I was reading recently that magnetars have such powerful magnetic fields that our electrons would become deformed and cause our very biochemistry to cease.  The universe could have existed such that all space was completely filled with magnetars or black holes, but that's not how it happened.  We don't live because the universe has laws, we live because it has laws and also happens to have quasi-exceptions to these laws. Why can't the EM drive be one of these loopholes?

My final point is that the writer's argument is feckless.  This isn't the tachyonic neutrino, something so obviously wrong that it would completely change our understanding of the universe.  It's more likely to be a unique quantum or space-time effect that relies on a set of very specific conditions, which this lab has happened upon, and which we can hopefully exploit in the future. 

The fact remains that something is happening that we do not understand.

If the author wants us to be cautious, it should be an argument based on how the device scales up.  We have no guarantee that the force exhibited by the device will grow as the device grows in size or that it will work in space the same way that it works on Earth.  It simply needs to be tested and understood, and it is a possibility of such significance that it is worth the investment and time that are necessary for those things.  In fact, it is better if the public gets excited about it so that it can get funding more easily so that we can see what's actually going on.

If all these labs are lying, they will be discredited -- their very careers will probably end.  If it's proved wrong, oh well, we feel disappointed.  Why should I avoid being disappointed by removing my hope?  What gain is there in that pursuit?  The result of that is I will only feel angry and annoyed for quashing my own emotions.  And if I do feel disappointed, I will become more mature overall once I get through it.  I'm with Herra and hoping for it to succeed.

[Mongoose]

Clearly it's the luminiferous aether.  FS3 confirmed.