The 'Impossible' EM Drive Being Tested By NASA May Finally Be Explained (technologyreview.com)

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.

Comments

Quantized inertia?

[Lisandro]

We'll eventually find out we really live in a simulation...

Thanks, Summary

[ScentCone]

Really appreciate the complete lack of even a whiff of the explanation in the summary.

You mean it could be real?

[shawn2772]

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?

[meerling]

Awesome would be a epic understatement if it actually works and can be scaled up.
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...

Re: Hoverboards

[hibiki_r]

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:never was complicated

[Sique]

Actually, that's all what a theory is about: Declare some events to be impossible. And a theory is better, if it correctly declares more events to be impossible. Imagine how many events are declared impossible just by the theory that brought us the first calendar (way back at least 7000 years, if we interpret the Goseck circle correctly).It declared it impossible for the sun to rise in the West. It declared it impossible to have less than 182 or more than 183 days between two equinoxes. It even declared it impossible to have days shorter than 24 hours.

A theoretical physicist should go around all the time and say: According to Theory T, this should be impossible!