NASA Eagleworks Has Tested an Upgraded EM Drive

An anonymous reader writes: A team of researchers at NASA's Eagleworks Laboratories recently completed yet another round of testing on Engineer Roger Shawyer's controversial EM Drive. While no peer reviewed paper has been published yet, engineer Paul March posted to the NASA Spaceflight forum to explain the group's findings. From the article: "In essence, by utilizing an improved experimental procedure, the team managed to mitigate some of the errors from prior tests — yet still found signals of unexplained thrust."

Comments

Scientists

[skovnymfe]

It's like someone has posted a theory on the internet which is wrong, but not knowing where the thrust comes from means they can't explain to this person why he's wrong. And it irks them to no end.

Re:Scientists

[jabuzz]

The problem is that extraordinary claims require extraordinary proof. This is an extraordinary claim because it at appears to violate one of the most sacred law of physics (the conservation of momentum) for which we have previously never had even the slightest hint might not hold.

That said unlike Mr. Rossi and his eCat for example there is no cloak of secrecy involved here. All details are out in the public for anyone to build one and test it out. This is where in part the fuss is arising because even the best labs are unable to show that it is baloney that every fibre of our beings tells us it should be.

In the end no matter how dear we hold the principle of conservation of momentum verified experimental results trump ALL theories without exception.

Personally I am highly sceptical of the EM drive. However I have to concede that the experimental results are so far with it, and thus further investigation is entirely warranted. In fact I would go further and say that further investigation is absolutely required.

Re:Scientists

[pla]

The problem is that extraordinary claims require extraordinary proof.

A working prototype counts as a pretty damned good proof of concept, at least until someone can demonstrate how it cheats.

Sure, someone might eventually figure out a way that it doesn't really cheat conservation of momentum - And that finding might have its own useful applications.

Re:Scientists

[jabuzz]

Sure verified experimental results trump everything. The problem at the moment is that the forces the device produce are very small 100uN. That means there is still the possibility that there are flaws in the experiment and the effect is not real. A bit like those superluminary neutrinos a while back.

My gut feeling at this point is stop messing about with an 80W drive, and build something a bit bigger say a few kW at least. That way the produced thrust should be large enough to rule out experimental errors. Of course this would require money...

Re:Scientists

[Beezlebub33]

One of two things is going to come out of this: they will determine that it's real, in which case we'll have some new physics to work with; they will determine it is experimental error, in which case we'll have a better understanding of how to measure small forces when the device is relatively large, in both air and a vacuum.

Either of these is a good thing; I'd bet on the second but would be happier with the first. In any case, the best course is to remain sceptically hopeful and continue testing.

Re:Scientists

[Anonymous Coward]

My gut feeling at this point is stop messing about with an 80W drive, and build something a bit bigger say a few kW at least.

OK, I'm going to go into some depth here because this is common sentiment, even from what I've read coming from Eagleworks, and it's probably wrong. Here's why I say that:

The inventor of the EMDrive is a retired aerospace engineer - he's too old to want to test anything but threw the idea for the EMDrive out there with a low-power test early in retirement as more or less an act of mental masturbation. Why is this important? Because his prior work, from which the EMDrive stems, is a laser-gyroscope functioning on the exact same principles as the EMDrive in reverse capable of measuring absolute accelerations based on relativistic effects without any outside coupling to the surrounding environment. Why is this important? Because it works so well it is in use in missile guidance systems and has been for decades. People tend to refer to Shawyer as a quack but he is the inventor of it, the invention came from sound and proven theory and all the hype about violating conservation of momentum isn't even correct based on the theory.

How does this relate to the "make it bigger" mentality? Shawyer's theory states the greatest way to improve thrust from existing models would be to make a perfect-Q cavity, at which point 1KW of power would be enough to lift a small car at Earth gravity. This isn't a difficult test - you just need a superconducting cavity. Thus far nobody has built an EMDrive with a superconducting cavity because they think Shawyer is just a crazy guy that stumbled into something interesting.

TL;DR: don't make it bigger, just make it superconducting.

Re:Controversial?

[ganv]

There is a simple reason this is controversial. Any Electromagnetic drive that produces more than 3.34 nanoNewtons per Watt by EM emission is a demonstration of new physics that is not included in our amazingly successful theory of quantum electrodynamics (QED). (The simple calculation is here: https://www.physicsforums.com/... They use a reflecting mirror, so an emitting craft would have half the force.) QED has been very precisely corroborated, sometimes to more than 10 digits (see https://en.wikipedia.org/wiki/... ). Claims of macroscopic objects that violate quantum electrodynamics simply have an extremely high prior probability of being false. (Just like claims of perpetual motion etc.). It doesn't mean we know a priori that they are false. By all means, do the experiments more precisely. But this is a claim that requires extraordinary proof because if it is true it will upset a lot of what we have good reason to think we understand about how the universe works.