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Uncertain Propulsion Breakthroughs?

centauri-dreams.org

41–50 of 95 posts

Re: Uncertain Propulsion Breakthroughs?

#41
"Inertial frames are the reference frames upon which the laws of motion and the conservation laws are defined, yet it is still unknown what causes inertial frames to exist or if they have any deeper properties that might prove useful."

"...we must begin a more in-depth experimental program using qualified and impartial labs, plus qualified and impartial analysts."

Maybe humans don't really belong in labs in the same way that they don't belong in factories.

Re: Uncertain Propulsion Breakthroughs?

#42
post #8

I hope we'll find out in practice: http://www.popularmechanics.com/science/energy/a22678/em-dri... (via lobster_johnson) "Proud to say that we have a partnership now - so the launch is already funded, and we hope to get a launch slot in 2017."

Being in space doesn't solve the problem of errant forces completely. You can push against the earth's magnetic field, for example.

If it does, I think that would be detectable. As the device gets into higher orbits, the magnetic field will get weaker and the force will drop. I'm not sure how much the orbit would have to change to make that apparent though. It might take a very long time.

Another way it might work is by freeing atoms from the backplate of the resonant cavity, like an ion thruster. I hope they include a method of measuring the degradation of the backplate.

I suspect it just won't work, though.

Re: Uncertain Propulsion Breakthroughs?

#43
post #38
post #8

Earlier quoted context omitted.

Being in space doesn't solve the problem of errant forces completely. You can push against the earth's magnetic field, for example.

So no proof will ever be enough for some? Are EM-Deniers going to be a 'thing' now?

If it can accelerate forever, thats proof enough for everyone. However violating the conservation of momentum is a Big Deal. Mathematically that shouldn't be possible due to Noether's. The bar to proof is therefore very high.

Re: Uncertain Propulsion Breakthroughs?

#44
post #35

Earlier quoted context omitted.

The "premise" for the em-drive has been determined to be a thorough misunderstanding of the physics involved, so you cannot rule out any potentially contributing force in the experiment. Yes you heard that right: guys who misunderstand physics go and design a reactionless thruster which, when measured in their shoddy experimental setup, produces a measurable thrust. If there really is a measurable thrust, then the La…

You sound very negative towards conducting more experiments on this, when the results have been unexpected every time it's been tested. You're displaying the kind of dogma that science has been fighting against since the dawn of time. Either it's true or it's not, but we can't tell until we test it. And so far, it's only been disproven in theory, not in practice. That's worth more experiments.

Occam's Razor says it is not true. If you read the linked article, it is saying, in the most polite and disinterested way possible, that it is not true although they allow, in the driest of terms, that it could be true. I expect if the same authors analyzed the Loch Ness monster or Big Foot, they would also disinterestedly point out the unlikelihood of either and point out the how awful the proofs put forth are while admitting there is no categoric proof that the monsters don't exist.

Pons and Fleischmann were straightforward in their error. This is bozo territory.

Re: Uncertain Propulsion Breakthroughs?

#45
If they have two versions of the resonant cavity, one that is tapered and one that is just a simple cylinder that to me would be a big step in the right direction to address many of the concerns. Basically the cylinder with no taper should show zero thrust. And the version with the taper should show a thrust. Then if they test that setup inside the huge Apollo program vacuum chamber far away from the side walls and change the orientation of the coolant and power wires into different orthogonal directions that sounds promising..

Re: Uncertain Propulsion Breakthroughs?

#46
post #19

IMO the "rational" approach is to treat the claims as a bunch of pointless lies until there's a repeatable demonstration. Remarkable claims demand at least some evidence before wild speculation commences. As it is, Harry Potter is just as credible a theory of reality. After all, they've made the same claim repeatedly for 15 years after their first experiments were demonstrably not what they claimed.

If it's rational to ignore everything unproven then science is irrational. Science is about proving things. Proving how they work, why they work, etc.

We have a thing, it's owner claims it works by either Method_A or Method_B, science is about taking the thing, testing the crap out of it, and being able to say at the end of all if it, "actually it turns out it works by Method_C"

It seems you have some wires crossed somewhere. Science and Rational behaviour are unrelated, they are quite well correlated but as separate concepts they are not causally linked. Historically connected obviously, but not causally linked.

Re: Uncertain Propulsion Breakthroughs?

#47

Earlier quoted context omitted.

The way science works is by doing experiments. The people have been doing experiments on the EM drive and have been getting unexpected results. Nobody really knows why yet, but that's kinda the point. Is thermodynamics flawed? Is it pushing off of "dark matter"? Is it a completely new and novel scientific effect? Any of these circumstances would be interesting.

Yes. Even if it's the most likely thing, experimenter error, for a half-dozen teams to all have errors and not spot them? That's quite interesting! It's the same situation we had with the FTL neutrinos a while back.

Except the neutrino paper then was a big lot of physicists asking colleagues to help them review, so as to find where the problem was. What I see here is just hype. The former, as opposed to the latter, is what gives confidence that the people involved are doing their darnest not to fool themselves. That what they're doing is actually science.

Re: Uncertain Propulsion Breakthroughs?

#48
post #35

Earlier quoted context omitted.

The "premise" for the em-drive has been determined to be a thorough misunderstanding of the physics involved, so you cannot rule out any potentially contributing force in the experiment. Yes you heard that right: guys who misunderstand physics go and design a reactionless thruster which, when measured in their shoddy experimental setup, produces a measurable thrust. If there really is a measurable thrust, then the La…

You sound very negative towards conducting more experiments on this, when the results have been unexpected every time it's been tested. You're displaying the kind of dogma that science has been fighting against since the dawn of time. Either it's true or it's not, but we can't tell until we test it. And so far, it's only been disproven in theory, not in practice. That's worth more experiments.

> it's only been disproven in theory, not in practice

There's a hell of an experimental body that led to (and supports) our current laws of motion. These laws aren't "just theory", and they definitely aren't dogma. Are these experiments probing the laws in a region they haven't been tested before? Can these unexpected results be reproduced outside of the framework of a cool engine for space travel?

E.g. there's a difference between measuring for the first time the spectrum of antihydrogen, which we predicted with the strongest confidence would be the same as hydrogen's; and measuring the spectrum of hydrogen with Rock&Roll sounding within, because "we can't know if any specific music genre will have an effect until we test it".

So yeah, if people want to spend their own resources testing this, the more power to them. But the way it's been done makes it look like they're more interested in a cool positive result than in unveiling the truth, and that mindset leads to things like the N-rays.

Re: Uncertain Propulsion Breakthroughs?

#49
post #45

If they have two versions of the resonant cavity, one that is tapered and one that is just a simple cylinder that to me would be a big step in the right direction to address many of the concerns. Basically the cylinder with no taper should show zero thrust. And the version with the taper should show a thrust. Then if they test that setup inside the huge Apollo program vacuum chamber far away from the side walls and c…

We don't know if the taper does anything though. If we don't have a working theory we can't really use variations of the working device to prove anything.
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