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[smirk]

Heck, it might not even work; mistakes have been made before. It'll be brilliant if it does work, but there's gonna be a hell of a lot of review and analysis first.

[Bauglir]

So, uh, we fucked conservation of momentum? I eagerly await the enormous piles of additional research that will inevitably discover a flaw in the methodology - but I really would love to be wrong on this one.

[Frumple]

If my reading of the article was right, it's a very, very low-power thruster mostly only good for satellites. Possibly space probes as well. No starships yet, sadly :/

Then again... if it just runs off the zappy, chunk a buggerhump load of solar panels on a thingy and many dozen of the things instead of, y'know, fuel or whatever. If quality fails, turn to quantity! Or maybe just a really big one. Low power thruster up in space still gets things moving given some time.

[Bauglir]

Yeah judging from the results, if this is legit, then the application will likely be as a replacement for fuel after launch - we're still going to need to send stuff up riding on the backs of explosions, for now, based on the force they're capable of generating.

[Descan]

Yeah. It's only getting *out* of gravity wells that you need a great deal of thrust in a short period of time (and windows, like the window of when mars and earth are close by, but even that lasts a few weeks)

Once you're at orbital speeds and are Douglas-flying by falling towards the earth so fast that you miss it, ANY thrust is preserved, there's not really any friction or air resistance. So if you can do it without fuel and without needing to REfuel, then it's a godsend, basically.

[alway]

Their test units supposedly generated about 0.1% the thrust of an ion propulsion system. But with 0 fuel costs, it would mean satellites could stay up and maneuver indefinitely, bounded only by their components breaking down.

Unfortunately, as the Ars Technica article points, out, it's probably just a measurement error: http://arstechnica.com/science/2014/08/dont-buy-stock-in-impossible-space-drives-just-yet/
Both test units produced the same amount of force.... problem being, one of the test units was a control group which shouldn't have seen any thrust.

[Knit tie]

There's always a possibility that the device might actually be functional and that we are simply too skeptical to not try to discredit it by all means possible, like how we were skeptical of computers, aeroplanes, books, radio and other world-changing inventions back when they were made. Still, more studies are definitely necessary.

Another possibility is that the device is perfectly possible, but that our understanding of physics is wrong instead.

[Putnam]

Skepticism is good. We should always be skeptical.

[Sergarr]

If you're going for propulsion without throwing fuel away, wouldn't using light as propulsion make sense?

[TheDarkStar]

If you're going for propulsion without throwing fuel away, wouldn't using light as propulsion make sense?

That depends. Solar sails have uses for going further out in the solar system, but they are too weak and unidirectional for maneuvering in Earth orbit.

[10ebbor10]

If you're going for propulsion without throwing fuel away, wouldn't using light as propulsion make sense?

If I recall correctly, the energy of light is equal it's momentum times the light speed.
Momentum for common objects is p=m*v.

So in order to get a momentum of 1 N*s, you need to spent 3*10⁸ joules, where otherwise it would just be 0.5 joule(1 kg object)

[MonkeyHead]

I don't get why people are getting so worked up when the experiment did not pass its own null hypothesis.

If you're going for propulsion without throwing fuel away, wouldn't using light as propulsion make sense?

If I recall correctly, the energy of light is equal it's momentum times the light speed.
Momentum for common objects is p=m*v.

So in order to get a momentum of 1 N*s, you need to spent 3*10⁸ joules, where otherwise it would just be 0.5 joule(1 kg object)

3*10^8 J is not a huge amount of light energy, when you consider that the stellar intensity at 1 AU is 1470 Wm^-2.

[10ebbor10]

Yes, obviously, but I was just making the point that firing laser for propulsion would use almost a billion times more energy.

[Lagslayer]

Obligatory xkcd comic

[Solifuge]

To what degree I understand the theory (if indeed it works), this drive wouldn't actually violate conservation of momentum. It provides force by projecting an electromagnetic field which pushes against non-classical matter; a fluid of charged Virtual Particles that blink in and out of existence according to Perturbation Theory. So instead of ejecting matter to push it along as with traditional thrusters, this pushes against a sort of matter that permeates the universe, but exists for so short a time span that it's not something we can easily observe.

The tiny amount of thrust NASA seems to have produced using this is much less than was claimed to have been generated in previous tests with similar thrusters, which could just be an issue of the scale of the test thruster. I think Roger Shawyer, who first developed the concept, saw people using arrays of them to drive atmospheric aircraft, ground vehicles, and so on... in the "This will revolutionize EVERYTHING!" sort of way. Mostly, I am excited about being able to convert any source of electricity, like radioactive decay, solar energy, etc. into thrust without having to worry about fuel. It could enable extremely deep-space exploration, much lighter spacecraft, and bring us a step closer to figuring out what's going on in the universe at a quantum level.

If it works, I motion that we call it Impulse Power, in part because it generates force as if spontaneously... but mostly because Star Trek.