Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

[phookz]

Interesting stuff, especially for those of you looking for new ways to do drives:

http://www.technologyreview.com/blog/arxiv/24499/

[austenandrews]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Reactionless drive?

[ajackson]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Photon drive, most likely. Pretty much anything that looks like a reactionless drive actually either doesn't do anything, or functions like a photon drive (in which case it also doesn't do anything unless you have an incredibly sensitive detector).

[Nyrath]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Reactionless drive?

 

"Although the proposed engine will consume energy for manipulation of the particles, the propulsion will occur without any loss of mass," says Feigel.

Hard to say. Could be like a photon drive like ajackson says, but the article does not mention any photons being emitted.

 

However, either way (reactionless or photon drive), theoretically both will have unreasonable power requirements, where one lousy Newton of thrust takes three hundred freaking megawatts!!

http://www.projectrho.com/rocket/rocket3am.html

 

And of course we know that reactionless drive have unintended consequences.

http://www.projectrho.com/rocket/rocket3a.html#advice

[austenandrews]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

"Although the proposed engine will consume energy for manipulation of the particles' date=' the propulsion will occur without any loss of mass,"[/i'] says Feigel.

Hard to say. Could be like a photon drive like ajackson says, but the article does not mention any photons being emitted.

Evidently it isolates a magnetic field from the quantum vacuum, so it's got no reaction mass. It magnetizes space.

 

However, either way (reactionless or photon drive), theoretically both will have unreasonable power requirements, where one lousy Newton of thrust takes three hundred freaking megawatts!!

No worries - by the time we figure out how to make a working Fiegel drive, Casimir negative-generators will be commonplace.

 

And of course we know that reactionless drive have unintended consequences.

http://www.projectrho.com/rocket/rocket3a.html#advice

Just because it's scary doesn't mean it's impossible.

[Nyrath]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Just because it's scary doesn't mean it's impossible.

I am not saying it is impossible. I'm saying it has unintended consequences, for the game master.

 

Do you, as a game master, want an SF universe where a tramp freighter's lifeboat can destroy all life on Earth?

[Duke Bushido]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Nyrath:

 

How about the old standby: "drive / powerfield / voodoo space magic arrests movement within X distance of a gravity field / planetary magnetism / etc?

 

don't get me wrong: I fully understand the need for a cop out. It was brought to my attention many, many years ago when I was reading an absolutely _horribly_ written novel about the destruction of earth. It seemed that earth had very nearly perfected a C-drive. At that moment, "the others" began their bombardment.

 

Their motivation was, of course, that a C-drive was the most powerful weapon of all, and that any life form (after themselves, of course) that developed one had to be eradicated before they discovered a super-C drive, because at that point, their doomsday weapons would be completely undetectable.

 

Something of a slap in the face to see an author go so fully against the enjoyable tropes of the genre, but refreshingly novel. If only the book itself had been written by someone with a shred of ability....

 

At any rate:

 

I find that, while I don't use it myself, I like the rubber science of "reactionless drive" simply because it takes so much technobabble to make it work that really, adding in "but for some reason, you can't use it near a planet" just slips right in there without batting an eye.

 

What about -- was it one of the Twilight 2xxx games, or one of the Traveller games?-- the "stutter warp." Endless cycles of one-inch teleportation. No genuine momentum, but would that be considered "reactionless?"

[Peregrine]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Traveller 2300, later renamed 2300 AD.

[Duke Bushido]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Thanks!

[Tom]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Nyrath:

 

{...snip...}

 

What about -- was it one of the Twilight 2xxx games, or one of the Traveller games?-- the "stutter warp." Endless cycles of one-inch teleportation. No genuine momentum, but would that be considered "reactionless?"

 

That sounds like something I'm remembering from a Poul Anderson book...

[Xavier Onassiss]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

The 'stutterwarp' drive of 2300 AD wasn't a reactionless drive. The defining feature of a reactionless drive is the production of thrust without the expenditure of reaction mass. The stutterwarp didn't actually produce any thrust, so technically, it's not a reactionless drive. Which doesn't make it any less useful or interesting -- I'm just clarifying the terminology here.

 

 

Don't look at me,

Xavier Onassiss

[Nyrath]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

What about -- was it one of the Twilight 2xxx games' date=' or one of the Traveller games?-- the "stutter warp." Endless cycles of one-inch teleportation. No genuine momentum, but would that be considered "reactionless?"[/quote']

As Xavier Onassiss already pointed out, it is not only reactionless, it is not a drive either. No thrust.

From the standpoint of physics, it is rubber science due to the teleportation.

From the standpoint of Star Hero, it is a bit more difficult to use it to turn a scoutship into a planet killer.

 

When you turn off the drive, the ship stops moving, except with the "intrinsic" velocity it had before using the drive.

 

Not totally impossible. As pointed out in Larry Niven's THE THEORY AND PRACTICE OF TELEPORTATION, what you have to do is park the ship so it is falling towards, say, Jupiter. You use the drive to teleport the ship so the ship does not move. However, the act of falling will steadily increase the intrinsic velocity of the ship.

 

Leave it parked there for a few months, and it will build up a planet-killing velocity.

[Nyrath]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

That sounds like something I'm remembering from a Poul Anderson book...

 

Yes, the Nicholas van Rijn stories of Poul Anderson used that sort of drive.

[Duke Bushido]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

Gotcha.

 

Thanks, Gents.

[Cancer]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

When you turn off the drive, the ship stops moving, except with the "intrinsic" velocity it had before using the drive.

 

Not totally impossible. As pointed out in Larry Niven's THE THEORY AND PRACTICE OF TELEPORTATION, what you have to do is park the ship so it is falling towards, say, Jupiter. You use the drive to teleport the ship so the ship does not move. However, the act of falling will steadily increase the intrinsic velocity of the ship.

 

Leave it parked there for a few months, and it will build up a planet-killing velocity.

Actually, if you choose your starting point correctly, you can still do lots of damage without iterated teleportations. The velocity dispersion of sun-like stars (that is to say, systems with plausibly habitable planets) is large enough so you could get 100 km/s of relative velocity difference "for free" fairly easily.

[phookz]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

I was watching Sci Fi Science on the Science Channel last night; the episode was "Exploring the Universe" and was about how to build a theoretically plausible FTL drive. I was surprised to see this exact theory in the show. It was a good episode if you can catch it - here's are some brief clips from it:

 

http://science.discovery.com/videos/sci-fi-science-exploring-the-universe.html

http://science.discovery.com/videos/sci-fi-science-traveling-at-warp-speed.html

[Nyrath]

Re: Quantum Propulsion Machine May Lead To Propulsion Without Change In Mass

 

More here

http://www.centauri-dreams.org/?p=10624

http://www.technologyreview.com/blog/arxiv/24499/

 

I'll believe it when I see it