h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: The Plasma Drive - A2526013
Author: lightgiver - U683596

Well, this is the first bit of writing that I consider anywhere near good enough to submit for peer reveiw. Please note that this will be updated if it needs to be, so any problems can be rectified. Oh, and I have tried to make it fit the guidelines as much as I can, but any sugestions on that front would be appreciated.

lightgiver, this looks very much like personal opinion, rather than established fact to me. There's no place in the Edited Guide for personally held theories.

What about the VAriable Specific Impulse Magnetoplasma Rocket (VASIMR)? See http://www.space.com/businesstechnology/technology/vasimr_rocket_020807-2.html. This is a plasma rocket. And it works.

Me, me, me, that's what this article sounds like. Remember to aviod personalisations!

By the way we are developing transporters. A team in Australia have managed to beam a light particle across a room!

Well, although it is a personal theory, the physics does back it up. It is possible to create the engine I described, and as soon as I do, It will be fact. Also, I'm not trying to make it me, me, me, and I'm sorry if I had. And I knew about the ozzies and the transporters.

Since you seem to know a bit about physics, perhaps you'd like to put something in the entry on the problem of movement in space, where you have nothing to push against, and the effects of large acceleration on the contents of the spaceship.

"By the way, the Plasma Drive is copyrighted and is a registered trademark. Don't try to steal my ideas, OK?"

You do realize, don't you, that neither copyright nor trademark are the type of intellectual property protections that one applies to an invention? That's what patents are for, and the process for obtaining a patent is quite different than for copyright and trademark.

Furthermore, if you're truly worried about people stealing your ideas, I wonder if h2g2 is really the best place for this. Anytime you are writing an entry here on h2g2, you are automatically granting a non-exclusive copyright to the BBC on the entry.

-- Mikey

Well, I hadn't actualy thought about that. I Think I will keep the entry on the site, and as for the problem of moving in space, I'll put that in my next bit of work, as well as how we can fold space and time.

The reason I suggested the bit about moving is space is because the Plasma drive as a form of propulsion when you understand the idea of exhaust speed being important. The reader will need to know this to understand the significance of your plasma drive.

The bit about what happens to the contents is the obvious question whihc must be answered if you are applying one huge burst of plasma rather than a continuous stream, which is what I think you have said your drive does.

Whatever: it doesn't exist, it hasn't been shown to work. It's all purely speculative. And anyhow, it's attempting to appropriate a name which could justifiably be given to other existing and working technology.

Apologies for my last posting being garbled.

I wrote an Edited Entry on the Space Elevator, which also doesn't exist and is speculative. Plasma drives are something that scientists are working on at the moment, so it should be possible to write an entry about them.

But this entry will have to change a lot. The questions I asked were the first stage. If the entry incorporates the answers to them, it may be possible to work it into a decent entry on plasma drives.

But the references to lightgiver's own plasma drive will have to be completely stripped out, since we have nobody's word but his own that he knows what he is talking about.

This entry is nonsense. It's just Star Trek fanboy wishful thinking. The key parameter is reaction mass - it doesn't matter if you eject the mass in the form of plasma, or reaction products, or big lumps of rock. This so-called "design" adds nothing to existing technology, and indeed probably (from the very vague description here) would be more likely to bore a hole into the ground than lift off it. Congratulations on your plasma drive, next stop the centre of the earth, or at least perhaps the Mohorovicic discontinuity, and try saying that after a martini.

>>The key parameter is reaction mass - it doesn't matter if you eject the mass in the form of plasma, or reaction products, or big lumps of rock.

Actually, that's completely wrong, Member, but I won't tell you why. If lightgiver knows what he's talking about, he'll be able to tell you.

I PR...

Tha practicalities would seem rather difficult.

Given the low efficiency of lasers, (<20-30% at best at present) you'd seem to need an awful lot of energy to heat up the gas, and a heck of a lot of cooling for the laser, which would lower the efficiency again.
You'd probably need a big, heavy laser as well.

What power source is supposed to drive the laser?

Injecting cold gas into the exhaust would seem likely to cool and slow down the plasma - could this be offset by sufficient acceleration to the cool gas.
The reason afterburners work on jet engines is that you're pumping fuel into hot gases that have sufficient oxygen left to enable the fuel to burn, so you get extra expansion (and thus thrust) at the expense of a loss in efficiency.

I suggest that lightgiver withdraws this from Peer Review until he has his prototype working. Then he can give us a demonstration and submit the entry again.

Well, that's a lot of good point.s I think I'm going to take Gnomon's advice and withdraw this entry from the peer reveiw untill my prototype is working. Oh, and in response to Potholer - the cold gas is injected at room temperature into the plasma exhaust, and should turn explosivley into plasma, only it would do so faster than the exhaust did, giving an extra kick of speed. By the way, I resent my idea being called "Star Trek fanboy wishful thinking". this is a genuine idea backed up by solid, proven physics.

Oh, and the reaction mass and the ejection velocity isn't an isue here, as the force to power the engine would come from the gas turning explosivley into plasma, not ejecting it.

Thanks, lightgiver. You've finally confirmed how little you know about physics. Perhaps when you understand what you've just said, you will be ready to start designing a plasma drive.

Yeah, thanks for that. I know what I'm talking about, and I understand exactly what I said. And have you ever heard the phrase "Genius and insanity are sperated only by degreees of success" ?

I don't believe you have a clue what you are talking about, actually. *All* rockets rely upon Newton's third law to propel them: it's the mass that gets ejected that provides the forward thrust. What is more, as the rocket speeds up, the overall specific impulse drops off (force * time / propellant mass). You need to eject gases at progressively higher speeds in order to get decent acceleration.

Another point worth making is that turning a gas into plasma requres a net input of energy. It doesn't generate any energy by itself, othewise we'd have an explosion every time we turned on a fluorescent light. So the act of ionising the propellant just for the sake of it would be pointless.

I have heard the expression you mention. It's bollocks.