Spaceships 2-8 new drives

[Fred Brackin]

Originally Posted by Joseph Paul

Thanks to PTTG for the number crunch. I will take a look at what that can do.

malloyd - interesting reduction of the standard model to a useful limit.

Fred - How do you feel about the defenses written by Shawyer and Woodward concerning the EMDrive and Mach Effect Thrusters respectively?

Never heard of them. I haven't gone into these things extensively but I've never seen anything to indicate that I should. It all sounds like a re-skin of the Dean Drive stuff.

The big thing would be my point about E=MC2. Even if some heretofore unexpected quirk of physics allows for a novel way of generating thrust I will be stunned and amazed if it revolutionizes things. The limits of energy->thrust are severe.

Consider it this way. Say you have some sort of EM Drive that turns electricity into thrust. Where does you electricity come from? If it's some hypothetical highly efficient fusion reactor you're turning a small percent of the reactor mass into energy with the most usable forms of that energy being in the form of the KE of charged particles. Gamma rays being produced are much more difficult to turn into usable energy in an efficient manner.

So you feed the charged particles into an MHD and get electricity which you feed into an EM drive to make thrust. How can this possibly be more efficient than using the charged particles directly as reaction mass? You're inserting a middle man into the process rather than cutting out some inefficient step.

So even if there is something there how can it work better than some simpler competitor? I just don't see it.