Milton Rothman, Obituary
"On another web page we find the breathless news of a new breakthrough in space propulsion. Listen carefully: ' . . . the quantum potential Q found in Bohm's hidden variable version of quantum mechanics is able to transform ordinary protons into virtual `faster-than-light' tachyons. This would permit the construction of a new type of rocket engine that would enable low-cost highly fuel-efficient practical interstellar flight for large manned spacecraft.' Using tachyons as the propellant, a large spaceship could be pushed to velocities approaching the speed of light, using a relatively small amount of energy."
I did not write the last sentence - that's Rothman. In any case I am no longer thinking along these lines. My only point is that finite momentum for thrust costs small energy if you had a tachyon beam. However, this would still be an impulse drive with g-forces not a weightless warp drive!
"My question is: how much energy does it take to generate a stream of tachyons? To provide a reasonable amount of thrust, the tachyon beam must have a certain amount of momentum. The relativistic relation between momentum and energy is surely the same for tachyons as it is for other particles."
No it's not Professor Rothman! We call him back from the dead in a seance! ;-)
When p = |M|c, E = 0 for a tachyon of imaginary mass M
And the mass-energy of the spaceship approaches infinity as the ship approaches the speed of light. So from where do we get this high energy efficiency? (Besides, nobody has seen a tachyon yet.)
The Late Rothman's article on me is inaccurate, attributes Roger Penrose's ideas on gravity and consciousness to me among other things. For now I only make one particular detailed comment.
Our Clueless Dearly Departed Debunker did not know that the mass shell condition changes
E^2 = (pc)^2 + (Mc^2)^2 ordinary particle c = 1
E^2 = (pc)^2 - (|M|c^2)^2 tachyon
Therefore the energy of the tachyon E limits to zero as the momentum p limits to |M|c, which was my point - tiny energy at finite momentum.
There is a special place in Dante's Inferno (where I have VIP status! ;-)) for all CSICOPERS. Rothman was humorless and probably died of boredom or shock looking in the mirror. He was a good example of those uptight tunnel-visioned mediocre "physics professors" that cause any imaginative artistic student to flee their class rooms. Rothman wrote this crap about me in 1996 - so of course it's quite out-dated, but he did not get the physics correct!
It is well known, though not to Rothman, that the special relativistic Bohm quantum potential for the Klein-Gordon equation bends the timelike world line of (in this case spin 0 massive particle) into a spacelike one outside its local light cone. Indeed you can make a closed timelike curve for time travel to the past . This is not same as Feynman zig-zag BTW. Ch 12 The Quantum Theory of Motion by Peter Holland, Cambridge University Press 1993
That is M = m(1 + Q)^1/2
Q ~ (h/mc)^2|Psi|^-1 D'Alembertian|Psi|
m = classical bare rest mass.
Therefore, when Q < -1, M is imaginary, i.e. tachyon.
Here Holland loses faith in Bohm's theory and goes through a song and dance that I think is wrong, but no time for that now - it's a book. My point is that Rothman was a fake! Like almost all those members of Csicops they are not as smart as they think they are.
"If we knew what it was we were doing, it would not be called research, would it?"
- Albert Einstein