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

I believe there a few problems with this design.

The fuel relies on antimatter. 100 tons of it. Today, creation of antimatter relies on supercolliders which produce "hot" antimatter. It then must be cooled and collected in a Penning trap. That antimatter (specifically anti-protons) is then mixed with electrons that have a charge slightly less than the anti-protons, cooling them further. The real problem is that CERN, the world's largest particle physics lab, can, at optimal efficiancy, only produce 10^7 anti-protons a second. Assuming total conversion to anti-hydrogen, which would be you're fuel, it would take 2 billion years to produce 1 gram. Even with the other labs and construction of new ones, Antimatter couldn't possibly become a viable source of fule for at least a millenium.

Second, if anything, anything, happened to the containment chamber, or the magnetic bottle, everyone would probably die. Any antimatter that touched regular matter would release 1.8 x 10^17 Joules of energy per kilogram, or the energy one would get if someone drank 18,000,000,000,000,000 drops of beer. I can warn you, that's more than a few rounds.

sorry to knock it...really, I am.

riverrunning

Beside all the problems mentioned I also wonder about the acceleration that such a spacship would have. As far as I know people aren't vary good at surviving large accelerations (moree than a few g's) and wit smaller ones would it take extreamly long to reach 92% of the speed of light.

Those issues mentioned above are correct, of course.
But you gotta bear in mind that this is not something that will be developed next year. The design of the engine is there. It's up to other to get the fuel and to think something out to let people survive on this ship.
It was designed by a physics guy, so people are irrelevant
That's for the medics and the biology guys to figure out

Hmm, one thing...

If you're firing particles out the back of the spacecraft at 20% of the speed of light, then yes, there is the obvious limit to how much that can accelerate the spacecraft in the opposite direction. But, isn't the limit relative to the speed of the fuel ejected, rather than relative to the Earth? And since the onboard fuel is accelerating away from the Earth along with the spacecraft...

*confused*

As Herr E said, everything is relative but yer in-laws.

I think the whole concept is theoretical but based on sound science so it can't be proven or disproven absolutely, much like some other theories (to the misplaced delight of some non scientists).

btw, love his ideas AND his mineral water.

you would need to flip to decelerate, acceleration Gs are only a factor if you are, in fact, accelerating (or decelerating) and while you are, you would just need the eqivilent of a gigantic spring (remember, this is the future, so think extreamly good crash couches). It would work, but not for a very long time.

its the future, anything can happen

First off:

"However, the sharp-eyed reader will have noticed that this first stage of thrust is still far from the claimed top speed of 92% of the speed of light. As the ship starts to approach 12 - 20% of light speed, the fusion reaction is starting to run out of force. Basic Newtonian physics states that if the exiting particles are travelling 12 - 20% of the speed of light, we cannot move faster than this"

wrong (IMHO). The particles would leave the "ship" at 12-20% SoL relative to the ship. Basic Newtonian phyics does not say "if the exiting particles are travelling 12 - 20% of the speed of light, we cannot move faster than this". You cannot ACCELERATE more quickly than you are accelerating the particles away from you... (actually that may not be right...)

Collision avoidance - what if the particle is not small (E.G. Asteroid size rather than dust?). And where does the "organic liquid" come from?

Gamma radiation - 10km of vaccuum would do very little to attenuate gamma radiation..

2 engines & tether - why not use both of them and string the habitation pod between them - thus all you need worry about are particles...

I'll let you physics guys argue the finer details yes it is a complicated device and we may be some way off developing the craft but I think the exciting thing about valkeryrie is that it is applying physics concepts to an engineering concept that could maybe one day produce a feasible solution.

As to riverrunning point about flipping this would not be needed as mentioned in the text the second engine is fired in the opposite direction to slow the craft without needed to flip the craft whilst travelling at near light speed!

Glad you all enjoyed the entry enough to create some debate about it!