Interstellar travel, matter-antimatter rockets, fusion ramjets etc‏

Hi everyone,

Any of you guys StarWars fans? Decided to goto the PowerhouseMuseum checkout their StarWars gallery and ended up having a field day! :-)) Apart from the models they used in the movies the most interesting display was the one with the concepts previously thought so far based on real Physics dealing with interstellar travel.

Although the concepts thought up so far based on our current understanding of Physics could work, none of them are practical: the matter-antimatter rocket for eg is nearly the size of Texas! All of them rely on the momentum principle (throw something backwards to go forwards) and all of them are bound to sublight speeds due to special relativity: the vacuum of space imposes a maximum terminal velocity, the speed of light, to everything in our Universe. This is a big problem (if you want to travel to nearby stars fairly fast), the 2nd closest star from us is Proxima Centauri at 4.2 light-years which means it takes light 4.2 years to travel to Proxima, all starships would take much longer because matter (the ship) cannot go faster than light.

The good news is our lack of understanding of the Physics of the vacuum of space and why the vacuum imposes this speed limit in nature means that this isn't the end of the story. The world's largest particle accelerator (the LHC) might give some clues when it becomes operational hopefully later this year...