I enjoy your podcast very much....may I suggest a show on Near Light Speed Travel / Faster Than Light Speed Travel? I'd like to hear some topics like time dialation discussed in some detail --- for example, if we could send a ship to Alpha Proxima and back at say .5 light speed about the round trip would take the ship about 16 years, but wouldn't some insanely large amount of time pass on earth -- like 10,000 years???
Also some discussions on the various theoretical propulsion methods. . . .sails, antimatter, tachyons. What other limitations would we face in an attempt to travel to the stars?