My admittedly wordy post above was an attempt to respond to that exact argument. First, a clarification: > Do you think that advances in interstellar travel ca

My admittedly wordy post above was an attempt to respond to that exact argument. First, a clarification: > Do you think that advances in interstellar travel capability will appear out of thin air? No. It should have been obvious from my post that this is a straw man, that I'm not arguing to halt all science and wait for advancements out of thin air. I want to pursue science efficiently, because we have limited resources. Also, the time scales involved here will radically change the nature of the problem beyond our comprehension. This 5 billion year problem you want to start tackling today changes immensely if in 1% of 1% of that time our descendants are all clouds of digitally encoded consciousness that propagate primarily through EM radiation and psychic clouds of gas. I'm not saying that change is particularly likely, but some change on that magnitude is all but certain on this time scale (ie, 1.5 times as long it took proto-bacteria to turn into apes). Suppose cavemen suddenly had a revelation that air transportation would some day change the world. It would be foolish and dangerous if they immediately devoted their free time trying to jump as high as possible, rather than just working on fire and wheels and spears. Ultimately fire, wheels, and spears are foundational technologies for the disciplines that made flight and rocketry possible. So even though they seem like distractions from air travel, they're actually the most efficient path to solving that problem. This is all the more obvious for probes, telescopes, and rovers. Those are the wheels, fire, and spears of space. Those all give us incrementally more information about the very nature of the universe, the nature of other possible planets, and how to build functioning intelligent machines that can survive in hostile environments. If there's some way to bend space to our will for instantaneous interstellar travel, or some way to get highly complex machines to shepherd us among the stars, we discover it there, not by putting a guy on a treadmill in microgravity.