06-07-2015, 02:14 PM
Yes, you've got it exactly right so far.
Put a really big reversible computer in the place you'd expect a star, and a bunch of bit erasers spread out in a periphery sphere 1AU away in all directions. Pack zeros into convenient sized rocks and toss them from the periphery to the computer. When they reach the computer, unpack them into grains of sand, position those very close to the computation. Reversibly swap the zeros for results to consume/erase. Collect the grains of sand back into a rock, and throw it back out. Throwing rocks back and forth is reversible. The periphery can use the results for something before zeroing out the bits and repeating the process. The latency of throwing rocks back and forth isn't terribly important to the computer, zeros are all the same, you can make up for greater latency with more rocks. The periphery would care about latency of rock throwing because that's how long it takes to get usable results.
Keep the central computer cold, and as compact as you can have matter without gravity being a bother. Maybe if it's cold enough we can use hydrogren and helium to construct the computer, which would be fortunate because those are the only raw materials that tend to be on hand. It could be computing arbitrarily fast; cold just means low entropy. The periphery can be a small fraction of the weight of the central computer. The temperature and surface area of the periphery determine how quickly bits can be erased (allowing new results to be reported). I suspect clearing bits would be the bottleneck rather than computing resources.
Put a really big reversible computer in the place you'd expect a star, and a bunch of bit erasers spread out in a periphery sphere 1AU away in all directions. Pack zeros into convenient sized rocks and toss them from the periphery to the computer. When they reach the computer, unpack them into grains of sand, position those very close to the computation. Reversibly swap the zeros for results to consume/erase. Collect the grains of sand back into a rock, and throw it back out. Throwing rocks back and forth is reversible. The periphery can use the results for something before zeroing out the bits and repeating the process. The latency of throwing rocks back and forth isn't terribly important to the computer, zeros are all the same, you can make up for greater latency with more rocks. The periphery would care about latency of rock throwing because that's how long it takes to get usable results.
Keep the central computer cold, and as compact as you can have matter without gravity being a bother. Maybe if it's cold enough we can use hydrogren and helium to construct the computer, which would be fortunate because those are the only raw materials that tend to be on hand. It could be computing arbitrarily fast; cold just means low entropy. The periphery can be a small fraction of the weight of the central computer. The temperature and surface area of the periphery determine how quickly bits can be erased (allowing new results to be reported). I suspect clearing bits would be the bottleneck rather than computing resources.