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Beamed propulsion is a farther out technology, requiring development of more powerful lasers capable of pushing a crewed vehicle in reasonable amounts of time a

Beamed propulsion is a farther out technology, requiring development of more powerful lasers capable of pushing a crewed vehicle in reasonable amounts of time and has the issue that it is difficult to slow down at the destination. Nuclear rocket engines were already being developed during the cold war. Both suffer from the irrationality that the more useful they are capable of being, the more they can be misconstrued as orbital weapons.

pfdietz 2y ago
I am amused you are objecting to a technology for interstellar travel on the grounds it is "farther out", especially in the context of what hypothetical aliens that are around for millions or billions of years would be using. We could build a 1% c starship using hydrogen bombs. But it wouldn't make much sense to build it, since in the time it would take to get to even the nearest star we'd likely have something much faster.
- dotnet00 2y ago
  I'm not objecting to it, my initial post was trying to emphasize the closeness of technologies capable of reaching the nearest stars, lasers are an option, but imo nuclear propulsion is "closer" in terms of time taken to achieve the energy densities needed to take humans there. Sure it's only a difference of a couple of decades at worst between the two but in the context of a human lifetime, that's significant.
  - Nevermark 2y ago
    In what important sense is nuclear closer? If we sent a nuclear craft today, a future laser or other propulsion craft will still get there much sooner. Worse, we don’t actually have a nuclear craft design. By the time we worked out a design and built it, the other tech will already be ready. That is because other tech will require less mass, which will “massively” simplify and reduce cost of the venture. Given the time the trip will take, it will actually be decades at least, before the optimal time to design and send a ship - even if we had an unlimited budget with the only objective of getting there the soonest we can

pfdietz 2y ago

I am amused you are objecting to a technology for interstellar travel on the grounds it is "farther out", especially in the context of what hypothetical aliens that are around for millions or billions of years would be using. We could build a 1% c starship using hydrogen bombs. But it wouldn't make much sense to build it, since in the time it would take to get to even the nearest star we'd likely have something much faster.

dotnet00 2y ago
I'm not objecting to it, my initial post was trying to emphasize the closeness of technologies capable of reaching the nearest stars, lasers are an option, but imo nuclear propulsion is "closer" in terms of time taken to achieve the energy densities needed to take humans there. Sure it's only a difference of a couple of decades at worst between the two but in the context of a human lifetime, that's significant.
- Nevermark 2y ago
  In what important sense is nuclear closer? If we sent a nuclear craft today, a future laser or other propulsion craft will still get there much sooner. Worse, we don’t actually have a nuclear craft design. By the time we worked out a design and built it, the other tech will already be ready. That is because other tech will require less mass, which will “massively” simplify and reduce cost of the venture. Given the time the trip will take, it will actually be decades at least, before the optimal time to design and send a ship - even if we had an unlimited budget with the only objective of getting there the soonest we can