3 ms·

I think that just as cost is based on physics, time is best measured in terms of lifespan. Probes with travel times measured in the thousands of lifespans take

I think that just as cost is based on physics, time is best measured in terms of lifespan. Probes with travel times measured in the thousands of lifespans take too long. Might as well ask Archimedes to send a probe.

tsimionescu 6y ago
Even beyond lifespans, there are problems with materials and resilience. While a conductor wire seems solid enough for us, that's only true for some hundreds of years. Even if we lived 1000 years each, that doesn't guarantee we can make mechanisms of any kind to last 1000 years, nevermind 10000. Hell, I'm not even sure we can make a computer that actually lasts 100 years.
- lisper 6y ago
  > I'm not even sure we can make a computer that actually lasts 100 years. I'm pretty sure we can. I have a 40-year-old calculator that is still working just fine.
  - tsimionescu 6y ago
    Well, it still has 60 years to go before you can contest my hypothesis. Still, I was probably too ambitious when I said "computer". I was thinking more that we can't make a PC or server-style computer that would actually last 100 years, while in regular operation. Also, 1980s calculators have much, much fewer moving parts than today's computers. They don't have any kind of active cooling, they don't go through rapid heating and cooling cycles, they probably have three orders of magnitude less electrical components than a modern PC. For me at least, all of the PCs I have had so far have had a few electrical components giving out after at most 10 years (usually some condensers leaked).
    - lisper 6y ago
      But all that is just because computers are not designed for longevity, they are designed for capability. We could easily design them for longevity if we wanted to: lower the clock speed so that passive cooling is all that's needed. Make all the PC traces five times fatter than they need to be. Use non-electrolytic capacitors. The resulting computer would be big and slow but it would last forever. In fact, it would not surprise me a bit if you could run a Raspberry Pi Zero for 100 years.
- adrianN 6y ago
  Given an energy source that lasts the duration of the trip, I'm sure we could figure out how to build a ship that we can keep repairing quicker than it falls apart.
  - tsimionescu 6y ago
    Then we're back to the energy requirement, yes. I wouldn't even be convinced then that we have the technology today. Any repair system would necessarily suffer from the same kinds of failures.
    - adrianN 6y ago
      I think the amount of mass lost is small enough that extra provisions can be carried around. For anything else you just have to fight entropy. Given enough energy you can probably do that.

tsimionescu 6y ago

Even beyond lifespans, there are problems with materials and resilience. While a conductor wire seems solid enough for us, that's only true for some hundreds of years. Even if we lived 1000 years each, that doesn't guarantee we can make mechanisms of any kind to last 1000 years, nevermind 10000. Hell, I'm not even sure we can make a computer that actually lasts 100 years.

lisper 6y ago
> I'm not even sure we can make a computer that actually lasts 100 years. I'm pretty sure we can. I have a 40-year-old calculator that is still working just fine.
- tsimionescu 6y ago
  Well, it still has 60 years to go before you can contest my hypothesis. Still, I was probably too ambitious when I said "computer". I was thinking more that we can't make a PC or server-style computer that would actually last 100 years, while in regular operation. Also, 1980s calculators have much, much fewer moving parts than today's computers. They don't have any kind of active cooling, they don't go through rapid heating and cooling cycles, they probably have three orders of magnitude less electrical components than a modern PC. For me at least, all of the PCs I have had so far have had a few electrical components giving out after at most 10 years (usually some condensers leaked).
  - lisper 6y ago
    But all that is just because computers are not designed for longevity, they are designed for capability. We could easily design them for longevity if we wanted to: lower the clock speed so that passive cooling is all that's needed. Make all the PC traces five times fatter than they need to be. Use non-electrolytic capacitors. The resulting computer would be big and slow but it would last forever. In fact, it would not surprise me a bit if you could run a Raspberry Pi Zero for 100 years.
adrianN 6y ago
Given an energy source that lasts the duration of the trip, I'm sure we could figure out how to build a ship that we can keep repairing quicker than it falls apart.
- tsimionescu 6y ago
  Then we're back to the energy requirement, yes. I wouldn't even be convinced then that we have the technology today. Any repair system would necessarily suffer from the same kinds of failures.
  - adrianN 6y ago
    I think the amount of mass lost is small enough that extra provisions can be carried around. For anything else you just have to fight entropy. Given enough energy you can probably do that.