3 ms·

> If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g ac

by messe 5y ago

> If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c. No, we couldn't. The energy density of fusion isn't anywhere near close enough to make a lighthugger, you'd need insane mass ratios[1] and ramjets are probably unfeasible (as in, even-if-your-a-Kardeshev-II-civilization-unfeasible[2]). [1]: http://www.projectrho.com/public_html/rocket/slowerlight3.php#id--Go_Fast--Relativity--Mass_Ratio http://www.projectrho.com/public_html/rocket/slowerlight3.ph... [2]: https://www.sciencedirect.com/science/article/pii/S0094576521005804 https://www.sciencedirect.com/science/article/pii/S009457652...

thereddaikon 5y ago
Another atomic rockets enjoyer. I've killed so much time on that site. I don't agree with every one of Winchell's conclusions. But they are small things. And I don't know of a more comprehensive and grounded take on future spaceflight technologies.
- messe 5y ago
  I was saddened to hear about Winchell's cancer diagnosis last year[1]. I've wasted a ton of time there too, it's an oddity compared to the rest of the modern internet. I know very few other useful sites like it, and I love it all the more for its strange aesthetic. I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation. [1]: https://twitter.com/nyrath/status/1436010987086286853?s=20 https://twitter.com/nyrath/status/1436010987086286853?s=20
  - thereddaikon 5y ago
    Oh man, I hadn't heard about that. Best of luck to him but he's right prostate cancer is a pretty bad one. What are the other few sites you do know of? And you are absolutely right about the rocket equation. You can't really get around it.
    - messe 5y ago
      I'm sure there's more but the first few that come to mind are Greg Egan's homepage[1], Xenology[2], and on a completely different topic "Gramadach na Gaeilge"[3] (Irish Grammar). [1]: https://gregegan.net https://gregegan.net [2]: https://xenology.info https://xenology.info [3]: http://nualeargais.ie/gnag/gram.htm http://nualeargais.ie/gnag/gram.htm
      - messe 5y ago
        It's too late to edit, but the link to xenology should be http and not https: [2]: http://xenology.info http://xenology.info

by messe 5y ago

thereddaikon 5y ago

Another atomic rockets enjoyer. I've killed so much time on that site. I don't agree with every one of Winchell's conclusions. But they are small things. And I don't know of a more comprehensive and grounded take on future spaceflight technologies.

messe 5y ago
I was saddened to hear about Winchell's cancer diagnosis last year[1]. I've wasted a ton of time there too, it's an oddity compared to the rest of the modern internet. I know very few other useful sites like it, and I love it all the more for its strange aesthetic. I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation. [1]: https://twitter.com/nyrath/status/1436010987086286853?s=20 https://twitter.com/nyrath/status/1436010987086286853?s=20
- thereddaikon 5y ago
  Oh man, I hadn't heard about that. Best of luck to him but he's right prostate cancer is a pretty bad one. What are the other few sites you do know of? And you are absolutely right about the rocket equation. You can't really get around it.
  - messe 5y ago
    I'm sure there's more but the first few that come to mind are Greg Egan's homepage[1], Xenology[2], and on a completely different topic "Gramadach na Gaeilge"[3] (Irish Grammar). [1]: https://gregegan.net https://gregegan.net [2]: https://xenology.info https://xenology.info [3]: http://nualeargais.ie/gnag/gram.htm http://nualeargais.ie/gnag/gram.htm
    - messe 5y ago
      It's too late to edit, but the link to xenology should be http and not https: [2]: http://xenology.info http://xenology.info