Ask Lemmy
A Fediverse community for open-ended, thought provoking questions
Rules: (interactive)
1) Be nice and; have fun
Doxxing, trolling, sealioning, racism, toxicity and dog-whistling are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them
2) All posts must end with a '?'
This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?
3) No spam
Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.
4) NSFW is okay, within reason
Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com.
NSFW comments should be restricted to posts tagged [NSFW].
5) This is not a support community.
It is not a place for 'how do I?', type questions.
If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.
6) No US Politics.
Please don't post about current US Politics. If you need to do this, try !politicaldiscussion@lemmy.world or !uspolitics@lemmy.world
7) No Hit-and-Run questions.
Please don't delete your post for no apparent reason. If you plan on deleting a question later, say so in the post, or if you feel that you have a good reason to remove it, message a mod beforehand. It's not fair to the ones who took their time to answer, and it's not in the spirit of the community.
8) No Bots.
Posts or comments from bots, LLM's, AIs, Neural Networks, Transformers, or Marvin the Paranoid Android are not welcome in AskLemmy. Real humans only please.
Reminder: The terms of service apply here too.
Partnered Communities:
Logo design credit goes to: tubbadu
view the rest of the comments
Space elevators. I used to be a huge fan but I've lost faith in the concept. For one thing, there's been little progress toward creating the unfathomably long carbon fiber tether - about 35,000 km (22000 mi). Then there's the tether's vulnerability to damage or destruction - a fixed target in an unstable world. A break means total failure. We also have no idea how the material would degrade over time. Not that the technology is impossible, I just expect space travel to become cheap enough to make space elevators obsolete long before the tech is there to build them.
When space elevators were first discussed, there were no materials that could possibly be used. Now we have carbon nanotubes that may be strong enough. That’s huge progress.
But yeah, the political issues will prevail. If we can’t even agree enough to build California high speed rail, think of the impossibility of a major infrastructure project several orders of magnitude bigger and more complex, several orders of magnitude more costly, and where a failure is essentially a weapon of mass destruction affecting hundreds of millions of people.
In 2003 Liftport forecast they would build the first space elevator by 2018. Since then, nobody has been able to solve the problem of catalysts gradually degrading, and other issues that limit the length of carbon nanotubes to about half a meter. So research has mostly given up on trying to make really long nanotubes tubes and is focused on weaving shorter ones together into a "yarn". But the yarn has only 1 or 2% of the tensile strength of individual nanotubes - too weak to be a tether material.
So it's not like there's a steady stream of progress. The field seems to be waiting for a new revolutionary nanotube making process that avoids the original problems. Recent forecasts I've seen don't expect the tech to get here until near the end of this century. With climate change becoming a more pressing issue (finally) my bet is more like well into the next century. That's what makes me think better, cheaper rocket propulsion will come along sooner.
I liked the idea that any space elevator might be built elsewhere, such as mars. The lower gravity makes it less impossible, the lower population reduces the impact of catastrophe, and you are more likely to have space based trading and supply once you’re outside earths gravity