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An extrasolar world covered in water?

nouvelles.umontreal.ca

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Re: An extrasolar world covered in water?

#101

Post by 7thaccount »

Melatonic wrote: post #92
ryandrake wrote: post #21

Earlier quoted context omitted.

Don't have to go light speed, thanks to relativity. If we could achieve and sustain even 1G acceleration, live humans could make the 100LY trip in approx. 9 years (spaceship time). You could leave, visit the planet, and come back only 18 years older and tell the next-next-next-next-next generation all about it. EDIT: To be fair, 1G over 100LY will result in a maximum speed around 0.9998c so I guess you would have to…

Is this really how time dilation works?

Speed through space + Time adds up to the speed of light or something like that (not a physicist). So as you get closer and closer to the speed of light, your motion through time (from your point of view) slows tremendously. So a few years to you, could be centuries to outside observers. Source: some Kip Thorne lectures I saw like 15 years ago.

Re: An extrasolar world covered in water?

#102

Post by thomond »

ben_w wrote: post #96
NoGravitas wrote: post #62

Only 83 days at warp 6.2, the standard cruising speed for an Intrepid-class starship (or 7.13 days at warp 9.975, maximum sustainable speed for the same ship).

I wish the script writers had been more self-consistent. 100 ly in 7.13 days would’ve had them home in 13.6 years even without shenanigans. (The warp speed graph I saw suggested more like 7 years, which is even worse for the fundamental plot contrivance of the show).

How long would it have taken to warp to the Gamma Quadrant wormhole I wonder?

Re: An extrasolar world covered in water?

#103

Post by myko »

detritus wrote: post #91
barbazoo wrote: post #40

Earlier quoted context omitted.

Another book along those lines I enjoyed reading was "Children of Time" by Adrian Tchaikovsky.

Wonderfully written, but for my shame I expected a different storyline and put it down a year or so ago after only reading 60 pages or so and haven't gone back to it. I keep packing it one times away, but... . One day I might learn how to have a kid AND read books :/

I started reading the Foundation trilogy out loud to my infant. One gets through the books a lot more slowly but it works! I must admit that even if he falls asleep I'll cheat and finish the chapter (still reading vocally).

Bonus: it lets me practice voices for DM'ing DnD games

Re: An extrasolar world covered in water?

#104

Post by TheOtherHobbes »

koheripbal wrote: post #24
cstever wrote: post #20

Earlier quoted context omitted.

I have enjoyed reading "The Songs of Distant Earth" by Arthur C. Clarke which talks about seed ships and the culture rise from that. It's an interesting read.

The seeds of humanity won't be humanity at all, but the AI.

It's all fun and games until you think about the practicalities of building a self-repairing machine that can keep running for hundreds/thousands/millions of years with no significant software or hardware errors.

Re: An extrasolar world covered in water?

#105

Post by SCAQTony »

NoGravitas wrote: post #62

Only 83 days at warp 6.2, the standard cruising speed for an Intrepid-class starship (or 7.13 days at warp 9.975, maximum sustainable speed for the same ship).

Warp factor 1 is the speed of light. Accelerating safely to the speed of light at a constant 1G acceleration would take 354 days. After that, you would arrive instantaneously no matter where or how far since time stops for you once you reach the speed of light.

https://setiathome.berkeley.edu/forum_thread.php?id=34381#:~....

Re: An extrasolar world covered in water?

#107

Post by ornornor »

criddell wrote: post #93
ornornor wrote: post #90

That’s fascinating. > As soon as we can, we will book time on Webb to observe this strange and wonderful world. How does that work? Is there a hotline you call to book time? Is it free or paid? How is the instrument not booked solid for the next few years?

As I understand it, you write a proposal: https://www.space.com/james-webb-space-telescope-observing-t...

Interesting read, thanks.

Re: An extrasolar world covered in water?

#108

Post by somenameforme »

Melatonic wrote: post #92
ryandrake wrote: post #21

Earlier quoted context omitted.

Don't have to go light speed, thanks to relativity. If we could achieve and sustain even 1G acceleration, live humans could make the 100LY trip in approx. 9 years (spaceship time). You could leave, visit the planet, and come back only 18 years older and tell the next-next-next-next-next generation all about it. EDIT: To be fair, 1G over 100LY will result in a maximum speed around 0.9998c so I guess you would have to…

Is this really how time dilation works?

Yip, although there's also length contraction in play. The universe just starts contorting itself to ensure nothing ever exceeds the speed of light.

What the GP post is referring to is called a 'relativistic rocket'. You can find plenty of calculators for them, like here [1]. It leads to really mind-bending scenarios. For instance a single human could easily travel a billion light years within their lifetime, requiring "only" to travel at 1G acceleration for 40 years. Of course in that time a billion years would have really passed outside of our relativistic rocket.

If it ultimately turns out that there is no fundamental law of the universe that makes long-term rates of relatively low acceleration impossible, then the future will be a simply unimaginable place. Time itself will start to lose meaning as it becomes as variable as distance is today, at least for those able to travel.

[1] - https://www.anycalculator.com/starshipcalculator.html

Re: An extrasolar world covered in water?

#110

Post by semi-extrinsic »

koheripbal wrote: post #25
metalliqaz wrote: post #16

Earlier quoted context omitted.

I have thought about this a lot. I have said for a long time that human space exploration doesn't make any sense to me. Space is so hostile to our life in general it seems that only purpose-built machines make any sense for the job. But of course for the preservation of our species, we would want to be able to send the "seeds" of our ecosystem to other places. But then, if we have progressed to that level of technolo…

I think the AI will find little reason to take us with them to the stars.

I don't understand people who say things like this. If we invented AGI tomorrow, how would it achieve domination over us humans?

It is like Voltaire, Rousseau, Locke, Milton, Hobbes, Rawls never even existed and we don't have any sort of coherent understanding of political philosophy and how power is gained and enacted at the consent of the governed.

I also find that discussions of interstellar travel tend to conveniently ignore the fact that a society that develops to the point where this is feasible, must necessarily also have developed to the point of a fully post-growth economy, which leads to fundamental questions of why that society (or parts of it) would seek to undertake interstellar travel at all. It's a boring answer, sure, but many facts of life are quite boring.

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