An extrasolar world covered in water? • Hacker News Board

Re: An extrasolar world covered in water?

#121

Post by ant6n » Thu, Sep 01, 2022, 9:01 PM UTC

ryandrake wrote: post #21

prox wrote: post #15

Earlier quoted context omitted.

We can’t do lightspeed with the best tech available, so it’s more like 300-400 years probably.

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…

At those speeds you will have problems with the rocket equation even if you have an mass-to-energy drive.

Re: An extrasolar world covered in water?

#122

Post by gus_massa » Thu, Sep 01, 2022, 9:09 PM UTC

klyrs wrote: post #116

This is both exciting and somewhat disappointing. It sounds like the water is so deep that it's probably solid ice (due to the intense pressure) before you get to a rocky core. Life on earth needs nutrients extracted from the rocks. If life formed on this planet, any non-buoyant corpse would sink to the bottom and disappear forever. That is to say, it would almost certainly die out very quickly from lack of nutrition…

A lot of minerals dissolve in water. Without oxygen in the air (like here, before those nasty cyanobacteria released a lot of oxygen) you can get also iron salts disolved in the oceans. https://en.wikipedia.org/wiki/Great_Oxidation_Event#Geologic...

Also, if there are volcanos, they will create plumes dirty of hot water with a lot of disolved things. Something like https://en.wikipedia.org/wiki/Hydrothermal_vent

And you may even have some floating islands made of pumice https://en.wikipedia.org/wiki/Pumice_raft

Re: An extrasolar world covered in water?

#123

Post by raattgift » Thu, Sep 01, 2022, 9:45 PM UTC

ornornor wrote: post #107

criddell wrote: post #93

Earlier quoted context omitted.

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

Interesting read, thanks.

To give you an idea, Hubble Space Telescope observation proposals look like this https://www.stsci.edu/hst/phase2-public/16642.pdf> and https://www.stsci.edu/hst/phase2-public/16701.pdf> (chosen because these two are what the HST has been doing in the couple of hours before I typed this). The ABSTRACT sections are probably the parts most of interest to you.

PS: https://spacetelescopelive.org/latest> might also be of interest over time, as that will eventually report what Webb is looking at.

Re: An extrasolar world covered in water?

#124

Post by ProjectArcturis » Thu, Sep 01, 2022, 9:45 PM UTC

klyrs wrote: post #116

This is both exciting and somewhat disappointing. It sounds like the water is so deep that it's probably solid ice (due to the intense pressure) before you get to a rocky core. Life on earth needs nutrients extracted from the rocks. If life formed on this planet, any non-buoyant corpse would sink to the bottom and disappear forever. That is to say, it would almost certainly die out very quickly from lack of nutrition…

You might have tiny pockets of life around undersea volcanic vents.

Re: An extrasolar world covered in water?

#125

Post by neurobashing » Thu, Sep 01, 2022, 9:56 PM UTC

If we're collecting scifi references to water planets, "Neptune's Brood" by Charlie Stross features a very large water world, and the problems of certain minerals (like uranium) dissolved in the oceans. Also the fun things that happens to ice under extreme pressure.

Re: An extrasolar world covered in water?

#126

Post by melony » Thu, Sep 01, 2022, 10:10 PM UTC

neurobashing wrote: post #125

If we're collecting scifi references to water planets, "Neptune's Brood" by Charlie Stross features a very large water world, and the problems of certain minerals (like uranium) dissolved in the oceans. Also the fun things that happens to ice under extreme pressure.

I am surprised more cryptocurrency people do not read Stross. His books feature many speculative examples of crypto backed transactions.

Long live robo kitty!

Re: An extrasolar world covered in water?

#127

Post by bergenty » Thu, Sep 01, 2022, 10:25 PM UTC

scohesc wrote: post #10

nekoashide wrote: post #9

Earlier quoted context omitted.

Programming machines to make the trip and then seeding with human life seems to be the best answer to distance.

That would be so interesting - could be many a sci-fi stories created on that premise. Some mechanical robot/starship storing frozen embryos for 100 years to be released on a far-away exoplanet, the starship taking care of them while they grow up and learn how to live on this new world - the beginnings of a new civilization - a technological adam and eve of sorts.

We’ll never get governments to approve and fund this. Elon/Bill if you’re reading this you have to do this going rogue. Make it happen. Send human life out to a hundred different planets!

Re: An extrasolar world covered in water?

#128

Post by bergenty » Thu, Sep 01, 2022, 10:28 PM UTC

hoosieree wrote: post #51

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…

Mo' acceleration, mo' trolley problems. Go on vacation; come back; everyone's dead.

Alright, alright, alright.

Re: An extrasolar world covered in water?

#129

Post by ianmcgowan » Thu, Sep 01, 2022, 10:39 PM UTC

bpodgursky wrote: post #44

koheripbal wrote: post #24

Earlier quoted context omitted.

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

Kind of a fun hybrid where AI is clearly dominant in an established solar system, but it ends up being impossible to miniaturize the enormous supply chain necessary to fabricate microprocessors, so to colonize a new solar system it actually ends up being necessary to send self-replicating carbon-based humans who will then bootstrap the industrial supply chain necessary for AGI. (repeat ad infinitum for the rest of th…

I'd buy that book!

Re: An extrasolar world covered in water?

#130

Post by sliken » Thu, Sep 01, 2022, 10:49 PM UTC

ryandrake wrote: post #21

prox wrote: post #15

Earlier quoted context omitted.

We can’t do lightspeed with the best tech available, so it’s more like 300-400 years probably.

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…

True, but we can only manage 1G for minutes, and even hours is a pretty far off.

Without exotic tech like anti-matter or bending space time nothing is particularly close to light speed. Even city size laser arrays are targeting 1-3% of light speed .... for a few grams!

It's a mind boggling amount of energy to get any decent fraction of the speed of light, even without the relativistic increases in mass.