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Water found on a potentially life-friendly alien planet

nationalgeographic.com

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Re: Water found on a potentially life-friendly alien planet

#81

Post by caseymarquis »

amelius wrote: post #65
ajconway wrote: post #18

Earlier quoted context omitted.

Theoretically, you can. At 0.99c 111 light years take about 15 years of ship time to travel.

And how much time will it take a person to reach that speed at human-safe acceleration? And how much energy would it take?

Just under a year at 1g (according to google. I'm on mobile and would have to derive from F = ma on paper to solve). Energy is variable. I'd assume energy isn't relevant, as it's currently impossible, so we're taking that for granted.

Not really that long.

Re: Water found on a potentially life-friendly alien planet

#83

Post by [deleted] »

gist wrote: post #19
Miner49er wrote: post #12

Earlier quoted context omitted.

Well, I suppose I'm using a bit of hyperbole. Maybe I should say sad. And don't worry, I won't think about it very long.

Why is it sad at all? What would it do for you? It would be about as relevant as being able to communicate in some way with people in the past. Would be interesting and entertaining but a leap to imagine it would yield some kind of better quality of life in the current day.

[deleted]

Re: Water found on a potentially life-friendly alien planet

#84

Post by [deleted] »

enraged_camel wrote: post #32
gist wrote: post #19

Earlier quoted context omitted.

Why is it sad at all? What would it do for you? It would be about as relevant as being able to communicate in some way with people in the past. Would be interesting and entertaining but a leap to imagine it would yield some kind of better quality of life in the current day.

>>Why is it sad at all? What would it do for you? Some of us refuse to allow this kind of constant cynicism and pessimism that surrounds us to crush our sense of awe and wonder.

[deleted]

Re: Water found on a potentially life-friendly alien planet

#85

Post by scrumbledober »

yellowapple wrote: post #35
transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

I wonder if we could work around the stronger gravity by using a spaceship as the anchor for a space elevator or skyhook? Both of those technologies are pretty far off, but so is getting humans to another star system.

currently we have no known materials that would actually be strong enough to support their own weight at the length of a space elevator on earth. double the gravity and the length will also at least double (possibly quadruple? not sure on the math here) so it may also be impossible to build a space elevator on one of these planets, at least without the use of active suspension (possible? theoretically.)

Re: Water found on a potentially life-friendly alien planet

#86

Post by scrumbledober »

fooker wrote: post #74
typeformer wrote: post #25

I say let's go. Now, whether you believe it or not, it is a fact that the US government has acquired alien technology and yet continues to keep it hidden by being stuck in a cold war mindset of, "well, we can't let the Chinese or Russians get their hands on this". That is the ultimate expression of narrow thinking, especially when there is a whole universe out there! Bring on the downvotes but history will vindicate…

Evidence?

clearly it's all being hidden in area 51...

Re: Water found on a potentially life-friendly alien planet

#87

Post by partiallypro »

archgoon wrote: post #4
transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

It's 111 light years away. For all intents and purposes, that's a one way trip right there; irregardless of the rocket equation. Even at relativistic speeds, you can't come home anymore.

But that's assuming you're traveling at the speed of light, right? In reality it would take much much longer than 111 years.

Re: Water found on a potentially life-friendly alien planet

#88

Post by gcthomas »

TheOtherHobbes wrote: post #27
transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

Surface gravity will be around 2g, so even if it has a rocky surface it's not going to be a very comfortable home from home.

Given the published figures for size and mass, it will be closer to 1.5 - 1.6 g. Still tricksy to walk for unmodified people, but not impossible, especially given how long it will take to reach it. Plenty of time to work out how to change people.

Re: Water found on a potentially life-friendly alien planet

#89

Post by partiallypro »

sky_rw wrote: post #76
dsfyu404ed wrote: post #59

Earlier quoted context omitted.

So a 150lb person will weigh 300lb. Sure that's gonna suck on day one but there's plenty of people who weigh that much who get by. Without all the health complications from high body fat it wouldn't be that bad. You'd probably die young but I don't think that would bother people.

Not sure the two are comparable. 300lb obese person's bone structure weighs the same, their heart and lungs weigh the same. I suspect 2x the weight on every organ is going to be seriously detrimental for sustained periods.

Not to mention you'd go from years and years of near 0G gravity to twice the gravity of earth. You wouldn't even be able to walk.

Re: Water found on a potentially life-friendly alien planet

#90

Post by gcthomas »

hinkley wrote: post #60
jerf wrote: post #48

Earlier quoted context omitted.

"At some point your planet is massive enough that you can't get into orbit with chemical rockets (even, I think, by flying them up like Burt Rutan?)." Nuclear rockets don't seem to be very hard. They're somewhat dangerous if they explode, but they aren't very hard. Fairly solid prototypes were built decades ago and there's little to suggest they couldn't have been made production-grade [1]. We'd have them now if we d…

Do solids settle out of air on a high gravity environment faster? The air would be thicker. Does gravity or buoyancy win than tug of war? I spent a day once trying to figure out what the Bronze Age would be like for marine creatures. Oxidation is less of a problem but galvanic action is huge. Fire pretty much doesn't work, which blocks a whole bunch of precursors like ceramics.

Atmospheric density it a little more complicated: Venus has the same gravity as Earth but a thicker atmosphere, while Titan is a lot smaller and still has a surface pressure 50% more than we do at sea level.
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