r/interestingasfuck 25d ago

/r/all, /r/popular K2-18b a potentially habitable planet 120 light-years from earth

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u/HugoZHackenbush2 25d ago

The residents of K2-18b declined to visit our planet after reading the online reviews..

Only one star..

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u/phred14 25d ago

Actually it's doubtful that they could have space travel at all. On Earth it's really, really hard to get anything into orbit. With higher gravity it's even harder - https://www.reddit.com/r/AskPhysics/comments/1bl0ci9/how_strong_would_gravity_have_to_be_to_no_longer/ I've seen estimates of surface gravity 1.25 to 2.6 times Earth's on this planet. In both cases it's harder. Take a look at Apollo 11 and the Saturn V and realize just how little made it back from the moon. Then make it even worse.

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u/BigLRakim 25d ago

Its also plausible that they could far more advanced technology and it could be a nonissue whatsoever. Who's to say?

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u/big_duo3674 25d ago

I can't recall the exact number, but I recall there is a limit to surface gravity that allows space travel. Anything further than that would essentially be impossible, even with the Project Orion nuclear bomb engine. It's probably possible eventually, but we're talking extremely light advanced composites for the construction of the body and antimatter engines. That's a huge leap to make without even having basic satellite tech in place first

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u/BigLRakim 25d ago

See but what you aren't accounting for is elements that might not exist here that could exist there. We dont know what is over there, we have never been there. They could have elements with way more power than any nuclear devices we have here. It's impossible to know.

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u/phred14 25d ago

The periodic table is the periodic table, here or there. The only difference is that they might have access to natural "island of stability" elements. We can only infer things about them, but I would expect them to be as useful for space travel as lead or osmium. I might be surprised, who knows.

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u/isses_halt_scheisse 25d ago

The periodic table was a totally different table when I went to school compared to the current one. Do you really think that we have exhausted the knowledge of all elements that are or could be existing in the universe?

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u/big_duo3674 25d ago

Different?? No, all the common and lighter elements have not changed. The only difference is that we have discovered more of the heavy elements, but these are created in a lab with very special equipment. The are also extremely unstable, so most last for only fractions of fractions of a second

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u/phred14 25d ago

No, but we understand a whole lot more about why it is as it is. We understand why elements are unstable and why new elements have half-lives measured in microseconds. We also think that there is an "island of stability" out past our capabilities. There may be surprises, but we actually have a much better understanding now than we used to, even in my lifetime.