Lmao

Comments

• Thorry@feddit.org ⁨23⁩ ⁨minutes⁩ ago

  The interesting thing about this is that it could be a double whammy. The collision that formed the Moon not only made Earth smaller, it also ejected a lot of material away from the orbit. This made Earth even smaller than it would otherwise have been, had the two bodies merged. And the Moon also took up some of that mass. The Moon also causes the tides which are theorized to have a significant beneficial effect on evolving more complex forms of life.

  So just being small might not be enough and having a big moon might also not be enough, but Earth was lucky enough to have both. And that’s just some of the things in a long list of things that have to go right to get complex life on a planet.

  My feeling is that life is pretty rare, but given there are so many star systems in our galaxy there might be a lot of it still. But most of it is probably very simple stuff. Getting to where Earth is, might be a once every couple of millions of years event within our entire galaxy. So there really might be nothing intelligent out there at this moment in time, there might have been earlier and there might be in the future, but for right now we are it.

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  • MadMadBunny@lemmy.ca ⁨4⁩ ⁨minutes⁩ ago

    Yup, I wonder sometimes, all those sci-fi tales about a long lost ancient civilisation that spread throughout the galaxy before everyone else did, what if we’re set to become that, before space-faring life eventually emerges, then thrives and flourishes all over the galaxy?

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• sp3ctr4l@lemmy.dbzer0.com ⁨1⁩ ⁨hour⁩ ago

  Imagine a terrestrial planet that is Earthlike in all respects, but it simply has more persistent cloud cover, such that seeing an open cloudless sky is miraculously unlikely, as unlikely as humans seeing an asteroid impact.

  No ground based astronomy.

  No technological discoveries or culture that derives from ground based astronomy.

  No celestial navigation on the ground.

  Very different / stunted / more difficult cartography.

  Technological civilization is capable of emerging, but it would not be able to well understand anything beyond the terra firma, not untill it generated aircraft capable of breaching the cloud cover layer, and thrmen developed airborne observatories.

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  • Drekaridill@lemmy.wtf ⁨1⁩ ⁨hour⁩ ago

    Have you read Hitchhiker’s Guide to the Galaxy?

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    • JoeBigelow@lemmy.ca ⁨1⁩ ⁨hour⁩ ago

      Yea but they were playing cricket with the Galaxy

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    • sp3ctr4l@lemmy.dbzer0.com ⁨50⁩ ⁨minutes⁩ ago

      Hah, actually no I have not.

      -1 nerd point lol

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  • IAmNorRealTakeYourMeds@lemmy.world ⁨1⁩ ⁨hour⁩ ago

    I wrote and tried publishing a short story about a species like that.

    where only occasionally people on top of mountains see stars, and they chuck it as a consequence of low pressure. eventually they invented flight, and assume pilots going high enough to see stars are having cognitive issues due to lack of air.

    They asked pilots to draw the stars they see, and they get different drawings (they sent pilots at different times of the year because they couldn’t ever expect stars to shift) and assume its proof that thise stars are a cognitive artifact.

    Eventually a pilot swears they are real and can actually use then to navigate, skepticism, he proves it. brand new research field emerges.

    Although the story focuses more on deep DEEP time an omniengineering. (A term I just made up because mega engineering is a concept way too small compared to the one in the story).

    If you want I don’t mind putting that story in the conversation.

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    • DanVctr@sh.itjust.works ⁨1⁩ ⁨hour⁩ ago

      Post it for sure

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    • sp3ctr4l@lemmy.dbzer0.com ⁨48⁩ ⁨minutes⁩ ago

      Shit yeah go for it, I love those kinds of stories!

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    • JoeBigelow@lemmy.ca ⁨1⁩ ⁨hour⁩ ago

      I’d read it

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    • clay_pidgin@sh.itjust.works ⁨55⁩ ⁨minutes⁩ ago

      Heck yeah, I’d read that.

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  • Whirling_Ashandarei@lemmy.world ⁨58⁩ ⁨minutes⁩ ago

    Project Hail Mary has a bit about this, don’t want to say more to keep it spoiler free.

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    • sp3ctr4l@lemmy.dbzer0.com ⁨49⁩ ⁨minutes⁩ ago

      Haven’t seen it yet, I appreciate the nonspoiling =D

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• riskable@programming.dev ⁨2⁩ ⁨hours⁩ ago

  Jokes on us: Because of the gravity issue, alien life on such planets jumps right to stargate technology.

  “They spent almost a thousand years fooling around with rockets!”

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  • thenextguy@lemmy.world ⁨1⁩ ⁨hour⁩ ago

    Uhh, one stargate doesn’t go anywhere.

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    • Whelks_chance@lemmy.world ⁨1⁩ ⁨hour⁩ ago

      You can accelerate it into space at g forces which would liquify living beings, perhaps?

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• turdas@suppo.fi ⁨4⁩ ⁨hours⁩ ago

  According to Wikipedia this planet has an estimated surface gravity of 12.43 m/s^2 with a margin of error of about 2 m/s^2. That’s only up to 50% higher than Earth’s 9.8 m/s^2 (on the high end of the error margin) so it probably would be possible to get into orbit.

  That said we don’t actually know much about it for sure. We don’t know if it’s a terrestrial planet for example. It could be composed mostly of gases and liquids like Neptune.

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  • gami@piefed.social ⁨2⁩ ⁨hours⁩ ago

    (Not a rocket scientist or mathematician, but I spent 100s of hours playing KSP RP-1)

    Just doing some estimates using data from the wikipedia page:

    The dV (delta-V) needed to get into low Earth orbit is around 9.4km/s.
    The dV for K2-18b might be around 19km/s, more than double that of Earth’s.

    It’s practically impossible I think, you would need such a massive launch vehicle. For double the dV, you would need exponentially more fuel assuming current rocketry tech (fuel+oxidizer tanks and engines). There wouldn’t be any single-stage or two-stage rockets that could do this. With a 3 or 4 stage rocket maybe? But you would be sending nearly 100% fuel off the launchpad with virtually zero payload.

    I tried to factor in:

    spoiler

    • Atmospheric drag - K2-18b’s atmosphere is quite dense with a huge radius:

    The density of K2-18b is about 2.67+0.52/−0.47 g/cm3—intermediate between that of Earth and Neptune—implying that the planet has a hydrogen-rich envelope. […] Atmosphere makes up at most 6.2% of the planet’s mass

    • Since the atmosphere is so thick and takes up a lot of mass, I’ve picked 500km as the low orbit altitude (comparing to Earth’s ~100km Karman line, it makes you appreciate how thin our atmosphere is ).

    • Rotational assist - I’m assuming it’s tidally locked since it orbits so closely to its star (33 day years), and so you wouldn’t get the assist from rotation like you do on Earth:

    The planet is most likely tidally locked to the star, although considering its orbital eccentricity, a spin-orbit resonance like Mercury is also possible.

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    • matsdis@piefed.social ⁨42⁩ ⁨minutes⁩ ago

      Check out the “tyranny of the rocket equation”.

      Or ask Randall Munroe How many model rocket engines would it take to launch a real rocket into space?

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    • ColeSloth@discuss.tchncs.de ⁨1⁩ ⁨hour⁩ ago

      Build a large enough magnetic rail launcher and you could save shit tons of fuel. Get a ship doing 2000 mph before it leaves the ground and needs its rockets and you’ll have a pretty good head start.

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  • sylveon@piefed.blahaj.zone ⁨3⁩ ⁨hours⁩ ago

    It’s probably still a lot harder though. You’re not just heavier, but also slower which means you’ll spend more time fighting gravity. And all the extra fuel you bring for that makes the rocket heavier which means you need even more fuel to launch the fuel. Higher surface gravity likely means a thicker atmosphere too which is a big issue and a more massive body also has a faster orbital velocity. Although in this case the larger diameter might counteract that a bit because higher orbits have slower velocities.

    My point is that this would probably still be a lot harder than just building a 50% bigger rocket. If you’ve ever tried launching from Eve in Kerbal Space Program you know the pain. Although in that case you also have to fly the entire rocket there first which is its own challenge.

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    • crank0271@lemmy.world ⁨2⁩ ⁨hours⁩ ago

      you’ll spend more time fighting gravity

      Aw man. This is already a significant portion of my day.

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  • Speculater@lemmy.world ⁨2⁩ ⁨hours⁩ ago

    It would actually be impossible for them to get to orbit using chemical rocketry, like we use. The could theoretically do it with nukes.

    Chemical rocketry limits

    Nuking your way to orbit

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  • expr@piefed.social ⁨3⁩ ⁨hours⁩ ago

    I assume it’s not just about the gravity, but also the much larger radius of the planet would mean much larger distance from the surface, and thus much more fuel needed.

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    • potatopotato@sh.itjust.works ⁨3⁩ ⁨hours⁩ ago

      That’s how how…what???

      F = G * (m1 * m2) / r^2

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    • turdas@suppo.fi ⁨3⁩ ⁨hours⁩ ago

      That’s, uh, not really how that works. A taller atmosphere would mean you have to go through more of it, but unless it’s not a terrestrial then the atmosphere won’t be that much taller.

      If it is a non-terrestrial planet, it’s unlikely anyone would be building rockets on there to begin with.

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    • degenerate_neutron_matter@fedia.io ⁨3⁩ ⁨hours⁩ ago

      You're sort of right. The change in distance from the surface is insignificant, but a spacecraft orbiting a bigger planet has to travel further with each orbit so its speed must be faster to avoid falling out of orbit, even if the gravitational acceleration at its orbital height is the same.

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  • cogitase@lemmy.dbzer0.com ⁨3⁩ ⁨hours⁩ ago

    I’ve been wondering what a hypothetical perfect habitable planet for spacefaring would look like. Could you have one where a plane line the SR-71 Blackbird or an even less capable aircraft could simply “fly” into orbit? Or what about something Earth-like but with a flat plateau at 15,000 m where you could launch rockets from?

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    • turdas@suppo.fi ⁨3⁩ ⁨hours⁩ ago

      I think Mars, assuming you terraform it, would be pretty close to that on both counts. Space planes might still be difficult, but the delta V is much lower and Olympus Mons would pretty much sit above the atmosphere.

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  • suodrazah@lemmy.world ⁨3⁩ ⁨hours⁩ ago

    Orbital speeds would be very hard to reach compared to low Earth orbits.

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  • JasonDJ@lemmy.zip ⁨3⁩ ⁨hours⁩ ago

    Or Uranus.

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    • AugustWest@lemmy.world ⁨2⁩ ⁨hours⁩ ago

      Or your mother’s.

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• Calfpupa@lemmy.ml ⁨1⁩ ⁨hour⁩ ago

  No rockets maybe, but what about a space elevator?

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  • LaLuzDelSol@lemmy.world ⁨1⁩ ⁨hour⁩ ago

    Those would be harder too though. Right now we humans don’t have a material strong enough and the higher the gravity the stronger the material you would need.

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  • pennomi@lemmy.world ⁨48⁩ ⁨minutes⁩ ago

    I mean, that’s probably what’s keeping US down. The aliens out there are probably from worlds with low enough gravity to make a proper space elevator. And they never come to visit us because our world is just too damn big, you’d need some kind of controlled explosion to get back up from a gravity well that deep.

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• Duke_Nukem_1990@feddit.org ⁨1⁩ ⁨hour⁩ ago

  Maybe it was “”“too easy”“” for us to get to space so that chemical propulsion was good enough. Who knows where we would be if that wasn’t the case.

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  • HeyThisIsntTheYMCA@lemmy.world ⁨1⁩ ⁨hour⁩ ago

    i’ll tell you where. we’d be eating empanadas and drinking coffee at the good cuban place that bought the yellow shack restaurant that i’ve been trying to buy for 20 years.

    damn good empanadas.

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• StillAlive@piefed.world ⁨4⁩ ⁨hours⁩ ago

  I assume the amount of energy required for ’only’ 50% more is massive.

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  • turdas@suppo.fi ⁨3⁩ ⁨hours⁩ ago

    Apparently with 50% higher gravity it would be pretty much impossible with chemical rockets, but with the median of the estimate (so about 12.43 m/s^2^) it would be possible, you’d just need an incredibly large rocket, or non-chemical propulsion (e.g. nuclear).

    A space program on that planet would definitely advance much slower than on Earth.

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    • meco03211@lemmy.world ⁨3⁩ ⁨hours⁩ ago

      How well funded have our space programs been? Maybe they aren’t diverting massive portions of their resources to war and can actually focus on space.

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  • Jokulhlaups@lemmy.world ⁨3⁩ ⁨hours⁩ ago

    Also i wonder since the diameter is larger, is this effectively like putting everything in a higher orbit which is also more difficult then if it was just twice as dense.

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    • hemko@lemmy.dbzer0.com ⁨3⁩ ⁨hours⁩ ago

      That really depends on the atmosphere. The lower the orbit the easier, but if you have too much drag from the atmosphere, you ain’t staying on that orbit easily

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• mvirts@lemmy.world ⁨1⁩ ⁨hour⁩ ago

  That’s what the martians said about Earth

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• CIA_chatbot@lemmy.world ⁨2⁩ ⁨hours⁩ ago

  A while back I read an article that stated earth was about as high G as you could get and still be able to get to orbit with chemical rockets (barring huge leaps in tech). I could be remembering that badly though, so take it with a grain of salt

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• SharkAttak@kbin.melroy.org ⁨4⁩ ⁨hours⁩ ago

  Getting to orbit? I don't know if they can even stand up 😆

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  • chgxvjh@hexbear.net ⁨3⁩ ⁨hours⁩ ago

    Already a struggle at 1g sometimes catgirl-flop

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  • OpenStars@piefed.social ⁨3⁩ ⁨hours⁩ ago

    What does not kill them makes them stronger? 😎

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    • generallynonsensical@lemmy.world ⁨3⁩ ⁨hours⁩ ago

      John Carter of Mars? That you?

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• degenerate_neutron_matter@fedia.io ⁨2⁩ ⁨hours⁩ ago

  It might take them a few more centuries than us to develop the tech, but just because we use chemical engines doesn't mean it's the only viable method. I'm sure they'd figure something out eventually.

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• Spacehooks@reddthat.com ⁨3⁩ ⁨hours⁩ ago

  Now try escaping birch world.

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• SsxChaos@lemmy.ml ⁨3⁩ ⁨hours⁩ ago

  You call Kepler I call it heaven, because if you think of it heaven is either fictional or a real existing place and I chose that planet as my impossible to reach place.

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  • sp3ctr4l@lemmy.dbzer0.com ⁨1⁩ ⁨hour⁩ ago

    Ask your nearest Mormon about Kolob.

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