The Astronomy Thread

MusicForFish said:

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Manned Moon landings are much more difficult than LEO or rovers

They may still beat us back to the moon if we don’t get the lander shit sorted out. Long term Starship would be beneficial if the cargo capacity pans out, since it will significantly reduce the costs of setting up a base. Short term though it isn’t clear how much lander work they’ve done since they just seem focused on atmospheric reentry Starship at the moment

Big Phoenix said:

You can still explore and colonize the galaxy without ftl and anti matter propulsion or something equivalent.

It will just a hundred thousand or two years but still very viable. Fusion rocket could get a good sized starship to alpha centauri in 40-50 years. One way trips for anyone going.

Equally big question that is never considered is the long term effects of low gravity on human development. How healthy ia someone conceived and raised in a .5g environment? Might be you need 1g until adulthood so people don't develop into Mr glass.

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Maybe. Let's say you figure out the deep space travel part - reliable craft that can travel for decades or hundreds or thousands of years without a hitch while keeping everyone alive the entire time. At that point question becomes why? You're too far to trade or make things economically viable with our system, so the only logical reason is you just want to colonize your own planet far away from Earth.

So say that is a good enough reason. And let's say you actually find a planet with similar temperature ranges and gravity and atmosphere to Earth. If the planet has life on it, then you run the risk of having a fatal allergic reaction or dying to microbes in short order because you didn't evolve in that environment. At worst nothing is genetically compatible with you and microbes just see you as a warm bag of water they can multiply in while your immune system is helpless because it doesn't know wtf it is dealing with. Planet pollen or spores triggers extreme allergic reactions because again your immune system doesn't know wtf it is dealing with. Or if stuff is genetically compatible, then you run the risk of getting space ebola or whatever. You'd be on a planet with life and still need to survive inside environmental suits and sealed dwellings. Unless you have the technology with you to genetically engineer the next generation to be able to live on the planet no problem as if they were a true native, then that is a long term issue.

And if it doesn't have life, then in theory you have a "clean slate" to work with, but terraforming isn't trivial and you're still living in suits/sealed dwellings.

You really have to look at the "lines" from the book house of suns to get a good idea of the mindset of a traveler. Their lives are all about experiencing cool sunsets and finding amazing things to see and smell and feel. Kind of like the society of sensation from planescape.

When they first started, sunsets and rainbows and huge pretty ring systems around candy coloured gas giants were all they had. But by the time they made a circuit humanity had spread out a bit and gotten more interesting. Circuits take 250 thousand years planetary time, but for the lines only 100 or so at the start.

So eventually you can trade information for good wine or ship upgrades or better ways to pass the years. They eventually find a tech for slowing or speeding up time in a small cabinet. This is way better than cold sleep because it also reduces the forces on the body because of the time difference, so you can accelerate harder or survive impacts with rocks etc.

You still have the problem that even making a circuit, you only see a small handful of worlds. Most of your time is spent in boring transit. So what they do in the books is meet up every circuit and share memories. Eventually after 50 or so circuits you've experienced a good chunk of the galaxy.

Void said:

On top of that, unless you have perfected cryo sleep or suspended animation, you're essentially condemning generations to a life of nothing but the ship. They'll see and hear about all these cool things people that grew up on planets got to experience, but never know them. Assuming they don't eventually revolt and turn the ship around, the intermediate generations might even adopt a "who cares?" attitude because only the landing generation needs to actually know stuff besides maintaining the ship (and at that point it is likely an AI can do most of that anyway). If you're generations 3-8 of a 10+ generation trip, for example, it is going to be sort of difficult for those people to give a shit. More than likely you'll find everyone turning towards a hedonistic lifestyle because they know they are just going to die in deep space, and they may even stop having kids because why condemn your kids to that too?

Obviously there are ways to somewhat counter some of that, but it wouldn't take much to get everyone to stop giving a shit. Let's just use up all the alcohol and fuck ourselves blind (with birth control) until we die out. They literally have nothing to live for except the promise of their future generations, but just because the initial people you send have the conviction to see it through doesn't mean their grandkids do.

So yeah, without suspended animation or AI gestating embryos or something, I don't see generation ships working at all. And that's skipping all the other hurdles once you get there, like Cybsled talked about.

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Meh, how is this really any different than current people living on the current ship (earth) traveling through space? Life is what you make it. Humans adapt to their situation and their outlook depends on how they are indoctrinated & educated.

As for stories about what living on a planet was like, people opine about some fictitious golden age of past human existence all the time. White America during the 50s seems to be popular around here. If you didn't live through it, you don't really know what your missing.

Any ship capable of being a generational ship is going to need to be HUGE, similar to how they depicted the generational ship on The Expanse (plus possibly encased in some form of very thick rock shield). So it's not like they are all going to be stuck on some "tiny" aircraft carrier eating shoe leather and drinking sea water.