Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[LordBaal]

Ah I see. Well what if their biology allows for sleeper ships? Anyway, for us? We must spread life as we know it, because that's the only one we are sure exists. And we should do it aggressively as long we don't find any other life, once we get to that point we'll should see, is it's just microscopic life then cataloguing, backing up and then colonizing if suitable/possible should be the way. Planets/moons with multicellular life should be treated different perhaps. Anyway there is little hope of ruling the existence of microbial life on a planet entirely. We could colonize Mars and find out years later microbes living kilometers deep or even caverns filled with multicellular life subsisting on gas bags or whatever (highly unlikely and speculative).

All these shouldn't be reasons to stop colonizing. Right now we, as mankind, should be focusing on permanent scientific outposts in the moon to test out all kind of technologies (from propulsion to habitats), if there's anything economically viable from the moon then a industrial enterprises could get there, then Mars, orbitals and so on (not necessarily in that order).

We could get to that assholey Deponia or Elisyum style were the rich live in perfectly designed habitats while the poor toil in their mines bellow in a barely terraformed planet (if at all). Either living on the station cheaper places and making regular trips of duty or simply living in basic shelters on the surface, whatever is cheaper.

[Max™]

Mining and lifting material out of a gravity well when there is a whole pile of orbiting rocks floating around past Mars is never going to be cheaper.

Gravity wells are terrible uses of material, but people don't do a good job of thinking about shit thirty years from now and the failure mode of a planet like this one is survivable.

Get yourself uploaded into a vacuum capable body and space is great.

[LordBaal]

Mining and lifting material out of a gravity well when there is a whole pile of orbiting rocks floating around past Mars is never going to be cheaper.

Gravity wells are terrible uses of material, but people don't do a good job of thinking about shit thirty years from now and the failure mode of a planet like this one is survivable.

Get yourself uploaded into a vacuum capable body and space is great.

With space elevators in places like Mars and the moon the economics could work out, way cheaper than transporting a huge rock that hurls in space at God know which relative speeds and vectors. As long the resources are there of course. I think right now, or in the feasible future is more realistic to build an space elevator on Mars and mine whatever we can there than to move/mine asteroids from the belt.

[KittyTac]

I don't think sentience should be the cutoff. There's just too much to learn from studying bona-fide alien life.

Also, just a minor point of terminology, they wouldn't be bacteria, per se. Microbes yes, but bacteria are a specific kind of microbe.

There's nothing wrong according to you and me, we should strive for it. However if some of us, from the same planet, same species and heck, same hemisphere disagree over it, imagine the wildcard it would be another completely different train of thought. They could come "in peace", or "in war", or in "I don't really care but you are in my way", or "ughh look at those gross things, squash them before they get out!", or "Non electronic lifeforms found, hence no life forms present at all, begin converting all mass into more replicants"....

On the other hand terraforming could be attractive if you can get to the point it sustains itself for as long as you want/need (thousands or millions of years) as I.E. no one has to make sure Earth AC keeps running or the sewage pumps don't burn out. Of course that kind of tech and energy required would mean you probably have the means to make huge space habitats too.

But what if their religion prohibits such habitats? Or they see a low hanging fruit as xenoforming this planet won't be that hard and it will be suitable to harbor billions of our kind in just X amount of time?

I think there's some confusion here: I'm not talking about hypothetical sentient aliens, I'm talking about us and how we might live in space. Though it should be noted that sustainable habitats are an absolute must for any species wishing to cross interstellar distances. If their religion prohibits them, then they're not going to be able to make the trip in the first place.

This is why I said we should study it, then consign the non-sentients to a habitat. Sentient life should have equal rights to humans, though. Non-sentients should only have rights if they do not get in the way.

[Dorsidwarf]

With space elevators in places like Mars and the moon the economics could work out, way cheaper than transporting a huge rock that hurls in space at God know which relative speeds and vectors. As long the resources are there of course. I think right now, or in the feasible future is more realistic to build an space elevator on Mars and mine whatever we can there than to move/mine asteroids from the belt.

I'd just like to point out that assuming the often-floated figure of $100 per pound of material moved into orbit with a space elevator, moving the mass of a single 2km diameter asteroid into space would cost in the region of $800,000,000,000,000 if my math is correct. This would be less on Mars because Mars has a lesser gravity well, but the point is that space elevators only make transporting material into space cheap compared to every other method of doing so.

[Madman198237]

I more often see the figure 1$ per pound. 100$ per pound is just about a 1/10 of what it costs now, IIRC. With a space elevation supposedly you can reduce that by a factor of a thousand.

[Trekkin]

I more often see the figure 1$ per pound. 100$ per pound is just about a 1/10 of what it costs now, IIRC. With a space elevation supposedly you can reduce that by a factor of a thousand.

I more often see the figure 100 GPa. I'm curious what manner of nanotubes people are blithely handwaving in as a cable material these days, because none of them actually work at those scales.

[LordBaal]

On Mars or Luna it would be feasible with current materials. I don't feel like making math because only sleep one hour but fuel and machinery costs to move asteroids into secure orbits around anything you feel like would be massive too, mining in site requires constant transportation which could be an easier solution? Still you need to place industrial complexes. Whatever choice you make it's bound to be between expensive and fucking astronomical.

However if we apply current economics and technological capabilities I'm sure we could come up with the cheapest way. Of course this is taking for granted there's anything worth to lift off from Luna and Mars to justify a space elevator.

I had an idea for a novel were future generations outright ban heavy mining and industry on Earth and all polluting and heavy industry are moved to orbitals, the moon, mars, and this eventually create tensions and whatnot. This concept has been done to death however.

Fakedit: I got the appointment last night at 5:00 am here!

[redwallzyl]

So forgive me if this is already common knowledge but wouldn't a space elevator work with way less expense if it operated as a counterweight system? You bring stuff up and bring a equal amount down.

[Madman198237]

Correction: Carbon nanotubes are strong enough if we can extrude them in long enough lengths, but atomic-scale defects can ruin the integrity of such a cable. We do NOT need anything "exotic" or anything not using regular old atomic bonds that we know of.

[Trekkin]

So forgive me if this is already common knowledge but wouldn't a space elevator work with way less expense if it operated as a counterweight system? You bring stuff up and bring a equal amount down.

If you want to use a counterweight, you need to move the cable -- or at least a cable (and then we have to worry about how to couple the lift cables to the support cables.) That means the cable cannot taper, which vastly increases the cable mass that must be maintained. You also need a station in the middle of the cable to switch from one counterweight to the other, since both ends of the elevator are pulled away from the middle, so now there's more mass and more hassle with vibrations up and down the cable.

EDIT:

Carbon nanotubes are strong enough if we can extrude them in long enough lengths,

If anyone's curious, "long enough lengths" are, at minimum, about two billion times longer than the longest nanotube ever fabricated.

[Reelya]

We must spread life as we know it, because that's the only one we are sure exists. And we should do it aggressively as long we don't find any other life

Must we? Sure, it seems like a good idea from our perspective, but we can't just assume that's some objectively true universal good. Also, if the universe is doomed to some sort of death anyway, it's ultimately a futile gesture, like prolonging palliative care as long as possible.

The planet Earth can support maybe 10-20 billion humans if we really tried. Sure, we could have "more people" if we live in space, but what's ultimately the point of having more people at once? The more rapidly we expand, the more resources we consume, and the less efficiently we do so.

Pretty much whatever changes we make will increase entropy, and thus speed up the heat death of the universe, reducing the total carrying capacity of the universe (across it's lifespan) for sentience. In terms of added entropy, seeding life on other planets and waiting for sentience to arrive is inefficient, but also playing God in a cruel way. You have to own all the suffering you're going to create along with the joy.

However, we might in the future be able to model sentience, and we could do that in a way that minimizes the rise in entropy per "unit" of sentience (however it could be measured), and also doesn't create inadvertent suffering. Seeding a few suitable planets here and there with life might make sense in a "nature reserve" sort of way, but it's not the main game. The longterm main game is space-based computational arrays that draw energy straight from sunlight.

[Starver]

If you want to use a counterweight, you need to move the cable -- or at least a cable (and then we have to worry about how to couple the lift cables to the support cables.) That means the cable cannot taper, which vastly increases the cable mass that must be maintained.

An energy only counterweight (work-recovery on descenders used to at least partly boost the energy input taken to move the risers - need not even be at the same time if there's a method of storage and discharge) would be not much more of a complication from a 100% 'fed externally' system. Given everything else.

You also need a station in the middle of the cable to switch from one counterweight to the other, since both ends of the elevator are pulled away from the middle, so now there's more mass and more hassle with vibrations up and down the cable.

Any cable not missing the opportunity (and/or constructive necessity) to have a geostationary station in the 'middle', from which both ends (the long length of cable to Earth and the probably shorter length of cable tied to sufficient counterweight to keep things just taught enough and act as an 'outflinging' station, for fuel-saving interpkanetary launches out of a trapdoor) dangle is going to be set up for roping-counterweights exactly as you say (up from/down to Earth, down out/up in from orbit), regardless of whether it actually does.

[WillowLuman]

Mining and lifting material out of a gravity well when there is a whole pile of orbiting rocks floating around past Mars is never going to be cheaper.

Well, mining mars is cheaper if the material you mine is going to be used on mars. In-situ resource use will always be cheaper than importing from another body.

Likewise, asteroid mining would best be used in space rather than pulling down into a gravity well.

[KittyTac]

Re: Expanding our population

There is no need to. Labor can be done by robots, which don't require much living space. Scientific research could be done by augmented humans collaborating with intelligent AIs. There is no practical need to expand our population on Earth. Other planets? Maybe. But not Earth.