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There’s no planet B

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Re: There’s no planet B

#91

Post by mac01021 »

charles_f wrote: post #83
mabbo wrote: post #32

Let's set aside the part that making a planet where we could live is hard. Just presume we did that, to start. Let's talk Logistics . Presume there are only 1 billion people left on Earth when we decide it's time to go. How do you get them there ? The gravity well holding us here (and holding the air down so we can breath it) is pretty darn strong. Today we're hoping to get cost-to-orbit down to around $100/kg. I wei…

> Presume there are only 1 billion people left on Earth when we decide it's time to go The scenario that leads to have only 1B left from where we're at would entail such a catastrophic meltdown of society that even building a rocket would likely not be feasible, let alone anything significant for a human exode. Think about it, you're fighting against something that killed 7B people, be it the end of fossil fuels, cli…

The GP was just setting a lower bound of 1B to establish a basis for calculating the cost to move humanity offworld. The cost for 5B people or 7B people would be even more cost prohibitive.

But also the shrinkage would not have to happen abruptly. In theory you might be able to get to a population of 1B over the course of 200 years without the kind of catastrophic meltdown you're describing.

Re: There’s no planet B

#92

Post by Consultant32452 »

paulryanrogers wrote: post #51
roryisok wrote: post #41

Earlier quoted context omitted.

The idea of finding another Earth is not so much about moving everyone from Earth to somewhere else, but rather about "backing up" our species and civilisation in additional places. If an asteroid is going to wipe out Earth, we can't evacuate 8 billion people, or even 8 million people. but if we had a few generations of colonists in domes on Mars, or floating in the clouds on Venus, or somewhere else, the species its…

> But we're crazy to keep all of our existential eggs in a single basket and hope it all works out. While the cost to colonize elsewhere is "mine the earth to a wasteland" it does make sense to preserve the basket we have. At least until we can afford to buy another basket without ruining the original.

The Earth is a giant ball of resources and we have only just begun to scratch the surface.

Re: There’s no planet B

#93

Post by fleventynine »

lapcat wrote: post #86
fleventynine wrote: post #81

Earlier quoted context omitted.

Only until the colony can become self sufficient. The colonists will eventually develop more loyalty to each other rather than silly institutions on a planet 9-48 months away that know nothing of the harsh reality of martian life.

What does loyalty to each other mean exactly? Do Americans have loyalty to each other? Do North Koreans? The (hypothetical) colonists would develop loyalty to their own silly, strictly hierarchical government that was imposed on them. (For some strange reason, many Americans still have loyalty to a 200 year old document. And others have loyalty to 2000 year old documents.) As usual, some people will benefit greatly f…

I'm skeptical of any such top-down hierarchy surviving for generations, especially if it isn't willing to be open to some form of self-governance necessary for political stability.

If things eventually do escalate to interplanetary warfare, Mars has the significant advantage of having a much shallower gravity well. It's much cheaper for them to send missiles to Earth than vice versa, so perhaps the MAD threat will be enough to keep them safe.

Re: There’s no planet B

#94

Post by __MatrixMan__ »

adrianN wrote: post #47
api wrote: post #17

Earlier quoted context omitted.

This is a straw man. I still don’t hear anyone serious saying humanity will pick up and move to Mars or anywhere else. They say a very small number of humans (relative to the billions of us) may try to go to the Moon or Mars. That is conceivable. In our lifetimes I could picture basically McMurdo station on the Moon and some flights back and forth to Mars. I could picture a mostly autonomous settlement somewhere in 1…

I think autonomy will take longer. We have pretty incredible manufacturing technology but it all requires long supply chains. Think about how difficult it is to make for example a lubed ball bearing and how many different specialties are needed to make it and maintain the infrastructure needed to make it. Replicating that on a different planet will take time.

I don't disagree about it taking longer, but wrangling our supply chain complexity problem is something that many are motivated to do here on Earth, so it's convenient that much of the work will get done independently of the colonization effort.

I hope we'll converge on manufacturing infrastructure that depends on a somewhat constrained set of inputs. Not because we're designing for Mars, but because that's just good fault-tolerant design.

Like maybe the plans call for steel but al that we have on hand is brass, and it's ok if this one is weaker, so we'll print it in brass: improvising to avoid logistic complexity.

Turns out, that's what you'd need for mars too. You can't be ordering part numbers manufactured on earth all the time. Wherever possible you're probably better off just importing tungsten (or whatever) and machining it local, likely using the same machine that we do on Earth.

I think this sort of periodic-table-of-manufacturing approach would also be necessary to make recycling work. Whatever we call recycling today, it's nothing compared to what we'll need on Mars.

Re: There’s no planet B

#95

Post by TeMPOraL »

Tangurena2 wrote: post #10
chriswarbo wrote: post #2

> This futuristic dream-like scenario is being sold to us as a real scientific possibility, with billionaires planning to move humanity to Mars in the near future. As far as I'm aware, no billionaire has ever said anything about "moving humanity" to Mars or anywhere else; except to dismiss such claims as nonsense. Nobody is "planning" such a thing; let alone for "the near future". Musk wants there to be a colony on M…

That's a "motte & bailey" [0] type of argument. The billionaires talk about "saving humanity" or "making a lifeboat" but when they get questioned, they maneuver the discussion to the motte: "there is no planet B" (or the equivalent). Then, when the attention is elsewhere, back to fantasies of Mars. [0] - https://rationalwiki.org/wiki/Motte_and_bailey

It's usually the other group that's doing a Motte and bailey here. The billionaires were and are actually quite specific and up-front with their space ideas. It's the media (traditional and social) that invents fantasies here, either to sell or discredit the ideas, depending on which way the wind is blowing.

(As is the case here. We're in the middle of "let's tear down Elon Musk" phase right now, so the strawmen are getting impressively absurd.)

Re: There’s no planet B

#96

Post by ben_w »

zdragnar wrote: post #89
ben_w wrote: post #79

Earlier quoted context omitted.

Hmmm. While I would be actively surprised if the Moon, for example, had every element necessary for semiconductors, one of the things I absolutely do expect to be possible on its surface is 3D printing an extremely clean clean-room. Furnaces? Well, I think it would take a polishing step after printing, but if you have aluminium you can do a rough parabola out of it and focus sunlight on a patch of regolith. Can you t…

> electrolysis That's a process that involves drawing ions through solution towards a cathode and anode. A direct beam won't do. A solar furnace would suffice for the first half of the smelting process if you have access to ore which is not pure alumina, as well as melting the cryolite flux. Actually separating out the aluminum from alumina requires PV panels, high temperature rods and some means of synthesizing the…

> That's a process that involves drawing ions through solution towards a cathode and anode. A direct beam won't do.

OK, thanks for the info. Can you go into more depth about this specific part, or is this a thing where I need to do the whole degree to understand the answer?

Re: There’s no planet B

#97

Post by adrianN »

paulryanrogers wrote: post #85
adrianN wrote: post #66

Earlier quoted context omitted.

Which laws of physics prevent a permanent base on Mars?

Gravity primarily and the lack of carbon on the surface. Also the lack of a magnetic field to maintain atmosphere and shield from radiation.

Mars has carbon in its atmosphere. I don't think we have the necessary data to say that Mars' lower gravity prevents long-term settlement. Mars has enough mass to keep an atmosphere for millions of years, but you probably want to mostly live underground for the foreseeable future.

Re: There’s no planet B

#98

Post by Lutger »

pfdietz wrote: post #12
truculent wrote: post #11

Earlier quoted context omitted.

When going boldly requires shared resources and has knock-on effects for everyone, shouldn't we all have a say?

No? I mean, if people who have money want to spend it on something like that, why should we have a say? It's their money, not ours. EDIT: ah, the perennial game of rationalizing taking from others when they aren't doing what you want them to do.

> requires shared resources and has knock-on effects

> It's their money, not ours

No? Does not compute: its our resources and we are the recipient of knock-on effects, not 'they'. For example: if India will decide to geo-engineer their way out of the climate crisis (a bargain, really), I imagine most countries would rather appreciate a consultation _before_ launching the stuff in the sky. Even if its their stuff.

So go spend your billions on porn and perfume, but don't act surprised when people protest as you are about to possibly destroy their world.

Re: There’s no planet B

#99

Post by tannhauser23 »

This article is full of strawman arguments. I'm not aware of anyone who's arguing for moving billions of humans to another planet or for dedicating the resources of Earth to terraform Mars. It's not like Mars colonization proponents are keeping their plans secret - the authors could easily have googled what the actual propositions are, to wit:

- Use current or near-current tech to send human missions to Mars

- Use existing resources on Mars to the extent possible to support a research station

- Let the settlement grow organically. It will be science-focused at first but may develop economic value over time (Robert Zubrin suggests asteroid mining or deuterium harvesting)

Terraforming, if it happens at all, will be a centuries-long process by the Mars inhabitants, largely using resources available on that planet. No one's suggesting strip-mining Earth to make Mars habitable.

I don't know why some people think that human missions to Mars are incompatible with fixing Earth's problems. We have the resources to do both.

Re: There’s no planet B

#100

Post by tuatoru »

ben_w wrote: post #79
giantrobot wrote: post #68

Earlier quoted context omitted.

That's just magic woo though. You can't just "3D print" a clean room to build semiconductors or furnaces to smelt metal. Pretty much all heavy industry on Earth that makes all our high technology runs on petroleum products in some fashion. You can't just "3D print" lubrication and good luck building heavy industrial pieces without it.

Hmmm. While I would be actively surprised if the Moon, for example, had every element necessary for semiconductors, one of the things I absolutely do expect to be possible on its surface is 3D printing an extremely clean clean-room. Furnaces? Well, I think it would take a polishing step after printing, but if you have aluminium you can do a rough parabola out of it and focus sunlight on a patch of regolith. Can you t…

> one of the things I absolutely do expect to be possible on its surface is 3D printing an extremely clean clean-room.

My understanding is that there is lots of very fine dust near the surface of the moon. It's continually being bombarded with micrometeorites that kick up the dust.

So perhaps a moderately cleanish room.

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