I'd rather gather them from the asteroid belt if possible so we could stop/limit the terrible effects of mining on the environment on earth. Also if we can setup manufacturing and fuel creation in space it would let us build larger and go farther because we wouldn't have to lift the pieces up out of our gravity well and atmosphere. At the very least we could build the bodies of spacecraft and fuel them in space and just lift harder to build stuff like electronics from Earth.

As long as we are just sending satellites up into LEO that takes far less energy than you might think. Flying around the world or getting to space are not that far apart. SpaceX for example is only worth ~20 billion because there is simply less demand for rockets and they cost less than many assume.

Now, if we want to colonize outer space then asteroid mining becomes necessary. But, with current tech there is little personal benefit to being in space vs staying home.

PS: I am not going to try and predict what happens 1,000 years from now, but space is unlikely to be a nice place to live any time soon.

Even short of full colonization sourcing materials from space will allow much larger structures and shapes that would be difficult. Ultimately right now we're severely limited by the fairings, inflatables like Bigelow Aerospace solves some of that but ultimately there still limits to the volumes.

I agree we're pretty far out from being able to live comfortably in space but I think to get there we kind of inevitably have to mine resources from space.

But what's the point of having large structures in space without people?

We can already get big stuff into space aka building sized, so you're taking about mega structures which seem rather pointless right now.

"just the world's oceans"? I think you understate just how vast the oceans are. That's some seriously diluted gold.

I suspect the comparison was against asteroid mining. The oceans are vast and difficult, but less vast and less difficult than space.

My point is the earth is huge.

260 billion cubic miles worth of asteroids without going into space. Sure we are currently limited to a tiny fraction of that but start processing magma directly is an option.

Each person’s 5kg of gold also comes with a bonus of about 1/6 of a cubic kilometer of seawater. Hopefully yours is near a beach so you don’t have to haul it too far.

But we do have a need for rare earth metals. Not as much as we thought we did in 2011, but it would still be a fantastic boon to manufacturing.

It wouldn't just be profitable in the sense that you can sell 1000 kilos of dysprosium to manufacturers; it would be profitable in the sense that those manufacturers could make more products, employ more people, build more electric cars or LED bulbs, etc.

Say you also own an electric car company...

rare earth metals are not nearly as rare as you might think.

The problem is they don't concentrate that much in any one area not that they can't be extracted for most places. So, we could extract them at 100x the current rate for the next 1,000 years and recycle them forever.

If everyone consumed like an American we’d need something like 4x Earths. There are not enough resources on this planet unless westerners start scaling back their consumption and members of developing societies scale their ambitions down to match the new, lower consumption models of the West.

Then making that consumption sustainable and reducing waste would be a far better investment than pipe dreams of asteroid mining.

Keep in mind scarcity of resources is not the only issue. If everyone on Earth really ever started consuming as much as Americans then it doesn't matter if there's enough surplus material in space, the ecosystem on Earth would be dead anyway and we'd have much bigger issues.

There's enough resources (especially since they don't just disappear and can be recovered by recycling), afaik, except for food - that's what we're consuming too fast to replenish.