The Astronomy Thread

Tuco

Tuco

I got Tuco'd!
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Dandain_sl said:
I think you're right in this respect Tuco, asteroid mining will be the catalyst than enables human expansion, but I disagree with your comment that it enables human exploration. Asteroids and their value come from the infrastructure you can build with it, repair with it. And harvest large enough amounts of water to continue growing/sustaining populations at expansion points.

Asteroid mining - as an endeavor is basically just proxy for the task of "gathering resources in space". Clearly being able to harvest and secure resources safely and reliably that can be used to maintain and expand human populations is paramount to even populating anywhere away from Earth. We can't ship shit from Earth to help off Earth populations, just will never effectively work that way. We can send robots, and some few explorers from Earth, but to explore distant stars with more than a machine or a limited crew exploration ship, resource harvesting is key.

Either building shipyards in the asteroid belt, or bringing asteroids to our shipyards in space will certainly be a step in the expansion of humanity.
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I'm not really sure what you're saying here. It seems like you said "asteroid mining doesn't enable human exploration" then described how asteroid mining would enable human exploration in space.

If the EMDrive does everything shawyer says, that'd enable human exploration too
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Tuco

Tuco

I got Tuco'd!
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rewatching that bit just to check that it's the whiffle balls I remember, man that guy is bullshitting so hard.
 
khorum

khorum

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A big assumption is that we would WANT to send that ore to the surface AT ALL. I alluded to this earlier----the costs to lift tungsten, boron, zinc and iron into orbit are so prohibitive that slapping a 90's tech ion impulse engine to sloooooowly get it from a jovian orbit into an L4/L5 cislunar position is a MASSIVE profit.

So if those resources arrive in orbit, it'sMORE VALUABLE IN ORBITthan sending it down to earth to make Ikea shelves or some shit.

Furthermore, unless we find large organic asteroids or something, any large-scale structural shit like an elevator or an Elysium-style colony for rich white people are gonna need sooooo much carbon from the surface that all the lift capacity would have to maximize for it, so any materials we can get get elsewhere---like say the belt---would have to be all the non-carbon stuff like water and metal.
 
Palum

Palum

what Suineg set it to
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Stop trying to Star Trek this shit, the only reason to mine asteroids right now is to make more and better iPads.
 
khorum

khorum

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Yeah but we need to be like OUT OF ALUMINUM for aluminum that's already in orbit to be less valuable IN ORBIT than sending it to earth. Even if we somehow finished a space elevator tomorrow, the amortized costs of building it would still make just about ANY METAL that's already in orbit to be more valuable IN ORBIT than sending it down to Earth.

We'd still need iPads in space you know.

And building that space elevator or O'Neill Cylinders or Elysium-style habitats would require gobs of CNT or Graphene manufactured from orbit anyway, so those carbonaceous asteroids which are closer would prolly be the first targets.
 
Ukerric

Ukerric

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khorum_sl said:
Yeah but we need to be like OUT OF ALUMINUM for aluminum that's already in orbit to be less valuable IN ORBIT than sending it to earth.
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The real question isn't whether it's more valuable in orbit than on earth, it's that whether it's cheaper from orbit than on earth. It's a classic import question: if producing at point A and shipping it here is cheaper than producing at point B and shipping it there, then you produce at A.

Now, for aluminum, it's a bit more complicated since the production has two steps: digging the bauxite, then using electricity to separate the aluminum. Which is why Iceland is a major producer of aluminum: it's actually cheaper to ship bauxite there, use very cheap geothermal electricity on the spot, then ship back the aluminum. I'll let future economists calculate the best combo.
 
Tuco

Tuco

I got Tuco'd!
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Cad_sl said:
Why do they call the emDrive a "warp drive" ? It's no such thing, in any way.
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Because journalists like clickbait. Even if they call it warp drive in quotes and debunk the idea it's still the same eye grabbing nonsense.



Khorum, nobody is talking about shipping aluminium from orbit to earth. We're talking platinum-level ore here. But I agree 100% that the greater contribution of asteroid mining isn't enriching our supply of plat on earth, it's enriching our supply of water, steel, alum etc in space. However, that only becomes valuable on the back of getting more platinum to earth.

I mean sure, we can get a big chunk of ice and float it over to the ISS to lower their costs, but that's chump change compared to a space-gold rush that would make use of massive amounts of materials solely to bring all that gold, cobalt, osmium, palladium, platinum, rhenium, rhodium, and ruthenium home.

And that industry that is immensely profitable will pave the road to all the other stuff space nerds want.
 
Ukerric

Ukerric

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Cad_sl said:
Why do they call the emDrive a "warp drive" ? It's no such thing, in any way.
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Given that nobody has any idea how the emDrive can work, why wouldn't it work by warping spacetime asymetrically and thus generating some acceleration (which, in my absolutely layman opinion, sounds mildly less impossible than providing action without reaction).

But yea, at the moment, it's more of anImprobability Drivethan a warp drive.
 
Cad

Cad

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Ukerric_sl said:
Given that nobody has any idea how the emDrive can work, why wouldn't it work by warping spacetime asymetrically and thus generating some acceleration (which, in my absolutely layman opinion, sounds mildly less impossible than providing action without reaction).

But yea, at the moment, it's more of anImprobability Drivethan a warp drive.
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I guess when I think warp drive I think of something that warps space rather than provides thrust. The emdrive just provides (or doesn't provide, to be fair) thrust in an unlikely massless fashion.
 
Tuco

Tuco

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The other part I don't see talked about is what exactly happens when the cost of those materials plummet. I don't know enough about metallurgy to know what cool technology would be made plausible if palladium went from 20k USD a kilo to 10k. Or 5k. Maybe it'd just reduce the cost of research projects and a few very specialized technologies (EX: the platinum in exhaust gas recirculation in vehicles. The things people get ripped off their vehicle). But it's an interesting question.
 
khorum

khorum

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Water and other volatiles that would be just too prohibitive to boost into orbit would've been a better example, sure. But Aluminum is still a critical resource for orbital construction and it was cited by NASA's own proposals to mine asteroids in the next decade.

The argument for economically-driven space resource exploitation has always been for something that maximizes weight/value: energy. Helium3 fuel for fusion reactors have been getting A LOT of attention from private speculators and even China's Chang'e lunar mission had a big chunk of its footprint dedicated to exploring helium3 mining opportunities. It's reasonably easy to recover, light enough to boost off the moon and also light enough to recover on the surface with a parachute.
 
Ukerric

Ukerric

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Cad_sl said:
I guess when I think warp drive I think of something that warps space rather than provides thrust. The emdrive just provides (or doesn't provide, to be fair) thrust in an unlikely massless fashion.
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Well, in my wild-ass imagination, the space-time inside of the resonant cavity gets warped (curved), and thus, because classic relativistic gravity is basically acceleration based on space-time curvature, you get some acceleration of the mass in that warp. If the warp is symmetric, but the cavity asymmetric, then you get different mass x force component across the warp, i.e. a net force acting on the overall device.

There, I've just invented a gravity warp drive. Enjoy.
 
Cad

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Ukerric_sl said:
Well, in my wild-ass imagination, the space-time inside of the resonant cavity gets warped (curved), and thus, because classic relativistic gravity is basically acceleration based on space-time curvature, you get some acceleration of the mass in that warp. If the warp is symmetric, but the cavity asymmetric, then you get different mass x force component across the warp, i.e. a net force acting on the overall device.

There, I've just invented a gravity warp drive. Enjoy.
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I guess since nobody is providing any explanation for how an emdrive works thats as good as any.
 
khorum

khorum

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Ukerric_sl said:
Well, in my wild-ass imagination, the space-time inside of the resonant cavity gets warped (curved), and thus, because classic relativistic gravity is basically acceleration based on space-time curvature, you get some acceleration of the mass in that warp. If the warp is symmetric, but the cavity asymmetric, then you get different mass x force component across the warp, i.e. a net force acting on the overall device.

There, I've just invented a gravity warp drive. Enjoy.
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Alcubierre beat you to that. But he's mexican so if you file the patent first, you win.
 
Ukerric

Ukerric

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khorum_sl said:
Alcubierre beat you to that. But he's mexican so if you file the patent first, you win.
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Nope, slightly different warpage. Alcubierre's works by warping space-timearoundyour ship, not inside your drive, and having the local flat space-time "slide" along that warp. That's why it can go FTL, while this gravity drive can't.

Of course, Alcubierre's drive has good and strong math foundations, and a model of why it works, it just needs materials with negative mass which don't exist. While the emDrive has no model, no math, and thus, anything goes!
 
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