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You Promised Me Mars Colonies but I Got Facebook

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Re: You Promised Me Mars Colonies but I Got Facebook

#221

Post by zanny »

7thaccount wrote: post #189
zanny wrote: post #181

Earlier quoted context omitted.

I don't think there is any chance we make it a thousand years without either reaching technological singularity or destroying ourselves. In the 80 years of transistor technology we went from string manipulation via pneumatic tubes to real time ray tracing. Though to be fair, both outcomes basically end biological human life - a technological singularity obsoletes carbon based biology and any rational successor specie…

Paul Davies (head of SETI) has a fantastic book called "The Eerie Silence". It was the first time in years that I had read a good science book written for the layman that taught me not only a lot of new scientific ideas, history I didn't know about, and made me think about humanity in a new light. I really can't recommend it enough. Ok, so he makes an argument that made me put down the book (ok 17 year old me) and re…

We are in effect the same tragedy that encompasses Octopoda. They are provably relatively intelligent and emotive creatures but have extremely short lifespans for their mental capacity and thus can never take real advantage of their learning ability.

Humans are still that, just on an order of magnitude longer time scale. Its still hugely limited when compared to orders of magnitude larger time scales than that.

Re: You Promised Me Mars Colonies but I Got Facebook

#222

Post by DennisP »

pfdietz wrote: post #220
DennisP wrote: post #219

Earlier quoted context omitted.

The reactor would only be about 5MW, and the wall of the reactor core can be however far away it needs to be to not get melted by x-rays. It's not like it's surrounded by superconductors or breeding blanket, it's just vacuum containment. Generally it's neutron radiation that's considered difficult to deal with, and there'd be little of that. And the reactor won't produce net power at all unless they're right that bre…

The reactor is described to be 5 MW average output. But if it's very bursty the instantaneous power will be far higher. Damage to the wall will be determined by heating of the surface by these flashes (and possibly mechanical damage from shocks induced by vaporization in that surface layer). Keeping the instantaneous power low enough to avoid damage could make the reactor unacceptably large.

So your criticism is that maybe, possibly, the reactor will be too big. I'll take it.

Re: You Promised Me Mars Colonies but I Got Facebook

#223

Post by pfdietz »

DennisP wrote: post #222
pfdietz wrote: post #220

Earlier quoted context omitted.

The reactor is described to be 5 MW average output. But if it's very bursty the instantaneous power will be far higher. Damage to the wall will be determined by heating of the surface by these flashes (and possibly mechanical damage from shocks induced by vaporization in that surface layer). Keeping the instantaneous power low enough to avoid damage could make the reactor unacceptably large.

So your criticism is that maybe, possibly, the reactor will be too big. I'll take it.

That is a central problem with fusion: the volumetric power density of fusion reactors sucks. It's not a trivial criticism, it's an economic showstopper.

LPP's concept has other problems, of course, like the aspirational physics of those putative 1000 T plasma knots, and direct conversion by Handwave Engineering.

Re: You Promised Me Mars Colonies but I Got Facebook

#224

Post by DennisP »

buboard wrote: post #140
DennisP wrote: post #122

Earlier quoted context omitted.

Then NASA should completely give up being the uber for space, instead of spending gobs of money on SLS. But if you are going to get into the launch business, then do it right.

i mean, they also want a cheaper kind of flight, but for different reasons

I'm sure there are NASA engineers who want it, but the tangled mess of NASA/ULA/Congress is doing nothing to achieve it.

Re: You Promised Me Mars Colonies but I Got Facebook

#225

Post by chr1 »

trixie_ wrote: post #203
chr1 wrote: post #196

Earlier quoted context omitted.

There is a big difference between "the only thing preventing development of better rockets" and "one of things". NASA and every other country would be doing it now if better computers were the only thing needed for reusable rockets. There is no sharp line dividing computers that made spaceX possible and slow ones, and with a little bit worse computers spaceX could develop the rocket after more failed attempts, spendi…

The decade doesn't matter. NASA is making poor decisions today with SLS, just as it did with the shuttle in the 80s. The reality is it was possible to build cheap reliable reusable space vehicles with 70s technology.

Have you worked on any task related to modeling physical processes, based on my short experience modeling parts of airplane, i believe building something comparable to falcon with 70s technology would have been multiple orders of magnitude harder.

The fact that NASA makes poor decisions today doesn't prove that SpaceX would have been able to create and implement the good plan 40 years ago.

Re: You Promised Me Mars Colonies but I Got Facebook

#226

Post by heavyset_go »

foxrider wrote: post #214
heavyset_go wrote: post #211

Earlier quoted context omitted.

> But there is little to gain living on the bottom of the ocean. What? You're surrounded by water, you can produce oxygen through electrolysis and generate hydrogen fuel, there's food living all around you, there are plenty of seamounts to mine. > It's much harder if not impossible to create something self-sufficient underwater than on Mars All of you supplies need to live on Mars need to come from elsewhere. All of…

Most of the ocean is just dead water with nothing in it. Life blooms near geothermal sources or near surface. But even there getting the resources that you theoretically have is not easy - electrolysis is like charging a battery - you don't get ANY energy from it, because you would need the oxygen, and hydrogen needs oxygen to react with. And even in that reaction it would release less energy than you've spent separa…

> Most of the ocean is just dead water with nothing in it.

You're closer to life than you would be when you're on any other planet than Earth.

> But even there getting the resources that you theoretically have is not easy - electrolysis is like charging a battery - you don't get ANY energy from it, because you would need the oxygen, and hydrogen needs oxygen to react with

I'm aware of how thermodynamics work, and I bring it up because our nuclear submarines rely on electrolysis to generate oxygen so that they don't have to resurface for long periods of time.

They just release their hydrogen as waste gas, though.

> Compare it to Mars - you get sunlight for crops

There is barely an atmosphere on Mars.

> you get it for solar panels

You can capture wind, solar, tidal or geothermal energy while sitting at the bottom of the ocean.

> There is water on Mars as we know now, so you can use it while also having easier time building

There is a incredibly small amount of water on Mars. Meanwhile in the ocean, you're surrounded by it.

I don't think the bottom of the ocean would be a good place to survive an extinction event, because there are plenty of places on the surface or beneath the surface that are better suited.

I use the bottom of the ocean as an example because it is Earth, our home, yet we still have an extremely difficult time surviving in it. Despite that, it is infinitely more livable than any other planet in our solar system.

Re: You Promised Me Mars Colonies but I Got Facebook

#227

Post by rhizome »

georgeburdell wrote: post #103
rhizome wrote: post #35

Mars colonies don't come from the private sector, Elon and Jeff notwithstanding. The problem is that public science has been starved of funding for decades through tax cuts. If the author would take off his (it's always a he) blinkers of technocracy he might see that profitability is not the only measure of "why." Some things are not profitable, yet are still worth doing. Andrew Yang-lite doesn't account for this at…

>Mars colonies don't come from the private sector, Elon and Jeff notwithstanding Exploration has a long history of rich benefactors and private interests. Monarchs, Dutch East India Corporation, etc., are closer to Musk and Bezos than a modern democratic state >The problem is that public science has been starved of funding for decades through tax cuts. This graph suggests otherwise? In current dollar terms, R&D spend…

I am skeptical of the success rate of rich benefactors for a technology with only a century of practice, vs. boats that have been used for thousands of years.

>In current dollar terms, R&D spending is double what it was in the 1970s.

https://en.wikipedia.org/wiki/Budget_of_NASA#/media/File:NAS...

And there are more budgets to be involved than just these two.

Re: You Promised Me Mars Colonies but I Got Facebook

#228

Post by telotortium »

Animats wrote: post #71
scythe wrote: post #25

Why is it always space? Space technology requires lots of energy and our society is currently in the middle of realizing that our current way of getting energy is going to kill us. Of course we're not making large-scale investments in energy-intensive exploration. I wish EDS maglev, fusion power or quantum computing generated so much excitement, to say nothing of grid batteries, magnetocaloric heat pumps, or electric…

Why is it always space? Good question. The best off-earth real estate in this solar system is worse than the worst on-earth real estate. It's easier to build colonies in Antarctica or underwater on the continental shelf than on Mars. Mars is small, cold, and nearly airless. We're not short of low-value real estate, after all.

I agree with you about Antartica, but I think the pressure underwater at even quite shallow depths makes it harder to build any large-scale inhabitance there than on any of the bodies in this solar system that we'd want to go to, which have (I think) lower atmospheric pressure than earth. Of course, resupplying an oceanic habitat is much easier than resupplying anything off-planet, but besides that, I wouldn't be surprised at all if we have space colonies well before oceanic colonies.

Re: You Promised Me Mars Colonies but I Got Facebook

#229

Post by ElFitz »

lioeters wrote: post #205
kobayashi wrote: post #198

Earlier quoted context omitted.

Please post the Thiel article

"We wanted flying cars - instead we got 140 characters." Quote is from the article, "What happened to the future?" https://foundersfund.com/the-future/

Thank you!

Re: You Promised Me Mars Colonies but I Got Facebook

#230

Post by trixie_ »

chr1 wrote: post #225
trixie_ wrote: post #203

Earlier quoted context omitted.

The decade doesn't matter. NASA is making poor decisions today with SLS, just as it did with the shuttle in the 80s. The reality is it was possible to build cheap reliable reusable space vehicles with 70s technology.

Have you worked on any task related to modeling physical processes, based on my short experience modeling parts of airplane, i believe building something comparable to falcon with 70s technology would have been multiple orders of magnitude harder. The fact that NASA makes poor decisions today doesn't prove that SpaceX would have been able to create and implement the good plan 40 years ago.

Multiple orders of magnitude? Do the rockets/engines today look anywhere close even to a single order or magnitude better than before?

The computers are much better yes, but not good enough yet to obviate the need for real engine testing and wind tunnels for aerodynamics. Computers in the 70s were already capable of landing autonomously on other planets - as demonstrated multiple times.

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