You Promised Me Mars Colonies but I Got Facebook • Hacker News Board

Re: You Promised Me Mars Colonies but I Got Facebook

#211

Post by heavyset_go » Sun, Nov 17, 2019, 4:31 PM UTC

foxrider wrote: post #206

heavyset_go wrote: post #182

Earlier quoted context omitted.

In the face of all extinction events, the bottom of the ocean would be more habitable than an alien planet.

But there is little to gain living on the bottom of the ocean. Space expansion offers us more than just survival, it bring orbital mining, Low G manufacturing, scientific projects and so on. It's much harder if not impossible to create something self-sufficient underwater than on Mars, since due to huge pressure any mechanical failure of your equipment is much more catastrophic. There are virtually no light or any go…

> 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 your necessities from life need to come from elsewhere. If you want to live on Mars for any appreciable amount of time, you need a robust supply chain that'll supply resources to you from Earth.

On the seafloor, you are surrounded by water, sources of oxygen, and food.

> you can't mine underwater effectively,

We've yet to mine anything that isn't on Earth. We may never be able to mine effectively anywhere other than Earth.

> there is sunlight

There is barely an atmosphere on Mars, and it lacks oxygen.

Re: You Promised Me Mars Colonies but I Got Facebook

#212

Post by scottLobster » Sun, Nov 17, 2019, 6:16 PM UTC

pfdietz wrote: post #191

scottLobster wrote: post #176

Earlier quoted context omitted.

I'm not sure the public's imagination is ever gripped by grand visions for very long. Just look at how quickly Apollo ended once we made it to the moon, and how controversial its budget was at the time. Going further back, remember that most of the Western settlers we romanticize as "pioneers" with "the spirit of exploration" today were in fact looking for economic profit and an escape from bad working conditions in…

Defense against asteroids is a bad justification for space exploitation. The first thing that would have to be done is telescopic search, and with very high probability nothing really dangerous would be found, and so no further space activity could be justified on the basis of defending against that threat. Defense against long period comets might be a better bet, as they are harder to rule out.

That's the thing with public opinion, you don't need a good justification to get things done, only a sufficient one.

If a devastating asteroid did hit and NASA/ESA/etc got all the funding they ever wanted to catalog the sky, and announced they'd finished 2 years later, a large slice of Joe Public would respond "you said the chances were 1 in a million last time. Why should we trust you now?" With the right resources that could be leveraged into a Mars colony with actual sustainability in mind.

I think you'd find the threat of asteroids to be a much more relatable and palatable threat than Climate Change. It's an purely external force of nature that no human can claim responsibility for or point fingers over. An asteriod strike would also be the single, short-term-but-devastating situations humans have a evolved to deal with, as opposed to the long-term creeping rot of Climate Change. Likely much easier to get action over asteriods.

Hell, asteroids are already #2 on the list of things NASA should focus on according to a recent PEW survey. https://arstechnica.com/science/2018/06/nasas-priorities-app...

Re: You Promised Me Mars Colonies but I Got Facebook

#213

Post by scottLobster » Sun, Nov 17, 2019, 6:27 PM UTC

buboard wrote: post #179

scottLobster wrote: post #176

Earlier quoted context omitted.

I'm not sure the public's imagination is ever gripped by grand visions for very long. Just look at how quickly Apollo ended once we made it to the moon, and how controversial its budget was at the time. Going further back, remember that most of the Western settlers we romanticize as "pioneers" with "the spirit of exploration" today were in fact looking for economic profit and an escape from bad working conditions in…

> most people just want to drink, watch TV and die Religion is a counterexample to this. it has driven people to change their lives

I'd argue it's the other way around, that those seeking to change their lives for the better are a relatively self-driven minority and likely would have succeeded with or without religion, religion was just a convenient vehicle due to widespread availability and approach-ability.

It's anecdotal, but I was raised Baptist and married into a Catholic family (although neither my wife nor I are particularly religious). The people I've met in church over the years are no more or less driven than any other segment of the population I've encountered.

Re: You Promised Me Mars Colonies but I Got Facebook

#214

Post by foxrider » Sun, Nov 17, 2019, 8:27 PM UTC

heavyset_go wrote: post #211

foxrider wrote: post #206

Earlier quoted context omitted.

But there is little to gain living on the bottom of the ocean. Space expansion offers us more than just survival, it bring orbital mining, Low G manufacturing, scientific projects and so on. It's much harder if not impossible to create something self-sufficient underwater than on Mars, since due to huge pressure any mechanical failure of your equipment is much more catastrophic. There are virtually no light or any go…

> 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 separating it from water, it's a thermodynamic dead end. If you don't have sunlight for power (if you are deep enough) the only source apart from nuclear is gas/oil that you would extract from the seabed if you'll be very lucky to get where you'll establish. The food is around you, this is true - microshrimp, jellyfish, algae - non of this is consumable by a human. We tried that already - soviets experimented with algae and krill consumption for astronauts on the space stations - out digestive systems would not be able to handle it.

Compare it to Mars - you get sunlight for crops, you get it for solar panels, etc. There is water on Mars as we know now, so you can use it while also having easier time building. The only downside is how hard it is to get to the Mars compared to the bottom of the ocean. But once we would figure out hurling cargo it's going to be easier. I fully agree that you need supply chain to exist for some time, a long time even, but after a while you would be able to grow food on Mars.

We have places on Earth where you can get close-to-Mars experience, near the poles. There are some entirely lifeless patches of just ice cold land where some of the Martian tech gets tested.

Re: You Promised Me Mars Colonies but I Got Facebook

#215

Post by p_l » Sun, Nov 17, 2019, 9:13 PM UTC

merpnderp wrote: post #188

p_l wrote: post #52

Earlier quoted context omitted.

NASA projects are endangered by politicians. The difference is that SpaceX funded reusability on their own, instead of depending on fickle funding from Congress that killed the original STS (leaving us with the one that flew and costed as much as Apollo per launch). And sometimes it wasn't Congress zit was president - like Nixon deciding to kill nuclear space propulsion for no known reason. The cutthroat politics of…

Nixon killing nuclear space propulsion for no known reason? You mean the Orion project and thousands of nuclear bombs in space? I’d say keeping space nuclear weapons free in the face off with the Soviet Union counts as a known reason.

The nuclear propulsion project was unrelated to Orion. And yes, the reason is unknown, because in giving his Executive Order there was no reason attached.

It was nuclear thermal engines, similar were being developed in Soviet Union in fact. IT was even tested for safety in case of crashing on Earth (and could run on earth, though the target was using it in space).

Re: You Promised Me Mars Colonies but I Got Facebook

#216

Post by p_l » Sun, Nov 17, 2019, 9:17 PM UTC

pfdietz wrote: post #201

p_l wrote: post #52

Earlier quoted context omitted.

NASA projects are endangered by politicians. The difference is that SpaceX funded reusability on their own, instead of depending on fickle funding from Congress that killed the original STS (leaving us with the one that flew and costed as much as Apollo per launch). And sometimes it wasn't Congress zit was president - like Nixon deciding to kill nuclear space propulsion for no known reason. The cutthroat politics of…

Nixon killed nuclear propulsion because there was no mission on the horizon to justify it. It was the right decision, although developing the shuttle was not.

Under pure "will this bring immediate profit", both were wrong decisions. Building the STS as it actually flew was a wrong decision, but that wrong came out of political pressures that resulted in NASA begging USAF for money, and USAF requiring features that were never used but which killed the reusability benefit and arguably stopped US launcher R&D for better part of 30-40 years.

As for no mission - the missions on the horizon are locked by available launchers and bus systems available, with NERVA engines opening significant options. Despite Congress actually voting the money into budget Nixon killed it with Executive Order, and so far I haven't seen any real explanation why, except possibly internal politics and some people's ego.

Re: You Promised Me Mars Colonies but I Got Facebook

#217

Post by pfdietz » Sun, Nov 17, 2019, 9:21 PM UTC

DennisP wrote: post #207

pfdietz wrote: post #204

Earlier quoted context omitted.

TAE: it was explained to them 20 years ago why their idea didn't work, even theoretically. General Fusion: acoustic compression was shown to be unworkable, so they pivoted to a slower scheme with a central conductor down the middle of the chamber. Good luck getting that conductor to survive 100T magnetic fields and orders of magnitude higher neutron loading than in conventional reactor concepts. Commonwealth and TE:…

I'm not trying to claim that these particular projects will succeed. I'm just saying that some VCs are in fact funding the sort of high-risk breakthrough physical technologies that the article claims are not being funded. But a nitpick on LPP: wall engineering isn't really an issue for them since they're attempting boron fusion. Like Helion they're also planning direct conversion, since the output is a pulsed beam of…

Of course wall engineering is going to be a problem with boron fusion. Any very hot plasma will emit photons, and H-11B plasmas will emit them even more than DT plasmas (because the rate of emission increases rapidly with the charge of the nuclei). In fact, a H-11B plasma will normally emit photons faster than it can reheat itself from fusion. LPP makes noise about making tiny knots of plasma that are so dense and ultramagnetized that this doesn't happen -- but as those knots expand, the supposed effects that suppress radiation would die away, and out would pour the photons.

Re: You Promised Me Mars Colonies but I Got Facebook

#218

Post by 205guy » Sun, Nov 17, 2019, 10:23 PM UTC

guelo wrote: post #115

numair wrote: post #86

All of these articles and ways of thinking always miss the bigger, more fundamental shift in human society — we now know there is literally no place we can access in any meaningful amount of time where the “grass is greener” than the places we’ve already been. This is profound, semi-depressing, and enlightening at the same time. Rather than seeking something new somewhere else, our new obsession is in improving what…

I try to imagine humanity a thousand years from now, still bound to the same increasingly inhospitable planet, paying for the sins of our generations but nowhere to escape to. With probably an abandoned Mars or moon colony. Just nothing to explore. Even the boundaries of natural science would be mostly understood by that point. It would be so depressing. Our only salvation would be if we still have enough resources r…

I agree with the first half of your comment: humanity will be (mostly) Earth-bound and energy-bound, trying to deal with a fragile ecosystem in a humanitarian way. However, I disagree with the pessimism in the second half.

To explore the ocean floors will take another 200 years, and probably another 100 for land before we even start. This will be driven by the need to decipher weather and climate, with currents of heat, salinity, nutrients, carbon exchange, and who knows what else through the atmosphere and oceans. Those seem like the priorities we'll need to solve climate stability, including associated tech for renewable energy and feeding whatever population we finally (hopefully) level out at (peacefully).

And then I think we will still have many fascinating frontiers to explore, such as molecular biology, genetics, history, and the big one in my mind: psychology. We know so little about all the different ways our minds work and our studies are so primitive we think all people think alike. Just consider the huge difference between introverts and extroverts, and what it implies for people to be so fundamentally different--science isn't even considering these questions yet.

In a thousand ears, things will just start to get interesting. To retreat into virtual worlds would be premature--though I have no doubt they will be explored in parallel.

Re: You Promised Me Mars Colonies but I Got Facebook

#219

Post by DennisP » Mon, Nov 18, 2019, 1:05 AM UTC

pfdietz wrote: post #217

DennisP wrote: post #207

Earlier quoted context omitted.

I'm not trying to claim that these particular projects will succeed. I'm just saying that some VCs are in fact funding the sort of high-risk breakthrough physical technologies that the article claims are not being funded. But a nitpick on LPP: wall engineering isn't really an issue for them since they're attempting boron fusion. Like Helion they're also planning direct conversion, since the output is a pulsed beam of…

Of course wall engineering is going to be a problem with boron fusion. Any very hot plasma will emit photons, and H-11B plasmas will emit them even more than DT plasmas (because the rate of emission increases rapidly with the charge of the nuclei). In fact, a H-11B plasma will normally emit photons faster than it can reheat itself from fusion. LPP makes noise about making tiny knots of plasma that are so dense and ul…

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 bremsstrahlung will be suppressed long enough by the plasma's magnetic field. If it is, then most of the energy will go into the alpha particle beam.

Re: You Promised Me Mars Colonies but I Got Facebook

#220

Post by pfdietz » Mon, Nov 18, 2019, 1:17 AM UTC

DennisP wrote: post #219

pfdietz wrote: post #217

Earlier quoted context omitted.

Of course wall engineering is going to be a problem with boron fusion. Any very hot plasma will emit photons, and H-11B plasmas will emit them even more than DT plasmas (because the rate of emission increases rapidly with the charge of the nuclei). In fact, a H-11B plasma will normally emit photons faster than it can reheat itself from fusion. LPP makes noise about making tiny knots of plasma that are so dense and ul…

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.