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Earth-like planet spotted orbiting Sun’s closest star

nature.com

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Re: Earth-like planet spotted orbiting Sun’s closest star

#231

Post by ethbr0 »

spywaregorilla wrote: post #209
ethbr0 wrote: post #194

Earlier quoted context omitted.

Not must be. Is probably achievable, and is worth attempting, even at the cost of lives. You can argue from either the perspective of futility of attempt (no chance of success) or futility of outcome (success wouldn't be worth it), but I'm pretty convinced both would be weak arguments, both logically and historically.

I'm probably an optimist on Mars travel. I think, with a fuck ton of starships, you could get people living on Mars. But there's some big asterisks on that. You'd more or less have to live in the starships, dependent on shipments from earth, with self sufficiency failing on pretty much every category. Over a very long period, most people would probably die a bit earlier from radiation and dust. Not much would be prod…

The suspicion I have about self sufficiency pessimism is that it's an apples to oranges comparison. Are there any modern analogies? As near as I can tell, it hasn't been required after the 16th century, due to access to relatively timely transportation.

And if it hasn't been required, then how are we to look at existing practice and say we're bad at or incapable of it?

Re: Earth-like planet spotted orbiting Sun’s closest star

#232

Post by divbzero »

kibwen wrote: post #225
ethbr0 wrote: post #144

Earlier quoted context omitted.

Here's a good collection of details about the entire star system of Proxima Centauri, including its planets. https://www.star-facts.com/proxima-centauri/ Also fascinating, a relative distance vs time graph of close stars. It turns out we'll have closer distances for 6 in the next 10,000 - 50,000 years. https://www.star-facts.com/wp-content/uploads/2020/08/Neares... Somehow I feel like Elon Musk has a print out of tha…

"Unlike the Sun, which will evolve into a red giant in 6.5 billion years and reach the end of its life at an age of about 10 billion years, Proxima will stay on the main sequence for another four trillion years due to its low mass and low energy production." They laughed at me when I bought investment property on Proxima Centauri b, but who'll be the one laughing in 10.000000001 billion years?

“Stars with a mass of less than 0.25 solar masses do not evolve into red giants.… Toward the end of the blue dwarf phase, Proxima will become considerably more luminous, reaching up to 2.5% of the Sun’s luminosity. Once it runs out of hydrogen fuel, it will evolve into a white dwarf, skipping the red giant phase, and gradually lose all its heat energy.”

So we just need to tackle climate change and learn to live sustainably on Earth, then we’ll have a few billion years to figure out how to get to Proxima Centauri.

Re: Earth-like planet spotted orbiting Sun’s closest star

#233

Post by kibwen »

ethbr0 wrote: post #153
samatman wrote: post #97

Earlier quoted context omitted.

Mars has dust storms which last months or years, it has no ionosphere, and that dust contains enough perchlorates to poison anything we could eat, including us. Ok, that sentence went somewhere odd at the end but, it's true. A large asteroid has only one of these problems, by virtue of not coming with any atmosphere, ionic or otherwise. I kinda hope Elon is bluffing and actually plans to head to the Belt. I've pencil…

Isn't long term zero-g pretty hostile to our biology?

Mars is 0.3 G, which is just as hostile for long-term habitation. No human child conceived, born, and raised in that environment would have the ability to stand on Earth without an Aliens-style rigid exosuit. Their heart might not even be capable of pumping blood to their head.

Re: Earth-like planet spotted orbiting Sun’s closest star

#234

Post by pharke »

TheOtherHobbes wrote: post #180
ethbr0 wrote: post #149

Earlier quoted context omitted.

Going to {the Middle East, Europe / Asia, Australia, the New World, interior South America, the North American West) seems pretty useless to me at this time. It’s a super hostile environment and we don’t have the technology yet to have a self sustaining base there. Give it a few decades and progress in {insert technology} will make a base much easier. There is plenty of work to be done on {current place}. We have to…

This is absolutely, objectively, incorrect. You might as well argue that you can build a self-sustaining base on Antarctica. Of course you can't, because Antarctica can't support life. No amount of shouting into a bullhorn about adventure will change that. It might be possible with an absolutely epic effort to airlift soil, nuclear reactors, nuclear and other fuels, machinery for every eventually (including chip fabs…

> soil

Both aquaponics and aeroponics provide ways to grow plants without soil. Breeding insects or algae may provide nutrition with very small amounts of mass needing to be transported.

> nuclear reactors

Yes, these are a necessity but we've sent one to Antarctica before and we could send a more modern one to Mars.

> nuclear and other fuels

The good thing about nuclear fuel is that you need a very small amount of it to produce a lot of energy for a long time.

> machinery for every eventuality (including chip fabs)

Colonists by necessity must make do with less and that does mean a lower standard of living and higher mortality but you know what they do it anyways because some things are worth trading comfort and a decade or two of life for. English colonists didn't bring the entire industrial infrastructure with them to the New World. They brought what would fit on the boats and had to make do with what they could create from local resources or do without. They had the benefit of subsequent voyages but I don't think anyone here is imagining colonizing Mars or Antarctica with a single expedition.

> raw materials

Mars (and Antarctica for the most part) do lack anything biological in origin, no oil or wood or crops as feedstock for chemical reactions but there are always alternatives. We usually don't use those alternate sources here because they are too labour or energetically or materially expensive but when they are your only option price and effort become less of a concern.

> all the challenges are at least an order of magnitude harder

No one who is attempting to work towards this is doing it because it is easy. I remember there being a speech about that which ended up with some pretty spectacular results.

Re: Earth-like planet spotted orbiting Sun’s closest star

#235

Post by kibwen »

ako wrote: post #172
oceanplexian wrote: post #128

Earlier quoted context omitted.

> Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Mars might not be sustainable in our lifetime but in a century or two? I think it's within the realm of possibility. As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disa…

Even if we completely screw up liveability on earth, it's probably still going to be way more hospitable then most planets we can reach.

In addition to the fact that there's almost nothing you could do to Earth that would make it less liveable than Mars, any political problem that plagues the Earth is going to plague Mars just as easily. Earth didn't create human political problems, humans did. The only way to keep political problems from plaguing Mars would be to keep humans off of it.

Re: Earth-like planet spotted orbiting Sun’s closest star

#236

Post by [deleted] »

netcraft wrote: post #174
galacticaactual wrote: post #159

Earlier quoted context omitted.

It achieved those speeds by falling into a gravity well. Reaching Alpha Centauri requires escaping one.

I very well may be wrong about this, but I believe thats not exactly true. Parker required the fasted launch as of its time because it had to shed the momentum of the earth that it started with to be able to fall into that gravity well. quoting from reddit: > You may be thinking of the Sun as a big gravity well and how you can just drop things in a well. But orbits don't work anything like that at all. Sure if you ar…

[deleted]

Re: Earth-like planet spotted orbiting Sun’s closest star

#237

Post by R0b0t1 »

spaetzleesser wrote: post #207
oceanplexian wrote: post #114

Earlier quoted context omitted.

It sounds like a very chicken or egg problem to me, who's to say that progress in robotics doesn't come from trying to establish a base on Mars? Progress is often times non-linear, I mean here we using computers and communication technology based on Integrated Circuits technology furthered by the Apollo program; say we never went to the moon, computing technology and Moore's law might have been set back a decade or t…

I am not against Mars but I just think it’s premature. Build up robotics for a while and Mars will be much easier. There is no rush to become a multi planetary species. There is no credible threat of a big asteroid or volcano in the next decades. All threats we may be facing are self made. My favorite moonshot project would be to create robotics that can clean up the environment and handle recycling. Having the techn…

I think all of this is premature. Focusing on life extension technology and life science would see a lot of other technological benefit, and in the worst case just mean we can wait it out.

Re: Earth-like planet spotted orbiting Sun’s closest star

#239

Post by s1artibartfast »

qwytw wrote: post #219
s1artibartfast wrote: post #171

Earlier quoted context omitted.

The notable difference is that they don't have a monopoly on violence

Most premodern states (at least) in Europe didn't really have a monopoly on violence in the strict sense either. Kings were constrained by a variety of laws and customs which they couldn't easily change without triggering violent opposition and had to co-opt the local elites (who usually acted as independent actors) whenever they wanted to impose their will outside of the area they directly controlled. Even an 'absol…

Fair enough, it seems that you are primarily attacking the word Monopoly. What if we were to soften the claim to dominance. Rulers always maintained power based on their ability to resist violence from within and without. Economic leverage only existed as long as one could protect themselves from violent opposition. A trade embargo meant nothing if the opposition can seize your assets and production by force.

In today's world, mega corporations have no defense if a government actor decides to use force against them.

This utter defenselessness against violence is the main difference between a modern corporation and a feudal actor.

Re: Earth-like planet spotted orbiting Sun’s closest star

#240

Post by ufmace »

semi-extrinsic wrote: post #60
uwuemu wrote: post #33

Earlier quoted context omitted.

A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget. I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think abou…

Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool). Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant. Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a…

I don't think that a compact fusion powerplant specifically is needed. But I do agree that a truly self-sufficient Martian colony (I.E. able to exist for more than a few years without ships coming from Earth) would need a gargantuan level of infrastructure to have even a small chance of being viable.

From a standpoint of reducing emissions on Earth, it would be cool to see Elon Musk's best take on how to build a practical fusion generator though. I've heard of a few potential paths that could lead to net power much faster and cheaper than ITER. Supposedly superconducting magnets have gotten considerably better since ITER was proposed, and since power output in a tokamak reactor is something like the third or fourth power of the magnet strength IIRC, there's potential for a newer and smaller reactor design to outdo it in both timeline and cost.

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