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A Lonely Universe

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Re: A Lonely Universe

#191

Post by ncmncm »

hyperpallium2 wrote: post #50
Causality1 wrote: post #2

Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and…

Re: too old The Moore's law-like analysis of the exponentially increasing comlexity of life over time suggests the time for life of our complexity is... about now. We may he first.

Earth started out very late. Billions of years late.

Re: A Lonely Universe

#192

Post by ncmncm »

7thaccount wrote: post #164
TheRealNGenius wrote: post #111

Earlier quoted context omitted.

that one can't discern the difference, yet would undergo this procedure themselves, is telling in and of itself

Can you elaborate? I think sharding yourself (breaking yourself into clones, not pooping on yourself) would be pretty interesting. A lot of problems could be worked on simultaneously. There are of course philosophical implications. I think it is fine as long as it isn't forced.

Would your shards have rights to spend your money?

Re: A Lonely Universe

#193

Post by ncmncm »

slothtrop wrote: post #143
Causality1 wrote: post #2

Either intelligent life is rare in the universe or there's something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets. Maybe 99.99% of species ruin their own climate before getting off-world. Maybe they all decide it's happier living as hunter-gatherers. Unless we're alone, there is some fate that's common to all intelligences and…

More than likely, we're early (as expansionist intelligent lifeforms go), and the race is still on to colonize.

More than likely, expansionists aren't welcome in the galaxy, and are curtailed by non-expansionists when they begin to become a nuisance.

Re: A Lonely Universe

#194

Post by me_me_me »

mrjangles wrote: post #182
me_me_me wrote: post #133

Earlier quoted context omitted.

I dunno, the dark forest trilogy definitely sparks interesting conversations. But a counter example to it is that only via cooperation a tribe can become technologically advanced. All those tribes are just tribes due to their constant squabbling and fighting, while the other that cooperated, traded and exchanged ideas ended up advancing. Wars were/are part of humans but in Europe it quickly became evident that techno…

Yes sure, but I feel like this stuff came later. Once we had the technology, knowledge about each other, institutions, rule of law, etc, then people could begin to trust each other and work together. This is what happened everywhere slowly. But at the start where everything is unknown and everything is new, and we can't see beyond the next tree, when we don't know what is out there and what they want. In that world,…

I have a hard time seeing an analogous scenario in the spacefaring species case.

1. You are barely space capable meeting advance civ. Its like modern country meeting tribe. They hold cards but dont really care about you or maybe help you.

2. Opposite of 1, but the outcome is the same. Why destroy them if they are technologically inferior.

3. Both equally advanced, if you were both capable of fighting would it make sense to actually fight?

The dark forest holds true if there were a lot of civilisations out there and if you can have magical tech that can wipe a star system or fold it into 2d, but if all you have spears you can at best only threat the guy on the other island - or trade with them.

Re: A Lonely Universe

#195

Post by pfdietz »

ncmncm wrote: post #186
pfdietz wrote: post #125

Earlier quoted context omitted.

We can achieve relativistic speeds with technologies we can imagine (specifically, laser light sails). This would require just millions of years to get to M-31, for example (which is 2 million light years away).

Arriving not in atomically finely tattered shreds is left as an exercise for the descendants. And, stopping.

They'd presumably do this starting from the fringes of the galaxy where the gas is thinner, and with a sufficiently big vehicle (perhaps assembled out of parts that are accelerated separately) that it could withstand some erosion. The sail itself would be discarded after acceleration.

Drag on the interstellar medium using magnetic fields could be used for deceleration.

Re: A Lonely Universe

#196

Post by pfdietz »

foobarian wrote: post #141
pfdietz wrote: post #123

Earlier quoted context omitted.

No, exponentially. I used that word precisely, because the mass ratio in the rocket equation is exponential in (delta V)/(exhaust velocity).

Thanks for the reply. Context: there are so few exponential processes in nature, especially around classical physics that it really stuck out here, so I made the comment. I should have searched and read up on it instead, but thought there is still some value in others seeing the conversation. And lastly: that is really depressing :-(

That exponential dependence comes from the use of chemical rockets, which have a pretty firm upper limit on their exhaust velocity. Once in space, lower thrust could be used, which admits the possibility of higher exhaust velocity. If one can vary the exhaust velocity then the problem can be evaded (although the specific power (power/mass) of the vehicle must be allowed to become very large, or else acceleration will decrease.)

Recent example: https://phys.org/news/2022-02-laser-mars.html

Note the very high specific power. High Isp rocketry is all about the heat dissipation.

Re: A Lonely Universe

#197

Post by slothtrop »

ncmncm wrote: post #193
slothtrop wrote: post #143

Earlier quoted context omitted.

More than likely, we're early (as expansionist intelligent lifeforms go), and the race is still on to colonize.

More than likely, expansionists aren't welcome in the galaxy, and are curtailed by non-expansionists when they begin to become a nuisance.

The capability of "curtailing" another race from expanding is contingent on having expanded into the galaxy.

Re: A Lonely Universe

#198

Post by ncmncm »

slothtrop wrote: post #197
ncmncm wrote: post #193

Earlier quoted context omitted.

More than likely, expansionists aren't welcome in the galaxy, and are curtailed by non-expansionists when they begin to become a nuisance.

The capability of "curtailing" another race from expanding is contingent on having expanded into the galaxy.

It is contingent on having the physical capacity to have expanded, had they cared to.

Re: A Lonely Universe

#199

Post by DrBoring »

WalterBright wrote: post #178
DrBoring wrote: post #132

Earlier quoted context omitted.

I'm ignorant in the matter of food scarcity in USA, but I would say that hunger is far from solved. USA may produce more food than it can consume, but there is still the cost of production and delivery of food. Hunger will still be a thing if food costs more than people can pay. USA may collectively have enough money to buy food for everyone, but the will to spend public money is not there at the current cost of food…

I've never seen anyone in my life in the US showing the symptoms of starvation. I've never heard of anyone starving to death in the US, that was not the fault of some underlying disease, alcoholism, or drug addiction rather than privation. Having some hunger now and then is actually healthy for people. Fasting for a day or two here and there is a good practice. It also substantially lowers one's food expenses. If you…

Hmm, interesting point. You're probably correct. Incidents of death by poverty induced starvation in the US have got to be low.

Incidentally, my name is Walter too.

Re: A Lonely Universe

#200

Post by ncmncm »

pfdietz wrote: post #195
ncmncm wrote: post #186

Earlier quoted context omitted.

Arriving not in atomically finely tattered shreds is left as an exercise for the descendants. And, stopping.

They'd presumably do this starting from the fringes of the galaxy where the gas is thinner, and with a sufficiently big vehicle (perhaps assembled out of parts that are accelerated separately) that it could withstand some erosion. The sail itself would be discarded after acceleration. Drag on the interstellar medium using magnetic fields could be used for deceleration.

Standing up to millions of years of relativistic erosion seems difficult.

Accelerating ISM ions near your destination to slow down would necessarily consume as much energy as it took to get up to speed, and without assist from folks at home (who are anyway a different species by now). You will have plowed through untold tons of relativistic IGM on the way that I suppose you could collect on the way and then fuse to power your EM brakes.

Retaining all that IGM seems mainly a matter of dissipating heat, provided you have discovered how to keep it from instead blasting bits off of your bumper. It would, also, all need to be accelerated to match your speed. A substantial fraction of it would be neutral, so purely ballistic.

Maybe you have a million (or ten; hundred?) km of very diffuse spray foam for your front bumper, that you will wring out for protons when time comes to stop?

Presumably you want to stop where whatever you made the trip for is, assuming it is still there ("lo!") those millions of years later. It must be something you couldn't find anywhere among the half-trillion stars back home. (You did look, right?) Or maybe you just wanted not to be there -- neighborhood gone downhill, galaxy too small for both you and the ex?

Given that you can weather a million years of relativistic battering, and actually collect industrial feedstocks from it, maybe you don't really need a galaxy or anything in one anymore, and can just keep going. It ought to be safer out there, without an ever-present threat of magnetars around always threatening to belch slightly and sterilize everything for much farther than can be seen without a telescope.

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