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A Lonely Universe

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Re: A Lonely Universe

#91

Post by kkjjkgjjgg »

Maybe some evolutionary steps prevent them from happening again in other branches, because they take over the world so quickly?

For example human intelligence might have quickly wiped out or constrained to small populations all other mammals on the path to the same level of intelligence?

Early forms of life may also have multiplied so fast that all chemical resources useful for it became involved in the "lifecycle" of life and hence were not available for other types of life to evolve.

Re: A Lonely Universe

#92

Post by ncmncm »

brabel wrote: post #85
ncmncm wrote: post #19

Earlier quoted context omitted.

A galaxy is really a pretty dangerous place for organic life. One supermassive black hole merger in the same or nearby galaxy, a biggish black hole merger within 10,000 light years, a magnetar hiccup within 500 ly, or a workaday supernova 5 ly off might be enough to sterilize a whole solar system. There is no guessing how many times life has been wiped clean that way. The sooner our descendants can get the hell out o…

I think we are in a relatively safe corner of the galaxy though... IIRC there's no cosmical existential threat we know of within the next billion years or so, and the kind of cataclism you're talking about would be the kind of thing we should already be able to predict millions of years in advance.

Sol orbits the galaxy independently of all other bodies. We don't know where most of the magnetars are, never mind their orbits, which are anyway unpredictable. (The nearest we know of is ~5kly? away. Or more, or less.) We don't know where any but two of the black holes are, although there must be a billion or more. Less than ten million years ago we flew into a dust cloud left over from a recent supernova.

We could have been in sterilization range of a magnetar dozens or hundreds of times since life evolved, so we're just lucky none erupted when we were. The core supermassive black hole blew somehow just 100Mya, fortunately pointed somewhere else.

The only safe-ish corner is very far from everything else, and off-axis from the central black hole. We are deep in the thick soup.

Re: A Lonely Universe

#93

Post by dcvz234 »

lubujackson wrote: post #24
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…

The third option is that everything is simply too far apart and any detectible transmissions are either too faint or buried behind all those massive fusion furnaces. For instance, if our best Earth tech was pointed at Earth from a distant star, how far away would we be able to detect our own traces of life? We know that life is "a little rare" at least, but there is a huge range of rarity where life is everywhere acr…

Maybe we give ourself too much indulgency about how further we are in the technological evolution. Maybe we are just at caveman level +1 and looking for radio signals is like trying to find smoke based communications in NY.

Maybe we are still missing something fundamental about the universe and we don't know, like we ignored electricity or nuclear forces existed just decades or 150 years ago.

That UFO the US navy has in footage, from 2019, making a diving nose maybe at 200 mph into the ocean without making a single wave or splash, is telling you something: you don't know everything about physics, just yet.

Re: A Lonely Universe

#94

Post by wruza »

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…

Expansion is a property of k>1 reproduction. We could make a sustainable happy civilization even on this dirty planet, if not our biological drive to multiply and eat all gifted to us resources with time. My bets are not on climate ops or hunting-gathering for mature civilizations, but simply on k~=1, the simplest form of existence that brings more value with time instead of more size.

Re: A Lonely Universe

#95

Post by dcvz234 »

Maybe we were already found and we are just being contacted right now, but we're still in the early stages of the contact, after all we know what happened when technological advanced humans contacted less advanced human civilizations.

Hence is quite reasonable our fellow alien visitor probably would be better than us at contacting very agressive cavemen with nuclear weapons.

Re: A Lonely Universe

#96

Post by WalterBright »

hoseja wrote: post #89
WalterBright wrote: post #87

Earlier quoted context omitted.

> But those things take millions of years at least Perhaps. But we may not be spacefaring for very long. Now's the chance. We've been exploring Mars for 45 years now. No life yet. As I said, the people who regard life as a malignancy will never be satisfied. There's always a deeper hole to look in. > contaminate Earth life isn't "contamination". > unknown-unknown phenomena we shouldn't blindly rob ourselves of Instea…

If you let air into my high vacuum electron microscope I will not be passing moral judgement on the air but will nonetheless be unable to study my specimens.

Life on earth has not prevented you from using your electron microscope.

What science has life on earth prevented? What secret of the universe has life blinded us to?

Re: A Lonely Universe

#97

Post by wruza »

dcvz234 wrote: post #93
lubujackson wrote: post #24

Earlier quoted context omitted.

The third option is that everything is simply too far apart and any detectible transmissions are either too faint or buried behind all those massive fusion furnaces. For instance, if our best Earth tech was pointed at Earth from a distant star, how far away would we be able to detect our own traces of life? We know that life is "a little rare" at least, but there is a huge range of rarity where life is everywhere acr…

Maybe we give ourself too much indulgency about how further we are in the technological evolution. Maybe we are just at caveman level +1 and looking for radio signals is like trying to find smoke based communications in NY. Maybe we are still missing something fundamental about the universe and we don't know, like we ignored electricity or nuclear forces existed just decades or 150 years ago. That UFO the US navy has…

But we can’t deny a natural barrier. Modern sci-tech if used in 18 century would dramatically explode into fundamental discoveries. Einstein Bohr et al would jump for joy having these “toys”, cause all they’ve had was basically pen and paper. But now sci-tech mostly supports existing theories for many decades. Not saying there is nothing new, but there is nothing groundbreaking either in fundamental parts of nature.

Re: A Lonely Universe

#98

Post by rewgs »

lubujackson wrote: post #24
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…

The third option is that everything is simply too far apart and any detectible transmissions are either too faint or buried behind all those massive fusion furnaces. For instance, if our best Earth tech was pointed at Earth from a distant star, how far away would we be able to detect our own traces of life? We know that life is "a little rare" at least, but there is a huge range of rarity where life is everywhere acr…

Yeah, I think that the Fermi Paradox can be pretty easily explained: the universe is fucking huge.

Those who talk about the feasibility of alien life visiting us very simply haven't thought it through, or are ignorant of the reality of space.

It's just too staggeringly big.

Re: A Lonely Universe

#99

Post by jakey_bakey »

deltaonefour wrote: post #83

I always felt the drake equation was BS: https://www.wikiwand.com/en/Drake_equation#:~:text=fp%20%3D%... ) Those arbitrary constants are arbitrary and made up. The argument presented in this article makes a lot more sense.

Oh absolutely, the Drake equation is a popular-science construct

Re: A Lonely Universe

#100

Post by rewgs »

Scarblac wrote: post #88
api wrote: post #37

Earlier quoted context omitted.

Theoretically if you could travel very close to the speed of light time dilation would make the trip fairly short. Of course it’s one way since it would take hundreds of thousands to millions of years for everyone else. If you came back you would be returning to a different geological epoch. Of course the energy requirements are insane and would require some kind of physicists nightmare propulsion system like antimat…

> Of course the energy requirements are insane and would require some kind of physicists nightmare propulsion system like antimatter rockets. Lose reactor containment and you are instantly converted into plasma and gamma rays. If you hit something the size of a dust particle it will destroy your spacecraft. And, this one spacecraft needs to be able to slow down, have the telescopes and equipment needed to identify ex…

Ha! Funny, I've never considered it even though it's so incredibly obvious: the spacecraft needs to be able to slow down out of light speed. That might honestly be even harder than getting up to light speed, and that of course is almost certainly impossible.

Imagine the "runway" you would need. How many lightyears would it take just to slow down? And that's before you even consider how some sort of reverse propulsion mechanism would even begin to turn on without tearing the ship apart in a microsecond.

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