61–70 of 161 posts
Staring into those deep field images sometimes gives me an out-of-body sensation. The vastness of it is so over-the-top.
If looking at a few images gives you that sensation, then you should try out the Space Engine (traveling through space in 3D): http://spaceengine.org/ A demo: https://www.youtube.com/watch?v=ve0Bpmx8Fk0
Earlier quoted context omitted.
> How, when given the evidence of practically infinite planets out there [...] can we even consider the possibility that this is the only planet with life? Human minds aren't good with very large numbers. What seems "practically infinite" to us - isn't, really. The number of all planets in the universe is said to be in the ballpark of 10^24. Meaning (obviously) if you keep on dividing it by 10, in just 24 steps you g…
We don't know all the factors under which life can exist. Even the lifeforms that we do know of, occupy a very broad spectrum in all metrics, existing at all sorts of extremes. We even have evidence of life we have never seen, will never encounter, and may never even have conceived as being possible to exist without that evidence: the enormous dinosaurs.
Look, humans already adapted to being in space for prolonged periods of time. We adapted to every climate. But drop a naked human in a random spot on our planet, and he will die with high degree of probability. And that's after billions of years of evolution.
I think other lifeforms exist in the universe, but the probability that they live in the same timeframe or that the two lifeforms meet each others is ridiculous
And some people still aren’t sure if there is other life beyond Earth. :) That's entire galaxies. Not just stars, and that's just the observable universe. We are still being surprised by the lifeforms we observe here on Earth, and the environments and conditions they can thrive in (including the outer hulls of our spacecraft), and we still have yet to discover and catalog all the life on our planet. Life may even com…
Ehm... sorry to be a bit pedantic, but the distinction between the two has no effect on your argument here. Either way there are ten times as many environments in which stuff happens.
Also, as b3lvedere's comment points out elsewhere, you really shouldn't trust gut instincts when it comes to reasoning about infinities. Unless you're a mathematician specialized in the subject, you're pretty much guaranteed to be wrong about them.
(having said that, I'm also more inclined to believe that there's plenty of life out there. I'm not as hopeful about complex life-forms escaping planets though)
Earlier quoted context omitted.
> And some people still aren’t sure if there is other life beyond Earth. :) Until we actually observe it, no, we can't be sure; the probability of it existing is high simply due to the sheer amount of dice rolls there are in the universe, but the likelihood of us observing it is low. We already know there is and was no intelligent life in our solar system besides what's on Earth; there's still hopes of finding traces…
>I also doubt humanity will find a way to travel fast enough to get to another solar system within a human lifespan. The next solar system is only four lightyears away. Given the will to break nuclear test ban treaties we think we could develop nuclear pulse propulsion drives that achieve about 10% the speed of light. Even after accounting for acceleration and deceleration that gets us there in a human lifespan. Gran…
It gets _something_ there in a human lifespan. The only really well though out models for that are Daedalus and Icarus, and they would involve flybys only of probes the size of a hockey puck, or a washing machine at most. The cost of which would be civilisation impoverishing.
I think it's a very reasonable chance that humanity will never, as a functioning human populated civilization, ever spread beyond this solar system. Now 'never' is a pretty long term statement, but no matter how advanced our technology becomes, it's still likely to be constrained by the physics we know. It looks like spreading beyond this system would cost a very large fraction of all the resources we have in the system to start with, if it ever becomes practical at all.
And some people still aren’t sure if there is other life beyond Earth. :) That's entire galaxies. Not just stars, and that's just the observable universe. We are still being surprised by the lifeforms we observe here on Earth, and the environments and conditions they can thrive in (including the outer hulls of our spacecraft), and we still have yet to discover and catalog all the life on our planet. Life may even com…
> How, when given the evidence of practically infinite planets out there [...] can we even consider the possibility that this is the only planet with life? Human minds aren't good with very large numbers. What seems "practically infinite" to us - isn't, really. The number of all planets in the universe is said to be in the ballpark of 10^24. Meaning (obviously) if you keep on dividing it by 10, in just 24 steps you g…
However I do think that you vastly underestimate the probability of life. Take a look at https://en.wikipedia.org/wiki/Earliest_known_life_forms . See how quickly life appeared once the earth had cooled down? It's almost immediately!
I'm pretty convinced that almost all star systems have some complex energy conversion cycles that could be classified as life. Let's not make the mistake of assuming all life has to be carbon based.
And some people still aren’t sure if there is other life beyond Earth. :) That's entire galaxies. Not just stars, and that's just the observable universe. We are still being surprised by the lifeforms we observe here on Earth, and the environments and conditions they can thrive in (including the outer hulls of our spacecraft), and we still have yet to discover and catalog all the life on our planet. Life may even com…
Infinity is fun :) It reminds me of that (totally wrong) quote in The Hitchhikers Guide To The Galaxy that the population of the universe is mathematically zero. The Universe is a very big thing that contains a great number of planets and a great number of beings. It is Everything. What we live in. All around us. The lot. Not nothing. It is quite difficult to actually define what the Universe means, but fortunately t…
> it is impossible to import things into something that has infinite volume because by definition there is no outside to import things from.
If you cut a 2d plane with a line, then both halves are infinite, yet both have "outside". You can repeat this and get infinite (aleph 0) number of divisions, each still as infinite as the initial plane.
Same way you can cut infinite 4d universe into countably many infinite 4d universes.
> not all of them are populated; therefore only a finite number are
By same logic: not all integer numbers are even, therefore only a finite number of numbers are even.
And some people still aren’t sure if there is other life beyond Earth. :) That's entire galaxies. Not just stars, and that's just the observable universe. We are still being surprised by the lifeforms we observe here on Earth, and the environments and conditions they can thrive in (including the outer hulls of our spacecraft), and we still have yet to discover and catalog all the life on our planet. Life may even com…
> And some people still aren’t sure if there is other life beyond Earth. :) Until we actually observe it, no, we can't be sure; the probability of it existing is high simply due to the sheer amount of dice rolls there are in the universe, but the likelihood of us observing it is low. We already know there is and was no intelligent life in our solar system besides what's on Earth; there's still hopes of finding traces…
And some people still aren’t sure if there is other life beyond Earth. :) That's entire galaxies. Not just stars, and that's just the observable universe. We are still being surprised by the lifeforms we observe here on Earth, and the environments and conditions they can thrive in (including the outer hulls of our spacecraft), and we still have yet to discover and catalog all the life on our planet. Life may even com…
mankind has been extremely lucky with our environments, among others: - Jupiter & Saturn pick out most of the comets, so we encounter massive reset only very rarely - thanx to hitting other planet long time ago, we have a spinning molten metal core inside planet generating magnetic shield for all nasty radiation - moon gives us tides & stability - our sun is just the right size and age to be stable - we're located at…
Given we didn't arrive until 14.5bn years into the universe's existence, I'd find that extremely hard to fathom.
And some people still aren’t sure if there is other life beyond Earth. :) That's entire galaxies. Not just stars, and that's just the observable universe. We are still being surprised by the lifeforms we observe here on Earth, and the environments and conditions they can thrive in (including the outer hulls of our spacecraft), and we still have yet to discover and catalog all the life on our planet. Life may even com…
mankind has been extremely lucky with our environments, among others: - Jupiter & Saturn pick out most of the comets, so we encounter massive reset only very rarely - thanx to hitting other planet long time ago, we have a spinning molten metal core inside planet generating magnetic shield for all nasty radiation - moon gives us tides & stability - our sun is just the right size and age to be stable - we're located at…
While it's true that life "out there" may look vastly different, I feel like sometimes ET-optimists use that as a hand-wavy defense that overlooks two curious details: First, we haven't found any different-looking-life-out-there on, say, Venus, or Mars... so clearly even in a solar system with some "lucky" aspects for life there are plenty of environments where life just doesn't "find a way." Second, the relative quickness with which our kind of life appeared in Earth's history suggests an oddity that we haven't even found other examples of our-general-kind-of-life out there.
A good book that explores some of the proposed solutions to the Fermi Paradox is Where is Everybody? by Stephen Webb. (It does a good job using math to explain why it's a little surprising that we haven't found ET life even within our own galaxy, and it does a good job knocking down most of the sociological explanations by noting that it would require every other civilization in the galaxy to behave that way with no exceptions.)