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Observable Universe contains 10x more galaxies than previously thought (2016)

spacetelescope.org

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Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#121

Post by QAPereo »

Razengan wrote: post #3

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…

https://en.m.wikipedia.org/wiki/Great_Filter

https://www.haystack.mit.edu/hay/staff/jball/etiy.pdf

Dark Forest

The tyranny of ‘c’

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#122

Post by lucozade »

TeMPOraL wrote: post #96
lucozade wrote: post #58

Earlier quoted context omitted.

> It would also ultimately kill off most of our existing religions I think you may be underestimating the tenacity of religions

Maybe. But I would love to see how mainstream religions of today try to handle a definitive proof of a separate tree of life elsewhere in space.

I'm going to guess they'll handle it the same way as they handled definitive proof that the Earth is more than a few thousand years old, that the Earth revolves around the Sun, evolution by natural selection etc etc.

Unconditional belief in the unknowable gives you an awful lot of wiggle room when it comes to evidence.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#123

Post by dghughes »

piquadrat wrote: post #30
Razengan wrote: post #3

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…

@ASmallFiction had a beautiful, succinct take on this recently: "Are we alone in the universe?" she asked. "Yes," said the Oracle. "So there's no other life out there?" "There is. They're alone too." https://twitter.com/ASmallFiction/status/946608733982822401

I like that it makes sense.

I'd say there certainly is life out in the Universse and it's quite possible there is intelligent life.

But the distances are so large that we will never meet any other intelligent life before our own civilization vanishes.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#124

Post by truantbuick »

Razengan wrote: post #3

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…

When we talk about something so big that it might as well be infinite, we call it "astronomical". We've all heard the awesome facts: we know we're an invisible dot in our town; we know the town is an invisible dot on the planet; we know the planet is an invisible dot in the solar system; we know the solar system is an invisible dot in the galaxy; we know the galaxy is an invisible dot in the universe.

But, as impressive as that all sounds, that's describing scale with exponential growth, but exponential growth pales in comparison to combinatoric growth.

The number of ways you can arrange 100 people is far greater than the number of estimated atoms in the universe. And not _just_ greater, greater in a way that is difficult to explain. A drop in a bucket? No. A drop in the ocean? No. All our metaphors are physical, and so they're inadequate, but let's just it's beyond all that.

Of course, that doesn't mean the probability of other intelligent life is best assumed to be of a combinatoric nature, but let's get ahead of ourselves and let our awe of the universe's size cloud our judgement. It's far from infinite, and silly to assume intelligent life is certain.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#125

Post by maze-le »

CuriousSkeptic wrote: post #108
maze-le wrote: post #52

Earlier quoted context omitted.

> Right now there is more evidence for the universe to be finite rather than infinite. There is the observable universe and there are good reasons to believe that there is "some universe" beyond the observable universe. The observable universe is finite, the reason for that is the geometry of spacetime and the consequences of it (cosmological horizon/particle horizon). But I would not make absolute statements about w…

But if there can be no data about it. Does it even make sense to talk about it as existing? IIUC everything in the observable universe is sufficiently far away from anything else that any causal relationship with anything is either from before inflation or within the universe we can observe. And given how the existence of matter seems to be rather connected to time, it self a by product of interaction, it seems to fo…

That is an interesting metaphysical objection. Does a particle exist, if you cannot measure it? There is certainly no reason to think it does. But is there reason to categorically deny is existence? Very hypothetically, you might build a "Laplacian supercomputer" that could answer this question. But until this can be done (wich I doubt very much), the agnostic approach, to leave the question as undecidable, is prudent here.

>> IIUC everything in the observable universe is sufficiently far away from anything else that any causal relationship with anything

I don't think that is correct. Suppose you have a particle that is very very near the horizon. This particle has its own observable universe and we are at the edge of its horizon. Now, this particle can have casual contact with the other parts of the universe (the parts beyond). But by the time the interaction takes place, it has already slipped out of our horizon. So from the perspective of the particle casual contact is possible. But from our perspective: Not even a chance to detect this interaction.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#126

Post by bcaulfield »

V-2 wrote: post #44
Razengan wrote: post #3

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…

Great reality check. I'll remember this point every time I read an article spouting the "there MUST be life out there because there are SO many planets" line.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#127

Post by [deleted] »

Razengan wrote: post #3

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…

[deleted]

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#128

Post by falsprofet »

ajuc wrote: post #67
b3lvedere wrote: post #8

Earlier quoted context omitted.

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…

I know it's wrong on purpose, but still... > 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…

Wouldn't you get aleph_1 divisions, if, by methods left as exercise to the reader, making a cut for each real number? For example, how many angles are there in a circle? But the real kicker is, that taking the 2D surface of a ball, certainly the area is finite even if there are no bounds at all.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#129

Post by rdruxn »

I’ve seen a lot of posts recently discussing humanity’s concept of the size of the cosmos throughout history, but never a timeline of discoveries and the prevailing estimate du jour. I would love to see something like that and Wikipedia doesn’t do it justice.

Re: Observable Universe contains 10x more galaxies than previously thought (2016)

#130

Post by hackeraccount »

V-2 wrote: post #90
olegkikin wrote: post #62

Earlier quoted context omitted.

There's a huge difference between what evolved organisms can adapt to, and the conditions necessary to start life. 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.

Out of which some 3 billion years had to pass before unicellular forms of life evolved into multicellulars. Who knows if this jump alone should be taken for granted - plus, not many planets could provide 3 billion years of "good weather" (or staying habitable) to start with.

That is the odd thing about the history of life on Earth isn't it? Prokaryote popped up almost as soon as was conceivably possible. And then. Nothing. For billions of years. The plausible explanation is that you need Oxygen for Eukaryotes and that's how long it to change the chemistry of a planet. It just seems weird to me.
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