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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)

#51

Post by tome »

Razengan wrote: post #47
tome wrote: post #41

Earlier quoted context omitted.

Can you suggest another one?

• Robots that perform all the functions humans do, including making copies of themselves and teaching each other. • Hive-mind species where there are no individuals. • Species without any gender or sexual reproduction, whose individuals are spontaneously "born" in specific locations and conditions on their planet. • "Species" consisting of a single, massive/long-lived individual. • Parasitic intelligences that "infec…

When dom96 said "there could be very many ways for life to exist" I understood that to mean there could be very many different "biological substrates" (for want of a better term), nothing to do with how the species organises itself socially. The challenge is to come up with a hypothesis for "life" that's not based on long carbon chains.

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

#52

Post by maze-le »

vog wrote: post #14
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 this is not meant to be taken seriously, but some claims don't even make sense from a purely mathematical point of view. > Area: The area of the Universe is infinite. Right now there is more evidence for the universe to be finite rather than infinite. But apart from that: Just because it has no borders doesn't mean it is infinite. This is a classic failure in understanding infinity. For example, the area of th…

> 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 what lies beyond the horizon(s), since there is (and can be) no data that would justify a statement about the infinity of space or the falsification of it.

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

#53

Post by citation_please »

FreeHugs wrote: post #50
V-2 wrote: post #44

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…

Meaning if there are 24 factors crucial for life to evolve, and each has a 10% chance of occurring - it's actually quite likely only one planet would win on this lottery. Is it? What is the probability?

I believe the post above was working out math that would make it so the probability would be 1 / #(of planets in the universe), which, following the law of large numbers, would mean that given an infinite number of universes, those universes would tend to have exactly one planet (Earth in our universe's case) that would have life.

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

#54

Post by mtgx »

0xBA5ED wrote: post #28

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

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

#55

Post by TeMPOraL »

Razengan wrote: post #9
coldtea wrote: post #6

Earlier quoted context omitted.

> How, when given the evidence of practically infinite planets out there (considering that every star has at least one planet, and there are even rogue planets [0] that don't orbit any star), can we even consider the possibility that this is the only planet with life? For the "rogue" planets, it's easy -- we can be pretty sure they don't have any life. For the others, we'll believe it when we see it.

> For the "rogue" planets, it's easy -- we can be pretty sure they don't have any life. Why? Even if you assume all life requires heat and/or light, a rogue planet could produce heat/light from geothermal or other chemical activity. A rogue planet drifting through certain nebulas might have more surrounding material for the processes of life to work with. The life on a rogue planet may even be "artificial", say a col…

> A rogue planet drifting through certain nebulas might have more surrounding material for the processes of life to work with.

Keep in mind that nebulae are in reality less dense than industrial-grade vacuum. From the point of view of a rouge planet passing through one, it's pretty much still empty space.

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

#56

Post by gilleain »

Razengan wrote: post #45
V-2 wrote: post #44

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.

However, all the life we know of is part of the same Earth system. Just because some extremophile exists in a freezing desert or boiling pool does not necessarily mean that the same environments on other planets would have those organisms.

Life on Earth evolved and spread under specific conditions - our gravity, sun brightness, geology, magnetic field, large moon, etc etc. It then spread to all possible environments on the planet and evolved to live there.

Unfortunately, it could be that the 'growth conditions' for life are quite specific even if - once it gets going - life can evolve to more general environments.

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

#57

Post by TeMPOraL »

millstone wrote: post #33
laumars wrote: post #18

Earlier quoted context omitted.

One could flip your argument and say defining life as purely organic is a failure of imagination. The thing about searching for "life" over "intelligence" is that life doesn't necessarily need to be intelligent for it to be interesting. I also think the SETI example you've made is a tad unfair because their process dictates that their search be for intelligence (crudely put, radio transmissions). Whereas when you're…

> One could flip your argument and say defining life as purely organic is a failure of imagination. That's right! So how would you define life? Or the meta-question, why bother? We gain nothing from figuring out what's "alive" and what has "merely" a rich complexity. "Search for life" is a category error. > The thing about searching for "life" over "intelligence" is that life doesn't necessarily need to be intelligen…

> Isn't that even more interesting? Why hope to find life, when we know life is already possible?

We know it's possible, but we've also seen it happen only once. The observational data we have suggests the universe is mostly dead - that is, not complex. Or, in other words, boring. Discovery of any complex process on a comparable level to even simplest of what we call life would be a civilization-changing breakthrough. It would prove the universe is not boring.

(It would also ultimately kill off most of our existing religions.)

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

#58

Post by lucozade »

TeMPOraL wrote: post #57
millstone wrote: post #33

Earlier quoted context omitted.

> One could flip your argument and say defining life as purely organic is a failure of imagination. That's right! So how would you define life? Or the meta-question, why bother? We gain nothing from figuring out what's "alive" and what has "merely" a rich complexity. "Search for life" is a category error. > The thing about searching for "life" over "intelligence" is that life doesn't necessarily need to be intelligen…

> Isn't that even more interesting? Why hope to find life, when we know life is already possible? We know it's possible, but we've also seen it happen only once . The observational data we have suggests the universe is mostly dead - that is, not complex . Or, in other words, boring . Discovery of any complex process on a comparable level to even simplest of what we call life would be a civilization-changing breakthro…

> It would also ultimately kill off most of our existing religions

I think you may be underestimating the tenacity of religions

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

#59

Post by saiya-jin »

tome wrote: post #51
Razengan wrote: post #47

Earlier quoted context omitted.

• Robots that perform all the functions humans do, including making copies of themselves and teaching each other. • Hive-mind species where there are no individuals. • Species without any gender or sexual reproduction, whose individuals are spontaneously "born" in specific locations and conditions on their planet. • "Species" consisting of a single, massive/long-lived individual. • Parasitic intelligences that "infec…

When dom96 said "there could be very many ways for life to exist" I understood that to mean there could be very many different "biological substrates" (for want of a better term), nothing to do with how the species organises itself socially. The challenge is to come up with a hypothesis for "life" that's not based on long carbon chains.

I agree that only our imagination is the limit when discussing potential life. If matter that is not completely frozen (ie atoms stop moving) will eventually organize into some self-replication, any energy source could be enough.

It could be on the surface on active star, neutron star (someone already tackled that in sci-fi), all kinds of dwarfs, nebulas, maybe even something living off dark energy? Or black hole.

Energy means movement, and if matter/energy will eventually arrange into something 'alive', it might be enough.

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

#60

Post by TeMPOraL »

Razengan wrote: post #47
tome wrote: post #41

Earlier quoted context omitted.

Can you suggest another one?

• Robots that perform all the functions humans do, including making copies of themselves and teaching each other. • Hive-mind species where there are no individuals. • Species without any gender or sexual reproduction, whose individuals are spontaneously "born" in specific locations and conditions on their planet. • "Species" consisting of a single, massive/long-lived individual. • Parasitic intelligences that "infec…

The question is, how would it form by itself?

The fundamental thing about life as we know it is not just that it's made of the few particular elements it uses. It's about those elements being a sweet spot for molecular nanomachinery. It's not clear that any other combination of elements might be able to form a stable replicator and bootstrap itself into large-scale complex system. In fact, it might be that life can only arise by itself using materials our life is made of, directly because of laws of physics in our universe.

Or put in another way - if abiogenesis of our life is improbable, a spontaneous creation of robots - large scale machines with digital brains - is orders of magnitude less likely still.

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