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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)

#31

Post by dom96 »

saiya-jin wrote: post #17
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…

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…

You're assuming that all life will be like ours. This is a safe bet, but there could be very many ways for life to exist.

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

#32

Post by SEMW »

ngcc_hk wrote: post #5

Need less dark mass and dark energy then. ...

No? The data for the makeup of energy in the universe is mostly from CMB anisotropy (plus various measures of how fast the universe is accelerating, like how much supernovae have been redshifted). Finding out that galaxies in the early universe used to be smaller and more numerous than previously thought doesn't much affect any of that. (there's quite a lot of different data sources now all pointing towards an omega_lambda of 0.7).

To be clear, per the article, the new discovery isn't about the early universe being a significantly different density (i.e. anything other than 'approximately flat', total omega ≈ 1) than the current one. Like, it's not that there was more mass-energy in it that's somehow vanished, rather that it's just distributed between more & smaller galaxies

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

#33

Post by millstone »

laumars wrote: post #18
millstone wrote: post #15

Earlier quoted context omitted.

Me, I think there is no life beyond Earth. > How, when given the evidence of practically infinite planets out there (considering that almost every star may have at least one planet, and there are even rogue planets [0] that don't orbit any star, and that asteroids and comets or even dense nebulas could also harbor life), can we even consider the possibility that this is the only planet with life? Who gives a shit? If…

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 intelligent for it to be interesting.

If something is interesting, why do we care if it's "life?"

Anything we find is likely to operate on some scale vastly different than what we're familiar with. We won't even agree on whether it's alive.

> Whereas when you're visiting a planet, you can observe a wider scope of life as it need not be intelligent (as we can perceive anyway) for markers to be identified.

My hope is we'll find markers that are clearly weird and that aren't evidence of life but maybe something more and weirder that we don't understand.

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

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

#34

Post by [deleted] »

hanbura wrote: post #26
Cthulhu_ wrote: post #22

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…

[deleted]

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

#35

Post by gfodor »

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…

It's extremely odd that we don't see autonomous probes from other civilizations that are used to monitor and disable technology that exposes existential risk to them. (For example, runaway AI would jeopardize all life if it were to expand at light speed.)

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

#36

Post by jules »

rbanffy wrote: post #19
millstone wrote: post #16

Earlier quoted context omitted.

This is an equally excellent argument that aliens speak English.

If the universe is large enough, with enough inhabited planets, it's very likely some alien, somewhere, speaks perfect English. At the same time, it's extremely likely we never encounter them.

For very large values of large enough that is always true. Even on the condition that they use the Latin alphabet and have exactly the same set of words and exactly the same set of meanings of words, there are still n factorial ways of assigning a meaning to each word. For n=1000 words that is already gigantic. Even if there is a civilisation that speaks English words on every planet in the observable universe, the probability that any one of them assigns the same meaning to words practically zero.

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

#37

Post by [deleted] »

rbanffy wrote: post #19
millstone wrote: post #16

Earlier quoted context omitted.

This is an equally excellent argument that aliens speak English.

If the universe is large enough, with enough inhabited planets, it's very likely some alien, somewhere, speaks perfect English. At the same time, it's extremely likely we never encounter them.

[deleted]

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

#38

Post by Razengan »

gfodor wrote: post #35
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…

It's extremely odd that we don't see autonomous probes from other civilizations that are used to monitor and disable technology that exposes existential risk to them. (For example, runaway AI would jeopardize all life if it were to expand at light speed.)

Can you imagine the likelihood of detecting such probes?

Can we even detect any of the probes that we ourselves have sent out, without knowing exactly where they are and how to communicate with them?

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

#39

Post by SideburnsOfDoom »

inventingwithmo wrote: post #10
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 realise I'm arguing against a work of comedy, but: > But not all of them are populated; therefore only a finite number are. There are infinities of different sizes

My understanding is that the infinity of "all integers greater than zero" and of "all integers greater than zero and divisible by 2" are in fact infinities of the _same_ size.

The same would apply for "divisible by 100" or "divisible by 1 million". This would apply to the fraction of worlds that are populated, whatever fraction of them are.

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

#40

Post by kowdermeister »

gfodor wrote: post #35
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…

It's extremely odd that we don't see autonomous probes from other civilizations that are used to monitor and disable technology that exposes existential risk to them. (For example, runaway AI would jeopardize all life if it were to expand at light speed.)

Maybe if they are advanced enough to send those probes specially if it's for _their_ defense then it's pretty well cloaked and small?
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