Aliens: Yes Or No?

[dragoner]

We're kind of a sad case, watching us die is not good, though helping us, and our spreading, given the first condition, is probably not ethical either.

 

[Professor Murder]

The universe is too large for there not to be other examples of consciousness elsewhere.
and
The universe is too large for any other conscious beings to ever come here.

We are in the space boonies. If there were a large number of similar solar systems within striking distance of us, things would be different, but I just feel we are too far from the galactic core to ever encounter any alien civilizations.

 

[Parmandur]

Is this true, I though that it is still an open question. we do know it is bigger than we can observe.

There are dissenters, but the Big Bang model is very well established at this point.

 

[Corinnguard]

So, amino acids are not "life". Amino acids don't even replicate themselves. There are no amino acids used in terrestrial life that can be shown, or even be reasonably argued, cannot easily arise naturally given a complex chemical soup and some energy (like radiation, volcanism and lightning can provide).

Thus, "amino acids are seen on meteors" doesn't make a statement about the origin of life. It makes a statement on the ubiquity of conditions to create amino acids - and thus that amino-acid-based life could also be ubiquitous.

True. Do you know how many amino acids exist in nature? About 500. And of that 500, only 22 of them appear in the genetic code of all life on this world alone. Amino acid - Wikipedia While they might not be life, they are the building blocks for carbon-based life, as we know it.

 

[Dausuul]

Statistically speaking, in a infinite universe, other intelligent life is pretty much assured.

In an infinite universe containing infinite matter, everything that appears once can be expected to appear an infinite number of times.

But we do not live in such a universe. There are various cosmological theories (e.g., eternal inflation) which propose a multiverse, which would be infinite; but even under those theories, each universe within the multiverse remains finite in both space and matter. And statistically speaking, in a finite universe, we have absolutely no idea whether other intelligent life is likely to exist.

 

[Blue]

So, amino acids are not "life". Amino acids don't even replicate themselves. There are no amino acids used in terrestrial life that can be shown, or even be reasonably argued, cannot easily arise naturally given a complex chemical soup and some energy (like radiation, volcanism and lightning can provide).

Thus, "amino acids are seen on meteors" doesn't make a statement about the origin of life. It makes a statement on the ubiquity of conditions to create amino acids - and thus that amino-acid-based life could also be ubiquitous.

This is not my subject of expertise, so I will direct your to others.

Wired article

Did the Seeds of Life Ride to Earth Inside an Asteroid?

Biological amino acids could have celestial or terrestrial roots. An experiment simulated their formation in deep space—but the mystery isn’t solved yet.

www.wired.com

Here's a paper on the animo acids for terrestial life having potential extraterrestial origin from 2017.

Did life on Earth start due to meteorites splashing into warm little ponds?

Life on Earth began somewhere between 3.7 and 4.5 billion years ago, after meteorites splashed down and leached essential elements into warm little ponds, say scientists. Their calculations suggest that wet and dry cycles bonded basic molecular building blocks in the ponds' nutrient-rich broth...

www.sciencedaily.com

Another from this year.

Insights into the formation and evolution of extraterrestrial amino acids from the asteroid Ryugu - Nature Communications

Amino acid concentrations from 2 particles returned from different touchdown sites on the surface of Ryugu are reported. Differences in chemistry suggest different levels of aqueous alteration are recorded at the 2 sampled locations.

www.nature.com

Oh, and that without Animo Acids we wouldn't have life as we know it, so it's a necessary building block. This is an article from John Hopkins university from this year. So it's not just about "amino-acid-based-life" as if that's something different than what exists on the Earth.

Ancient proteins offer new clues about origins of life on Earth

In early Earth simulation co-led by Hopkins researchers, scientists gain insights into how amino acids shaped the genetic code of ancient microorganisms

hub.jhu.edu

 

[UngainlyTitan]

There are dissenters, but the Big Bang model is very well established at this point.

The big bang does not make the universe finite. Even if it is finite there is (as far as I know) there is no consensus as to how big it might be. It is bigger than what we can see or ever see.

 

[briggart]

That's...not accurate. The universe is big, but finite.

That kind of depends on what you consider the Universe to be. The portion of the Universe from which we can currently receive signals has a finite size, since our Universe began 13.8 billion years ago. If the current phase of accelerated expansion will keep going on forever, we will ever be able to observe (or send signals to) a portion of the Universe that is 2-3 times larger than what we currently observe, even with infinite time. From this point of view, the Observable Universe is indeed finite.

But the Universe as a whole is larger than what we currently observe. We don't know if it is finite or actually infinite but, based on the properties of our region of space, we know that is must be at least 200-300 times larger than the currently Observable Universe.

 

[Stalker0]

In an infinite universe containing infinite matter, everything that appears once can be expected to appear an infinite number of times.

But we do not live in such a universe.

There is no current scientific consensus on whether the universe is infinite or finite, we simply do not know with any certainty.

 

[Parmandur]

The big bang does not make the universe finite. Even if it is finite there is (as far as I know) there is no consensus as to how big it might be. It is bigger than what we can see or ever see.

That is precisely what it entails: finite in size, and with a finite starting point. As evidence points towards the heat death of the universe being the end, it is finite in time ilin the future, too.