Light from an ionized state of helium in a distant galaxy

https://www.quantamagazine.org/astronomers-say-they-have-spotted-the-universes-first-stars-20230130/

by theafh • 3 years ago

151 121 3 years ago

If we take the eventual heat death of the universe to be at about 10^100 years, the era we are in with stars and so on only lasts about 10^14 years. Which means light and stars and galaxies are actually just a tiny tiny blip at the start of the lifespan of the universe. Nearly all of the life of the universe will be dark with no stars, just black holes and dark distintegrating rocks and isolated particles.

https://en.wikipedia.org/wiki/Future_of_an_expanding_univers...

Sweet dreams

bjornlouser• 3 years ago

"Nearly all of the life of the universe will be dark with no star"

Maybe it will turn out that many of the double star systems were created by intelligent life

ben_w2• 3 years ago

How are you thinking about stars in a way that double stars will help?

SamBam• 3 years ago

Isaac Asimov's The Last Question is an excellent short story that explores whether future civilizations will ever be able to reverse entropy. [1]

Also, Ten Chiang's Exhalation is another short story about trying to stave off the entropy-death of the universe. [2]

1. https://astronomy.org/moravian/C00-Last%20Question.pdf (pdf)

2. https://www.lightspeedmagazine.com/fiction/exhalation/

GalenErso• 3 years ago

I refuse to believe that the Universe isn't cyclical, because I believe the Universe has existed forever, otherwise there is no answer to the origin of everything other than something from nothing or God.

PUSH_AX2• 3 years ago

Why is one of those answers better than the other?

permo-w• 3 years ago

why does there have to be an answer?

nullspace• 3 years ago

Amusingly (to me) the third attitude towards this is: "It just is that way. I'm sorry that the answer does not satisfy you, but the universe does not owe you a satifying answer." :)

gilleain• 3 years ago

This reminded me of the idea of a 'block universe' -

https://en.wikipedia.org/wiki/Eternalism_(philosophy_of_time...

which I first heard about in an interview with Alan Moore.

nh23423fefe• 3 years ago

I'm a "nothing" doesn't exist person

GordonS• 3 years ago

But... if there is a god, what created the god?

kypro• 3 years ago

I've often wondered whether something and nothing are just concepts that only make sense from the perspective of a subjective observer.

Is `1 + -1` something or nothing? And what is `2 + -2`? Is it something, nothing, or also `1 + -1`? And I could continue like this proving every number you could possibly imagine can exist in some manifestation of nothing.

So perhaps we're just one of the infinite manifestations of nothing. From our subjective perspective we are something, but from the perspective of an objective observer nothing is really happening because all the subjective manifestations equate to nothing.

I have no idea what I'm talking about, but this always made more sense to me than trying to understand why there is something and how long that something existed for. Perhaps it's both.

efdee• 3 years ago

But "forever" only makes sense within our universe, since time itself is intrinsically a property of the universe. If the universe exists within something else, "forever" doesn't necessarily mean anything there.

Aperocky2• 3 years ago

This is YOLO on the universe level.

ye-olde-sysrq2• 3 years ago

"How can the net amount of entropy of the universe be massively decreased?"

andai• 3 years ago

For the uninitiated: https://users.ece.cmu.edu/~gamvrosi/thelastq.html

MichaelZuo2• 3 years ago

What does 'net amount of entropy' mean?

bena4• 3 years ago

This sort of thing always fascinates me. This is all true and it absolutely does not matter.

The thought of the universe sitting essentially idle for 10^86 years seems like it should feel wasteful. But why? Wasting what? Does our consciousness imbue the universe with any special quality?

It's all so weird. Even some of our most fantastical science fiction only projects out a few millennia.

Star Trek gets to the 31st century (or 3000s). Foundation is at least 12,000 years in the future. Dune takes place from about 23,000 to about 28,000. Warhammer 40k gets its name from the fact it takes place in the 40,000s. The Time Machine reaches to the 800,000s for the majority of its action. Red Dwarf is set the furthest at 3,000,000-ish.

All of which fall way short of even 1 billion years. The Andromeda and Milky Way galaxies aren't scheduled to meet up for another 5 billion.

We aren't even a blip.

lanna• 3 years ago

The thought of the universe sitting essentially idle for 10^86 years

10^100 years minus 10^14 years is not 10^86 years. It is roughly 10^100 years.

badcppdev• 3 years ago

Small correction to your maths but not your sentiment.

10^100 years - 10^14 years = approx. 10^100 years

In the same way that:

10^6 - 10^3 = 1,000,000 - 1000 = 999,000 which is more or less approx. 10^6

Edit: Although this is one of those relatively uncommon situations where it doesn't really matter if you're off by 100 trillion years.

hinkley3• 3 years ago

They’re all dead, everybody’s dead, Dave.

euroderf2• 3 years ago

A great AR art project for the coming years would be to speed up the collision with Andromeda by a factor of a zillion, so that it takes place over a few years.

kldavis4• 3 years ago

Since you mentioned some works of science fiction, this is one thing that is pretty awesome about Cixin Liu's Three Body Problem and how the series encompasses the present and all the way past the end of our universe. It is a really jarring perspective change for us as mortal humans that I think is something that only well thought out science fiction can accomplish.

anjel• 3 years ago

Try telling that to yeast

ridgeguy• 3 years ago

Check out Vernor Vinge's Marooned in Realtime for a murder mystery and love story that transpires over millions of years.

chihuahua• 3 years ago

This is one reason why true immortality would be a bad idea.

thisismyswamp2• 3 years ago

This is meaningless, nothing about those numbers matters neither does it say anything conclusive about the nature of reality. It's just our best guess right now, and we are very early.

Aperocky2• 3 years ago

I find this interesting about human nature, that is in the want to believe in something eternal.

Even if current theory about Universe is proven correct, it will most likely have no effect whatsoever on current human lifetimes. But doesn't preclude us from wanting to believe that the universe is eternal and constant, that there will be flashes of life and activity 10^50 years down the line.

didntreadarticl4• 3 years ago

True, there are other options

https://en.wikipedia.org/wiki/Big_Crunch

https://en.wikipedia.org/wiki/Big_Rip

https://en.wikipedia.org/wiki/False_vacuum_decay

etc

__MatrixMan__2• 3 years ago

If this haunts your dreams, consider "The Life of the Cosmos" By Lee Smolin, as antidote. In that book he proposes that each of those black holes has a child universe associated with it, some of which have sets of physical constants that allow for grandchildren.

It's a fun read.

xwdv3• 3 years ago

First generation stars are so massive, couldn’t there be vast numbers of planets in habitable zones orbiting one? Seems good for a sci-fi setting with feasible interplanetary travel and trade amongst many different worlds.

astroH5• 3 years ago

Unfortunately not. These stars have no elements heavier than hydrogen and helium so you wouldn't be able to create a rocky planet that's habitable. Furthermore their lifetimes are only 3 Myr which is much to short to form a rocky planet and also the explosion from SN if it happens or direct collapse of the star to a black hole would immediately destroy any life.

xwdv3• 3 years ago

Ah fuck, there goes that idea then I guess.

astroH5• 3 years ago

As an expert in this space, I can confidently tell you that nothing about this observation is conclusive about the presence of the "First Stars" or what we call "Pop. III" Stars. By definition, the first stars are nearly completely devoid of elements heavier than hydrogen and helium. The spectra shows absolutely booming emission from Oxygen III ions at 5007A so there are heavy elements in the system and at best there is a mix of Pop III stars and more normal stars. The lifetimes of the stars are very short, ~3 Myr, so the chances of seeing them are very low which is likely the limiting factor (along with their brightness) and thus there is a strong Bayesian prior against seeing them with a narrow field of view. The mass of the system at 10^7.35 solar masses is much greater than what we expect from theoretical models that form Pop. III stars and you must ask how it's possible to not have any metals pollute the gas. The main piece of evidence for Pop III stars is HeII emission at 1640A which is a prediction of Pop. III stars, but you can also get this in many other ways, for example X-ray binaries. We see this plenty in the local Universe and we fully expect this to happen elsewhere. So to me this is headline chasing with little conclusive evidence.

dang2• 3 years ago

Thanks! I've replaced the overstated title with what seems to be a better phrase from the first paragraph. If there's a better (more accurate and neutral) title, we can change it again.

astroH5• 3 years ago

I think this is perfect! If only we can convince the author of the article...

perihelions2• 3 years ago

The "isotope" part is a mistake in the article. The writers heard "He II" and very reasonably wrote down "helium-2", and added some exposition about that (hypothetical) nuclear isotope. But they're in fact unrelated things: "He II" in this context is an ionization state of helium (the +1 state) -- not an isotope. What the research is observing is high-energy radiation from stars stripping electrons from helium atoms. No rare isotopes in sight!

hinkley3• 3 years ago

You’re saying a lot of things here, but is one of them that an event could be detected far away because it’s old, or because it’s such a rare event that the chances it happens near us are vanishingly small?

astroH5• 3 years ago

These systems are very far away because you are looking more than 13 billion years back in time. The argument is JWST has a small field of view and these Pop III stars are like flashes in comparison to the age of the galaxy. So the probability of catching one that is bright enough to be detected is just super low. Which is why there is a strong prior that the HeII could be from other physics that is relatively well understood. But really the OIII emission is the biggest sign that this isn't a "primordial galaxy"

xtreme• 3 years ago

Pop 3 stars were formed in the very early universe and have been long gone. So there is no way for us to see the light they emitted without looking at the most distant galaxies.

JumpCrisscross• 3 years ago

mass of the system…is much greater than what we expect from theoretical models that form Pop. III stars

I would have thought the mere presence of a solar system excludes a star from Population III. Is that inaccurate?

LarryMullins2• 3 years ago

"First Stars" or what we call "Pop. III" Stars. By definition, the first stars are nearly completely devoid of elements heavier than hydrogen and helium.

I thought Pop III stars initially formed with only Hydrogen and Helium, but they promptly created heavier elements up to Iron within themselves through fusion.

astroH5• 3 years ago

Indeed, but we define their "metallicity" (mass fraction of elements heaver than helium) typically by the gas that they formed from. And the key point is that since they form from metal-free gas, you don't expect to see emission lines from metals which come from the star illuminating the surrounding gas with radiation.

dguest• 3 years ago

They create most of the heavier stuff when they blow up. But that's a pretty small fraction of their lifetime, even for stars with a relatively short lifetime (a supernova takes minutes, these things live for millions of years).

UI_at_80x24• 3 years ago

~3 Myr

Just curious, when you mentally say that do you pronounce it: ~3 MEGA-years or ~3 MILLION-years

I realized that I keep flipping it back and forth and I can't settle on the 'correct' version. Like saying data vs data. =)

In addition, thanks for the comment. The information on Pop. III stars was great!

Natsu• 3 years ago

Why do the populations seem backwards? You'd think the first stars would be Pop. I, then the next Pop. II, then III, and maybe someday we'd get to IV. Instead they seem to work backwards?

LeifCarrotson• 3 years ago

Because the names were determined by when they found those groups of stars, rather than when the stars they found were formed. They only later realized that their distinct groupings based on observed metal content were caused by stellar formation processes.

Regrettably, the stars didn't show up in their telescopes with labels and histories attached.

phkahler• 3 years ago

This isn't literally an observation of a single star at that distance is it? If they only lasted a few million years then it will be unlikely to see a cluster of them devoid of other 2nd generation stars. It's doubtful (to me) that they all formed at the same time so as to not co-exist with other types.

jwuphysics• 3 years ago

Agreed, thanks for saying this. I'm also another astronomer by trade and I'm very surprised that Quanta ran with this title. I like the work that Xin Wang has done, and I'm usually a fan of Quanta Magazine reporting and Simons Foundation work -- I'm currently organizing a conference at the Flatiron Center for Computational Astrophysics -- but this is really lowering the bar for science journalism.!

ericmay• 3 years ago

I know this is probably a silly question but what is the significance of locating earlier and earlier star formations versus other objects? Is it because that's what we can readily identify and improve accuracy of identifying?

chaps2• 3 years ago

Without those stars, we wouldn't have most of the elements we have today. But these stars no longer exist, so we have to look really far back. It's an important question!

FreeHugs• 3 years ago

    Astronomers Say They Have Spotted
    the Universe’s First Stars

Isn't the size of the universe potentially infinite?

If that is the case, we can see only an infinite small fraction of the stars in the universe. Under that assumption, I find it hard to have a concept of what spotting the universe's first stars could mean.

The oldest stars among those that we can see?

chaps2• 3 years ago

What does size of the universe have to do with this? ;)

The question is about the relationship between the age of the universe (well, after the big bang) and stars that came into existence afterwards. We have a pretty good idea how old the universe is, and with the universe expanding, light from the early days of the universe still makes it to earth from billions of light-years away.

svachalek• 3 years ago

You could postulate that we arised from A Big Bang rather than The Big Bang, and somewhere outside the visible universe some alien species watched it happen. At least as I understand things, nothing we know about the visible universe puts any constraints, age or otherwise, on the rest of it.

But for similar reasons, unless some fundamental understanding of time and space changes, nothing outside the visible universe really matters.

ben_w2• 3 years ago

The oldest stars among those that we can see?

Yes.

If I've understood the lectures correctly, time isn't really well-ordered, and on scales like this the deviation makes a substantial difference.

However, what we are looking at in cases like this is stars far enough away that the light took most of the age of the universe to reach us, so it's not unreasonable to call those stars (members of the set of) "the Universe’s First Stars".

perihelions2• 3 years ago

Am I blind or does the paper not mention helium-2 at all?

https://arxiv.org/abs/2212.04476

It talks extensively about "He II", the astrophysics notation for singly-ionized helium (a helium atom with one electron removed; He+). That isn't notation for a helium isotope. I can't see anything in the paper mentioning isotopes, nuclear reactions, or anything in that direction. (?)

pfdietz• 3 years ago

2He is not being observed, as it is not a bound nucleus.

And this is a good thing! If 2He were bound, the pp fusion reaction would be much faster, our Sun would long since have burned out, and we would not be here.

jonnywithoutanh2• 3 years ago

Yes sorry, author here. This was my mistake and has been changed.

Light from an ionized state of helium in a distant galaxy

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