How Can a Star Be Older Than the Universe?

[ajay-d]

GN-z11 is a galaxy that's 32 billion light years away. Here's the note from wikipedia:

At first glance, the distance of 32 billion light-years (9.8 billion parsecs) might seem impossibly far away in a Universe that is only 13.8 billion (short scale) years old, where a light-year is the distance light travels in a year, and where nothing can travel faster than the speed of light. However, because of the expansion of the universe, the distance of 2.66 billion light-years between GN-z11 and the Milky Way at the time when the light was emitted increased by a factor of (z+1)=12.1 to a distance of 32.2 billion light-years during the 13.4 billion years it has taken the light to reach us.

[1] https://en.wikipedia.org/wiki/GN-z11#Notes

[namirez]

Also, despite the age of the universe (13.8B years), the diameter of the observable universe is 93 billion light years. That's because the universe expanded (and probably still is expanding) faster than light.

[marzell]

Seriously... what's the difference between 'universe expansion' and 'travel'? A particle can't travel faster than c but it can effectively if the universe expands in addition to its travel speed? Are there any established sci-fi concepts that replace the concepts of wormholes with 'universe compression'?

[leggomylibro]

So, is it possible for an event in the Milky Way to ever affect GN-z11 (or vice-versa)? Or are the galaxies permanently 'read-only' to each other?

[hinkley]

This still doesn’t add up. For one, now it’s saying that when the universe was .4 billion years old we were already 2.6 billion light years apart, so now you have to explain that first.

[novia]

Short answer: it's only older than the universe if you ignore the error bars of the estimate.

[joe_the_user]

I thought the answer was more like "all our figures are quite rough currently and a lot of work needs to be done".

They mention that the current universe age fits "within the bars", for example but also mention arguments for universe being younger as well, which would again put the measurements at odds.

Basically, both of these values involve a string of assumptions and while getting every single one of them to high accuracy is a remarkable achievement, the chance of some glitch in either measurement is significant.

[TallGuyShort]

And it's only older than the universe if you assume the Big Bang was the beginning of the universe, which there's really no evidence to suggest. Pretty much everything else in the universe all seems to suggest that it all originated from a similar point in time and space and that it rapidly expanded outward. Okay. But what was going on in this particular space back then is completely unknown, so... could there have been some stars forming already from matter that wasn't part of the Big Bang? Why not?

[alan-crowe]

We've been here before, with stars older than the age of the universe. Last time, we thought that there was only one kind of Cepheid variable. This lead to underestimating the age of the universe. Later, astronomers realized the nearby Cepheid variables (used for calibrating the period/luminosity relationship) differed systematically from the bright Cepheid variables that we could see in distance galaxies.

Understanding the difference between Type I and Type II Cepheid variables lead to a greater estimate for the age of the universe, resolving the difficulty. So I expect some interesting astronomy to come out of tracking down the cause of this discrepancy.

[svdr]

A great cosmology faq, answering this and a lot of other questions: http://www.astro.ucla.edu/~wright/cosmology_faq.html

[amp108]

> It's composition meant the star must have come into being before iron became commonplace.

Hypothesis 1: the star formed in a way that did not involve or produce a lot of iron.

Hypothesis 2: the star is older than the universe itself.

Clearly, hypothesis 2 is the more likely.

[hypothesis-3]

Hypothesis 3: Due to inherently incomplete information, our understanding of the age of the universe is not yet perfectly correct, and the universe may be older than current models and theory.

Strap yourselves in folks, maybe The Big Bang is but one event woven amid a deeper tapestry of events, significant only in its capacity to occlude deeper periods of time.

It should surprise no one that we might be wrong about some centralized, focal aspect of the universe, given how wrong we've been before, about things we assumed to be the center or origin, previously.

[gpderetta]

3 our estimate of the age of the universe or of these stars need to be improved.

[Nohnce1]

It's a hard sell to someone who has cursory interest on the subject had the title been your first hypothesis. Still, not great.

[madrox]

This remind me of a similar story with the age of the earth and the solar system. Scientists using new methods were starting to discover that Earth was far, far older than originally predicted...so old, that it seemed to predate our sun. It turns out it our estimates of the solar system's age were wrong, but it took some time to figure out why.

I imagine something similar is going on here. The article mentions that once they got an age older than the universe, they started looking at how to make the star younger...finally by acknowledging the margin of error in estimates. That sounds like bad science to me.

[progval]

> The article mentions that once they got an age older than the universe, they started looking at how to make the star younger...finally by acknowledging the margin of error in estimates. That sounds like bad science to me.

Later (in section "Taking a closer look at the age of the universe"), they tell that your theory is also being looked into.

[hirundo]

I think, by Occam's Razor, the most likely explanation is that there's a skybox surrounding the solar system that Voyager 1 may run into any day now, like Truman Burbank at the end of The Truman Show. It seems to be a more parsimonious explanation of the available facts that we're looking at the result of a super duper planatarium projector, as opposed to an actual vast and frequently inexplicable universe.

[crooked-v]

If you're going in that direction, you may as well say that the universe is a simulation. Planck limits on measuring time and space as a continuum would pretty useful for putting a hard cap on required rendering resources per volume of space-time...

[sthomas1618]

Reminds me of https://en.m.wikipedia.org/wiki/Century_Rain

[egdod]

I was hoping for some weird time-bending effect from general relativity, but no, it’s just that the ages are within each other’s error bars.

[dmix]

Still an interesting read and thought experiment.

[drclau]

This reminds me of Iain Bank’s Excession. Great book, strongly recommend it.

[cpeterso]

The relevant bit from Excession is the discovery of a mysterious entity that is 50x older than the universe.

[inetknght]

Why can't the star be older because of relativity? I imagine that, particularly in the early universe while everything was nearer to everything else, relative background gravity was higher (and thus relative time) is different than now. Would the star not age at a different rate if it's a remnant from violent beginnings of the universe?

[Ancalagon]

I think, if I understand your question correctly, that a star couldn't age more, only less, from our perspective.

EDIT: I could be wrong though, and additionally I believe the star being referenced by the article is actually in a similar reference frame so relativity likely isn't the answer anyways.

[dotancohen]

The star would need to be in a _lighter_ background gravity than us, to appear older to us.

[thrower123]

The most likely answer is that either the measurement or the theory is wrong. Both are probably about as likely.

[KingCobra]

It reminds me of the same question asked in this book, "The Birth of Time: How Astronomers Measured the Age of the Universe" by John Gribbin. The bottom line was that the calculations always have some approximations, which can throws off a number by a large factor.

[bena]

Did anyone read the article and get a feeling it was mostly just a fluff piece describing how we're refining our ability to tell the ages of stars?

[imvetri]

Start over space theories all over again. Lets not build our assumptions on previous generation findings.

Only if we take path of how the previous geniuses went through we will have a flawless exploration. Instead of doing that, if we work on someone else's work, its like eating someone else's recipie and trying to remake the tase of it without understanding the ingredients in it.

[mirimir]

Given the norm for question titles, the answer must be "It can't." Also simply based on what a universe is.

What we have are just different estimates for the age of our universe. And none of them involve simple measurement, obviously. So the challenge is finding the artifact(s) that generate the disagreement.

[accnumnplus1]

Does the microwave background come from the centre of the universe where the big bang was; and the light from stars on the far side, flying in the opposite direction to us, take longer to reach us than the microwave background does?

[turndown]

The Big Bang happened everywhere in the Universe, at once. Our CMBR is coming in from all directions, at all times, as more distant locations(eg further away from us at the start) finally reach us.

[johnklos]

I would REALLY love to read this, but space.com is one of those asshole sites that wants to take a gigabyte of memory (I'm not joking) and wants a full 30 to 45 seconds of CPU just to load the page.

[zarriak]

It loads almost instantly without javascript. I can understand not using adblocking but why are you complaining about loading times when not using umatrix or noscript?

[xhgdvjky]

crashed my mobile browser

[blackflame]

What came first, the photon or the electron? Can a photon be emitted without a change in energy state?

I’m new here, so instead of answering questions is the protocol just to downvote?

[yosefzeev]

Oftentimes. I gave you an upvote just because sometimes around here you will get downvoted because the gods of zeitgeist decide it must be so.

[Ancalagon]

wow what an interesting article. Finding not one, but multiple stars that are much older than the predicted age of the universe means something is likely very wrong with one of our theories: dark energy, star aging, or using the cosmic background as a measure of the universe's age.

[exabrial]

I was thinking maybe it was traveling a large fraction of c and there was a relativity thing going on