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How Can a Star Be Older Than the Universe?
- lacriz 7y agoTl; dr: They don't know either
- ReptileMan 7y agoA question - how common are such old stars? Because it is right in our backyard. 190 light years away are nothing. And if those stars are rare - that makes our neighborhood unusual - we have life and some of the oldest object in the universe in almost the same spot.
- acqq 7y agohttps://en.wikipedia.org/wiki/Stellar_population#Population_II_stars https://en.wikipedia.org/wiki/Stellar_population#Population_... "Thus far, they have uncovered and studied in detail about ten ultra metal poor (UMP) stars" https://en.wikipedia.org/wiki/List_of_oldest_stars https://en.wikipedia.org/wiki/List_of_oldest_stars
- 4ad 7y ago190 light years is in our backyard compared to the size of the universe, but I was curious about how many stars are that close to us. It turns out that we have around 100k stars within 190 light years. 0.120 stars/parsec^3 * 4/3 * pi (190 ly * parsec/3.26ly)^3
- bArray 7y agoAlmost everything of interest essentially happens in our backyard because that's the place we can see with the most detail. It's a little like looking out at the Universe and coming to the conclusion that we're in the middle of it because the "edges" are all around us. Even if this was rare and there happened to be tonnes of very old stars only close to us, this could again be coincidental, especially if intelligent life is more common than we currently know.
- 4ad 7y agoThis is precisely true, only very small stars last very long, and small stars are very dim. All the old stars that we see must be very close. The bright stars that we see that are far away only live for a few million years.
- inetknght 7y agoWhy 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 7y agoI 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.
- AnimalMuppet 7y agoNo, but we (our planet, stuff in our vicinity) could age less. What we'd need is most stuff (that gave rise to most stars and most of our measures of the age of the universe) to be in a higher-gravity region compared to the star in question. It seems unlikely, but I suppose it's possible... [Edit: I thought you were talking about GR time dilation due to gravity. A re-read shows that I may have been in error. Also, for a star 190 ly away, any relativistic explanation, either special or general, is probably wrong.]
- yongjik 7y agoI don't think there's such a concept as "higher-gravity region" in modern physics, unless you're thinking about "in the vicinity of a giant star, black hole, or something equally massive." However, if most of the known universe is sitting next to a gigantic mega-blackhole (or enough of them to cover the whole sky), then surely we would have noticed by now...
- inetknght 7y ago> I don't think there's such a concept as "higher-gravity region" in modern physics, unless you're thinking about "in the vicinity of a giant star, black hole, or something equally massive." I think at the beginning of the universe, there might be a lot of regional discrepancies. They might even just be "temporary" regional discrepancies from gravitational waves due to the inherent nature of the universe growing and everything still crashing together.
- Ancalagon 7y agowow 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.
- 4ad 7y agoJesus, what an aggresive website: https://i.imgur.com/1aCo9DV.png https://i.imgur.com/1aCo9DV.png.
- madrox 7y agoThis 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 7y ago> 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.
- novia 7y agoShort answer: it's only older than the universe if you ignore the error bars of the estimate.
- TallGuyShort 7y agoAnd 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?
- jerf 7y agoEven ignoring complicated questions about gravity and space metrics and their evolution over time, if a big bang occurred in an occupied region of space, we'd see the results of these two things crashing together. We see similar, but much smaller, such things all over the place in space. We do not see any collisions best explained this way.
- dmix 7y agoWhat would it even look like if it was occupied space? Uneven expansion?
- jerf 7y agoColliding bits of material produce light. Even colliding hydrogen clouds produce detectable signatures. If, for the sake of argument, two big bangs occurred and we could see where they met, there would be a large visible region in the universe putting out some sort of photons. (Not necessarily visible ones.) More subtle things would be visible too, like, yes, interacting gravity fields, but it wouldn't take such clever analysis; the impact points would literally light up in the sky.
- 7y ago
- egdod 7y agoI 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 7y agoStill an interesting read and thought experiment.
- amp108 7y ago> 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.A
- amp108 7y ago> 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.
- Nohnce1 7y agoIt's a hard sell to someone who has cursory interest on the subject had the title been your first hypothesis. Still, not great.
- hypothesis-3 7y agoHypothesis 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 7y ago3 our estimate of the age of the universe or of these stars need to be improved.
- blackflame 7y agoWhat 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 7y agoOftentimes. I gave you an upvote just because sometimes around here you will get downvoted because the gods of zeitgeist decide it must be so.
- svdr 7y agoA great cosmology faq, answering this and a lot of other questions: http://www.astro.ucla.edu/~wright/cosmology_faq.html http://www.astro.ucla.edu/~wright/cosmology_faq.html
- alan-crowe 7y agoWe'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.
- lottin 7y agoHere we go again... "scientists would look at the ripples in the fabric of space and time". Am I the only one who finds this expression very confusing? What fabric? There is no fabric. Space and time are coordinates. They do not exist physically at all. There cannot be a fabric of space and time.
- guerrilla 7y agoAre you sure that's how general relativity sees spacetime? What about graviational waves and vacuum energy? > On 11 February 2016, the LIGO and Virgo Scientific Collaboration announced they had made the first direct observation of gravitational waves. https://en.wikipedia.org/wiki/Gravitational_wave https://en.wikipedia.org/wiki/Gravitational_wave
- eljimmy 7y agohttps://en.wikipedia.org/wiki/Spacetime https://en.wikipedia.org/wiki/Spacetime
- tiborsaas 7y agoIt's a metaphor to help humans grasp it better. Space and time does exists physically. Does a shortest path between you and your workplace exists that you can traverse? Is it a straight line? No, it's not, but there's one path that you as a being can walk along physically. The buildings, roads, obstacles force you to diverge from the ideal straight line. That's another analogy of what space & time is. Fabric is just shorter.
- ssijak 7y agoWell, as farbas I understand quantum loop gravity, there is a fabric of space and time
- doliveira 7y agoTwists and turns like a fabric, waves like a fabric...
- bena 7y agoDid 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?
- drclau 7y agoThis reminds me of Iain Bank’s Excession. Great book, strongly recommend it.
- cpeterso 7y agoThe relevant bit from Excession is the discovery of a mysterious entity that is 50x older than the universe.
- ShamelessC 7y agoWhat's the explanation?
- cgrealy 7y agoWithout giving too much away, it's not from this universe. You really should read it, it's one of the best books in the culture series and Banks was a phenomenal writer. It also contains the Affront, a species that are almost comically awful and coined the term "outside context problem": "The usual example given to illustrate an Outside Context Problem was imagining you were a tribe on a largish, fertile island; you'd tamed the land, invented the wheel or writing or whatever, the neighbors were cooperative or enslaved but at any rate peaceful and you were busy raising temples to yourself with all the excess productive capacity you had, you were in a position of near-absolute power and control which your hallowed ancestors could hardly have dreamed of and the whole situation was just running along nicely like a canoe on wet grass... when suddenly this bristling lump of iron appears sailless and trailing steam in the bay and these guys carrying long funny-looking sticks come ashore and announce you've just been discovered, you're all subjects of the Emperor now, he's keen on presents called tax and these bright-eyed holy men would like a word with your priests."
- jackgavigan 7y agoYou left out the best bit! "An Outside Context Problem was the sort of thing most civilisations encountered just one, and which they tended to encounter rather in the same way a sentence encountered a full stop." Shades of Douglas Adams there...
- thrower123 7y agoThe most likely answer is that either the measurement or the theory is wrong. Both are probably about as likely.
- ajay-d 7y agoGN-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 https://en.wikipedia.org/wiki/GN-z11#Notes
- namirez 7y agoAlso, 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.
- NetOpWibby 7y agoThat’s fascinating to think about.
- calvertdw 7y agoAs observed, it's only 13.8, though, right?
- kijin 7y agoNo, it's observed as 93 billion light years. That's why we call it the "observable" universe. There is no meaningful spatial boundary at a point that is currently at a distance of 13.8 billion light years from us. We can detect (severely red-shifted) photons from beyond that point perfectly fine! The actual boundary is 46.5 billion light years away in both directions, hence the "observable" diameter of 93 billion. But of course the meaning of "observed" is kinda strange here, since we're not directly measuring the distance but estimating it based on from other observations.
- accnumnplus1 7y agoDoes 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 7y agoThe 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 7y agoI 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.
- KingCobra 7y agoIt 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.
- hirundo 7y agoI 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 7y agoIf 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...
- wruza 7y agoSimulation doesn’t have to obey the rules. For non-scientists it is enough to “tell” them how it works without actually rendering it, cause they’ll never check. For scientists, you have to make their brain believe that all is consistent with complex computations all the way down. Imagine that you know physics and math very good. But then simulation suddenly fails due to segfault and you realize that all your knowledge was just a gibberish nonsense and your work sessions and discussions were dream-like experience. Otherwise it was just a pretty dumb 3d simulation slightly better than a modern AAA game. Edit: I mean, a simulation argument opens a huge can of worms, if you consider the perspective of a lazy simulation developer them-self.
- simula 7y agoWhile a simulation doesn't have to obey the rules, any given simulation is likely to resemble a system that does adhere to rules, since a simulation is indeed simulating something else. Even if some external observer can pause, rewind, intervene and violate rules, the reason a simulation exists is to model something else. This "something else" will have some kind of rules, and the goal of the simulation will be similarity to the actual realm external to the simulation. Meanwhile, a lazy replication of a model by an unmotivated author would likely impose finite quantities upon scales of interaction, since a simulation won't be able to recreate a real time version of something larger than the external reality itself. We wouldn't notice a lagged simulation that tries to consume its footprint, but it's probable that an artificial creation would impose caps on aspects of a system to prevent runaway reactions that produce useless simulations. To us, those sorts of limitations would resemble extra physical laws, and while incontrovertible to the simulated entity, such limits might confront intuition in strange ways.
- dfilppi 7y agoWhich universe?
- exabrial 7y agoI was thinking maybe it was traveling a large fraction of c and there was a relativity thing going on
- tcarn 7y agoHN is making me wish I studied astronomy, such cool stuff.
- cgrealy 7y agoNonsense, the universe is only 6000 years old.... and it's a Libra.
- eximius 7y agoOkay... This implies the light was stretched along with the space, right? Because otherwise, the photons would just... Never reach here if space between us and the light expanded faster than c.
- paulmooreparks 7y agoCorrect. See... https://en.wikipedia.org/wiki/Horizon_problem https://en.wikipedia.org/wiki/Horizon_problem
- imvetri 7y agoStart 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 7y agoGiven 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.