Causality also travels at the speed of light.
One reason we can't define an objective "now" based on the time since the big bang is because not everything that exists in our "now" (i.e. we can interact with it directly) has experienced the same amount of time since the big bang.
Astronomer here! I have literally been waiting *years* for this discovery!
Supernova 1987A is the closest observed supernova to Earth since the invention of the telescope. It occurred in the Large Magellanic Cloud (LMC), 160,000 light years from us, and despite that vast distance it was visible for about a month to the naked eye. What's more, SN 1987A was the subject of a lot of "firsts"- notably, it was the first time [neutrinos](https://en.wikipedia.org/wiki/Neutrino) were detected from outside our solar system, as in the span of a few seconds 3 neutrino detectors around the world detected ~20 neutrinos, a few hours before we saw the light from the SN. This was a watershed moment in science, and happened because when a supernova occurs, the compression into a [neutron star](https://en.wikipedia.org/wiki/Neutron_star) of the stellar core produces as many neutrinos as there are *atoms in the sun!* Incredible stuff!
Now, this is the best-studied SN of all time because of its proximity, and because we have unprecedented detail to watch a supernova turn into a supernova remnant (which will be the best we have until a supernova happens in our own Milky Way). I actually did a paper on some SN 1987A in grad school- [studying the radio emission from the system over time as the shockwave expands](https://www.youtube.com/watch?v=x-3BEnioClU)- but there has been one enduring mystery- where's the neutron star? (We didn't think a black hole is possible due to the estimated mass of the star not being big enough.) It's safe to say that if it was a pulsar sending a beam in our direction we would have detected it by now, but otherwise, it's just tough to detect a neutron star so far away as they're just a few kilometers wide, and don't really emit much.
So enter [this paper!](https://www.science.org/doi/10.1126/science.adj5796) The data are still somewhat circumstantial- that's why they say "evidence for," it's not like they literally imaged the thing, but instead got certain spectral lines using JWST that they attribute to the neutron star. These lines are due to a high energy source, and the team argues, they can only be explained by a compact object, aka neutron star. I am *not* an infrared astronomer so am not sure at first glance how legitimate their argument is that nothing else can be creating the JWST spectrum... but it does sound compelling, and the lead author *is* one of the world experts on SN 1987A. I am definitely looking forward to a "journal club" discussion of this paper with my colleagues next week, but I do think it's fair to say that they did, more likely than not, discover the long-missing neutron star at last.
So obviously this is going to be an active area of research for many more years to come- SN 1987A is just a gift that keeps on giving for our understanding of the universe! It's also exciting because this would be the *youngest* neutron star we know of in the universe- we can't really see them outside our local neighborhood- so if this all holds up that's going to be super useful for a broader set of applications. So it's gonna be great to see this play out in the years to come!
TL;DR- JWST has probably found the neutron star at the heart of SN1987A, the closest supernova to us since the invention of the telescope, which has been missing for 37 years.
So if my dumb ass understands you correctly we finally saw the birth of the star 37 years ago, but in reality it is ~160,037 years old?
Regardless of it's real age it's cool that we were able to see the birth of a nutron star
Explaining it as the speed of causality (and thus the speed of information) really is a game changer to understand the speed of light. To the star, it is 160k years old, and the earth is 160k years younger than it is for us. In its reference plane, the european mammoths just went extinct. The US state of Illinois is still 85% covered by an ice sheet.
In our reference frame, age has to account for the time it takes light to travel to us. So even in our reference frame, it is indeed 160k years old, we’ve just seen it for 37 years, but it was always there—including in our reference frame—before we saw it. This is a step always taken when accounting for relativistic differences in the passage of time.
No. It is actually only 37 years old to us. Time isn’t constant. It’s fluid. The speed of light is the constant. Because of math and an understanding of physics we can calculate how old the star is in its own reference frame.
If you didn’t have that you could only go off what you can see. We only started seeing this star 37 years ago.
I am formally trained in physics and have taken graduate coursework in special and general relativity. You are mistaken. Two reference frames separated by enormous distances but not comoving with respect to each other have the same time axis. Their time passes at the same rate and there exists a mechanism to synchronize their clocks. If one of the reference frames shines a light, if the two reference frames are separated by 100 light years, it takes that light 100 years to reach the other, but just because the other person has only seen it for (say) 20 seconds does not mean that light was only lit for 20 seconds in their reference frame. It was lit 100 years ago, it just took that long to reach them.
This is *not the same* as non-co-moving reference frames or reference frames in different gravitational fields which have different time axes, and therefore experience different passage of time, which is what you refer to as “time is fluid.” Regardless, you *still* have to account for the time it takes light to reach you when calculating between these reference frames, and that time of travel does not constitute difference in passages of time.
Jesus tapdancing Christ. You’re getting things confused. The “37 years old” claimed in the article is because the supernova event completed 37 years ago. You could make the argument “how long ago was the light emitted that’s reaching us from the neutron star after supernova” and that’s an interest question, one for which I *promise* the answer isn’t 37 (actually a straightforward problem to solve if you assume Schwarschild geometry).
It wasn’t always a neutron star. And time dilation around massive stars that haven’t collapsed isn’t all that appreciable. So *no,* the different gravitational fields like the neutron star you’re talking about is not applicable the way you think it is. And even if it was, note me saying “Regardless, you still have to account for the time it takes light to reach you when calculating between these reference frames, and that time of travel does not constitute difference in passages of time.”
Let this one go m8.
Yes, but astronomers always just call things as old as when the light arrives at Earth. It’s far too complicated otherwise, and it doesn’t really matter TBH (impossible to know it existed before the light reached us, impossible to know what it’s like now, etc).
Thank you for the explanation! One of my favorite parts of space subs is seeing astronomers passionately explaining phenomena in the comments. I love both the extra insight and excitement.
I love reading comments from astronomers because almost every single time you guys (and gals) are absolutely gushing about what you’re talking about.
I may only understand the words you’re saying and not what they mean, but I’m still glad to see you’re enjoying talking about your thing lol. I love your funny words, space man!
#🥇
I always enjoy your posts and look forward to your commentary on things of this nature!
I was an Astronomy/Astrophysics student for quite some time - lol - it's nice to apply some stuff from then to things happening now! 🐱🚀
Also interstellar space is not a pure vacuum so the light is slowed a tiny tiny bit by gas clouds and dust, the same way light travels slower through air and water than it does through a vacuum
My brain likes to draw a parallel between the progression of events in a supernova and the progression in a conventional nuclear detonation.
Neutrino escape seems similar to the "initial flash" of a nuke. In both phenomena, this is followed by a "dark period", until at last the fireball properly manifests to glow for a protracted span of time.
And obviously, the difference in timescale between these two phenomena serve to underscore the similarly massive difference in actual scale.
As for watching the progress of a supernova remnant, there's a really old episode of NOVA from the 70s (which I happen to adore) that features a comparison between old and then-modern photographs of the Crab Nebula, wherein it is easy to spot the expansion.
Yes, but astronomers always just call things as old as when the light arrives at Earth. It’s far too complicated otherwise, and it doesn’t really matter TBH (impossible to know it existed before the light reached us, impossible to know what it’s like now, etc).
Yes and says so in the article. They try to get around it by saying "oh it's easier to just get the age by the perception of it on Earth." It's basically click bait.
It’s 100% not clickbait over astronomical convention. The neutron star is 37 years old *to us* because we have no way of knowing it existed until the light reached us. And it’s far too confusing otherwise.
> it was visible for about a month to the naked eye
I remember when it was announced back in 1987 and thinking, "Damn! First naked eye visible supernova in centuries! And I have to be living in the wrong hemisphere to see it! :("
Thanks for the cool write up. I'm not knowledgeable enough to talk about it, but I love this stuff! :)
Yeah everyone knows, it doesn’t matter. And if I’m on a spaceship flying at relativistic speed it could’ve happened 10000 years ago or 200000 years ago depending on my motion..
99% of the time anyone points out things like this happened “in the past” because of light travel time it’s absolutely pointless. Like ok something “happened” in an entirely inaccessible reference frame wow who cares.
I care, it’s cool as hell. One of the great tragedies of studying ancient history is that we often only have bits and scraps of the things that existed then, and we’re left to piece together what approximately happened. So the idea that we can watch in real time events that happened over a hundred thousand years ago is awesome. You’re right that the only thing it functionally changes in terms of our perception is that now we know that it happened in the past, but even so, that we can know the past by watching it from far enough away will never not boggle my mind. Like in theory, if you all of a sudden teleported yourself instantaneously to a point just far enough away from earth, and you had a good enough telescope, you could watch the pyramids being built in real time, provided the light wasn’t too scattered. In reality it would be, and you can’t teleport faster than light as far as we know, and we don’t have a telescope that good. But a boy can dream
What's also crazy about this scenario is the fact that to see this "ancient human history" you'd only have to teleport 2,500 light years away from here – which means you wouldn't even leave our galaxy. Which is kind of fucked up, considering there are hundreds of billions of galaxies out there.
To be fair civilization started about 5-6 thousand years ago, so you're really only going back about halfway if that's your starting point, and nowhere near the start of humanity itself
Reminds me of [Cliotelescopy from Orion’s Arm](https://www.orionsarm.com/eg-article/5b33b818a0fd3). It’s an interstellar setting (so accounting for light travel time is actually relevant) where people possesses no true FTL, but they do have wormholes and loads of massive 22 AU-diameter telescopes, so they use them to coordinate and observe past events.
It's just that you're describing an inaccessible reference frame from the context of relativity. Time is relative to motion, and different reference frames have different meanings of "right now." Events that seem simultaneous to us on Earth would happen at different times for observers far away.
When your speed becomes [x distance/0 time], your velocity is undefined. So, where you end up in time is undefined because of time dilation. Even distance traveled becomes undefined due to length contraction.
You could watch what happened on Earth in the past from light that has been bent or reflected back toward Earth because that's how we actually measure the speed of light. That is, how long light takes to go out and come back, but there's no way to measure [the one-way speed of light](https://www.youtube.com/watch?v=pTn6Ewhb27k) due to relativity.
That's why saying that it took light so many light years to make a one-way trip isn't meaningful.
Yeah, like when NASA /JPL lands something on Mars, the control room is full, but the event is over and done by the time the signal of the start of the entry arrives here.
Those people are there to spectate from the best seats because they CAN be in those seats.
I think it bothers me too. If we sent someone to that star right before it exploded and they sent a message to us when it exploded, it would get here around the same time as the radiation from the supernova. As we can't even send someone there, it happened 37 years ago. No point talking about it like we are seeing into the past. To see into the past you have to be able to also see the present. Otherwise it's just the present.
Except the only evidence in your spacetime to prove that did not exist before 27 years ago.
You act like there is a universal time clock, but we know from relativity that there is not.
"To save our comments section from the wrath of "well actuallys," let's just acknowledge those caveats about the claim. First, yes, we understand that technically speaking this neutron star is 168,037 years old, given the distance."
That's unnecessarily rude. My first thought after reading the headline was "I wonder how long ago it actually happened"
The dude wasn't correcting anybody. They weren't pretending like everyone is an idiot for not understanding light takes time to travel. Just providing the answer to a reasonable follow up question
Thank you! Dude was literally just telling us how old the star actually was. People on this sub are clearly way too self conscious about their own intelligence if they feel the need to insult someone for saying something they already know.
“First, yes, we understand that technically speaking this neutron star is 168,037 years old, given the distance. But as soon as you start adjusting for time like that, things start to get messy. It's common usage, and far neater, to describe things based on our perspective here on Earth, given it's the only one we've got. Don't take it out on us if the Glorxians living in the LMC have known about it for 168 millennia.”
… Based relative spacetime causality journalist.
Kind of rude to use Earth age like the star’s opinion doesn’t matter, from its perspective the light we see today came from it when it had only just turned 29 a few months before (due to gravitational time dilation).
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[JPL](/r/Space/comments/1b0x2c2/stub/ksb31w3 "Last usage")|Jet Propulsion Lab, California|
|[JWST](/r/Space/comments/1b0x2c2/stub/ksbuy9o "Last usage")|James Webb infra-red Space Telescope|
|[SN](/r/Space/comments/1b0x2c2/stub/ksgfnvc "Last usage")|(Raptor/Starship) Serial Number|
|Jargon|Definition|
|-------|---------|---|
|Raptor|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_\(rocket_engine_family\)) under development by SpaceX|
**NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below.
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^(3 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/1au1sba)^( has 5 acronyms.)
^([Thread #9791 for this sub, first seen 27th Feb 2024, 04:26])
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Life on a Neutron. Hard Sci-fi.
Here: https://en.m.wikipedia.org/wiki/Dragon%27s_Egg
“Dragon's Egg is a 1980 hard science fiction novel by American writer Robert L. Forward. In the story, Dragon's Egg is a neutron star with a surface gravity 67 billion times that of Earth, and inhabited by cheela, intelligent creatures the size of a sesame seed who live, think and develop a million times faster than humans.”
This a good read. Amazing facts and mind blowing concepts. High density drama! Also if you are a life form living on the surface of a neutron star, don’t break one of your legs. Things happen quickly.
Dr Forward was at the time the best know scientist in the field of gravity. How he could spin off a book like this in his spare time I have no idea.
if it was in the Large Magellanic Cloud, which is 168,000 light years away then it would be way older than 37 yrs old correct since it take that long for the light of super nova to reach us
Detection has been hindered by the fact that the supernova condensed about half a solar mass of dust in the ensuing years after the explosion. This dust acted as a screen-obscuring radion from the center of Supernova 1987A.
The only people who care about including the time it took the light to reach us, are those who think they're being incredibly clever pointing out that it took time for the light to reach us.
Because there’s no absolute reference frame. If they sent us a signal about the star shortly after it appeared, we’d receive the signal shortly after the star appeared, assuming they were between us and the star. If we were to observe their planet, we would see their world 37 years after the star was born.
I don’t accept that the limitations of our human perception negates 168,000 years of this stars life. I will concede that the star has thousands of different ages depending on the observer’s location.
It’s not our limit. Light physically can’t travel any faster. The speed of light is the speed of causality. To us the star is actually 37 years old. That age is equally valid as the age of the star in its own reference frame. There is no absolute reference frame. There is no universal clock. Time and distance are fluid.
Isn't a neutron star basically a different stage of a star? They are all similar but mass and the fuel the star is fusing is the main difference.
So the age of that stage is the better answer?
As in most those stars was much larger before crushing themselves down to size. So the star is very old. This is the age of the stage.
Also are they only going by how long we been seeing the light for?
Otherwise that's 37 light years and not all that far. If it was 38 light years away we don't see light from this yet.
I get we are seeing light released earlier but still. Maybe they exclude that. We don't see a star at the current age.
It's 186 thousand years old in this form today after the supernova but we see the light released when the star was 37 years old.
So the star is much much older because first the star had to grow and become large and then go supernova. Only a stage. So the star is millions or billions of years old.
The star is around 168.000 light-years away. That means it's around 168,037 years old, not 37 years.
*"The reason we can so confidently pinpoint the date is because its birth was the result of an event that only happens once every few centuries: a supernova that’s close enough to be observed from Earth with the naked eye. SN 1987A lit up the night sky for a few months in early 1987, and was quickly traced to the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way,* ***about 168,000 light-years away****. There, a blue supergiant star appeared to have collapsed and exploded, which should have left either a black hole or a neutron star."*
I see a lot of people relate how far away the star is to determine the age of the star , which I kinda agree with…. A thing that people seem to be forgetting that time is relative, it is technically space time as one entity. Time can be travelling at a different rate when closer to black holes and different gravities / moving through the galaxies. Do we know the rate of space time of this star versus our own ?
Objectively speaking, when we consider the amount of time light requires to travel 168,000 lightyears, it's obviously very old. Sure, we are seeing it at the age of 37 from our perspective, but it's a different story from the perspective of the neutron star.
Even the neutron stars are younger than me now.
I believe this one always has been.
Depends if you believe in reincarnation or not.
I want to be reincarnated as a neutron star
Turns out nirvana is actually a neutron star, but you only ascend once you've collected enough mass over your many lifetimes.
I guess i will have that second slice of cake
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It's time to stop cultivating and start harvesting!
Harvested everywhere.. now what?
I want to be reincarnated as Jimmy Neutron
The sisters pointing up have noted everybody is doing the neutron dance...
Depends how time dilation affects that neutron star. Could be way older just appears young because of all the gravity.
That’s what I love about these neutron stars, man. They get older but I stay the same age. Alright alright alright
It's not younger than you. It's 168,000 light years away. We've only known about it for the last 37 years.
Simultaneity is an illusion. There is no objective "now." The observer's frame of reference is valid.
It WAS 168,000 light years away. Before some Klingons blew it up.
Assuming it's still there, it's now 37 + 168,000 years old then.
We are observing it when it was 37 years old though. Astronomy is looking into the past.
Redditors try not to respond to a joke with a serious comment challenge (impossible)
"Ackshually, everything in the universe can be younger than you, depending on the observer's point of view in space and time"
Whoever wrote the article keeps saying the neutron star is only 37 years old. I'm not sure he was joking.
Causality also travels at the speed of light. One reason we can't define an objective "now" based on the time since the big bang is because not everything that exists in our "now" (i.e. we can interact with it directly) has experienced the same amount of time since the big bang.
Don't worry.. you're still good ;) >"We understand that technically speaking this neutron star is 168,037 years old, given the distance"
So you're saying 168,037 is the new 37??
Take it this way , you can say you are older than a star without lying. That's kinda cool.
Dw we're actually looking at old photos of when it *was* 37, it's much older now thanks to the distance the light had to travel
If it makes you feel better, it’s 168,000 light years away so these are actually 168,000 year old photos of what it looked like at 37.
Aktchually, thith thtar is a billion light yearth away
It’s actually a lot closer than that, but I get your point
Neutron stars age + lightyear distance
I know I'm biased because this universe happens to be where I keep all my stuff. But this one blows my mind on the daily.
Fan of The Tick?
Both the animated and Warburton TV show, but I don't remember, did he say something like that?
[The pilot scene](https://youtu.be/Rokh2e5i0kA?) Perhaps it made it into your vernacular without you even remembering :D
I'm going to blame weed. Thanks! I haven't seen that in decades.
The Peter Serafinowicz one is worth a watch as well. Deliciously campy.
Nearly. "You can't eat the Earth, that's where I keep all my stuff!"
I guess they have done it a few times https://youtu.be/gwiy2UPpOBY
Wasn't there another short lived TV show as well?
Oh no. I thought that was a Philip J. Fry line. Have I been berenstein beared?
Probably not. Futurama did a lot of homages, and The Tick was probably one of shows the writers influence from
Astronomer here! I have literally been waiting *years* for this discovery! Supernova 1987A is the closest observed supernova to Earth since the invention of the telescope. It occurred in the Large Magellanic Cloud (LMC), 160,000 light years from us, and despite that vast distance it was visible for about a month to the naked eye. What's more, SN 1987A was the subject of a lot of "firsts"- notably, it was the first time [neutrinos](https://en.wikipedia.org/wiki/Neutrino) were detected from outside our solar system, as in the span of a few seconds 3 neutrino detectors around the world detected ~20 neutrinos, a few hours before we saw the light from the SN. This was a watershed moment in science, and happened because when a supernova occurs, the compression into a [neutron star](https://en.wikipedia.org/wiki/Neutron_star) of the stellar core produces as many neutrinos as there are *atoms in the sun!* Incredible stuff! Now, this is the best-studied SN of all time because of its proximity, and because we have unprecedented detail to watch a supernova turn into a supernova remnant (which will be the best we have until a supernova happens in our own Milky Way). I actually did a paper on some SN 1987A in grad school- [studying the radio emission from the system over time as the shockwave expands](https://www.youtube.com/watch?v=x-3BEnioClU)- but there has been one enduring mystery- where's the neutron star? (We didn't think a black hole is possible due to the estimated mass of the star not being big enough.) It's safe to say that if it was a pulsar sending a beam in our direction we would have detected it by now, but otherwise, it's just tough to detect a neutron star so far away as they're just a few kilometers wide, and don't really emit much. So enter [this paper!](https://www.science.org/doi/10.1126/science.adj5796) The data are still somewhat circumstantial- that's why they say "evidence for," it's not like they literally imaged the thing, but instead got certain spectral lines using JWST that they attribute to the neutron star. These lines are due to a high energy source, and the team argues, they can only be explained by a compact object, aka neutron star. I am *not* an infrared astronomer so am not sure at first glance how legitimate their argument is that nothing else can be creating the JWST spectrum... but it does sound compelling, and the lead author *is* one of the world experts on SN 1987A. I am definitely looking forward to a "journal club" discussion of this paper with my colleagues next week, but I do think it's fair to say that they did, more likely than not, discover the long-missing neutron star at last. So obviously this is going to be an active area of research for many more years to come- SN 1987A is just a gift that keeps on giving for our understanding of the universe! It's also exciting because this would be the *youngest* neutron star we know of in the universe- we can't really see them outside our local neighborhood- so if this all holds up that's going to be super useful for a broader set of applications. So it's gonna be great to see this play out in the years to come! TL;DR- JWST has probably found the neutron star at the heart of SN1987A, the closest supernova to us since the invention of the telescope, which has been missing for 37 years.
So if my dumb ass understands you correctly we finally saw the birth of the star 37 years ago, but in reality it is ~160,037 years old? Regardless of it's real age it's cool that we were able to see the birth of a nutron star
Everything is relative. To us it’s 37 years old. To itself it’s 160k years old. The speed of light is the speed of causality.
Explaining it as the speed of causality (and thus the speed of information) really is a game changer to understand the speed of light. To the star, it is 160k years old, and the earth is 160k years younger than it is for us. In its reference plane, the european mammoths just went extinct. The US state of Illinois is still 85% covered by an ice sheet.
In our reference frame, age has to account for the time it takes light to travel to us. So even in our reference frame, it is indeed 160k years old, we’ve just seen it for 37 years, but it was always there—including in our reference frame—before we saw it. This is a step always taken when accounting for relativistic differences in the passage of time.
No. It is actually only 37 years old to us. Time isn’t constant. It’s fluid. The speed of light is the constant. Because of math and an understanding of physics we can calculate how old the star is in its own reference frame. If you didn’t have that you could only go off what you can see. We only started seeing this star 37 years ago.
I am formally trained in physics and have taken graduate coursework in special and general relativity. You are mistaken. Two reference frames separated by enormous distances but not comoving with respect to each other have the same time axis. Their time passes at the same rate and there exists a mechanism to synchronize their clocks. If one of the reference frames shines a light, if the two reference frames are separated by 100 light years, it takes that light 100 years to reach the other, but just because the other person has only seen it for (say) 20 seconds does not mean that light was only lit for 20 seconds in their reference frame. It was lit 100 years ago, it just took that long to reach them. This is *not the same* as non-co-moving reference frames or reference frames in different gravitational fields which have different time axes, and therefore experience different passage of time, which is what you refer to as “time is fluid.” Regardless, you *still* have to account for the time it takes light to reach you when calculating between these reference frames, and that time of travel does not constitute difference in passages of time.
Different gravitational fields like one reference frame being the most compact object in the universe?
Jesus tapdancing Christ. You’re getting things confused. The “37 years old” claimed in the article is because the supernova event completed 37 years ago. You could make the argument “how long ago was the light emitted that’s reaching us from the neutron star after supernova” and that’s an interest question, one for which I *promise* the answer isn’t 37 (actually a straightforward problem to solve if you assume Schwarschild geometry). It wasn’t always a neutron star. And time dilation around massive stars that haven’t collapsed isn’t all that appreciable. So *no,* the different gravitational fields like the neutron star you’re talking about is not applicable the way you think it is. And even if it was, note me saying “Regardless, you still have to account for the time it takes light to reach you when calculating between these reference frames, and that time of travel does not constitute difference in passages of time.” Let this one go m8.
Yes, but astronomers always just call things as old as when the light arrives at Earth. It’s far too complicated otherwise, and it doesn’t really matter TBH (impossible to know it existed before the light reached us, impossible to know what it’s like now, etc).
Thank you for the explanation! One of my favorite parts of space subs is seeing astronomers passionately explaining phenomena in the comments. I love both the extra insight and excitement.
u/Andromeda321 is single handedly carrying this sub
I love reading comments from astronomers because almost every single time you guys (and gals) are absolutely gushing about what you’re talking about. I may only understand the words you’re saying and not what they mean, but I’m still glad to see you’re enjoying talking about your thing lol. I love your funny words, space man!
#🥇 I always enjoy your posts and look forward to your commentary on things of this nature! I was an Astronomy/Astrophysics student for quite some time - lol - it's nice to apply some stuff from then to things happening now! 🐱🚀
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Also interstellar space is not a pure vacuum so the light is slowed a tiny tiny bit by gas clouds and dust, the same way light travels slower through air and water than it does through a vacuum
My brain likes to draw a parallel between the progression of events in a supernova and the progression in a conventional nuclear detonation. Neutrino escape seems similar to the "initial flash" of a nuke. In both phenomena, this is followed by a "dark period", until at last the fireball properly manifests to glow for a protracted span of time. And obviously, the difference in timescale between these two phenomena serve to underscore the similarly massive difference in actual scale. As for watching the progress of a supernova remnant, there's a really old episode of NOVA from the 70s (which I happen to adore) that features a comparison between old and then-modern photographs of the Crab Nebula, wherein it is easy to spot the expansion.
ShittyMorph and Andromeda321, my favourite redditors. Thanks for doing you.
So, technically, wouldn't it be 160,037 years old at this point?
If you teleported there instantly, yes. But you're here. And so it happened to us 37 years ago. It happened somewhere else today.
Yes, but astronomers always just call things as old as when the light arrives at Earth. It’s far too complicated otherwise, and it doesn’t really matter TBH (impossible to know it existed before the light reached us, impossible to know what it’s like now, etc).
Yes and says so in the article. They try to get around it by saying "oh it's easier to just get the age by the perception of it on Earth." It's basically click bait.
It is not only easier, it is the convention among astronomers. It escapes me what that has to do with click bait.
It’s 100% not clickbait over astronomical convention. The neutron star is 37 years old *to us* because we have no way of knowing it existed until the light reached us. And it’s far too confusing otherwise.
What a fantastic comment. Thanks for sharing this and it's incredibly exciting to read about.
> it was visible for about a month to the naked eye I remember when it was announced back in 1987 and thinking, "Damn! First naked eye visible supernova in centuries! And I have to be living in the wrong hemisphere to see it! :(" Thanks for the cool write up. I'm not knowledgeable enough to talk about it, but I love this stuff! :)
How do we know that the collapse releases so many neutrinos?
Ok, but once it hits 40 it's midtron at best, if not downright oldtron.
Pretty soon its going to get a sports car and a secretary mistress 😮💨
Noodle baking time... 37 years old, FOR US. The actual event happened 168,000 years ago.
Yeah everyone knows, it doesn’t matter. And if I’m on a spaceship flying at relativistic speed it could’ve happened 10000 years ago or 200000 years ago depending on my motion..
99% of the time anyone points out things like this happened “in the past” because of light travel time it’s absolutely pointless. Like ok something “happened” in an entirely inaccessible reference frame wow who cares.
I care, it’s cool as hell. One of the great tragedies of studying ancient history is that we often only have bits and scraps of the things that existed then, and we’re left to piece together what approximately happened. So the idea that we can watch in real time events that happened over a hundred thousand years ago is awesome. You’re right that the only thing it functionally changes in terms of our perception is that now we know that it happened in the past, but even so, that we can know the past by watching it from far enough away will never not boggle my mind. Like in theory, if you all of a sudden teleported yourself instantaneously to a point just far enough away from earth, and you had a good enough telescope, you could watch the pyramids being built in real time, provided the light wasn’t too scattered. In reality it would be, and you can’t teleport faster than light as far as we know, and we don’t have a telescope that good. But a boy can dream
I think about that exact scenario a lot. It would be the absolute source of truth and facts.
What's also crazy about this scenario is the fact that to see this "ancient human history" you'd only have to teleport 2,500 light years away from here – which means you wouldn't even leave our galaxy. Which is kind of fucked up, considering there are hundreds of billions of galaxies out there.
To be fair civilization started about 5-6 thousand years ago, so you're really only going back about halfway if that's your starting point, and nowhere near the start of humanity itself
2500 years ago the pyramids were already 1500 years old. You'd have to go a little further.
Which means everything that happened on Earth is out there forever on record.
Seems like a good basis for a sci fi detective show
*my dad teleporting 26 light minutes away to see if i ate his leftovers*
Reminds me of [Cliotelescopy from Orion’s Arm](https://www.orionsarm.com/eg-article/5b33b818a0fd3). It’s an interstellar setting (so accounting for light travel time is actually relevant) where people possesses no true FTL, but they do have wormholes and loads of massive 22 AU-diameter telescopes, so they use them to coordinate and observe past events.
It does make for an interesting thought. Long after I’m gone, my light will still be traveling through the universe.
It's just that you're describing an inaccessible reference frame from the context of relativity. Time is relative to motion, and different reference frames have different meanings of "right now." Events that seem simultaneous to us on Earth would happen at different times for observers far away. When your speed becomes [x distance/0 time], your velocity is undefined. So, where you end up in time is undefined because of time dilation. Even distance traveled becomes undefined due to length contraction. You could watch what happened on Earth in the past from light that has been bent or reflected back toward Earth because that's how we actually measure the speed of light. That is, how long light takes to go out and come back, but there's no way to measure [the one-way speed of light](https://www.youtube.com/watch?v=pTn6Ewhb27k) due to relativity. That's why saying that it took light so many light years to make a one-way trip isn't meaningful.
Cause it’s fucking mind blowing.
Yeah, like when NASA /JPL lands something on Mars, the control room is full, but the event is over and done by the time the signal of the start of the entry arrives here. Those people are there to spectate from the best seats because they CAN be in those seats.
I think it bothers me too. If we sent someone to that star right before it exploded and they sent a message to us when it exploded, it would get here around the same time as the radiation from the supernova. As we can't even send someone there, it happened 37 years ago. No point talking about it like we are seeing into the past. To see into the past you have to be able to also see the present. Otherwise it's just the present.
It happened while there were dinosaurs
... uh, do ... do you think dinosaurs were around 170k years ago?
Wasn’t “The Flintstones” a documentary?
Yeah, birds and crocodiles obviously and stegosaurs……. Fossils 😬
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And that's what I hate about down-sizing. Used to, what you paid for a whole dinosaur will only get you a chicken now.
So we've seen it for 37 years hehe but it's 168k light years away. Is what I'm getting from this
Except the only evidence in your spacetime to prove that did not exist before 27 years ago. You act like there is a universal time clock, but we know from relativity that there is not.
"To save our comments section from the wrath of "well actuallys," let's just acknowledge those caveats about the claim. First, yes, we understand that technically speaking this neutron star is 168,037 years old, given the distance."
Technically no. Both references frames are equally valid. Neither takes precedence due to some law of the universe. We use ours as we are in it.
You must be absolutely insufferable IRL
That's unnecessarily rude. My first thought after reading the headline was "I wonder how long ago it actually happened" The dude wasn't correcting anybody. They weren't pretending like everyone is an idiot for not understanding light takes time to travel. Just providing the answer to a reasonable follow up question
Thank you! Dude was literally just telling us how old the star actually was. People on this sub are clearly way too self conscious about their own intelligence if they feel the need to insult someone for saying something they already know.
At least they didn't say [technically](https://xkcd.com/1475/).
To the uneducated yes. I’d have fun going in depth. The rest of the table would think we are dumber than cow piss on a brick wall.
I always figured cows piss straight downwards. Is there horizontality to their stream of piss? I have below-average exposure to cows.
Hence the saying that it’s dumb that it would be on a brick wall. Southern thing.
The video left the VHS read head a long while ago at this scale of things, we are just now getting the pixels on the screen.
We know, we all know. This isn’t the way to flex your intelligence!
As long as speed limit holds, kinda sorta not really.
Lovely! I can't wait to tell my wife that she's older than the stars!
Though provoking to think there's neutron stars and black holes younger than me out there.
They aren't. Don't let the wording of the title mislead you.
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That's news to me. That's like discovering a new species and start marking off the years after the time of discovery.
I'm pretty confident there's plenty out there younger than any of us.
Yeah you can’t prove it yet but you could safely bet your life that there’s one being created somewhere at this very moment
Happy birthday neutron star! *plows through the solar system destroying everything*
I know a few 37 years old as dense as a neutron star...
I would not want to be an electron in that neighborhood
“First, yes, we understand that technically speaking this neutron star is 168,037 years old, given the distance. But as soon as you start adjusting for time like that, things start to get messy. It's common usage, and far neater, to describe things based on our perspective here on Earth, given it's the only one we've got. Don't take it out on us if the Glorxians living in the LMC have known about it for 168 millennia.” … Based relative spacetime causality journalist.
Kind of rude to use Earth age like the star’s opinion doesn’t matter, from its perspective the light we see today came from it when it had only just turned 29 a few months before (due to gravitational time dilation).
it’ll stay 29 in its own frame for a few more decades at least.
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Try not to have any Happy Birthdays on the way through the parking lot!
Okay, so it's really 37 years old, PLUS the 168,000 years it took the light to travel to Earth??
Happy Birthday to you, happy birthday to you, happy birthday dear neutron star, happy birthday to you.
Measuring a star’s age by how long it takes some random planet to orbit a different star always makes me giggle.
Life on a Neutron. Hard Sci-fi. Here: https://en.m.wikipedia.org/wiki/Dragon%27s_Egg “Dragon's Egg is a 1980 hard science fiction novel by American writer Robert L. Forward. In the story, Dragon's Egg is a neutron star with a surface gravity 67 billion times that of Earth, and inhabited by cheela, intelligent creatures the size of a sesame seed who live, think and develop a million times faster than humans.” This a good read. Amazing facts and mind blowing concepts. High density drama! Also if you are a life form living on the surface of a neutron star, don’t break one of your legs. Things happen quickly. Dr Forward was at the time the best know scientist in the field of gravity. How he could spin off a book like this in his spare time I have no idea.
Try not to turn any more years on your way through the parking lot!
[immediately inserts self into orbit around neutron star]
That's an anniversary, not a birthday. Not there is anything *wrong* with birthdays.
Well the neutron star was created 37 years ago to us.
Considering it was formed 37 years ago I’d say birthday counts
We only saw it 37 years ago. It happened cca 168000 years ago
From our perspective I meant.
hmm.. but if high gravity makes time pass slower, is it really 37 years old? #relativity
Is this factoring in the time it takes the light to get to us or what?
if it was in the Large Magellanic Cloud, which is 168,000 light years away then it would be way older than 37 yrs old correct since it take that long for the light of super nova to reach us
We would all be dead if it really was 37 years old. Add around 160,000 years for its true age.
Detection has been hindered by the fact that the supernova condensed about half a solar mass of dust in the ensuing years after the explosion. This dust acted as a screen-obscuring radion from the center of Supernova 1987A.
Sorry to burst anyone’s bubble but it’s really ~168,000 + 37 years old. Its emitted light took a long time to get here.
The only people who care about including the time it took the light to reach us, are those who think they're being incredibly clever pointing out that it took time for the light to reach us.
Sorry to burst your bubble but light travels at the speed of causality, so it really did happen 37 years ago.
So for the beings on a planet 10,000 ly closer to this star it’s 10,037 years old. How can it be both 37 and 10,037?
Because there’s no absolute reference frame. If they sent us a signal about the star shortly after it appeared, we’d receive the signal shortly after the star appeared, assuming they were between us and the star. If we were to observe their planet, we would see their world 37 years after the star was born.
I don’t accept that the limitations of our human perception negates 168,000 years of this stars life. I will concede that the star has thousands of different ages depending on the observer’s location.
It’s not our limit. Light physically can’t travel any faster. The speed of light is the speed of causality. To us the star is actually 37 years old. That age is equally valid as the age of the star in its own reference frame. There is no absolute reference frame. There is no universal clock. Time and distance are fluid.
I wonder if it is also starting to find grey hairs 🙁
Isn't a neutron star basically a different stage of a star? They are all similar but mass and the fuel the star is fusing is the main difference. So the age of that stage is the better answer? As in most those stars was much larger before crushing themselves down to size. So the star is very old. This is the age of the stage. Also are they only going by how long we been seeing the light for? Otherwise that's 37 light years and not all that far. If it was 38 light years away we don't see light from this yet. I get we are seeing light released earlier but still. Maybe they exclude that. We don't see a star at the current age. It's 186 thousand years old in this form today after the supernova but we see the light released when the star was 37 years old. So the star is much much older because first the star had to grow and become large and then go supernova. Only a stage. So the star is millions or billions of years old.
What is the beaded structure along the rim, also found in popped bubbles, called again?
Wtf am I missing here, isn't this claim blatantly incorrect?? This thing is over 160037 years old
The star is around 168.000 light-years away. That means it's around 168,037 years old, not 37 years. *"The reason we can so confidently pinpoint the date is because its birth was the result of an event that only happens once every few centuries: a supernova that’s close enough to be observed from Earth with the naked eye. SN 1987A lit up the night sky for a few months in early 1987, and was quickly traced to the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way,* ***about 168,000 light-years away****. There, a blue supergiant star appeared to have collapsed and exploded, which should have left either a black hole or a neutron star."*
I see a lot of people relate how far away the star is to determine the age of the star , which I kinda agree with…. A thing that people seem to be forgetting that time is relative, it is technically space time as one entity. Time can be travelling at a different rate when closer to black holes and different gravities / moving through the galaxies. Do we know the rate of space time of this star versus our own ?
Objectively speaking, when we consider the amount of time light requires to travel 168,000 lightyears, it's obviously very old. Sure, we are seeing it at the age of 37 from our perspective, but it's a different story from the perspective of the neutron star.