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Astronomers Successfully Predict Appearance of Supernova

Posted by timothy on from the lucky-guess dept.

schwit1 writes: For the first time ever astronomers have been able to predict and photograph the appearance of a supernova, its light focused by the gravitational lensing caused by a galaxy and the dark matter that surrounds it: "The NASA/ESA Hubble Space Telescope has captured the image of the first-ever predicted supernova explosion. The reappearance of the Refsdal supernova was calculated from different models of the galaxy cluster whose immense gravity is warping the supernova's light." What makes this significant is that the prediction models were based on the theory of gravitational lensing and required the presence of dark matter to work. That they worked and were successful in predicting the appearance of this gravitationally bent light (bent by the dark matter it passed through) is a very strong confirmation of both concepts.

44 of 86 comments (clear)

  1. Prediction of What? by tinkerton · · Score: 4, Informative

    They didn't predict that a supernova was about to happen. They'd already seen the supernova happening in its ghost image created by gravitational lensing. They predicted where another image of the supernova would turn up.

    1. Re:Prediction of What? by pjt33 · · Score: 4, Insightful

      "the first-ever predicted supernova explosion" certainly sounds that way. The subsequent mention of reappearance mainly serves to confuse.

    2. Re: Prediction of What? by Anonymous Coward · · Score: 1

      Don't contradict people and get it wrong. Reappearance means for something to become visible again. An additional supernova would be recurrence.

    3. Re:Prediction of What? by beastofburdon · · Score: 1

      I'll bring the popcorn.

  2. Re-Watching a Supernova by Henning+Rogge · · Score: 5, Interesting

    It is a quite interesting thing being able to "re-watch" a Supernova from the beginning because the light has multiple paths towards Earth so we got a "warning" when it will happen.

    The problem with a lot of Supernova explosions is that we often don't know what happened in the early phase (until it became bright enough to be noticed in wide-field pictures). It is most likely "a little bit" too far away to learn what type of star has exploded, but it still a great opportunity.

    1. Re:Re-Watching a Supernova by KGIII · · Score: 2, Interesting

      I'm just waiting for someone to pipe up that DM doesn't exist while not actually knowing what DM is. There are a few people who have valid opinions on it but almost all of the ones that I've noticed don't actually know what it is. (It's not really anything too specific yet, but we've got some ideas and some math. It's a placeholder.)

      --
      "So long and thanks for all the fish."
    2. Re:Re-Watching a Supernova by KGIII · · Score: 1

      Oh, it's almost a certainty that it will happen again. Yes. I'll check back in a while and see. Maybe, just maybe, it will have been prevented.

      --
      "So long and thanks for all the fish."
    3. Re:Re-Watching a Supernova by tomhath · · Score: 1

      I'm just waiting for someone to pipe up that DM doesn't exist while not actually knowing what DM is...(It's not really anything too specific yet, but we've got some ideas and some math. It's a placeholder.)

      Since nobody knows what it is, anyone who says it doesn't exist would not know what it is.

    4. Re:Re-Watching a Supernova by KGIII · · Score: 2

      Sort of true. I mean, yeah, it could turn out to be an effect caused by purple unicorn farts and it would still be dark matter.That's unlikely, and all, but it could happen. Something is causing this effect. Of course, some people seem inclined to not know the difference between dark energy and dark matter but that's a topic for another day.

      I am not a physicist. I am a mathematician. I do find it fascinating but it's just a hobby.

      --
      "So long and thanks for all the fish."
    5. Re:Re-Watching a Supernova by KGIII · · Score: 1

      That reminds me of one of my favorite jokes from childhood. Keep in mind, jokes were a bit different back then. We weren't so very clever, I guess. Anyhow, you may have heard it...

      Q: How do you keep a turkey in suspense? ;-)

      --
      "So long and thanks for all the fish."
    6. Re:Re-Watching a Supernova by KGIII · · Score: 2

      We don't really know. The naming is unfortunate. It makes people come to all sorts of conflated confused conclusions - often without any help from others. ;-) I liken it to calling it the God Particle. A very unfortunate naming process.

      What DM is, and I'm just a layman, is what ever it is that causes this effect. Now, we've got some ideas and some maths and some of it even works. Proving this seems to be a bit of a stretch at this point but there are some folks thinking we might be able to really test it a bit more and draw some conclusions. We seem to be able to detect something, something new, and that something is where the effect, gravitational lensing, is coming from.

      Given that they were able to make this prediction and then have it come true means we're getting a bit closer to at least detecting concentrations of DM if not actually finding out what it really is. The Chinese just sent up a satellite the other day. That may get us somewhere closer. This isn't going to be quick or easy and we're going to go through a lot of theories before we're able to come up with a consensus. The word "we" is "we as in humans." I am not a physicist. I am a maths geek and I find the subject fascinating. I do find QM a bit confusing. :/

      --
      "So long and thanks for all the fish."
    7. Re:Re-Watching a Supernova by Bite+The+Pillow · · Score: 1

      Why would you wait for ignoramus posts? And why tell us that's what you are doing? Starting the argument because no one else yet had? You are nonsense and noise.

    8. Re:Re-Watching a Supernova by KGIII · · Score: 1

      Pfft... Have you not seen the past half dozen, or so, threads where DM was mentioned? I'm awaiting it for the amusement factor. Why else would I be here? You've gotta be new here.

      --
      "So long and thanks for all the fish."
    9. Re:Re-Watching a Supernova by michelcolman · · Score: 1

      There's one thing I don't get: TFA says that "While the light from the cluster has taken about five billion years to reach us, the supernova itself exploded much earlier, nearly 10 billion years ago".

      I think someone's mixing up definitions of time and space here, or getting different reference frames into a tangle, because that doesn't make any sense to me.

    10. Re:Re-Watching a Supernova by Anonymous Coward · · Score: 1

      That's perfectly sensible. The cluster is five billion light-years from us, so the light from it has taken five billion years to reach us. The supernova is behind the cluster, at a distance of ten billion light-years, so it exploded ten billion years ago, and the light from it has taken ten billion years to reach us. (Five billion years to reach the cluster, and another five billion years to travel the rest of the way.)

      You can do things in another reference frame, of course, and get different answers, but the above is at least internally consistent.

    11. Re:Re-Watching a Supernova by KGIII · · Score: 1

      I realize you think you're being smart but, oddly enough, you're basically correct. Not only do *I* not know what it is, nobody else does either. They don't know how it works. They sure as hell have no idea how it exists. And, anyone who doesn't agree is *probably* an idiot. They may have a legitimate gripe but nobody has put forth a reasonable alternative.

      See, it's basically what ever it is that is causing this effect that we see. We can see the effect. It seems like, with this news, we can even predict this effect. Whatever this effect is caused by is Dark Matter. Dark Matter does not, as of yet, have a real definition except it's basically a placeholder for whatever it is that's causing this effect. "Strange shit we don't really understand but causes stuff like gravitational lensing and makes Newtonian Physics not quite right" is a very long name so Dark Matter it is.

      --
      "So long and thanks for all the fish."
    12. Re:Re-Watching a Supernova by KGIII · · Score: 1

      Nah, not all of us were bigots back then. Sure, many were but we were mostly just kids and being on base meant we were exposed to people from lots of cultures. Racism wasn't really that rampant where I was and by this time. It was elsewhere but I was kind of in an exclusion zone by virtue of living on or near base.

      --
      "So long and thanks for all the fish."
    13. Re:Re-Watching a Supernova by fredrated · · Score: 1

      I'm just waiting for someone to pipe up that DM doesn't exist while not actually knowing what DM is.

      I seem to recall that nobody knows what dark matter is, thus anyone saying anything about dark matter doesn't actually know what DM is.

    14. Re:Re-Watching a Supernova by michelcolman · · Score: 1

      O, of course, the supernova is behind the cluster. Yes, it makes sense then.

    15. Re:Re-Watching a Supernova by KGIII · · Score: 1

      It is just a title to use, a placeholder, to describe the results we're seeing. It could be purple unicorn farts and it would still be dark matter. Though, I presume, they'll change the name if it turns out to be purple unicorn farts. I find the choice of title to be rather silly, it's like the "God Particle" all over again.

      --
      "So long and thanks for all the fish."
    16. Re:Re-Watching a Supernova by KGIII · · Score: 1

      What I do find confusing is that I've seen, specifically, Polish jokes here on Slashdot that were moderated up. They're white so it's okay to be racist towards them? I've seen this happen on more than on occasion. One of them was, as I recall, +5 funny and I seem to recall 30% of the votes (if you click on 'em you can see 'em) were +1 informative.

      Sadly, the joke that I'm mentioning wasn't even a good joke. It was just crude. Someone had said the screen door on a submarine joke and the follow up was, "Why do the seagulls fly upside down over Poland? There's nothing worthwhile to shit on." I called 'em a racist prick and took -1 Troll like a man. And no, no I'm not white. I'm a mutt. In order, I am a Micmac, Irish, English, Black African. I look Asian and speak Spanish fairly well. I love to slip into Spanish and confuse people who are looking at me. With a little effort, I can kind of blend in with any race and many cultures. So, it has its benefits.

      --
      "So long and thanks for all the fish."
    17. Re:Re-Watching a Supernova by beastofburdon · · Score: 1

      It could also be those massive magnetic fields that we know exist but refuse to acknowledge any possible source for.

  3. Dark Matter testable predictions by Anonymous Coward · · Score: 4, Insightful

    ESA Hubble Space Telescope has captured the image of the first-ever predicted supernova explosion. ... What makes this significant is that the prediction models were based on the theory of gravitational lensing and required the presence of dark matter to work.

    The important part here seems like confirmation of testable predictions made by Dark Matter theories. That's how science works: you have to make a falsifiable theory that makes testable predictions. Those predictions are then tested, to lend evidence toward or against the theories. This is key evidence in favor of Dark Matter.

    1. Re:Dark Matter testable predictions by penguinoid · · Score: 1

      I don't see how this supernova business relates at all to Dark Matter. The supernova happened in a galaxy already known to be gravitationally lensed by this other galaxy. Therefore it is predicted to show up in the gravitationally lensed image. The only involvement of Dark Matter is that, yes, we still need it for galaxy gravity to match our estimates of galaxy mass and gravitational strength. Just like it was needed to match galaxy rotation speed and non-supernova gravitational lensing. I mean, I suppose we have some verification that the path-length of the lensing is what we expected it to be, but I expect that to have already been checked.

      --
      Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
    2. Re: Dark Matter testable predictions by penguinoid · · Score: 1

      Yes, but what does supernova lensing tell us that we didn't already know about dark matter?

      --
      Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
    3. Re: Dark Matter testable predictions by Anonymous Coward · · Score: 3, Informative

      That it obeys the rules that dark matter would have to obey, and disobeys every theorem of mond that has ever been proposed.

      Duh.

      What else did you think a test and validation of a theory would incur? Cookies and presents for all?

    4. Re:Dark Matter testable predictions by HiThere · · Score: 1

      That's probably the most important part, but being able to photograph an entire supernova explosion from slightly before the main event isn't without it's importance.

      I do, however, wonder just how tightly this constrains the properties of dark matter. That could (possibly) be a real breakthrough.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    5. Re: Dark Matter testable predictions by HiThere · · Score: 2

      It may well tell us details about the distribution and clumpiness of dark matter. That could be quite significant.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    6. Re: Dark Matter testable predictions by KGIII · · Score: 1

      This tells us that the math is probably correct. I'm a layman but I'll try to explain. The resultant lensing is different than it would be if we did not know about DM. (We don't actually know what DM is, really.) We can observe the effects of DM. This is demonstrating that we're not getting the results we'd expect without DM but we're getting the results we expect *with* DM taken into account and, because of this, we were able to accurately predict where and when we'd be able to get a picture of it.

      It's quite significant, I think. Note, the word "we" is "we the humans" and not "we" as in I am involved. I am purely a laymen with an interest in physics and astrophysics. I even have an interest in QM but I find that very confusing at times. Some of it, I get. Others? Well... The multiverse thing confuses me. But, I digress...

      Well no, I don't digress... See, if we can find out more about DM then we may be able to check the expected fingerprint, compare it with the maths, and then determine if, perhaps, we've ever collided with another universe. That is, of course, not my theory but one from Greene, Gates, Susskind, et al. Add to this the recent detection of the effects around the moon (perhaps in some sort of waves or strands) and a recent launch from China that is coming online soon well... Hopefully I end up getting some new documentaries to learn from.

      Speaking of documentaries, I really much prefer those like Cox or Green. Susskind should do some as should Gates. I appreciate when they say things like, "Well, if you believe in the current physics." Or, "This is what it might be..." Or, "Current mathematical models predict..." I appreciate them being open and honest and suggesting that things are not laws when they're simply theories (often at best, using a strict definition).

      Now that is digression but still fairly topical. At any rate, I look forward to learning more about this in the near future. I'm actually kind of excited. ;-)

      --
      "So long and thanks for all the fish."
    7. Re:Dark Matter testable predictions by KGIII · · Score: 1

      Nice! That's my thinking as well. This means, at least, that the maths that predict the results of Dark Matter are correct in this instance. This means that we're one step closer to, maybe, getting to figure it out a bit more. I read a bit of a study about some findings of "strands" (I think that's what they were calling them) that were quite close (around the moon) and that we're able to actually see, specifically, where the lensing is happening at it's greatest effect.

      Unfortunately, there has been some serious harm done by the title - in my humble opinion. Too many people see "Dark Matter" and, maybe, read a article about it where a wild prediction is made as to what it is and assume that it is something other than what it is. The reality is, buggered if they know. But, this shows that the math is correct (for this instance) and that they are on the right track.

      Frankly, I find it amazing and am a little giddy about it. I'm quite hopeful that they'll get me a new documentary out in the next six months or so. I find a good writer and presenter do better justice, for me, as it's not a scholarly pursuit but a general entertainment pursuit.

      --
      "So long and thanks for all the fish."
    8. Re:Dark Matter testable predictions by EdgePenguin · · Score: 1

      Dark matter has many testable predictions; armchair physicists who think they can second guess professionals only ever seem to know about rotation curves, and smugly decide that they know better.

      Modified gravity only has the benefit of fitting certain observations - it has no theoretical backing. With most current data, modified gravity doesn't fit that well anyway. Its largely out of favour with physicists, only with those people who think that without any formal training in the subject they understand it better than physicists

    9. Re: Dark Matter testable predictions by beastofburdon · · Score: 1

      I haven't heard about this weirdness around the moon yet, got a link?

    10. Re: Dark Matter testable predictions by KGIII · · Score: 1

      Here's the first written piece I came across:
      http://news.discovery.com/spac...

      They were able to, according to NPR, detect it with something to do with minimal shifts in light with the moon and the theory is we're growing a beard of Dark Matter.

      Yes, yes I phrased it just like that for you. :D Also, per your other comment, I'm betting it's Pink Unicorn Farts. What *is* interesting is that they were able to make some predictions and the maths worked out so that they were able to catch this on film. That's a damned good indicator but, alas, we still haven't a clue. It could, I guess, be magnets but we'd have to show that magnets are able to cause the lensing effects that are being seen. I am unaware of any properties that photons have that will be influenced by magnetic force.

      --
      "So long and thanks for all the fish."
    11. Re: Dark Matter testable predictions by beastofburdon · · Score: 1

      I actually already found and read this one. There was no actual observations to support this. It was nothing but a simulation based on speculation. It is an interesting thought experiment though.

    12. Re: Dark Matter testable predictions by KGIII · · Score: 1

      Yeah, I can't find the NPR transcript either. (I know it was NPR 'cause that's all I listen to on the radio - it pisses the missus off but I've noticed she's listening.) And no, they're just detecting fluctuations and they appear to have found concentrations and our moon may impact them though they have no (observed) effect on the moon. That was how I understood it, at any rate. I'm still thinking it's unicorn farts. I bet I could wire up some math that looked good and checked out and attribute it to unicorn farts. I wonder if I can get it published? ;-) April Fool's Day is coming up.

      --
      "So long and thanks for all the fish."
  4. Dark matter or MOND? by clovis · · Score: 1

    I wonder whether they could have used modified Newtonian dynamics to have made the same prediction.
    That is to say, I don't see how this prediction leans to either side in the dark matter vs MOND question.

    1. Re:Dark matter or MOND? by Khashishi · · Score: 3, Insightful

      MOND is largely discredited by the bullet cluster measurements.

    2. Re: Dark matter or MOND? by KGIII · · Score: 1

      Hmm... I thought, and correct me if I'm wrong, that MOND was rather specifically meant to be used to deal with situational results that were unexpected or did not conform to the existing theories and maths? So, in other words, one area of the galaxy would use a slightly different model than another as there might be different effects seen in those areas.

      An example would be that we'd find different areas of the galaxy with a greater concentration of dark matter than we'd find in other areas and thus, perhaps by mapping or observation, we'd adjust the maths to suit and work with that as the premise to account for things unknown, unmeasured, or unseen. Perhaps I'm not articulate enough but I've edited this a couple of times as I thought about it. Hopefully I'm expressing my curiosity well enough and clear enough.

      I think that, and I may be missing something, the most important thing is not the actual images (those are awesome) but that the prediction turned out to be true in this particular case. I'd absolutely hate to see the maths involved in this. Well, no... I guess I'd like to see them and have someone actually explain them to me - so long as I don't have to solve them.

      The more I think about it, well... It's quite fascinating. I've been lucky to have been alive at this particular time. I was born in the late 1950s and so much has changed. The refining of the maths, the discoveries, and the implications are fantastic to the point where I'd, as a young adult, have had difficulty believing we'd have come this far.

      I do wish Feynman were alive to see this. I guess I wish Einstein could see this too. Meh, at least we've still got Susskind, Gates, Cox, and Greene. There are surely more to add to the list but it has been great to see the progress made. I don't always understand it, not everything, but I'm frequently able to understand enough, just enough, to be fascinated.

      --
      "So long and thanks for all the fish."
    3. Re: Dark matter or MOND? by Anonymous Coward · · Score: 1

      Hmm... I thought, and correct me if I'm wrong, that MOND was rather specifically meant to be used to deal with situational results that were unexpected or did not conform to the existing theories and maths? So, in other words, one area of the galaxy would use a slightly different model than another as there might be different effects seen in those areas.

      The intent of MOND, at least with most work, is to develop a universal law of gravity in the situation of low acceleration (or an alternative interpretation that affects all forces at low acceleration). This came about because early on fitting one galaxy rotation curve for the parameter, the acceleration scale where things become non-Newtonian, produced a result that work pretty well for other galaxies. As time went on though, more examples of other galaxies made this difficult, and there are couple different functional forms of how exactly gravity becomes non-Newtonian at that scale. The goal was to produce a universal law that applied everywhere, so requiring different functional forms and different parameter values in different situations is a failure of the theory. The best fix that can be done for some failed MOND situations so far proposed is large amounts of unseen matter... meaning MOND requires dark matter anyway to be universal. Otherwise, it just amounts to a non-physical ad hoc fit to a bunch of situations, which makes it even more difficult to actually integrate into things like relativity and other potential conflicts.

    4. Re: Dark matter or MOND? by KGIII · · Score: 1

      Thanks! That was rather clear. You should write more often. ;-)

      --
      "So long and thanks for all the fish."
  5. Re: well go ahead and tell us the modification by HiThere · · Score: 1

    It may not quite be "making shit up", but it certainly appears to be "ad hoc adjustment after the experiment to fit the result returned by the experiment". This isn't always invalid, but is certainly not very convincing. Theoretical tests need to predict the result before the experiment is run.

    --

    I think we've pushed this "anyone can grow up to be president" thing too far.
  6. Neutrinos showing supernova by Etherwalk · · Score: 2

    It is a quite interesting thing being able to "re-watch" a Supernova from the beginning because the light has multiple paths towards Earth so we got a "warning" when it will happen.

    I though we were able to notice supernovas a short time in advance of when they occurred visually because neutrinos from the explosion make it out of the star well in advance of the other stuff. (So we see a few neutrinos and can tell the supernova is about to be visible).

    Can someone confirm or deny? It's been a long time since I took astrophysics.

    1. Re:Neutrinos showing supernova by Anonymous Coward · · Score: 2, Informative

      We can ... in theory. The trouble is that our neutrino detectors aren't as sensitive as our optical telescopes. We can detect optical supernovae billions of light-years away, but we can only detect the neutrinos from a supernova within a few hundred thousand light-years.

      The most recent supernova that was close enough to detect in neutrinos was in 1987 (SN1987A). Three detectors spotted neutrinos from it a few hours before the optical supernova, but they only noticed this coincidence after the fact.

      We're a bit more savvy about it now, and I bet that, if there was another nearby supernova setting off multiple neutrino detectors, they'd notice the coincidence and send out an alert within a few minutes. They just need another nearby supernova (roughly, within our own galaxy), which happens once a decade or so.

  7. Re: well go ahead and tell us the modification by KGIII · · Score: 1

    And another near brilliant observation on your part. That makes me strangely happy. ;-) The last half dozen threads about Dark Matter had me feeling a bit disappointed with people. I love to learn new things and that's why I'm here.

    At any rate, and correct me if I'm mistaken, that's why it is so important and impressive. This made a testable prediction and, yet again, we've determined that the math has been accurate enough to reasonably conclude that, well, the math is correct. This may, of course, imply more than that. What's important is that the prediction was made, tested, and verified.

    Now, in line with an above comment and two prior threads, I'm pretty sure that Dark Matter is actually a result of Purple Unicorn Farts. They are concentrated and have magical properties (that are consistent) and are causing the lensing effects that the maths hadn't previously accounted for. I've seen a few other strange theories, shall we say.

    At any rate, I think it was some guy from Russia who was postulating that if we could fingerprint this DM we might be able to find differences in where they are as to where they should be and those differences might be indicative of us having bumped into another universe. I'm suspecting that they'll prove no such thing but it will be really interesting to see what happens. I highly doubt that any consensus will be found in the dwindling numbers of years that I've remaining to me, but it's not against any of the laws of physics that I'm aware of. (Of course, I'm certainly not aware of all of them. Contrary to popular opinion, I do not know everything.)

    I guess my point in replying is that someone needs to thank you for taking the time to post. Sometimes mods don't know or aren't familiar with the subjects and you end up with very good posts not being recognized as such.

    --
    "So long and thanks for all the fish."