Check this out regarding the comment about an "atomic clock" on a mountain top......
Astronomers believe they caught the supernova within hours of its explosion, a rare feat made possible with a specialized survey telescope and state-of-the-art computational tools
An amazingly rare feat, as not only did they catch the supernova right away, they somehow violated the universal speed limit of c in order to do so. Someone call the physics police on "chill" or Soulskill or whoever made that summary.
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Neither am I, but I'm having to deal with a lot of time and space recently. Even the light we observe from the sun is 8 minutes old. To add insult to injury, gravity has an effect on the rate at which time runs, so an atomic clock at sea level will start to diverge from an atomic clock on a mountain. And our sensory data has a non-zero processing time. All of which makes it astoundingly difficult to even find out when "now" is, much less use that information for anything before it becomes "then."
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When will Then be Now?
by Amouth (879122) on Friday August 26, @09:18AM (#37218550)
i always loved that when our star dies - it will take 8min 30sec before we find out. also that given the nearest start is >4 years.. so right now there could be nothing out there, we just don't know it yet.
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Re:Astounding! (Score:3)
Maybe gravity and other forces have an effect on how fast matter decays, possibly as gravitational drag affects particles with mass such as neutrons... you know, like how they "Proved" relativity by putting a clock on a plane and firing afterburners, and saying it ran slower than the clock on the ground. Has nothing to do with the Gs applied to the clock.
Re:Astounding! (Score:2)
by black soap (2201626) on Friday August 26, @09:58AM (#37219032)
According to the tour at McDonald Observatory, the light takes many many centuries to get from the center of the sun to the outside, but then under 8 minutes to get all the way to Earth.
Paren
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Tell me about it. Seems like I've been dealing with time and space forever. No matter where I go, all hours of the day, it's time and space! Even on the weekends, time and space! I just can't get away from it.Re:
I would go so far as to say that not only is dkleinsc wrong about now in that he is intentionally missing the intent of the word "Now" in context, but is wrong on what now means at all. Since as far as modern science knows, information cannot move faster than the speed of light, no event can really be said to be happening "now". The best you could ever say is "maybe now". The meaning of the word in the article isn't just a "valid" way to look at the universe. It is darn near the ONLY way to view the universe
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It isn't the summary at fault, from TFA:
Astronomers believe they caught the supernova within hours of its explosion, a rare feat made possible with a specialized survey telescope and state-of-the-art computational tools.
I think it is assumed that when they say they that found it within hours, they mean they found it within hours of the first light of this event reaching Earth, but since they didn't say so explicitly, I imagine you won't be the only one repeating this like they found something clever.Re:
Now is there any data on what the star was doing 3 days ago, so we might have hints what an imminent-supernova might look like? That would mean the next one we could catch even earlier.Re:
This isnt 'major geek' pedantry, it's 'slashdot-marks-it-insightful' nitpickery. What's amazing is people actually consider this a low signal-to-noise ratio.Re:
There's no absolute concept of time anyway - it would not be more or less correct to say a few hours rather than a few million light years because it all depends where you are in space-time. Their frame
I think a lot of people are disregarding this supernova. True the Type II explosions tend to produce experts in supernovae. But it should be remembered that Type I explosions still scare people. My wife and I were on the couch last night and suddenly we were both like, "Did you feel that? It felt like a burst of neutrinos coming out of the ceiling!" Which surprised me because I just had the roofers here last week laying down Spanish tile to keep fermions out.
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It's amazing how wrong you can be... The neutrinos actually came up through the floor from the other side of the planet;)
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And the Spanish tile just reflected them, doubling their exposure! The fools!
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Oh come on. What would our cross section be if we had to compete with everything under the floor? You don't know where we live.
All that conversation is here:
http://science.slashdot.org/story/11/08/26/1236202/instant-cosmic-classic-supernova-discoveredThis supernova was very close to us. One thing that could be very promising is if this left any neutrino signature above the background level. Neutrinos are very hard to detect, the major detectors are things like IceCube
http://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory [wikipedia.org] or Super-K
http://en.wikipedia.org/wiki/Super-Kamiokande [wikipedia.org] which have very large containers of water or some other substance and you then carefully try to detect the very rare neutrino interactions over all the background radiation (neutrinos are very ghostly and don't interact very much. You have billions of them going through you all the time and you don't even notice). This has only happened with one supernova before SN 1987A
http://en.wikipedia.org/wiki/SN_1987A [wikipedia.org] which was bright enough and close enough to be seen by the naked eye.
One really cool thing about this was that we actually recorded the neutrino burst for SN 1987A before the light arrived (three hours before). At this point, most people get shocked because they know that nothing travels faster than the speed of light. What happened was that in a Type II supernova neutrino burst occurs at the very beginning of the supernova process, but the light has to work its way out of the whole star. This actually allows us to potentially detect supernova before they happen, and there's now an early warning network with the major neutrino detectors so astronomers can get a heads-up if a type II is about to happen so they know where to point the telescopes. http://snews.bnl.gov/ [bnl.gov] Since the neutrino flux drops off quickly (like 1/r^2), supernovae need to be very close to us for to be able to pick out the neutrinos over all the solar neutrinos and general background junk. I don't fully understand the dynamics of Type Ia supernova (and I'm not an astronomer or an astrophysicist) but my impression is that there's also reason to believe that type Ia will produce fewer neutrinos than a Type II supernova. Between that and the distance, this supernova was probably too far away for us to detect any neutrinos.I suspect that the people who run the major detectors are probably looking over their data for the last few days very carefully to see if they can pick up any signal that the regular automated systems missed.