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How to See a Supernova This Weekend From Your Backyard
- JacobAldridge 15y agoHours, and 21 million years, after it happened.
- unwantedLetters 15y agoThanks for pointing this out. I've obviously not gotten my head around the concept of space-time and the article fails to mention this. Also, http://newscenter.lbl.gov/feature-stories/2011/08/25/supernova/ http://newscenter.lbl.gov/feature-stories/2011/08/25/superno... is perhaps a more official story. They too don't mention that it's discovery was a few hours after it was possible to observe the explosion, not a few hours after the actual explosion.
- VladRussian 15y ago"The PTF survey uses a robotic telescope mounted on the 48-inch Samuel Oschin Telescope at Palomar Observatory in Southern California to scan the sky nightly. As soon as the observations are taken, the data travels more than 400 miles to NERSC via the National Science Foundation’s High Performance Wireless Research and Education Network and DOE’s Energy Sciences Network (ESnet). At NERSC, computers running machine learning algorithms in the Real-time Transient Detection Pipeline scan through the data and identify events to follow up on. Within hours of identifying PTF 11kly, this automated system sent the coordinates to telescopes around the world for follow-up observations." can it look like a planet-wide intelligence to an outsider? :) . Interesting to compare to the origins of cybernetics : http://en.wikipedia.org/wiki/Norbert_Wiener#During_and_after_World_War_II http://en.wikipedia.org/wiki/Norbert_Wiener#During_and_after... It seems to me that detect-track-target feedback-looped principle was one of key in the development of intelligence of animals and humans, and it seems to continue its work in developing the intelligence beyond that.
- sophacles 15y agoThese conversations are useless. Everyone knows that anything we see is strictly in the past and already has happened. Yet for practical purposes, a week ago there was no supernova there. Today a supernova is there. It may help you to look at it like this: a supernova is NOT the star exploding, it is the observation of the star exploding. In one sense, this is wrong, but in another it is really the only freaking thing a supernova can be. Therefore since it wasn't a supernova until humanity saw it being a supernova, it is currently happening. Further, the article only says the supernova is brightening, and that the telescope saw the star early in its explosion a few hours ago. From the reference point of observability, no claim is made that something 21million light years away is being watched now, just the effects of it are being watched right now. Relax and go watch the show.
- baddox 15y ago> Everyone knows that anything we see is strictly in the past and already has happened. Actually, that statement is nonsensical. Choosing the Earth as your point of reference, the supernova is happening exactly when we see it happening.
- jerf 15y agoI don't think it's nonsensical. There is a meaningful way in which it is in the past. Even if you turn yourself into photons, match positions with the supernova remnants, then return to physical form, the supernova is going to evolve though time for quite a ways beyond the current state we observe it in before your physical form has its rendezvous, even if the trip has zero duration for you. Putting a specific time span on how far in the past it is without further specification is dubiously meaningful, saying it is in the past is not nonsensical. Everything we see is always in the past, even if it's just on the other side of the room.
- baddox 15y agoIf you set a reference point, then I think it's perfectly sensical to say two events happen simultaneously or "now," but without a set reference point those notions are completely nonsensical. Most educated people understand the principle of relativity (which states that the laws of physics behave consistent in all frames of reference) and the fact that the speed of light is constant regardless of your frame of reference, but we tend to forget the resultant phenomenon called the relativity of simultaneity. Two observers in different frames of reference can't even agree on the order of events, much less the "exact time" they occurred. Now, you can certainly propose the semantic axiom that "everything happened in the past due to the finiteness of the speed of light," but I find that axiom to be pretty useless in scientific discussion. You can suppose that millions of years of stuff has happened to that supernova after "now," but none of those events could have any causal effects on us.
- mainguy 15y agoYeah, I thought that was a little misleading also.
- bfe 15y agoNot particularly exciting in the sense of being compared with Hollywood special effects. But I'm excited to look at it through my telescope and know that thing I'm looking at is a star exploding in a distant galaxy. And photons from that exploding star that have crossed 21 million light-years of intergalactic void are entering my eyeballs.
- artursapek 15y agoI hope you don't take offense to this but I laughed when I saw you're an attorney, because that is so poetic.
- bfe 15y agoI was an astronomer first.
- deleted 15y ago[deleted]
- baddox 15y agoI always have to point this out at the risk of downvotes: it doesn't make sense to say that an event you're currently seeing on Earth "happened 21 million years ago." Both space and time are relative, so if you're choosing Earth as your reference point, the supernova is happening right when you're seeing it.
- ars 15y agoNo, you are confusing relative time, with transit time (i.e. the time it takes for the information to reach you). Relative time is a real thing, certainly and messes with the idea of simultaneous. But transit time is not that. We and the supernova are more or less in the same frame of reference (we are not accelerating relative to one another, and there isn't much relative velocity difference either). And because of that it is correct to say it happened xxx years ago.
- baddox 15y agoIs that correct? Let's say Bill was born here on Earth on August 26, 2011, "at the same time" astronomers first detected this supernova. On Earth, we observe Bill's birth and the beginning of the supernova to be simultaneous events. However, isn't it true that an observer at the supernova (presuming he could survive) wouldn't agree that Bill's birth and the supernova were simultaneous, would he?
- mhb 15y agoHe would because he knows how fast information travels.
- ars 15y ago> On Earth, we observe Bill's birth and the beginning of the supernova to be simultaneous events. No, that is incorrect. We observe that the light from the supernova reached us now, yes. But we are well aware that it actually happened long ago. Both us and the distant observer agree about the order and relative timing of the events. It's only when we are not in the same frame of reference that we would disagree, and that is not the case here.
- Mz 15y agoI don't know exactly where it belongs/fits in this discussion, but some of the remarks here remind me of the example I have used on occasion that you see lightening before you hear thunder because light and sound travel at different speeds even though they both originate with the same event.
- thedjpetersen 15y agoVisually will the explosion appear any different than looking at a star with the naked eye?
- hvasishth 15y agoAt the moment, not really. In several hundred years it might become a nebula when it will look very different with a telescope. For example look up crab nebula.
- japaget 15y agoThis supernova has been hyped lately but is not something a casual observer will find to be particularly exciting. It is best seen with a telescope and will appear as a faint dot of light. The brightness will be magnitude 10 or 11, or about 100 times fainter than what the unaided eye can see in dark skies far from city lights. For more information, see http://www.skyandtelescope.com/community/skyblog/observingblog/128430288.html http://www.skyandtelescope.com/community/skyblog/observingbl... or http://washedoutastronomy.com/content/another-urban-supernova?page=1 http://washedoutastronomy.com/content/another-urban-supernov... or http://www.dailycalifornian.org/how-to-spot-new-supernova-in-nearby-galaxy-space-com/ http://www.dailycalifornian.org/how-to-spot-new-supernova-in...
- jacques_chester 15y agoStep 1: Move your backyard to the Northern Hemisphere.
- artursapek 15y agoNow I wish even more that I were back at school in Providence, the Brown observatory is open to the public. This would be a good humbling beginning to the school year.
- mturmon 15y agoPeople might be interested to know that this story is indicative of a sea change in astronomy. It has become apparent that there is a lot of variability in the nighttime sky, and we now have the technical means to discover lots of new things. One major factor in this change has been the advent of wide-angle surveys, that repeat often enough to find variable sources like SN's, blazars, asteroids, lensing events, etc., while they're still interesting. The Palomar Transient Factory (http://www.astro.caltech.edu/ptf/ http://www.astro.caltech.edu/ptf/) is the one mentioned in the article, but there are many others. They automatically detect and post events in a standard XML format for anyone (including robotic telescopes) to scoop up (e.g., http://www.skyalert.org/events/all/2/ http://www.skyalert.org/events/all/2/). One of the largest, LSST, is now being designed, and its data volume will prove to be a huge engineering/computer science challenge (http://www.lsst.org/lsst/science/petascale http://www.lsst.org/lsst/science/petascale). There's a sophisticated and multifaceted image processing pipeline to detect the changes in sources, to automatically extract photometric parameters, and to pass these parameters on to a classifier to separate the events into types of interest to various communities (the SN folks could care less about asteroids).
- Retric 15y agoIn a funny way it seems like Astronomy is catching up to particle physics. Once you add automation there becomes far to many data points to do anything but compare a model with outside events and look for discrepancy's that suggest either all models are wrong or one model is more accurate than other related models.
- mturmon 15y agoThere's definitely a parallel in the data demands of, say, LHC and LSST. Besides automation, another key thing is the element of time. It means there's scientific value in re-surveying the sky. Ever since gamma ray bursts, the time scale has been shrinking.
- cletus 15y agoReading things like this always brings me back to the Fermi Paradox [1]. There are lots of stars in our galaxy. Our observation of many nearby planetary systems and our understanding of the chemistry of life suggests life should be relatively common but we've seen no evidence of it. While life (on Earth) is at times incredibly resilient it's also really fragile. A supernova such as this must essentially sterilize space for light years around it and it bathes its neighbourhood in gamma radiation. Did this kill off some nascent civilization? Supernovas seem to be relatively rare (compared to the number of stars) but think: over billions of years what are the odds that such a thing--or something equally as deadly such as an asteroid or comet impact--won't happen? Space in incomprehensibly vast. The energy required to travel to even the nearest star systems seems... prohibitive. I'm inclined to think that there are also simply too many of us on this planet, a problem that we'll either correct or will be corrected for us as resources start to run out in the next century or two [2]. [1]: http://en.wikipedia.org/wiki/Fermi_paradox http://en.wikipedia.org/wiki/Fermi_paradox [2]: http://www.youtube.com/watch?v=F-QA2rkpBSY http://www.youtube.com/watch?v=F-QA2rkpBSY