Slashdot Mirror
Robotic Telescope Unravels Cosmic Blast Mystery
An anonymous reader writes "The Register is reporting that scientists from Liverpool John Moores University have used their robotic telescope in the Canary Islands to measure the polarization of light from a Gamma Ray Burst just 203 seconds after its detection by NASA's Swift Gamma Ray Observatory Satellite. The result suggests that the emitting material flowing out from the explosion may not be highly magnetized in the way that some theories had predicted."
It shouldn't surprise us that GRB's don't behave as we thought. Nearly everything we think we know about them is based upon assumptions and speculation that are only minimally supported by evidence. There is potential for error at every single step of this process. To continue to be surprised that our telescopes are returning anomalous data when that's what's been happening nearly every single day for years and years and years is silly. At some point, you have to go back to your assumptions and figure out where you went wrong.
"A man cannot begin to learn that which he thinks he already knows." --Epictetus, 1st Century A.D.
With explosions that size, wouldn't 203 seconds of lagtime before observation be a huge killer of the results?
Furthermore, is there any possibility of a dipole radiation distribution for the fraction of linear polarization? Perhaps for this particular sample, we caught the glimpse of a stellar pole? Wouldn't we need a larger sample size to make a more conclusive prediction if this was the case?
for sale
I'm a self-modifying sig virus
When a black hole forms, the matter trapped within the event horizon has (for all intents and purposes) left our universe. Perhaps GRB's are merely the thermodynamic return on all that lost mass?
You know... I've wondered about that myself in the past...
I also wondered what might happen to the matter trapped in the accretion disks of two black holes when they began to merge, especially if they had opposing rotation... matter travelling at virtually the speed of light, hitting yet more matter, travelling at virtually the speed of light in the opposite direction... meaning an effective speed of impact almost double the speed of light... and all that happening in an area of dilated time... you have to wonder what that would look like...
Maybe someone smarter than me could tell us!
GRBs are thought to emanate only from the poles of a supernova. So no, a GRB can indeed be 'aimed'.
I've often wondered if GRBs aren't simply the result of some technological civilization stumbling onto a new law of physics, and wiping themselves out in the process. It would certainly explain the absence of any voices in a galaxy that -- by now -- ought to be teeming with life.
FATMOUSE + YOU = FATMOUSE
The intense bursts of radiation observed from the vicinity of black holes (especially those forming as a result of supernovae) are generally the result of some pretty extreme interactions just before the matter enters the black hole, as this matter is subject to extreme heating and compression and such - enough, even, to perform fusion on some pretty tough stuff and get metals as heavy as uranium.
The World Wide Web is dying. Soon, we shall have only the Internet.
It shouldn't surprise us that GRB's don't behave as we thought. Nearly everything we think we know about them is based upon assumptions and speculation that are only minimally supported by evidence. There is potential for error at every single step of this process.
In fact the whole idea is to sometimes find out surprising things that find flaws in the old models and give information to drive the creation of more accurate models. (One definition of information transfer is how much the receiver is surprised. B-) )
That's what we're spending all this money for: To come up with physics that more closely matches the real universe. To do this we have to know what's NOT matching in the old models.
(For those - ideally few of the slashdot participants - who gripe that it's being spent at all: At some point the improved models will almost certainly produce some new and useful technologies and/or end squandering of resources on the pursuit of dead-ends. Of course you can't know up front WHAT technologies it will affect. That's part of what you're finding out.;)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
"I also wondered what might happen to the matter trapped in the accretion disks of two black holes when they began to merge, especially if they had opposing rotation... matter travelling at virtually the speed of light, hitting yet more matter, travelling at virtually the speed of light in the opposite direction... meaning an effective speed of impact almost double the speed of light... and all that happening in an area of dilated time... you have to wonder what that would look like..."
I haven't done the math, but I'm guessing it wouldn't be as interesting as you might hope.
The "worst" case seems to me would be the accretion discs would be spinning the same rotation (because if they were spinning the opposite way, the relative velocity of the intersecting parts of the accretion discs would be nearly the same, no?). If they were spinning the same way, and because accretion disc are generally present because of increased viscosity (w/o viscosity, the matter would generally just fall directly into the black hole), the discs would likely just merge and the composite disc would have approximatly double the angular momentum. If some of the theories current are correct, and that the polar jets are ways of bleeding the energy instead of mass to limit angular momentum, then the polar jets would likely more intense, but over two black holes, so the net effect seems like it wouldn't be that different.
If we when with the opposite, where the rotation was oppossing, the angular momentum seems like it would cancel each other so that there would be less of a reason to need polar jets to bleed energy and although I'm sure there would be lots of crunching, but this would be near the event horizon meaning most of it would just probably "fall-into" one of the black hole's event horizon.
BTW, just to be nitpicky, when two flash lights are pointed at each other, the photons don't hit each other at twice the speed of light in an area of dilated time (or any other reference frame). In the reference frame of one of the photons (what you are calling dilated time), the other photon is just travelling the speed of light towards it. However, the speed isn't conserved, but of course momentum is conserved within a frame of reference, so that ignoring the relativistic effects for the moment, the resulting momentum of the collision is the momentum of the other object in first object's frame of reference (just like the other object hitting you at near the speed of light, the fact that you are also going near the speed of light isn't gonna make this much different, no?). Now when we put relativistics effects in there, because of conservation of momentu, other object is gonna seem much heavier to the other moving object than to the stationary observer. Did that make any sense?
Going back, that means the "net" momentum after collision would be pretty much zero for your "worst" case. Big crunch, but now the relative angular momentum is low and all that matter is sitting right near a black hole, might be interesting to them, but would you see it?
Its a magnetar burp. Google magnetar+GRB
"There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another which states that this has already happened."
Maybe we are indeed seeing the outcome of this happening, just on a smaller scale. These guys are probably doing something incredously stupid, like playing with a very large ray canon or starting a large nuclear fusion reactor. Well, I say they got it coming to them. Nosy bastards.
I for one welcome our new gamma ray overlords! :)
Well, I do see some of your points... perhaps I just don't have enough depth in my physics education...
But, even assuming frames of reference etc the relativistic mass of the matter involved in the collision would be HUGE, far more than the original matter... and I don't think all that would dissapear into the black holes for several reasons... but one main one comes to mind:
- The accretion disks are by definition not inside the event horizon of either black hole, and therefore not at the point where any energy or exotic particles from matter colisions would be completely incapable of escape - if stuff releases energy at that point... it CAN escape, as long as it has enough energy - that's the whole reason we see the disks in the first place.
Whatever way the matter collides, close to the event horizon of a black hole is quite possibly THE fastest you're ever going to be able to smash atoms together (until we discover new physics) - while that collision happens outside of the event horizon (so we can see the results) and inside an area of time dilation (so from our frame of reference we can see the interations slowed down) that HAS to be interesting! or am I missing something?
However much scientists have learned from this set of data, gamma ray bursts remain hugely mysterious events. Lord Martin Rees, Astronomer Royal and president of the Royal Society said that science was "still flummoxed: by the underlying trigger of the explosions, and why they sometimes emit brief flashes of light. "Theorists have a lot of tentative ideas, and these observations narrow down the range of options," he added. Nice of you to summarize the article for everyone, but you left out the informative bits.
Those people who think they know everything are a great annoyance to those of us who do. (Isaac Asimov)
This is clearly an early test of the halo superweapon. The flood must have escaped from a nearby system.
I just thought I'd remind you that the original story is about some actual science carried out by real researchers, not a proposed plot for an episode of Star Trek.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
You aren't a good scientist, you are delusional. You get modded troll because you have all the characteristics of a complete and total quack. You parrot back information from disreputable sources, you say things you don't understand, you keep on bringing up things that have been disproved as if they were fact, you have a highly inflated sense of your own intelligence, you think everyone who disagrees with you is both a moron and out to get you. You ignore anything anyone says that proves you wrong. No one wants to debate you because you understand neither what they are saying, nor even what YOU are saying. It's utterly pointless.
You are one good rant away from being the next Time Cube guy, only not as entertaining. Go wank off at the electric universe site, we really don't care to watch.
Mods, go ahead and mod me down, this is totally off topic. I just had to get it off my chest.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Actually, there are teams of people that have been studying mergers (collisions) of two black holes for quote some time, and for awhile they could only solve the initial and final states of the system. Eventually their simulations got better and better and now they have pretty good understanding of the intermediate states of the collision too.
It's an interesting problem, and it deals with the generation of huge amounts of gravitational waves. The hope is that these simulations will now pave the way for what kind of gravitational wave signatures we can hope to pick up with such gravitational wave detectors like LIGO and LISA.
This lady just gave a colloquium at my school regarding this very subject. Her talk was interesting, she described the history of attempts to study black hole mergers. It took awhile before the computer simulations could get sophisticated enough to model the actual interactions and dynamics of the two rotating colliding black holes. The gist is that they attract, then combine quite spectacularly releasing 'radiating' TONS of gravitational waves in a characteristic distribution, and then spin down. The end result is basically one bigger black hole. They expect a handful of these events to occur each year, so hopefully LIGO and LISA can pick up on them.
make world, not war
To an observer outside of a black hole, it takes an ever increasing amount of wall-clock time to see something near the event horizon move (things look very still). Of course to the stuff falling into the hole, things sort of happen at "real-time" locally.
From your observer's perspective you might be thinking that all the collision will be in slo-mo which might be "interesting" or "the-matrix-movie-like", but in real-life you can only see photons, so everything will also be getting dimmer at the same time (red shifted until at the photons being emitted near the event horizon almost have zero frequency as their time gets stretched out and energy approaching zero and thus relatively invisible).
Short answer is they are having a party, but on the outside we probably don't get to see too much.
I'll bet you're a hoot at parties.
Just kidding, of course. Comments like these are exactly why I read Slashdot.
For security, the MD5 hash of this message and sig is 09f911029d74e35bd84156c5635688c0.
Isn't it fascinating when startrek can include enough real science conducted by real scientist to produce not only entertainment, but gadgets we all use today.
Sure I know this. And of course I didn't RTFA. Well at least untill after i had alread posted that. But sometimes, wondering what if, leads to real science conducted by real scientist too.
This old cnet article has a pointer to an animation about this and that talks about the black holes themselves colliding. The gravity wave phenomena is potentially very interesting.
However, the original question was about the accretion discs and being in some sort of time-dialated matrix-like slo-mo explosion, which is an entirely different thing...
"It is our blasphemy which has made us great, and will sustain us, and which the gods secretly admire in us." - Zelazny
Um hello, It wasn't MIT it was UCLA!
BTW, the doc called and said to inform you that your cranial-rectal extraction was scheduled Saturday.
"overwhelming nature of the disconfirming evidence for the Big Bang and stellar evolution"
. jpg
http://en.wikipedia.org/wiki/Image:Firas_spectrum
It seems more likely that GRBs and their lesser kin are more associated with keeping fungus down and making sure that little if any life beyond that level survives.
The universe may be teeming with life - but not necessarily beyond 1 cell. In any case, our violent universe with massive active forces seems to be more significant than originally thought.
One thought is - what about intervening material screwing up polarization? Also, an afterglow is not the supernova light - it's the lower energy equivalent of what caused the grb in the first place (as I understand the idea). That's likely to be a bit further away than the extremely high magnetic fields are likely to be around the star, probably dependent upon earlier sluffed off materials (planetary nebula sorta stuff). The magnetic field may likely be way down by that time frame. After all, it does tend to take minutes or hours before the supernova spectrum light becomes dominant.