Furthest Gamma-Ray Burst Ever Observed

jd writes "The SWIFT team have announced the furthest-ever observed super-massive gamma-ray burst (from 13 billion light years away). The burst was observed on the 6th of September and lasted for 3 minutes - long enough for a number of other telescopes to home in on the gigantic explosion. The distance is only barely within the reaches of the observable universe. The idea of the SWIFT telescope and follow-up observations is that they will discover both the cause of the bursts and the consequences to the star."

Comments

A long time ago in a galaxy light years away....

[mr100percent]

I feel a great disturbance in the Force (which we all know travels at the speed of light). As if millions of voices suddenly cried out in terror, and were suddenly silenced.

light instead of gamma

[slothman32]

When supernovae occur you can see them. Are they the brightest visible object? What would this look like if it were light instead of gamma? Or even alpha or beta?

Re:light instead of gamma

[Tablizer]

When supernovae occur you can see them. Are they the brightest visible object?

Galaxies are the brightest visable objects. Well, actually quasars are, but are thought to be galaxies or at least closely related to them. But the total energy put out by gamma bursts is far larger than the energy put out by supernova. It is just that they do it over a wider area of the spectrum such that their visible light component is roughly comparable to supernova but beat them by far in higher-energy radiation.

Re:light instead of gamma

[mbrother]

Well, the leading idea about (this type of) gamma ray burst says that they're associated with supernovas. So, they look like supernovas.

Quasars are the most luminous long-lived light sources. Gamma ray bursts can release more energy for short periods of time, but there are arguments about to what extent the energy is beamed in a preferred direction (complicating efforts to calculate total energy released).

I'm not sure what you mean by "alpha and beta?" Are you talking about alpha and beta radiation? Apples and oranges, although all are called "radiation". Gamma rays are a form of light (very high energy photons), while alpha and beta radiation isn't electromagnetic radiation at all, but rather particles (He nuclei and electrons).

Re:light instead of gamma

[UnrefinedLayman]

For being so feisty, are you quite sure there's no such thing as alpha and beta radiation?

http://www.orau.gov/reacts/alpha.htm

http://www.orau.gov/reacts/beta.htm

Both are particle radiation and both plentifully originate in stars. You can read more about them in Wikipedia also.

http://en.wikipedia.org/wiki/Particle_radiation

Re:light instead of gamma

[scapermoya]

supernovae and gamma-ray bursts are not the same thing. Gamma rays are of a much higher energy than visable light, so we can detect them from verylarge distances. gamma-ray bursts are theorized to be created when supermassive stars collapse on themselves, forming a black hole and somehow releasing a very large amount of energy. There are anywhere from 1 to 5, on average, gamma ray bursts detected by orbiting satellites every day, with the older ones being associated with a larger doppler shift (red shift) of their absorbtion spectrum.

supernovae are visable as very bright stars in the sky when they occur (rather when the light from their explosion reaches us, a long long time after they actually occur). The root nova means 'new' in latin, as these would appear in places in the sky where no (visable to us) star had been previously, before dying away.

alpha and beta radiation is not part of the same electromagnetic spectrum that gramma and other types of radiation, never mind that a simple peice of paper will stop alpha particles. alpha particles are composed of something akin to a helium nucleus, with two protons and two neutrons. beta particles are either electrons or positrons depending on the type of beta decay.

Re:light instead of gamma

[scapermoya]

i forgot, in OUR night sky, within the visable light spectrum, the moon is surely the brightest object, followed by venus, some other planets, and then i believe sirius. I supposed a realtively close and bright supernova could outshine all the other stars, and maybe even all the planets, but it would have a tough time competing with luna.

Re:light instead of gamma

[mbrother]

For a homework problem, I have my astronomy students calculate how bright the Galactic core would be if it were a quasar and there wasn't any obscuring dust in the plane of the galaxy. It turns out to be about the brightness of the full moon, but since it would be smaller, it would be more striking. That's at a distance of 8 kpc or so.

Re:light instead of gamma

[scapermoya]

wouldnt we be screwed if there was a quasar that close? they have a nasty habit of eating stars.

Re:light instead of gamma

[mbrother]

No. The effects of a black hole's gravity, even a supermassive one, are rather limited. We'd need to be within a few light years to have a problem with our sun being tidally disrupted. The radiation would destroy all life on Earth long before we got close enough to have problems associated with the supermassive black hole. We'd likely be fine with a weak quasar in the Milky Way as the gas and dust in the plane would block the vast majority of its radiative output in our direction.

Re:light instead of gamma

[Vellmont]

Light is usually defined as visible light. If you start using the term light to refer to radio waves, you'll only sound very confused.

As someone else already pointed out there is such a thing as alpha and beta radiation. I'd suggest some remedial physics classes before you discuss physics with anyone again.

Re:light instead of gamma

[scapermoya]

even after 10 billion years?

Re:light instead of gamma

[mbrother]

We already have a million solar mass black hole at the center of the Milky Way and billions of stars have been fine for billions of years. We orbit at a very safe distance, as do most stars. Only stars in the core, or in highly elliptical orbits taking them into the core, are in any danger of disruption. The central black holes of galaxies are only about 1/1000 as massive as the galaxies they live within, and it is the total galaxy gravitational potential that primarily determines the motions of stars making it up.

Re:light instead of gamma

[yatt]

especially after 10 billion years. ever heard of evolution?

Re:light instead of gamma

[some guy I know]

As others have pointed out, alpha and beta radiation exist.
The difference is that alpha and beta radiation are particle radiation, whereas radio waves, microwaves, infrared light, human-visible light, ultraviolet light, X-rays, and gamma rays are all forms of electromagnetic radiation.
If, in your post, you meant to write that there is no such thing as alpha and beta electromagnetic radiation, then that is correct.

The confusion between these two forms of radiation is what leads some people to erroneously believe that a defective microwave oven will cause cancer, or produce genetic defects in offspring.
Only some particle radiation (beta, I think), and high-energy E.M. radiation (UV and above), has a more than miniscule probability of doing that.
(All radiation, including visible light, has a non-zero chance of producing cancer/birth defects, even human-visible light; it's just that the chance is vey, very tiny.)

Re:light instead of gamma

[-brazil-]

But the total energy put out by gamma bursts is far larger than the energy put out by supernova.
AFAIK, the prevailing theory is that the total energy is much, much lower than the intensity indicates, because it is emitted in focussed beam rather than spread in all directions.

Re:light instead of gamma

[-brazil-]

Only some particle radiation (beta, I think), and high-energy E.M. radiation (UV and above), has a more than miniscule probability of doing that.

All particle radiation has that effect, and it's actually weakest in beta radiation. Alpha radiation is a lot more destructive (four nucleons instead of one electron!) but can be shielded much easier, exactly because it interacts more readily with matter. I think Neutrons are the worst, because they can activate (make radioactive) atoms they hit.

Re:light instead of gamma

[scapermoya]

perhaps you need to brush up?

we dont have a quasar at the center of out galaxy, the closest one is over 200 Mpc away. We are talking about a hypothetical situation, it has nothing to do with evolution.

Re:light instead of gamma

[yatt]

mbrother (739193): "We'd likely be fine with a weak quasar in the Milky Way..."

scapermoya (769847): "even after 10 billion years?"

me: "especially after 10 billion years. ever heard of evolution?"

your comment suggested that you thought that 10 billion years of exposure to the weak quasar would be more hazardous than the immediate threat. I would suggest the opposite is true because of evolution.

after 10 billion years with a weak quasar we would evolve resistance if resistance were needed. the presence of this hypothetical quasar is most dangerous when it first arrives and we're not used to the radiation.

so in this context i think you'll find you need brushing up. my logic is flawless, which is exactly why my army of NS5s will march out and effect a curfue.

Re:light instead of gamma

[lgw]

Some people have a hard time understanding this, so it bears repeating: at a distace, there's no difference between the gravitational attraction of a million-solar-mass black hole, and a million solar-mass stars. Gravity is gravity. What makes a black hole special is you can get very close to that source of gravity, as all the mass is in one place, as opposed to just being amoung a million stars.

Re:light instead of gamma

[EddyPearson]

it depresses me somewhat that people dont take this kind of thing more seriously (i refer of course to the HILARIOUS Star Wars gag above, my how i laughed...) its things like this that gives us MASSIVE insight into the beginnings of the universe and ultimatly how that little ghost in the machine they call life first sparked. slothman makes a very good point that if it were on the visible spectrum you'd most probably be scratching out your eyes by now ;)

Re:light instead of gamma

[stevelinton]

You can see supernovae if they are close enough. There are two notions of brightness: how much light (or other energy) we get from a thing, and how much it actually emits. The relationship between these is controlled by distance.

In the first sense, the brightest object is the sun unless you happen to be standing very very close to a search light or magnesium flare.

In the second sense, a galaxy is typically brighter than a supernova, but if it's close then it's diffuse, so it doesn't look so bright. Actually if you include its neutrino output, a supernova is, for a few seconds very much brighter indeed than it is for the next year or so, or indeed than pretty much anything we know. A quasar is brighter than a typical galaxy, but there are no nearby ones. A GRB might be (briefly) even brighter than that, or it might not be so bright, but beam it's output (in which case there are more of them than we see).

A GRB doesn't just emit gamma rays. It emits a short brief flash of gamma rays, followed by an "afterglow" of X-rays, UV, ordinary light and probably other things over an extended period. Alpha and beta are probably emitted too, but will be diverted by magnetic fields and slowed down and absorbed by the intergalactic medium.

Re:light instead of gamma

[D2Deek]

we dont have a quasar at the center of out galaxy, the closest one is over 200 Mpc away.

We don't currently have an active quasar in the center of our galaxy. When (note: not if) the supermassive black hole at the center of our galaxy begins feeding again (within the next billion years or so, when stars start getting thrown into its immediate vicinity by the gravity of the Andromeda galaxy), the quasar will go active again.

Quasars are just supermassive black holes getting fed lots of material. And as such, they turn on and off.

Re:light instead of gamma

[jdray]

So, what happens if this sort of thing happens (galactically) right next door to us, in our lonely little arm of the Milky Way? Do we just wake up dead one morning without even knowing it?

Re:light instead of gamma

[mfrank]

I thought gamma ray bursts were likely to be collisions of massive objects, like binary neutron stars/black holes orbiting closer and closer till they collide.

Re:light instead of gamma

[mbrother]

That's probably the case for the short duration bursts (there was one like this identified in April -- there's probably a NASA press release you cna find about it). The long-duration bursts like this one at z=6.3 have been associated with a type of supernova.

Re:light instead of gamma

[scapermoya]

i dont apprectiate the condescending tone, there is a huge difference between the two, density. a million solar masses spread out over a vast area is less gravitationally attractive than a singularity of that mass.

Re:light instead of gamma

[scapermoya]

i wasnt talking about the radiation, i was talking about the habit quasars have of eating stars. gamma radiation is vital to evolution, but being so brushed up, you knew that.

Re:light instead of gamma

[scapermoya]

you are confusing AGNs with quasars. by definition, a quasar needs to have a very high redshift, which would be somewhat difficult to pull off at ~8 kpc. Our galactic core could go active again, but it wouldnt make it a quasar.

Re:light instead of gamma

[lgw]

So when I addressed my post to "some people who don't understand this" instead of you, you were offended? In any case, you're entirely wrong - at least as long as the million solar-mass starts have a spherical distribution (as they would in the core).

At a distance (that is, anywhere outside the sphere), there is *no* difference between a sphere of uniform density and the same amount of mass as a singularity at the center. I remember not believing this in high school, and my physics teacher giving me the proof as an assignment to shut me up. :)

Black holes do *not* have any magic which gives them gravity higher than anything else with the same mass. I'm not sure where that idea came from - probably bad Sci-Fi - but like I said, it bears repeating. Black holes to not have any magic power to suck things in.

Re:light instead of gamma

[Vellmont]

I'd say its beyond the scope of high school physics, which IMO puts it out of remedial range.


Alpha and Beta radiation is beyond the scope of high school physics? I don't know where you went to school, but I was taught about different kinds of radiation in 9th grade physical science. This wasn't some fancy prep school either but a public school (though it was a fairly decent public school). If they didn't cover basic stuff like radioactive decay in high school the education system in the US is far worse than I imagined.

Re:light instead of gamma

[Tablizer]

But the total energy put out by gamma bursts is far larger than the energy put out by supernova.
AFAIK, the prevailing theory is that the total energy is much, much lower than the intensity indicates, because it is emitted in focussed beam rather than spread in all directions.

Good point indeed. However, it is still conjecture at this point.

Re:light instead of gamma

[Tablizer]

So, what happens if this sort of thing happens (galactically) right next door to us, in our lonely little arm of the Milky Way? Do we just wake up dead one morning without even knowing it?

Possibly. Space is risky. Unless it is a few light-years away, I imagine humans would take a few hours to die. It is mostly the radiation that is the problem, not movie-style poof blasts. Thus, at least we may get a hint about what killed us. If not that, then it will probably screw up our atmosphere big-time. Depends how far way and possibly how the radition points.

Re:light instead of gamma

[some guy I know]

All particle radiation has that effect, and it's actually weakest in beta radiation. Alpha radiation is a lot more destructive

OK; I guess that I got them mixed up.
I remembered that one was an electron (which I thought, incorrectly, was alpha, when it actually was beta), and could be stopped by a sheet of paper, and that the other was a helium nucleus (which I thought, incorrectly, was a beta, when it actually was alpha), which I thought took about a foot of water to stop, but I was wrong there, too.
I guess that I should have read the articles that UnrefinedLayman pointed to in his reply, or checked out the WP articles about alpha and beta radiation.
Sorry for the inaccuracies and just plain bad info.

Re:light instead of gamma

[yatt]

the other guy was talking about radiation so i didn't consider that you were talking about other effects.

i'll admit you have a point about the possibility of our star being eaten if quasarifying the galaxy increases it's mass and the velocities of the stars aren't adjusted.

if i remember correctly we are reasonably far away from the middle so unless the increase in mass is major then we may well still be safe. This is purely conjecture as it is beyond the scope of my evolution expertise.

"gamma radiation is vital to evolution..."
where did you get that idea?
yes gamma radiation causes genetic mutation and yes genetic mutation can create new genes that are advantageous and spreads through the species.

is mutation the only mechanism for evolution? no. without mutation there is still variety from the different ways that parental dna forms offspring(different sperm. different egg).
is gamma radiation the only cause of mutation? no.
what about bacteria absorbing useful genes from others? no radiation needed. what about errors in copying the dna? what about alpha and beta radiation? xrays? oxidants? carcenogens? monoliths? lightning?

Re:light instead of gamma

[scapermoya]

my point was that the reason our closest quasar is ~250 million parsecs away is that we exist. I have done loads of research into genetic mutation, and while some forms of bacertia are suprisingly good at resisting genetic desctruction from several types of radiation, it would be very unlikely that a major source of gamma radiation less than 10 kpc away would allow us to evolve the way we have. Also, the eating of the stars over a long period of time would surely shift the angular momentum of our galaxy, perhaps bringing us closer to the center, or perhaps flinging us out into empty space. who knows. gamma radiation is one of the most important methods of genetic mutation in OUR form of biology. Indeed, had there been some major difference in the levels of radiation when all of the details and chemicals were being sorted out a few billion years ago, things could have been a lot different. Chemicals, vectering, etc are all important contributers to mutation, but theres nothing quite like gamma radiation for affecting change. If gamma radiation simply ceased to exist NOW, evolution would take a hit. We both seem to know what we are talking about, and this is so "what if" that arguments are pointless.

Re:light instead of gamma

[mfrank]

Thanks.

Of course, one theory I've always liked is that we're seeing the tail end of alien matter-antimatter starship drives that temporarily are pointed our way. :)

Re:light instead of gamma

[rvw14]

Yeah, it wasn't very good.

http://imdb.com/title/tt0251075/

Re:A long time ago in a galaxy light years away...

[Michael Scott]

The force is strong in this one...

Re:first post

[Tablizer]

Maybe it was the universe's first post, or the explosion caused by the first moderators giving the first post first -1.

Black holes are where God divides by 0. Gamma explosions are where God divides by 0.0000000000000000001 - God's accountant

NOVA ran a program on gamma ray bursts...

[Propagandhi]

Imagine there are a few people rather lost at the headline (we're not all astronomers/cosmologists/whatever :) ). Anyway, NOVA ran an excellent show on this a couple years ago, and as usual there was an excellent companion website.

If that doesn't answer your questions, well... there's always Wikipedia. /I feel like a Karma whore linking to wikipedia, mod me as you see fit..

Re:NOVA ran a program on gamma ray bursts...

[zerocool^]

The distance is only barely within the reaches of the observable universe.

I remember hearing this phrase before, and hearing an explanation, but it didn't make sense. Can you explain this in idiot terms? Something about some things are never actually going to get to us because they're too far away, and that represents the boundries of our reachable universe?

~Will

Re:NOVA ran a program on gamma ray bursts...

[Propagandhi]

The observable universe is the total volume of the universe from which light could have reached us since the beginning of said universe (the big bang or whatever).

In other words, as you get farther away from our point of observation (Earth and the area immediately around it) you eventually reach a point in space which is so far from us that light could not have reached us. Assuming that nothing can move faster than the speed of light, this sphere would include everything that could have possibly affected us since the beginning of the universe. Ugh. I hope that makes sense, and I hope I didn't screw that up.

As usual Wikipedia has more information: Cosmic Light Horizon and Obxervable Universe

Re:NOVA ran a program on gamma ray bursts...

[zerocool^]

Ok, so, according to wikipedia, if something happened in the universe 78 billion light years away, it would just now be reaching earth, and if it happened 79 billion light years away from earth, we wouldn't know about it yet.

And then, it's argued that everything beyond this horizon doesn't exist? So, the universe (according to our understanding) is a constantly growing sphere with earth in the center?

It just seems wierd. I mean, I know that scientifically, if you can't observe something, for your given system, that thing doesn't exist. However, if you drove your Heart of Gold, or USS Enterprise, or whatever, to 78 billion light years from earth, and then went 10 feet further, the Universe is still there...

Wierd.

Thanks for the article links, too.

Re:NOVA ran a program on gamma ray bursts...

[Propagandhi]

So, the universe (according to our understanding) is a constantly growing sphere with earth in the center?

No, no. That's the key difference between the observable universe and the actual universe itself. The observable universe is just the part of the universe we can actually see/be directly affected* by.

Sorry, I think I left a few "observables" out of my original reply. You're absolutely right, there's still a universe beyond the observable universe. Problem is, by the time you get to that part of the universe it will have become part of the observable universe (because you can't go faster than the speed of light).

Important note: as you move your theoretically observable universe changes. So the observable universe for your hypothetical Enterprise would be different from ours, as it would be able to see light which had not reached Earth.

Re:NOVA ran a program on gamma ray bursts...

[Michael Woodhams]

Here's the simple answer:

About 13.5 billion light years ago, the universe changed from being opaque to photons to being transparent (an event inappropriately called "recombination"). No photon emitted earlier than this time could reach us, so we cannot observe further than about 13.5 billion light years away. (The photons emitted at that time are the cosmic microwave background.) So the observable universe is 13.5 billion light years in radius. A billion years from now, it will be 14.5 billion light years in radius.

However, it gets more complicated: the universe is expanding, so the space that photon travelled through has got bigger in the meantime.

Imagine two points in the universe. Because the universe is expanding, the distance between them is increasing with time. The rate at which the distance increases is a velocity (which you can think of as causing the red shift of distant galaxies.) Hubble's law says this velocity is proportional to the distance between them. If they are sufficiently distant, the relative velocity is greater than the speed of light.

So (for example) imagine this is twice the speed of light. A photon emitted from one point travels towards the other. After one year, it has travelled one light-year, but the points have got two light-years further apart - clearly it will never arrive. These two points are not in each other's observable universes. The edge of our observable universe are the points which have a recession velocity equal to the speed of light.

The discussion above assumes no acceleration. Of course, astronomers from Hubble onwards knew there would be acceleration, but it wasn't until the mid 1990s that we could measure it.

It turns out, contrary to general expectation, that the expansion of the universe is now accelerating. This means that as time goes on, points don't have to be so far apart before their recession velocity exceeds the speed of light, so in a sense the observable universe is getting smaller. (In the sense that points that were within our observable universe in the past are no longer so. But remember that the points are always getting further apart - the radius of the obserable universe is increasing linearly with time.)

I am an ex-astronomer, not a cosmologist. There may be subtle errors in the above, but I hope not.

Re:NOVA ran a program on gamma ray bursts...

[csrster]

In theory we could observe neutrinos from eras before electromagnetic-recombination, which would push the "observable" universe much further back towards the actual origin of the Big Bang - as far back as the point where the universe was optically thick even for neutrinos.

Re:NOVA ran a program on gamma ray bursts...

[Marvin_OScribbley]

But space is really what?

Well according to some interpretations of quantum theory, space is a seething of virtual particles. But what if space itself does not actually exist and is merely the absense of something? Then the boundary of the universe represents the point to which existence has reached at the speed of light.

It may be nothing more than a fixed volume inside a larger universe and everything inside is just shrinking and giving us the illusion that space itself is growing.

This would certainly explain the so-called "cosmological constant", i.e. if mass is shrinking at a half-life (half-size) rate of a billion years or so gravity would pull objects together faster then the rate of contraction up to approximately galaxy size, while galaxies themselves would not be affected fast enough to avoid the appearance of flying apart.

Re:NOVA ran a program on gamma ray bursts...

[AndersOSU]

I was with you until this:

relative velocity is greater than the speed of light

From what I recall of physics this is not possible, since the speed of light is the limit regardless of your frame of reference. The fastest anything can move away from you is the speed of light, but in order to do that it would have to have infinite energy.

If someone can clarify I'd love to hear it, because I've never been able to quite wrap my brain around cosmic boundries either.

Re:NOVA ran a program on gamma ray bursts...

[qray]

But space is really what? Who can really know? We are inside. It may be nothing more than a fixed volume inside a larger universe and everything inside is just shrinking and giving us the illusion that space itself is growing.

And that's what I've always found facinating about various theories scienist put forth. We're part of the system we're trying to observe. Our observations are going to be affected by that very fact.

For instance how do we really know it took 13 billion years for that light to travel. Maybe it was much longer, or shorter. The medium it is traveling in is supposedly expanded, so at the very least, the distance is probably more than 13 billion light years.

--
spork fogte heritoc mocru

Re:NOVA ran a program on gamma ray bursts...

[Kobun]

We will call you Point A. We will call another world with your evil goatee-wearing twin Point B.

Point A is moving at the speed of light. Point B is moving at the speed of light in directly the opposite direction.

The laser you fired to destroy your nemesis will never do its job, because it will never catch him.

Note that this does not require Point A to be moving. The other jerk running away really fast is enough to cause this.

Re:NOVA ran a program on gamma ray bursts...

[James_Aguilar]

Even if both are moving at the speed of light away from some constant point of reference, relative to eachother, they are also only moving at the speed of light. The laser would not do its job, but it would also do no worse than staying a constant distance behind its target. This is what the laws of special relativity are all about.

Re:NOVA ran a program on gamma ray bursts...

[coopex]

Imagine the universe as a flat rubber sheet. If you stretch the sheet uniformly, then points further apart "move" faster apart than points closer together. All the quote in question is saying is that at the some points in the universe, the fabric (calico IIRC, though there is a rival theory with tweed) is moving apart faster than C, nothing is really "moving" per se.

Re:NOVA ran a program on gamma ray bursts...

[dthomas9]

I was with you until this:

relative velocity is greater than the speed of light

From what I recall of physics this is not possible, since the speed of light is the limit regardless of your frame of reference. The fastest anything can move away from you is the speed of light, but in order to do that it would have to have infinite energy.

If someone can clarify I'd love to hear it, because I've never been able to quite wrap my brain around cosmic boundries either.

The rule "nothing can travel faster than light" from the Theory of Special Relativity has, in effect, a special exception in the General Theory of Relativity. Namely, "nothing can travel faster than light, except space itself".

In the grandparent's post, a photon is emitted from a point which is moving at 2*c (twice the speed of light) away from another. The moving space carries the photon's emitter with it. The photon then, is like a fish swimming at c upstream in a river travelling at 2*c - it never gets to its destination.

Re:NOVA ran a program on gamma ray bursts...

[Moraelin]

"Blah, blah, blah... Am I the only one that is sick and tired of hearing about the "age of the universe", "big bang", and "cosmic expansion"? Cosmology and Astronomy are so far from true science as to be almost laughable. I declare that there are x number of galaxies in the universe! Who is going to prove me wrong?"

No, rest assured that you're not the only one. There's a majority of dumb and uneducated people who need to mock science they never understood (or learned), and generally try to drag everyone back into the muck of mediocrity.

I assume that belittling everyone else's achievement makes them feel better about being dumb failures themselves.

And the dumber and less educated they are, the less they actually understand from that science, the more rabid they'll be in attacking it. The farther someone will be to the left of that IQ or education Gauss curve, the more they'll rant and rave about how everyone to the right is a quack and a witch-doctor spouting nonsense.

Either way, rest assured that you're not alone. You fit in that dumb and uneducated majority perfectly.

Re:NOVA ran a program on gamma ray bursts...

[AndersOSU]

I still think that it is impossible for something to be moving away from you at greater than the speed of light.

Consider this:
Two space ships leave earth traveling at opposite directions, both at .75c relative to earth.

However relative to eachother the spaceships aren't traveling at 1.5c, but rather 0.96c, determined using the Lorentz transform.

So it is impossible for two objects to be moving apart from eachother at greater than the speed of light.

Since it is impossible for a star to be moving away from us at greater than the speed of light it is also impossible for that stars light to be red shifted out of existance.

Re:NOVA ran a program on gamma ray bursts...

[AndersOSU]

It is still not possible for two objects to be moving away from eachother at greater than the speed of light, so it is impossible for the stream to be flowing at 2*c.

Re:NOVA ran a program on gamma ray bursts...

[Kobun]

Right, hence my final statement about point A getting to stand still. I mostly wanted to write about a goatee twin. A post above mine actually said everything that needed to be said.

Just to demonstrate to anyone reading who wants clarification: We will now place our fictional, non-goatee wearing observer on a spacecraft of extraordinary design. It can move at 1 kilometer per hour under the speed of light (and no warp drive to boot!). While moving at this fantastic speed our observer shines a flashlight to see what will happen. To the observer in the spaceship, the beam moves the speed of light. To the external observer, the ship is moving damn fast and the flashlight beam goes the speed of light. The slack just gets picked up in that the observer moving at relativistic speeds experiences time much differently than the external observer, who has decided they want nothing to do with my spaceship that goes nearly the speed of light with no one at the controls.

Re:NOVA ran a program on gamma ray bursts...

[wcrowe]

So the observable universe for your hypothetical Enterprise would be different from ours, as it would be able to see light which had not reached Earth.

Which brings up a matter which I've often wondered about. If we observe a star at position X. What we are really observing is that star at that position Y number of years ago. In reality that star's actual position now is somewhere else, correct?

So when we read or watch Sci Fi, and people are flitting about the galaxy, or whatever, it seems navigation much be a real bitch. Maybe impossible.

Re:NOVA ran a program on gamma ray bursts...

[lgw]

Too harsh by half, my friend - science is all about questioning assumptions. What folks need to realize is that all of the assumptions science is currently based on have been questioned by a great many smart people, and we're working with the best answers to those questions. Sure, there are some social factors that keep less-than-ideal theories alive for a while, but rarely for more than one generation, so you can pretty much assume that any theory over 20 years old isn't just some BS that scientists accept on faith!

Do take popular science reporting with a grain of salt, however, as what's being hyped to the public as the latest nifty idea bears little resemblance to what scientists actually believe.

Re:NOVA ran a program on gamma ray bursts...

[lgw]

There are many people trying to answer this question using relativity, but if you understand relativity in the first place you don't need to ask this question!

Imagine a rubber band held between two points. And ant walks from one end towards the other at 1 inch per second. However, that end of the rubber band is being pulled away at 1 foot per second. Will the ant ever reach the other end? The answer is yes: if you think about the ant's position as a percentage of the distance between the ends, stretching the rubber band doesn't change that. The ant is always making progress, though its speed as a percentage of the distance left to travel drops over time.

While the situation with light traveling through expaning space doesn't quite use the same equation, it's qualitatively the same thing.

Re:NOVA ran a program on gamma ray bursts...

[dslbrian]

There's a majority of dumb and uneducated people who need to mock science they never understood (or learned), and generally try to drag everyone back into the muck of mediocrity.

And then there is the majority of self-righteous "scientists" around who decry the foundations of their physical observations while at the same time hand waving about 10th dimensional space. Its truly laughable when you see these people putting down others for having religious faith, while at the same time trying to make people have "faith" in their string theory universe.

These would be the same people who spout everything they observe is true and fact, while being unable to explain something as simple as galactic rotation without throwing in mysterious unobservable physics. Yeah, you go on telling yourself that you know everything - you'll fit into that self-righteous majority of hypocrites perfectly.

Re:NOVA ran a program on gamma ray bursts...

[AndersOSU]

No the ant won't ever make it. If the rubber band is streched at the velocity for an infinite amount of time, the ant will never be able to keep pace, and hence will never reach the end.

If you think of the ant's position as a percentage the ant's position will shrink to zero as the length of the rubberband gets very long. So not only will the ant never get to the end, he will never leave the beginning!

The reason we are talking about relativity, is that the statement that objects are moving away from eachother at a speed greater than light, a condition that relativity says cannot exist.

Re:NOVA ran a program on gamma ray bursts...

[Anonym1ty]

Well I don't know about relative velocity, but what about an apparent velocity greater than light.

Lets say you had a big movie screen in the sky... (really big, 1 AU squared or bigger {64 square light-minutes? I'm not sure what a square light minute is so...um ok you get it I hope}) an put it far away (4+ AUs)

Now aim a super giant laser pointer at it. move the dot from one corner of the screen to the other.

The apparent velocity of the dot is greater than the speed of light, however no component of this experiment has moved at greater than the speed of light. What does it look like to the person with the laser pointer? How would this dot appear to an observer standing on the movie screen?

Re:NOVA ran a program on gamma ray bursts...

[wanerious]

Hi,
I don't know if anyone has answered this to your satisfaction yet, but there is a distinction between relative velocities and coordinate velocities. Relative velocities, as described by special relativity, involve measurements of coordinate differences. In general relativity (cosmology, here) there is no restriction upon the rate at which the coordinates themselves (used to describe positions and velocities) can change. As the universe expands, it is the coordinates that change faster than the speed of light, though any local measurements of these coordinates is bound by relativity. It is easiest to think of the galaxies as fairly stationary in space, but carried along by universal expansion. There is no limit to the rate of coordinate expansion.

Re:NOVA ran a program on gamma ray bursts...

[AndersOSU]

No, no one has really answered my question. My problem is that I have some understanding of relativity, so I know that any explination involving two objects moving apart at greater than the speed of light is bunk.

As far as coordinate systems go sure you can set them to change in any way you like, but it is also useless to have them change at a rate greater than c.

What I'm really wondering about is it possible that the boundry of the universe is different from the boundry of the observable univers, given that at the time of the big bang, our point in space was coincident with everyother point, and that no point could ever move away from us at a speed greater than the speed of light. I suppose since the universe was optically opaque to photons and neutrons before a certain point, and that objects moved away from us during that time, it stands to reason that there is a band of universe outside of what is visible to us. But I'm not sure if this band will become visible to us, or if it will always be outside of our observable range.

Now I've gone and confused myself

Re:NOVA ran a program on gamma ray bursts...

[Anonymous Coward]

As someone with a science background don't make the erroneous assumption that i'm limited in my knowledge. That being said your response (completely lacking in any topic foundation) is the same one that academics have been spouting for years without truly addressing the questions posed to them (i.e. I know nothing about your background but since you don't agree with me you must not have a clue). I've had any number of profs after initially looking at a lab result claim that it was not possible only to turn around two days later and admit they were wrong. To their credit they got that far and that is what science is about, creating a hypothesis, testing it, retesting it then putting it out there for the scientific community to test and confirm. When you start going down the road of Cosmic Background Radiation, Big Bang and other theories in Astronomy/Cosmology you remove the ability for reproducable testing to occur. You also open the door for people to interject with numerous whacked out ideas that have no basis in reality but people can't prove them wrong. When you purport to know the age of the universe but don't know exactly how our solar system formed you put yourself out on the edge of unreliable resource.

To just respond further to your flaming, no where in your response do you do anything but make the erroneous assumption that i'm uneducated. Problem being i'm extremely educated but in a branch of science that tests its theories as opposed to making crutches (read "dark matter", "dark energy") to prop them up. Have fun changing the age of the universe in 10 years time, by then we should've solved cancer by doing real science.

Re:NOVA ran a program on gamma ray bursts...

[lgw]

If the ant is just sitting in the middle of the rubber band, taking a break on his long journey, he will be in the middle no matter how far the endpoints move in the meantime. The rubber band stretches uniformly (just as space is thought to expand uniformly), so a point 50% of the way from start to finish will always be 50% of the way.

Let's look closer. Lets say the ant moves 1 inch per second, the endpoints begin at 8.333 inches apart, and move apart 8.333 inches per second.

• The ant's initial velocity is 12% of the seperation of the endpoints per second.
  
• After 1 second the ant's walking speed hasn't changed, but the distance has doubled, so he's now moving 6% of the current seperation per second.
  
• After 2 seconds the ant's speed is 4%/s.
  
• After 3 seconds the ant's speed is 3%/s and so on.

The total distance traveled (as a percentage) after some time T is the integral from 0 through T of (12/(1+t))dt. It's easy enough to solve for T where the definite integral = 100:
    [12 log(1+T)] - [12 log(1+0)] = 100
    log(1+T) - log(1) = 8.333
    1+T = e^8.333 = 4160
So, the ant would reach the other end in under an hour and 10 minutes. QED.

Re:NOVA ran a program on gamma ray bursts...

[mbrother]

You're being a science bigot here at best, very insulting at worst, and should stick to fields you know. Origins science is very important and very difficult, but not impossible -- there is a lot of modeling and testing that can and is done. It really just sounds like you're jealous of other sciences getting more airplay than your own. Cure cancer, and we'll talk.

Re:NOVA ran a program on gamma ray bursts...

[Elrond, Duke of URL]

And it's equally sad when somebody continues to put forth that there is some ravenous horde of atheistic scientists who get no end of satisfaction from belittling other peoples' religious beliefs.

The fact is, this is simply not true. Of course there are some. Any field always has nuts and jerks. But I have found that most scientists quite accepting of other peoples beliefs. Maybe they don't agree, but they hardly belittle.

Through my college career, I have worked with many astronomers. The two I have been (and continue to be) employed by are both very devout Catholics. Has this stopped them from probing the depths of the universe? Not at all.

As for your last comment... I would hardly call galactic rotation "simple". It's really quite complex, but given our current understanding, we can make predictions on how it should behave. What has been found is that galaxies are rotating faster than their masses should allow. Thus dark matter is introduced. Nobody is claiming to factually know what dark matter is. It's not a "thing" to base decisions on. Rather, it is a placeholder. Eventually, somebody will figure out that a) dark matter is made of substance X, or b) our original theory about how galaxies rotate was wrong.

That's just how science works.

Re:NOVA ran a program on gamma ray bursts...

[Michael Woodhams]

Good analogy and analysis, thank you.

So in a uniformly expanding universe, every point will eventually be observable (although the time until observability is exponential in the distance.)

This can fail for accelerating expansion - for example, if the rubber band doubles in length every second, the relative distance the ant travels halves every second.

My intuition is that the exponential time to arrive of the linear case is so close to never arriving, so even very mild accelerations (e.g constant acceleration, rather than exponential as in my example above) will suffice to prevent the ant reaching the end of a long-enough rubber band. However, I'm too lazy to prove it.

Re:NOVA ran a program on gamma ray bursts...

[Michael Woodhams]

Quick summary of the troll:

"It isn't immediately obvious to me how they can support their conclusions. Therefore, without any attempt to find out what their reasoning was, I declare that their conclusions are unsupportable."

Re:NOVA ran a program on gamma ray bursts...

[dslbrian]

And it's equally sad when somebody continues to put forth that there is some ravenous horde of atheistic scientists who get no end of satisfaction from belittling other peoples' religious beliefs.

The fact is, this is simply not true. Of course there are some. Any field always has nuts and jerks. But I have found that most scientists quite accepting of other peoples beliefs. Maybe they don't agree, but they hardly belittle.

It would be sad if it weren't true, but in fact it is (in this I disagree with you). I've found that not only do such people belittle others religious beliefs, but they in fact DO get ravenous when anyone throws back at them the fact that their theories are just that - theories. Media and schools have taught the -theories- of evolution, the big bang, and modern physics (newtonian, relativity, quantum, and all that jazz) for so long that people have accepted them as fact, and the aforementioned people go nuts when anyone even questions it (such as how the GGP post belittled the GGGP post calling him "dumb" despite the fact that the GGGP post is in fact exactly correct - see, you didn't have to look far to find such a nutjob). If this were a previous point in time the GGP poster probably would have called the GGGP poster dumb for calling the world round, because all known scientific observations clearly indicated the world was flat.

I would hardly call galactic rotation "simple". It's really quite complex, but given our current understanding, we can make predictions on how it should behave.

But it IS a simple problem, its simply a problem of gravity. Obviously there is something wrong in the mix - enter dark matter. But what is dark matter? Its this ambiguous nebulous correction factor that is placed arbitrarily where its needed and eliminated from where it is not. I just find it very hypocritical that some people belittle others for their beliefs or for questioning the above theories-held-as-fact (some of which are clearly wrong given they don't answer the simple aforementioned problem), while at the same time postulating Nth dimensional space and mysterious physics.

Re:NOVA ran a program on gamma ray bursts...

[James_Aguilar]

Good explanation =).

Re:NOVA ran a program on gamma ray bursts...

[lgw]

Yeah, exponential expansion makes a big difference, and would set a fixed limit on the size of the observable universe - except that the analogy might be innaccurate at that point. The relativity equations for redshift between rapidly receeding objects always did make my head hurt.

But that's not nearly as strange as a Cosmological Constant that changes over time!

Re:NOVA ran a program on gamma ray bursts...

[wanerious]

No, no one has really answered my question. My problem is that I have some understanding of relativity, so I know that any explination involving two objects moving apart at greater than the speed of light is bunk.

But it is not "bunk"; it is reality. I see you have some understanding of relativity, but I'm suggesting that your understanding is incomplete. I'm not picking on you, but there is a subtle issue at stake. When you say "moving apart", you have to be careful in assigning coordinates to those objects. Objects cannot move relative to a set of coordinates faster than the speed of light, but there is no such restriction on how fast the coordinates themselves can expand.

As far as coordinate systems go sure you can set them to change in any way you like, but it is also useless to have them change at a rate greater than c.

No, not useless. In fact it is a prediction of general relativity and most cosmological models, and borne out by simple explanations such as the cosmological redshift, which is not really a Doppler shift at all, but a consequence of the expansion of space-time itself.

Re:NOVA ran a program on gamma ray bursts...

[Michael Woodhams]

No assumption, your rants abundantly reveal it.

Re:NOVA ran a program on gamma ray bursts...

[Kobun]

Thank you, I'm glad you liked it.

An honest question...

[SpectreBlofeld]

How do we know the universe is 13.7 billion years old? It was recently discovered that the universe's expansion is accelerating as time goes by. Assuming this change in acceleration has been the case all along, doesn't that really fudge with the numbers we used to estimate the universe's age?

Re:An honest question...

[Peyna]

How do we know the universe is 13.7 billion years old? It was recently discovered that the universe's expansion is accelerating as time goes by. Assuming this change in acceleration has been the case all along, doesn't that really fudge with the numbers we used to estimate the universe's age?

There are many ways to estimate the age of the universe, not all of which involve calculating the expansion of the universe.

http://www.astro.ucla.edu/~wright/age.html

Re:An honest question...

[mbrother]

Ned Wright's cosmology page you linked to is one of the best sources of information out there for cosmology at a variety of levels. Highly recommended.

The quoted age estimate in the original post takes into consideration the acceleration, rest assured.

Re:An honest question...

[Anonymous Coward]

Correct. For instance, the easiest way is to just cut the universe in half and count the rings.

Re:An honest question...

[Shimmer]

Hah! Now that's actually funny.

Re:An honest question...

[Yehooti]

When I was a kid, the universe was estimated at being around 2 billion years old. It seems that as I get older, so does the universe. I suspect that as our viewing methods improve, we see deeper and so our estimates become greater. Do you suppose there is no end to this?

Re:An honest question...

[l0b0]

There are three types of questions: The ones you ask your parents before moving from home, the kind you take to Google, and the kind you just look up: http://en.wikipedia.org/wiki/Age_of_the_universe

Re:An honest question...

[-brazil-]

It's not about viewing. As our technology and understanding of astrophysics improves, we get new data and interpret old data differently. That discoveries made between you childhood and now caused the estimated age of the universe to increase is a coincidence. It may well be that the next big discovery causes the esitmations to be lowered again.

Re:An honest question...

[Decaff]

How do we know the universe is 13.7 billion years old? It was recently discovered that the universe's expansion is accelerating as time goes by.

I think a better way to describe things is that some evidence was recently discovered which may be interpreted as suggesting that the universe's expansion is accelerating. As our understanding of the universe changes frequently (for example, the idea of a Big Bang was controversial when I was young), it seems to me to be too soon to say anything definite. The idea of acceleration is simply this year's/decades's latest theory.

Re:An honest question...

[suitepotato]

We don't know exactly how old it is. And we think up new things to test every day against observation.

For instance, many years ago when the first 3d plots of the spacing of galaxies in the observed universe were being trotted around and people we wondering how the universe could look this way assuming an homogenous start, I looked and thought, "that's the effect of multidimensional spherical harmonics. Big bang, big vibration, multi-dimensional expanding spherical universe, that gives you the differences that caused the clumping until gravity took over and it looks this way because we don't have a privileged external view to see the surface of the spehere."

It wasn't until this year that I saw someone else actually print that idea in Scientific American.

Who knows? Between the current possibility of the universe speeding up expansion like an evaporating foam, the original inflation put forward by Guth, harmonics, and energy freeze-out (like the separation of electromagnetism into totally separate forces which almost certainly will happen in a universe with open-ended expansion) and particle decay... There's a lot of goofy stuff about the universe to test out.

I'm just glad these bursters seem not to be going off in our neck of the woods. We'd all be dead otherwise. That's not a theory.

Re:An honest question...

[fabe3k]

http://en.wikipedia.org/wiki/Age_of_the_Universe

Re:An honest question...

[mfrank]

Since it only lasts a few minutes, wouldn't it depend if it's visible in the sky? Similar to "Inconstant Moon" by Larry Niven? What I've read is that if one occurs within 6000 light years or so, it'll kill everything on the side of the planet facing it. Since half the ozone layer would be gone, in a few days air currents would redistribute what was left so whoever survived would have to deal with ozone layer being reduced to half its level.

Slashdot is late again

[No Salvation]

Wow, Slashdot really dropped the ball on this one, this news is 13 billion years old.

Re:Slashdot is late again

[saskboy]

I predict that if the explosion is pulsating, then it's likely we'll see pulsating dupe stories about it too. Go ahead, mod me offtopic, but I'll have the last laugh when this story shows up again tomorrow.

Re:Slashdot is late again

[SpaceLifeForm]

It won't be a dupe, it will be the effect of gravitational lensing.

Re:Slashdot is late again

[Alsee]

Well, on the bright side maybe they'll wait another 13 billion years before running the dupe.

-

Re:A long time ago in a galaxy light years away...

[Tablizer]

I feel a great disturbance in the Force (which we all know travels at the speed of light). As if millions of voices suddenly cried out in terror, and were suddenly silenced.

Well, Cuba did offer to help, but....

You Are Here

[Doc Ruby]

I like to cruise around in Celestia, but I can't find models on a scale larger than galaxies. The "sky show" I saw at the Hayden Planetarium (or whatever they call it now, "Rose" something) last year, a "zoom out" from NYC to "the biggest picture" of the whole Universe, looked a lot like a Celestia animation. Is there some kind of model I can run on my Linux machine to cruise the *whole* universe? To look at those several degrees of "superstructures" surrounding us, without that annoying 30min time limit, or Tom Hanks' annoying voice?

Re:You Are Here

[dpp]

The software you saw at the Hayden might have been something to do with Partiview:

Re:You Are Here

[Doc Ruby]

It's hard to tell at first, because Partiview is so much slower on a PIII/800/i810 cheapo to which I downloaded it, compared to the Hayden, or even Celestia on that cheapo. But the fonts look different (though maybe I can change the fonts). When I can figure out how to zap over to the Solar system, the planets might look the same, which could mean the same program is working. In any case, Partiview looks really cool - thanks for pointing it out.

I am wondering about the source code, inevitably. I don't see it available, or mentioned - its license isn't mentioned beyond the clickthru. Which is purportedly an "open source" license, but I don't see the source. Maybe it's stored somewhere in Partiview, maybe in a locker, in a disused lavatory, down a dark flight of stairs, behind a door with a sign saying "beware the leopard", on Magrathea.

Re:You Are Here

[Doc Ruby]

The source code is available from UIUC, even though the AMNH/Hayden website doesn't seem to offer it.

Wouldn't it be interesting..

[saskboy]

If the distant explosions are caused by aliens, like that Slashdot article the other week claimed? When you think about it though, if it is possible to blow up a solar system, such as in the Star Trek 7 movie, then perhaps this is how we're going to find out we're not alone in the Universe - by observing our neighbours knock down a distant tree [proverbially].

Re:Wouldn't it be interesting..

[Tablizer]

If the distant explosions are caused by aliens

Since they seem to go back to the time that the universe was only 1 billion years old, that is fairly unlikely. Stars back then were too immature to produce enough complex elements thought needed by life. It takes several birth-death cycles for stars to produce non-simple elements, such as carbon.

Further, even if they did arise that early, having the Cosmic Nuke back then would almost certainly have resulted in more noticable changes. One could argue that they blew themselves up, but gamma bursts seem fairly uniform over time and space. Weapons technology growth and use tends not to be uniform, based on earth history.

Finally, they don't seem clustered (repeating in same vacinity). Most wars produce clusters of weapon usage, near the front lines. These so far seem random.

Re:Wouldn't it be interesting..

[saskboy]

You're probably right about not being enough complex elements, unless we're wrong about how matter is organized, or pops into our universe.

"Most wars produce clusters of weapon usage, near the front lines. These so far seem random."
Unless the physics of the universe only permit solar destruction in a particular way, and so each advanced species always will eventually come to the same conclusion, and possibly same end. Or the star destroying alien race(s) have almost always existed, and can travel vast distances instantly, and it just takes them a few thousand years here and there to get mad enough or bored enough that they want to smoke a few stars.

But this is of course just my imagination running wild. It's entirely more likely that nature itself is just acting out, much like lightning storms on earth: Flashy, loud, and scary.

Re:Wouldn't it be interesting..

[flyingsquid]

It's an interesting concept though: look for aliens by trying to see them blow the shit out of each other.

I mean, what would be the effects of a nuclear war, for instance? Given that we came pretty close to lobbing missiles at each other over Cuba, you'd expect that a reasonable number of civilizations would engage in nuclear exchanges. Is clusters of hydrogen bombs going off simultaneously going to be something we could pick up from hundreds of light years away? Of course, such events would be brief... and probably unlikely to repeat themselves in any location.

Re:Wouldn't it be interesting..

[nihilogos]

13 billion years ago there wouldn't have been any aliens. Unless they were based on hydrogen and helium, which doesn't seem very likely. But hell, it's probably not too much of a stretch for star trek.

Re:Wouldn't it be interesting..

[saskboy]

Obviously any planet nuked to death would have an easily seen radioactive green, or possibly yellow glow to it. Oh wait, that's cartoon physics I'm thinking of, never mind.

Re:Wouldn't it be interesting..

[ozmanjusri]

I mean, what would be the effects of a nuclear war, for instance?

It'd sting a bit at first...

There would be next to nothing detectable at astronomical distances from a nuclear war, and the inevitable fall of the (un)civilisations which participated would be likely to prevent them being involved in any sort of astronomy for a long time afterwards.

Re:Wouldn't it be interesting..

[mbrother]

Actually, there seem to be quite a high abundance of elements seen in quasars at these high redshifts. It's probably from very rapid evolution of many generations of stars very quickly in the cores of the first massive galaxies. The lifespan of a massive type O star is only a million years, and a billion years is plenty of time. There are some other subtle issues, but the high-redshift quasars show emission lines indicative of plenty of metals.

Having said all that, the environments in which the elemental abundances grow so quickly would also probably be inimicable to all life for quite some time, so I agree with the main point.

Re:Wouldn't it be interesting..

[Tablizer]

and it just takes them a few thousand years here and there to get mad enough or bored enough that they want to smoke a few stars.

I smoke two stars in the morning.
I smoke two stars at night.
I smoke two stars in the afternoon, it makes me feel alright
I smoke two stars in time of peace, and two in time of war
I smoke two stars before I smoke two stars,
And then I smoke two more ...

Re:Wouldn't it be interesting..

[Leomania]

If the distant explosions are caused by aliens

It was caused by the Vogons. I read about it in the meeting minutes of a planetary planning meeting somewhere in around Alpha Centauri awhile back.

Re:Wouldn't it be interesting..

[Tablizer]

Is clusters of hydrogen bombs going off simultaneously going to be something we could pick up from hundreds of light years away?

I suspect it would be nearly indistinquishable from big asteroid/comet entries. Maybe something could be detected, but not a strong enough signal to know if it is natural or artificial.

Re:Wouldn't it be interesting..

[Tablizer]

Obviously any planet nuked to death would have an easily seen radioactive green, or possibly yellow glow to it. Oh wait, that's cartoon physics I'm thinking of, never mind.

What the hell kind of cartoons did you watch as a kid? :-)

Even the Coyote never nuked the road-runner that I remember.

Re:Wouldn't it be interesting..

[mbrother]

It's ironic that GRBs were first discovered by the military using systems designed to detect nuclear explosions. They turned the system on and got a steady stream of hits, except they weren't coming from Earth. Kind of interesting.

Re:Wouldn't it be interesting..

[nihilogos]

Thanks for that.

Re:Wouldn't it be interesting..

[Alsee]

Oh, it doesn't matter if it ever actually happened in a cartoon or not. Once you've watched enough cartoons you just absorb how the physics works. Then you just start seeing it when you look at things out in the "real world".

For example you look at a bowl of cherry jello... you just *see* the cartoon physics of how a high speed animal impact would interact with a giant cube of cherry jello. First the jello would elastically expand into a large thin pancake without splattering. Then it would instantly snap back to a perfect cube, the viscosity coefficent would ensure the animal would be suspended in the exact midpoint of the cube. The penetration path would have snapped shut and resealed without a trace. The entire cube (with embedded animal) would dissipate any remaining impact energy through a fairly leisurely oscillation. Any attempt for the animal to reach or climb out of the jello would result in the jellow adhering to the arms/legs/head or other body part, and merely having arm/leg/head shape jello encased protusions sticking out of the cube. The only possible way to escape would be to inhale and swallow the entire cube on one shot. Of course this results in a cube shapped torso and facinating mathematics of oscillating locomotion.

It doesn't matter that I've never actually seen that in a cartoon, I've just internalized the physics. Once one has watched enough cartoons one can look at any new invention and just see where the smoke will come out when it malfunctions.

-

Re:Wouldn't it be interesting..

[Alsee]

Is clusters of hydrogen bombs going off simultaneously going to be something we could pick up from hundreds of light years away?

Well lets work up a comparison example. First lets note that the Hirosima bomb was about fifteen kilotons. Fifteen thousand tons of TNT. But the Hiroshima bomb wasn't very big. So lets take the the largest bomb ever detonated on earth, the Russian Tsar Bomba (Emperor Bomb). It was built and detonated purely as part of cold war intimidation tactics. The bomb was so big that is and was entirely useless for military purposes. Anyway, the Tsar Bomba was a fifty megaton blast. Fifty million tons of TNT. It was well over three thousand times as powerful as the Hiroshima bomb. Ok, lets go with the Tsar Bomba as a big fat alien detonation.

Now we need something to compare it to. Do you remember comet Shoemaker-Levy? That was the comet that hit the news for crashing into Jupiter. Telescopes all across earth were trained on the event. Well, the comet Shoemaker-Levy impact was a THREE HUNDRED GIGATON blast. Three hundred Billion tons of TNT. It was a SIX THOUSAND times bigger blast than the bigest nuclear bomb ever constructed, the Tsar Bomba.

Well, the three hundred gigaton blast of comet Shoemaker-Levy was reasonably visible from earth, but only if you had a Big Fat Telescope.

That Jupiter blast was about a half billion miles from earth. In other words it is really really CLOSE. Jupiter and that three hundred gigaton blast was right in our lap. The closest star to earth is Proxima Centauri. Proxima Centauri is twenty five trillion miles from earth. That's fifty thousand times farther than the Jupiter blast.

So we are looking for a blast SIX THOUSAND times smaller than the Shoemaker-Levy Jupiter impact, and FIFTY THOUSAND times farther away. Note that brightness falls off with the square of the distance. So (6000 times smaller blast) * (50000 times farther away) * (50000 times farther away) equals....

15,000,000,000,000 times dimmer than trying to see the Jupiter blast.

Oh, and lets not forget the Jupiter blast was pretty much a flash in the middle of the dark, excellent viewing conditions. Looking for a nuclear blast on another planet... well from earth that other planet is going to be right on top of it's own sun in the telescope. So you are looking for an incredibly faint dot of light right on top of intense the glare from its sun.

In summary, you'd have about as much luck trying to see a static spark when someone on the moon walked across a carpet and touched a doorknob.

-

Re:Wouldn't it be interesting..

[lgw]

OTOH, the Jupiter crash was the lamest giant explosion in our history.

meanwhile millions of miles away in space
the incoming comet brushes jupiter's face
and disappears away with barely a trace...

"was that it? was that the jupiter show?
it kinda wasn't quite what i'd hoped for you know... "

So lame the Cure wrote a song about it. [Is Slashdot *ever* going to fix the bug with the extra blank line in a blockquote? How many years has it been?]

Re:Wouldn't it be interesting..

[lgw]

So it would have to be "life, Jim, but not as we know it".

I think Wyoming tried...

[mbrother]

I *think* we observed, or tried to observe, this burst from our local observatory WIRO. At its high redshift, we probably just got limits with the optical camera that was on the telescope. I'll have to check with my student Cassandra Paul who was on and targeted a burst last week. They released some kind of circular.

As a quasar guy, I'm excited about this result but happy a quasar still holds the redshift record.

Re:I think Wyoming tried...

[mbrother]

What's your problem? Most observatories post public schedules with the times observers will be there, what instruments they're using, etc. When the papers are published, the dates and locations of the observations are recorded, and often the observers are noted (e.g., with footnotes about who was the visiting astronomer at Kitt Peak). There was already a circular that went out last week about these observations with her name on it, specifying exactly when and where she and another observer obtained the data. She was THRILLED to have her name on this.

I don't think you have a good idea about how this stuff works. If you're some sort of weird astronomer stalker local to Wyoming, let us know. We've never had a problem at our observatory other than the occasional minor accident or mountain lion, and no one is ever up there alone. The people here are few and far between, usually friendly, and usually armed.

Where are you from, because you're being weirdly paranoid?

Re:I think Wyoming tried...

[mbrother]

I talked with Cassandra this morning, and she indeed got a GRB last week, but not this one. The one they imaged wasn't at z=6.3, so there's no big news story about it. Some different observers at WIRO did try to image this GRB, and got nothing, which isn't surprising since hydrogen absorption wipes out all the optical light for an object at this redshift, and they were using an optical imager.

(Cassandra was amused/bemused by the trolling AC when I showed her the thread.)

Old news

[1337 man of steel]

from 13 billion light years away

If my physics class serves me correct, that makes this event happening around 13 billion years ago.

Which ends up around Sept6, 12999997995 BC.

Considering that light years = amount of distance light travels in one year, which is alot.

Re:Old news

[ryanjensen]

So, this happened 13 billion light years away, and therefore 13 billion years ago (assuming that gamma rays travel at the speed of light in a vacuum). How is it that we arrived at this point, here on earth, to observe this event *13 billion years* ahead of the light from the event? Especially if the universe itself is only between 13-15 billion years old?

Is the earth, our solar system, and the Milky Way travelling faster than the light from the Big Bang, then slowing down enough for light from this event to catch up? Or did this event not happen 13 billion years in *our* past, but just in the *general* past?

Gah! Confusing!

Re:Old news

[digitalchinky]

The big bang (I don't believe it myself!) happened 'everywhere' - not just at one point in space. That's the theory anyway.

Re:Old news

[Guppy06]

No, special relativity says that it happened 2005-09-06, and the gamma ray burster's calendar is 13 billion years slow.

Re:Old news

[Guppy06]

You're thinking "hand grenade in a vacuum." There was no space-time before the Big Bang, that's what it created. We're not racing away from everything, the space-time between us is spreading out. The two-dimensional analogy used in Sphereland is that of the universe being the surface of a balloon that's being inflated.

This is why the cosmic background radiation, which is a relic from the Big Bang, is visible in all directions with the same intensity.

Re:Old news

[bluGill]

Not exactly. By the theory of relativity you would correct, except the theory of relativity predicts that it does not work in conditions like the big bang. You have to get into quantum mechanics, and other theories that do no exist yet to understand what happened to space time within a few seconds of the big bang.

Of course since we don't have all the theories needed, we cannot be sure what happened to space time "before" the big bang.

In other news...

[Chairboy]

In other news... HULK SMASH!

Re:In other news...

[teknopagan]

Whomever modded this 'offtopic' obviously wasn't paying attention - how is a Hulk joke in a thread about a Gamma ray burst offtopic? I found this comment by specifically looking for Hulk references. I had been planning on saying something along the lines of :

"The scientist who spotted this phenomenon has developed strange mutations recently, and sold the movie rights to his story, on the condition that the movie suck as hard as possible."

Thanks for ruining it for me.

Re:Blackhole Question...

[qbwiz]

The burst emitted the light before the black hole collapsed. If any was created after the black hole was created, it was created in the area outside of the event horizon, so it could escape. No light can escape from inside a black hole, no matter how much energy it has.

If the entire galaxy was trapped inside a black hole, then we would be crushed into a point.

Re:A long time ago in a galaxy light years away...

[jacen_sunstrider]

Uhh....no it doesn't. lawl. It moves beyond light.

Re:first post

[mbrother]

Naw...it's the first flame war!

Grammar Whore

[Anonymous Coward]

ahem. Farthest Gamma-Ray... Farthest . 'Further' is a definition of degree. 'Farther' is a measure of distance.

Re:Grammar Whore

[Anonymous Coward]

There are certainly many people, especially in the US, who observe that distinction. However, there are also many people who do not make a strict distinction between 'farthest' and 'furthest'. I challenge you to find a dictionary that doesn't accept the usage of 'furthest' for distance comparison.

Re:Grammar Whore

[elrous0]

I bet you're the kind of guy who annoys the Hell out of everyone in the room when someone uses the term "refugee" to refer to someone from New Orleans or throws a hissy-fit if someone even IMPLIES that the millenium started in 2000, aren't you?

-Eric

Re:Dupe?

[Peyna]

Well, perhaps no, but I've been reading EVERY OTHER NEWS SOURCE, and they all already reported this.

Considering that Slashdot is not a news source (with the exception of a very few limited original articles) but instead, a place to comment about the news as already published elsewhere, this should not be surprising at all.

Re:first post

[mbrother]

Like Q said to Galactus, "I like your big funny hat, except for those weird horn things on the side."

Galactus said nothing.

This pissed off Q, who continued, "Hey big man. Feeling big and purple are we? What, want to eat a planet? That's nothing. I can eat a whole star!"

Galactus said nothing, again, but more loudly.

"Okay," said Q. "You have that ultimate nullifier thingee that makes you all so stuck up. Well, here, let me show you something!"

And then Q blew up the star as Galactus thought Troll and went looking for a planet to eat.

Re:Wouldn't it be somewhat worrisome ...

[athomascr]

I'd be a bit concerned, though, if bursts came in a repeated sequences of short and long bursts like dah-dit-dah-dah.

I can see SETI deciphering it now: "... have to call you back, running out of stars."

Everyone knows this is...

[gardyloo]

...just Sun's Bold New Ad Campaign.

Stupid Sun

[Helpadingoatemybaby]

I just read this article:

Sun's Bold New Ad Campaign!

Why post it twice? We already know they're trying to get our attention. Heck, they're even running ads on tv. Although now it makes sense now why Sun's Ad campaign was refused --

"This is a gamma ray burst! We can't air this! We'll kill all our viewers!"

Stupid McNealy. He'll kill us all.

SWIFT explained in song

[TheLoneDanger]

Here's SWIFT explained through a song by some astronomers who also sing a capella. Much more entertaining than RTFA.

brighest? yes

[weighn]

Yes, they are the brightest astronomical events that have been observed. The radiation emmited is across the spectrum, so yes, you would see it (if it wasn't massively red-shifted).

From the wikipedia article, regarding GRB 990123:

The combination of obvious brightness and implied distance of GRB 990123 led to two possibilities.

The first was that the radiation of the gamma ray burst was spread evenly. This implied that the gamma-ray energy released by the burst was equivalent to that which would be produced by converting the entire mass of a star 1.3 times the mass of our Sun completely into gamma radiation (see mass-energy equivalence). At visual wavelengths, if the burst had occurred 2,000 light years away within our own Galaxy, it would have shone twice as bright as the Sun.

Re:Blackhole Question...

[erichill]

If this massive gamma-ray burst resulted in a black hole, then how did the light escape enough to reach us here on earth, 13 billion light years away?

Someone or another asks something like this everytime anything related to black holes comes up on Slashdot.

The radiation emitted from black hole related events, such as quasars, gamma ray bursts, and Hawking radiation, for that matter, comes from processes near-sometimes very near, but still OUTSIDE, the event horizon. As long as you're outside the horizon, there are trajectories that escape.

As for,

Also, if a black hole was created at explosion, was this even more massive then we can see, yet the black hole swallowed up a majority of the explosion and what we see, is just a small glimpse of it?

According to the literature on very massive stars, there as mass ranges that results in the star collapsing completely into a black hole such that no significant amount of matter or radiation gets away at all.

Check out How Massive Single Stars End their Life. Figure 1 is particularly enlightening. It's a pretty math-free article, so I think anyone who's generally interested in this stuff can follow it, maybe with a bit of help from Wikipedia and Science World.

Re:Blackhole Question...

[scapermoya]

its the act of the collapse that (likely) causes these bursts. once it is collapsed, the only evidence we have of black holes is their gravitational effects on visable objects, and the x-ray radiation that results from them siphoning gases and other matter from neighboring stars at such speeds that the friction creates massive amounts of radiation around the hole. imagine if your toilet was so powerful that it made the swirling water emit high-energy radition simply from rubbing that fast.

Prediction

[Markus Registrada]

The source will turn out to be (angularly speaking) right next to a nearby Seyfert galaxy that has an improbable number of other particularly bright quasars clustered around it. The other quasars' redshifts will be found to decrease with angular distance from the galaxy.

Re:A long time ago in a galaxy light years away...

[PingPongBoy]

The history of Al Quaeda has been long indeed.

I don't understand how this works.Can anyone help?

[tabbser]

I have trouble with these types of statements. 13 billion lightyears away, the universe is not much older than that, at around 13.7. I understand that the further out you look the further back in time you are looking. If this exploded 13 billion years ago, and we've been exanding for 13.7 and we're just seeing it today, some 13 billion years later ... how come it took so long for us to see it ? Is it really travelling that fast away from us ? What 'speed' would that be ? It would seem to indicate a fantastically fast expansion speed to me, is this right ? I'm probably missing something really obvious, but to me I don't seem to be able to grasp that fundementally simple concept.

rast reaction, but how?

[tloh]

from the article:

"Swift detected the burst and relayed its coordinates within minutes to scientists around the world. Reichart's team discovered the afterglow using the Southern Observatory for Astrophysical Research (SOAR) telescope atop Cerro Pachon, Chile."

There just happened by chance to be a deep space optical telescope available for chasing after this event? I've always thought one needed to book time at observatories due to the high ratio of astronomers to available telescopes. How is it they can just take over an expensive instrument like this? What happens to anyone unfortunate enough to have reserved an observation run during this event?

Re:rast reaction, but how?

[jd]

SWIFT is a space-based telescope designed specifically to chase gamma-ray bursts. It has amazing thrusters, capable of spinning the telescope faster than anything else we have in space.

My understanding is there's a low-res, very wide angle gamma-ray detector that they can use to scan vast sections of the sky. If the computers see anything interesting, they spin the probe to get a better look. If it's still a strong candidate, it then notifies anything and everything on Earth that is interested in such events.

The problem used to be that, precisely because they had to book telescopes and because telescopes are rather unwieldy, even if they saw something, it was too late to get an accurate enough fix to see what the cause was.

SWIFT was designed to solve this problem. In fact, it has discovered far more bursts than the astronomers were expecting and it started detecting them far sooner. (They got half-drowned in notifications, during the test and burn-in phase.)

So far, it has been an outstanding success - second only to Hubble, in the sense that Hubble generates better pics for the press and the average space geek. As far as I know, SWIFT was not designed to really record much in the way of actual hard data (other than location), it was more an early-warning system for giant space explosions. That is partly how it works so fast, but with the pitfall that it means that you HAVE to have additional telescopes available, if it does detect something.

Re:rast reaction, but how?

[mbrother]

We've had NASA support for GRB followup at Wyoming's observatory, WIRO. We have someone on call every night who gets an alert seconds after SWIFT localizes a GRB. They in turn call the WIRO observers on that night who finish their current exposure and then point at the GRB field. When everything is working, and the right instruments are on (e.g. imagers), and the weather is clear, we can start taking data within five minutes of the GRB. It's kind of cool, especially given that the system is not robotic.

The space telescopes, in general, are much more difficult to reprogram quickly aside from the systems like SWIFT designed to detect these GRBs.

Re:rast reaction, but how?

[DNS-and-BIND]

But if a GRB only lasts an average of 10 seconds (according to the article), what good does this do anyone? Even five minutes reaction time would have been too much for this record-breaking event (200 seconds).

Re:rast reaction, but how?

[Paul Dirac]

Swift (not an acronym, so don't capitalize all of the letters) does have a wide field of view gamma-ray telescope. The interesting thing is that it also has a narrow field of view x-ray telescope, as well as a narrow field of view UV/optical telescope on board. This allows the wide field of view instrument to find the burst, then have the telescope slew to position to observe it with the x-ray and UV/optical scopes.

Re:rast reaction, but how?

[MrBook2]

"There just happened by chance to be a deep space optical telescope available for chasing after this event? I've always thought one needed to book time at observatories due to the high ratio of astronomers to available telescopes. How is it they can just take over an expensive instrument like this? What happens to anyone unfortunate enough to have reserved an observation run during this event?"

You are mostly right. All major telescopes are scheduled. Some operate in a classical observing mode (you are granted x number of nights, you go to the telescope and use them when you are scheduled to), some operate in a queue based mode (your observation is approved, the coordinates are put into a list and a computer automatically observes them when conditions are right) and some operate in a mixed mode (some nights classical, some nights queue). Because of this, one type of time award that you can be granted is called "target of opportunity" or interrupt time. Dr. Reichart's team (who I work with and will be joining full time in a few weeks) has interrupt time on both SOAR and Gemini South.

The basic chain of events is this: SWIFT sees a gamma ray burst go off and immediately relays the position of the of the burst to the ground. Reichart et. al. has a set of robotic telescopes in Chile called PROMPT. These telescopes (still being built, 3 are mostly operational right now, all six should be up and running later this year) are always running in queue mode. When a burst comes in, it goes to the top of the queue. If it is observable from Chile (if the Sun is down and the object is high enough in the sky) and if the weather is good, the PROMPT telescopes stop whatever they were doing and immediately slew to the position of the burst and start taking data. This all can happen in less than a minute from the initial burst. Meanwhile, folks on the ground have recieved email and text message notification of the burst and are deciding if they want to interrupt on the big telescopes. In the case of SOAR, it is currently in engineering and is not yet running in full scheduled mode. So if the telescope isn't being worked on, they can observe the target. In the case of Gemini South, it was operating in classical mode, so it couldn't be used until two days later. If you have real interrupt time, you can bump someone who is using it in classical mode. Since UNC (where Reichart is) is a partner in SOAR, he has true interrupt time. If he bumps an observer, he is charged for the time and the person who was bumped gets a time credit.

While the "burst" only lasts for a short time (usually tens of seconds) that doesn't mean the show is over. After the initial burst, the light output decays over a period of days. So while getting on them as quickly as possible is important, there is also a need for getting data in the days and weeks that follow.

Re:rast reaction, but how?

[mbrother]

No, because there's a difference between the gamma rays and the visible light. The optical afterglows last much longer, although they too fade relatively quickly. Robotic systems can get on some GRBs in ten seconds. But an optically bright GRB will be easy to spot from a professional telescope for hours and perhaps days. Most aren't so bright, however. Ideally someone at one of a number of telescopes with GRB programs will spot the afterglow in the first minutes or hours, put out a circular, and permit someone at a big telescope like Keck or Subaru (as in the press release) to get a spectrum to measure the redshift. Such spectra are normally obtained hours or even days after the GRB.

A long time ago in a galaxy far, far away

[renrutal]

Earthlings, say cheese! *Flash* Mr. Alien, your film developing estimated time: 26 billions years and 1 hour.

One addition (or, rather, subtraction)

[jd]

Light travels at C in a perfect vaccuum, but the early Universe was quite definitely more crowded than it is today. In consequence, although C would have been the same (the speed of light in a vaccuum is the speed of light in a vaccuum, no mater what space is doing), light itself would have travelled fractionally slower because it had a denser medium to travel through.

In consequence, although the absolute upper limit of the observable Universe is C * (age of Universe), the actual upper limit must be lower than this - though probably not by very much.

In fact, when very early structures formed, the density was still quite significant. The boundary of the observable Universe, then, can't be uniform but will resemble something closer to rather lumpy rice pudding.

Re:One addition (or, rather, subtraction)

[alw53]

Pick up a copy of "Faster than the Speed of Light" which is a wonderful book about physics and physicists. It's an argument that light may have travelled much faster in the early universe than it does now.

Re:One addition (or, rather, subtraction)

[stevelinton]

Of course in this dense early universe, some other kind of signal may have travelled faster than light (although not faster than c) and would enable us to see a little further. Neutrino's maybe, or the hypothetical "axions" that might make up some of the dark matter in the universe or....

Re:Blackhole Question...

[centauri]

If the entire galaxy was trapped inside a black hole, then we would be crushed into a point.

Though I've heard that if there were a black hole as large as the universe, it would have a density roughly equal to that of... the universe. Think about it.

Re:Blackhole Question...

[Guppy06]

I Am Not an Astronomer/Cosmologist

"If this massive gamma-ray burst resulted in a black hole, then how did the light escape enough to reach us here on earth,"

Only stuff inside the event horizon after a star has collapsed that far gets trapped. The bits of the implosion/explosion outside that radius gets out. Newton dictates that whatever pushes in against the core of a star to collapse it into a black hole also pushes the pusher in the opposite direction.

"I would love to see some pictures or even video of this event,"

A new pinpoint of light appears, then goes away after 3 minutes (assuming you can see gamma rays). Even the most powerful telescopes looking at Alpha Centauri only sees a pinpoint of light. They can get brighter or dimmer, but never "larger."

"Another question comes to mind, what if Earth and the entire Milky Way Galaxy itself, was actually trapped inside of a giant blackhole???"

Things closer to the center wouldn't be visible to us, because the light would be going the other way. Things farther away than us would only be visible as high-energy stuff, with other galaxies probably blue-shifted well into the gamma radiation range of the EM spectrum. Laterally, we might be able to see ourselves with powerful enough telescopes.

"yet the black hole swallowed up a majority of the explosion and what we see, is just a small glimpse of it?"

It's an all-too-big part of it. If the gamma ray burst that we saw was in our galaxy and still pointed at us, we'd be dead.

Re:Blackhole Question...

[bombshelter13]

If you think about it for a second, it makes no sense. If you crushed the entire universe to a point, that would by definition change it's density.

Re:Blackhole Question...

[centauri]

I'm afraid I no longer remember where I heard this. But I didn't say "crush the entire universe to a point." I said "if there were a black hole the size of the universe," meaning, I guess, one with an event horizon 13 billion light-years in radius. Frankly, I can't explain it. Mostly I was hoping that someone here could confirm or correct me. Sort of like what you attempted to do, but more pleasantly.

Mind Blow.

[hot_Karls_bad_cavern]

I am a computer engineering kid. Sexy hardware gets me hot, tight software that climbs up to a level i've not pondered is sexy to me ... or even down to a level i don't play in.

But i have to ask, do you ever just look at the sky at night?

Do you? Do you really sink deep into your mind the vast firestorm that goes on above your head every day and nigh? Do you look at the stars and ... just for a second imagine the roiling, nuclear fire that churns inside each one ... the amount of matter transformed into energy by each one, each second you watch?

Do you?

Break your mind for a second and imagine the scale of this place your little planet wanders around .. and marvel your face off.

Re:Mind Blow.

[NCraig]

Do you?

No, but I do wish I could moderate your post (Score:420, High As A F*cking Kite).

Re:Mind Blow.

[the_2nd_coming]

I would except that I live in a city area and all teh damn light pollution makes the night sky look like an all night sunset.

Re:Mind Blow.

[caveat]

No, because it looks flat and uninteresting. Looking up into the night sky is looking into infinity -- distance is incomprehensible and therefore meaningless.

Re:Mind Blow.

[Man Eating Duck]

HAHA, laughing my ass off, hilarious :)

People around are giving me strange looks...

Re:Mind Blow.

[Alsee]

distance is incomprehensible and therefore meaningless.
Facts do not cease to exist because they are ignored

-

Re:Mind Blow.

[milimetric]

Fuck YEAH man, FUCK YEAH!!!

Re:Mind Blow.

[cr0sh]

The sky above the port was the color of television, tuned to a dead channel...

- William Gibson, Neuromancer

Re:Mind Blow.

[RealProgrammer]

From the Greatest Film of All Time Evar, Men In Black:

K: They're beautiful, aren't they?

J: Huh?

K: The stars. We never just look at them any more.

Re:Blackhole Question...

[bombshelter13]

A black hole must, by definition, be infinitely small in size. If it's the size of the universe, it's not a black hole, and won't function as one.

Re:Blackhole Question...

[promatrax161]

A black hole is of a finite size (Schwarzschild radius in case of a non-rotating one). But you are right, inside all the matter is concentrated in a point, a singularity. But again, what appears to the outside observer as a black hole is of finite size. A black hole with the solar mass would have a radius of about 3km.

Only for point singularities

[jd]

If there's a Kerr Ring singularity, then it is theoretically possible for an object to survive, so long as it is encircled by the ring singularity.

Of course, there is absolutely no possibility of that being the case - for a start, even if you survived the gravitational effects, anything inside of a black hole will suffer from intense x-ray and gamma-ray blasts from matter being squeezed out of existence as it enters the black hole.

(It's also impossible for an object to reach the "safe" zone within a Kerr Ring singularity, as you'd be pulverized by the gravitational rip-tides then ripped apart by the massive gravitational gradients. Not to mention incinerated by all those x-rays and gamma-rays.)
p.
I believe it is possible the original poster may have been referring to the theory that the Universe is "closed" (ie: nothing can escape it) which is one of the characteristics of a black hole. That does NOT, however, make the Universe a black hole. The increase in the rate of expansion also implies that the Universe is in fact open, which makes the point moot anyway.

I was called to verify it....

[Boomshanka]

so I hopped outside and grabbed the old lookin lenses and saw it plain as day. It looked a lot like our sun .... ow my eyes hurt

Re:Blackhole Question...

[DurendalMac]

As viewed from the outside, yes, but you're talking about the diameter of the event horizon. The singularity itself is crushed into an infinitely small point. Thus, our universe couldn't be the interior of a black hole. We'd all be smashed into the same point in space. The matter in the universe is far too spread out to create any kind of event horizon.

Re:Blackhole Question...

[Tablizer]

The burst emitted the light before the black hole collapsed. If any was created after the black hole was created, it was created in the area outside of the event horizon, so it could escape. No light can escape from inside a black hole, no matter how much energy it has.

Man, it must be hell on the inside when the collision happens.....if it wasn't already before.

Hey! I am going to start a new religion that says Hell is inside black holes. Nobody is gonna go inside and return to prove me wrong. It is the perfect circular lie machine.

Ahem...

[Bob Cat - NYMPHS]

"News for Nerds..." ring a bell?

It's discouraging to see a story here that has been over-covered and under-understood elsewhere. I'd like nerds to get NEWS about such stuff soon enough to research it and help inform the info-less. This site is not the place for that, I guess.

I phrased it wrong

[slothman32]

I guess I should have put a disclaimer stating that it would be interesting if a start did emit zillions of electrons or He nuclei. Like neutrons now.
There is radiation of that sort. Carbon 14 emits it all the time. It isn't EM though.
Also when I said light I meant visible. I was actually thinking that when I wrote it but since this is /. I thought whatever.

P.S. just so you know, aardvark is the second word in my dictionary, paper variety.

Do we report this, sir?

[bombadier_beetle]

There has been an incident on Praxis. However, everything is under control, we have no need for assistance. Obey treaty stipulations and remain outside the Neutral Zone. This transmission ends now.

Re:Do we report this, sir?

[dontpanicgeiger]

AN INCIDENT??

Re:Blackhole Question...

[centauri]

I don't think it's as clear cut as that. For one thing, black holes of different masses will have event horizons of different sizes. That's what the saying I tried to paraphrase was probably referring to.

For another thing, some (e.g. http://arxiv.org/abs/astro-ph/0506506, haven't read it, got the link from wikipedia) theorize that no singularity occurs. Also, we can't really say for certain what's beyond the event horizon, and the equations break down when they get to the center. From what I gather, anyway.

By the way, I get what you're saying. I'm just saying it's not necessarily that clear cut.

Extremely over-simplified explanation

[jd]

Assume two objects to be stationary on the surface of an expanding object - say, a balloon. The angle between the two objects, relative to some point of origin, will be constant. However, when you measure the distance between the points along the surface, they move apart at a rate that is a function of the rate of expansion and their original distance.

Any object at the edge of the observable Universe would appear to be travelling away from us at the speed of light. Which basically means, we'd never see it. (The red-shift would be infinite, amongst other things.) That's not quite the definition of the observable Universe, but it'll do.

Anything marginally closer will be visible, but because there is an ever-increasing gap, the closer it is to the edge, the longer it'll take to see. (This is because although light travels at a fixed velocity, it is space that is expanding and therefore there is more distance to travel through.)

In fact, your question works rather better in reverse. Given the speed implied by the red-shift, can you calculate the fantastic distances that must be involved? The answer is yes, provided you can eliminate (or allow for) any unknowns.

For objects that have a well-defined spectral output and luminosity, it's easy. You simply compare what you see with what you should see. The shift in frequency and the reduction in output observed can both be used to guesstimate a distance.

For objects of an intermediate distance, it's harder. There are gravitational lenses, which can make objects appear further away. They're often not close enough to other objects to be able to measure an unknown against a known. Those tend to be tougher.

The further an object is, the less important lensing is, as you'd have to bend light more to add enough distance to be significant. By the time you get to 13 billion light-years, the lens would be so bloody obvious in its own right, you'd have probably spotted it first and allowed for it.

However, you can't verify calculations at all easily. At those sorts of distances, you're talking about phenomena that astronomers don't fully comprehend and cannot, therefore, tell what the profile would normally look like.

That is one reason it is important to get a good look with as many types of telescope as possible, so that we can see what created the gamma-bursts, or whatever. That way, we can verify our calculations.

(This is actually important - strange things can happen when you don't verify data. Superluminal motion, stars older than the Universe - all have been observed, but usually because of incorrect calculations or incorrect assumptions.)

Re:Extremely over-simplified explanation

[tabbser]

Thank you very much.

That did indeed help me understand it.

I had that feeling that it must be a fantastic expansion speed, but didn't realize it was actually close to the speed of light and that objects at those distances would appear to be moving away from us at such amazing speeds.

I'm currently reading Brian Greenes fabric of the cosmos, which I'm finding fascinating. I *thought* I understood how all this worked right up until I started reading this. It's added a lot of complexity, such as how gravity and acceleration are the same thing, we're being accelerated through curved spacetime.

I'm sure I'll understand it in the end.
Thanks for taking the time to write such an informative post.

Re:I don't understand how this works.Can anyone he

[Starker_Kull]

The way we figure the distance to the furthest objects (in the 1 - 14 billion light-year range) is precisely by the rate of retreat of the astronomical objects we observe. It was noted empirically (back in the 1920's, I think) that the further away an object is from us, the faster it is retreating, in roughly linear proportion. The rate of retreat is figured out by how much the object's spectra shifts (due to the Doppler effect). So yes, some very far away objects are retreating at speeds damned near the speed of light.

Originally, when Einstein came up with his field equations in General Relativity (1915?), they did not have a steady state solution; but an expanding universe WAS a possible solution. Apparently, this disturbed Einstein so much that he threw in a "fudge factor" called the cosmological constant, in just such a way that a steady state solution existed for the general configuration of the universe. Of course, as more and more observations poured in indicating that virtually ALL extra-galactic objects were retreating away from us, with higher speeds the further away, it became clear that the Universe was, in fact, expanding, despite the tastes of Einstein. He removed the mathematically ugly constant, and I think he later said that messing up his original equation with it was the "greatest mistake of my life."

Of course, you may wonder how we figured out how far some objects were to begin with to USE our distance = (constant) x speed formula. This post is getting a bit long, but it turns out that supernova, explosions of very massive stars at the end of their lives, tend to have an absolute maximum brightness that has a simple relationship to the length of time they "explode". Thus, supernovae can serve as a yardstick if we can spot them in other galaxies; and fortunately, they are bright enough so that we can - I think they are the ONLY individual stars we can discern in other galaxies; all the others are just too dim from those distances....

And how do we determine how far away the "first" supernova is? In other words, how did we calibrate that yardstick? Here I'm not sure; we haven't had a supernova go off close by (meaning, in our galaxy) in the last 500 years (and that's a GOOD thing - a supernova can shine as brightly as an entire galaxy at its peak! There was one in one of the Magellanic clouds (a pair of small, neighborhood galaxes) in 1987, I think); I know we have other yardsticks from direct parallax measurements (measuring the shift of nearer stars vs. their further cousins as the Earth shifts its position around the sun - good out to about 1000 light years now, I think), our knowledge of the absolute brightness to temperature as revealed by spectrum/color of stars on the main sequence, and some knowledge of the brightness patterns of ordinary novae...

There is a really good book called Parallax, which goes into the whole history of how we figured out how far away stuff in the Universe is - it's a fascinating, wonderful read; here is the amazon URL:

http://www.amazon.com/exec/obidos/tg/detail/-/0805 071334/ref=lpr_g_1/103-7798844-8308625?v=glance&s= books

Hope this helps.

13 billion light years away

[gtog]

The gamma ray-burst occurred 13 billion light years away. Does this also mean that this burst happened 13 billion years ago? The considered age of the universe is around 13 billion years, so what I don't understand is this: the burst was 13 billion years ago, at a distance 13 billion light years away from where we are now, how could the universe have been so big already by that time, considering the burst happened not to long after the "big bang" which started the universe (I mean stars, planets, galaxys etc.)?

Re:Blackhole Question...

[promatrax161]

That's true, but the question is how long does it take for everything to get smashed into the same point. Maybe long enough to fool us? :)

Re:I don't understand how this works.Can anyone he

[wumpus188]

There are many ways to calibrate the distance scale.
First - there is a strong relationship between the absolute magnitudes of stars and their spectral classess (Hertzsprung-Russell or "spectrum-luminosity" diagram). Knowing star spectrum it is possible to calculate star luminosity, and this gives the distance from the star to the observer. But this works only for relatively close stars...
For more distant objects, variable stars come to the rescue. There is an interesting relationship between period of pulsation of particular class of variable stars (cepheid) pulsation and their luminosity. That is how, in fact, the first distance to galaxies were measured... (more here)

It still doesn't make sense

[ThreeGigs]

Let's see...
13.7 billion minus 13 billion is 700 million.

So, this thing blew up 700 million years after the big bang. Matter doesn't travel faster than light, supposedly, so this thing blew up *no more than* 700 million light years from where the big bang occurred, right?

But... if it supposedly happened 13 billion LY away, that makes the center of the universe 12.3 billion LY away from us, at most (assuming *we* are moving away from the center at light speed). Assuming we and this explosion were on opposite sides of the big bang, that's 1.4 billion LY apart when it happened, right? Hrm, if it happened 13 billion LY away from where we *are*, and 1.4 billion LY from where we *were*, then the radiation took 11.6 billion years to "catch up" to us. Now, those numbers assumed we're moving at max velocity, but we're obviously not or the light would never have caught us. But... if we're moving more slowly, then all those numbers get smaller...And if the numbers get smaller, that might put the center of the universe *past* where that explosion occurred! Can someone draw a picture explaining the relationships between us and the explosion when it actually happened, and where we and this exploded object are now, and include some speed and time estimates? I'm really, terribly confused, as the NASA numbers just don't seem to add up to me.

But no matter what... this tells me that the farthest we can possibly "see" is just barely (if you call 700 million light years "barely") past the center of the universe!

Is that right? Can we really only "see" half of the universe?

Re:It still doesn't make sense

[rubycodez]

you have the wrong idea of "the center of the Universe". that's a meaningless phrase. We are at the center of our observable universe, but the universe as a whole is expanding, and you could call any body you wish the "center", and if you were located there you would see the rest of the universe moving away from you.

Re:It still doesn't make sense

[m50d]

Now, those numbers assumed we're moving at max velocity, but we're obviously not or the light would never have caught us.

We're moving pretty close to the speed of light, as shown by the fact it's taken 13 billion light years to by probably a lot less than 1.4 billion. The expansion of the universe is happening at the speed of light at the edges.

But... if we're moving more slowly, then all those numbers get smaller...And if the numbers get smaller, that might put the center of the universe *past* where that explosion occurred!

Certainly. We don't know enough to locate the centre of the universe from observations like this. Bottom line it could have been any "side" of us, with respect to the centre of the universe. 1.4 Billion LY is plenty big enough for there to be enough "space" on each side of us, because the expansion of the universe is really fast.

But no matter what... this tells me that the farthest we can possibly "see" is just barely (if you call 700 million light years "barely") past the center of the universe!

Is that right? Can we really only "see" half of the universe?

We can see pretty much all of the universe because, looking that far away, we're looking back to when that was the whole size of the universe. So we can only see 700 million LY past the centre of the universe - but we see it at a time when the universe was only 700 million LY in radius. The remnants of whatever produced this gamma ray burst could be 26 billion light years away by now, because they're expanding away from the centre of the universe too.

Re:I don't understand how this works.Can anyone he

[D2Deek]

Of course, you may wonder how we figured out how far some objects were to begin with to USE our distance = (constant) x speed formula. This post is getting a bit long, but it turns out that supernova, explosions of very massive stars at the end of their lives, tend to have an absolute maximum brightness that has a simple relationship to the length of time they "explode". Thus, supernovae can serve as a yardstick if we can spot them in other galaxies; and fortunately, they are bright enough so that we can - I think they are the ONLY individual stars we can discern in other galaxies; all the others are just too dim from those distances....

Specifically, we talk about Type A supernovae, which always have the same intrinsic brightness.

Type A supernovae are what happen when a neutron star is drawing matter from (feeding from) a companion normal star, usually in the main sequence. As it collects matter, it gets to a certain point and explodes. Usually, both of the stars survive, with the companion being somewhat less massive afterward. :)

The reason Type A supernovae are always the same brightness is that it always takes the same amount of matter for the neutron star to reach critical mass.

We can tell the distance for Type A supernovae by observing one occurring near a Cepheid variable star (and thus relatively nearby).

Cepheids are stars whose variability (the rate at which it dims and brightens) is directly related to its luminosity. So by looking at a Cepheid's variability, we can calculate how intrinsically bright it is. If a Type A supernova occurs near a known Cepheid, we can use the supernova's brightness to refine our calculations of how far other Type As are. And so we have two linked "Standard Candles" for the universe, one for relatively short distances and one for the rest of the universe.

Hope this helps. :)

Re:A long time ago in a galaxy light years away...

[Nuclear Elephant]

From TFA:

his powerful burst was detected September 4

From TFS:

The burst was observed on the 6th of September

I guess it took two light days for the submitter to read it.

I can't believe this.

[wadam]

Gah! I can't believe this. The geekiest place on Earth, and only one reference to the incredible hulk?! What, is gamma radiation now such a serious topic that we can't make fun of the news with a reference to ... unpopular culture?

Re:I can't believe this.

[DNS-and-BIND]

We might be nerds, but we're not comic book nerds. Even we have a little bit of pride.

Re:I can't believe this.

[jkeegan]

Then how about TV junkies?! The TV show was one of my all time favorite shows! Bill Bixby WAS Banner.. David Banner. You wouldn't like him when he was angry..

It's sorta like this

[Moraelin]

At the time, it couldn't have been more than 1.4 billion years away from where earth would have been back then, had the Earth and Sun existed. (They didn't yet.) The whole universe had a 0.7 billion year radius, yeah, so no points could have been more than 2*R apart.

But the universe has been expanding very quickly, and Earth point was basically running away from that beam of light trying to reach it. So it reached us after a whole 13 billion years.

Basically that 13 billion light-years away is measured from where the Earth is _now_, not from where Earth would have been back then. (Again, if Sol or Earth had existed at the time, which they didn't yet.)

It's sorta like this. Let's say I'm a shoplifter running away and you're the security guard trying to catch me. Let's say you start only 10m behind me, but are running only a little faster than I am. So you get to chase me a good 130m before you catch me. You started your chase only 10m from the point I was in the beginning, but 130m behind the point you actually caught up with me.

It's the same starting point in both cases, but the distance is measured from two very different points: (A) from where I was in the beginning, and (B) from where I am at the end of the chase.

If you replace me with the Earth and you with the gamma ray pulse, you get a very rough visual metaphor of what happened there. It's 13 billion years from where we are _now_. It is indeed larger than the R=0.7 billion light-years bubble that the observable universe was back then, because in the meantime the bubble has expanded and Sol and Earth have moved that far outside that space. If you were to plot the way back to where the Earth would have been back then, yeah, it would be a lot closer.

Well, this is only a very very rough visual analogy, and not particularly correct either, but it will hopefully do.

Need my eyes checked

[Sol_Web_Dude]

At first read, I saw "Funniest Gamma-Ray Burst Ever Observed"

I opened the article to find out if it was about the "Clowns from Space" Invasion.

Re:Need my eyes checked

[mhollis]

It was actually a Pigs In Space episode, where Ms. Piggy accidentially pushes the "Death Ray" button and Beeker gets toasted.

Re:I don't understand how this works.Can anyone he

[D2Deek]

Oops, it's not a neutron star that triggers a Type 1a ("Type A") supernova, it's a carbon-oxygen white dwarf that reaches the Chandrasekhar limit (aka "critical mass").

Re:A long time ago in a galaxy light years away...

[yiantsbro]

I know /. is famous for old news--but come on, this is 13 Billion years old...

Re:Blackhole Question...

[-brazil-]

The singularity itself is crushed into an infinitely small point.

A singularity has, by DEFINITION, infinitesimal size. The general theory of relativity predicts a singularity of space-time curvature at the center of a black hole. However, a lot of astrophysicists think that that theory cannot accurately describe what happens inside the event horizon.

Props for NASA

[bjomo]

So where are the props for NASA? Everyone is so quick to knock them when they have difficulty, but I see little praise for their missions of great success.

NASA does have its problems. The administrator is working to get the agency out from under the shuttle and space station. But there are lots of other programs worthy of accolades. http://www.nasa.gov/missions/timeline/current/curr ent_missions.html

So lets hoist a mug to the men and women of the NASA SWIFT program! May your craft fly right, and the GRBs be bright!

Comment removed

[account_deleted]

Comment removed based on user account deletion

John Titor would know

[elrous0]

I suspect he's been anally probed many, many times.

-Eric

Writing rule 1: know your audience/

[FuzzyDaddy]

A team led by Nobuyuki Kawai of the Tokyo Institute of Technology used the Subaru Observatory on Mauna Kea, Hawaii, to confirm the distance and fine-tune the redshift measurement to 6.29, using a technique called spectroscopy.

Who in the world would know what a redshift measurement of 6.29 meant, but would NOT know what spectroscopy is?

Re:When do we get to see the big bang?

[Thrymm]

Doubtful if this is true from CNN...

http://www.cnn.com/2005/TECH/space/09/12/space.exp losion.reut/index.html

"While this gamma ray burst is the most distant explosion ever detected, scientists have found one object that is even further away from Earth -- a previously discovered quasar. Quasars are believed to be produced by gas falling into a massive black hole."

FYI

[Retric]

Neutrons are the worst type of radiation for several reasons.

They are neutral in charge so they tend to pass though mater and magnetic fields easily, which makes them hard to shield.
They tend to be sent out at high energy's so they tend to create lots of ions along their travel path before they slow down enough to be absorbed. These ions tend to do significant cellular damage.

When they are finally absorbed they tend to create an unstable element which will decay and emit more radiation possibly some other type of radiation and possibly more Neutrons.

Re:When do we get to see the big bang?

[cnettel]

Without getting into the details of what the expansion of the universe really means and that there would be no point of origin of the Big Bang, we won't see it, anyway. At high enough temperatures, the photons and matter are regularly interacting. This means that light is constantly absorbed and re-emitted. Compare it to projecting an image on a metal sheet and then trying to look at the image from the other side. You will only see a heated piece of metal and all you can see is the heat energy it has absorbed from the possibly detailed projection.

This is the background radiation, a black-body signature of a high temperature that's then been red-shifted into the area of a few Kelvin. By measuring slight differences in this radiation, we can still make some statements about how quickly the universe expanded before the point of losing the "opacity", but that's about it, unless some genious runs a strange PhotoShop filter on it and reveals the face of the Intelligent Designer. (joke)

Re:A long time ago in a galaxy light years away...

[Andy Gardner]

Shouldn't this be modded informative. Jees, millions of voices probably were suddenly silenced!

Me

[bluGill]

I know what redshift means, but I have never heard of spectroscopy before.

To be accurate, have no clue what units that 6.29 is in. I have no clue it means 13 billion light years away, as opposed to really close, but moving away fast (which could happen for small red shifts up to whatever moving at C would be). It is Doppler shifts, same as a train whistle moving away, only with light.

Re:When do we get to see the big bang?

[lgw]

The cosmic microwave backgroud radiation is the closest to seeing the big bang as we can get. Up to a certain early point in the universe's history, the entire universe was effectively opaque, though glowing brightly with its own heat. At some point the universe expanded enough to become transparant, and the light of that moment is visible in every direction all the time, as weak microwave radiation.

Burst

[Impy the Impiuos Imp]

> The SWIFT team have announced the furthest-ever
> observed super-massive gamma-ray burst (from 13
> billion light years away).

Hmmmm. That means when God created the universe 6000 years ago, he placed the gamma rays already 99.999953% of the way to earth.

Better make sure the schools teach this!

Re:Blackhole Question...

[John Bayko]

Laterally, we might be able to see ourselves with powerful enough telescopes.

No, light can orbit a black hole laterally at about twice the redius of the event horizon. A bit closer, you can get a quazi-eliptical cycle, with a crease at your end, like a peach[1], that gets deeper as you get closer to the event horizon, until the light can only escape vertically, so can't make a trip back to yourself. Within the event horizon, as you say, light can't go outward in any way, so there's no path back to yourself.

What you would see looking out would be a cone. At first, on the horizon itself, it would be 180 degrees, as light from behind you will come in from the side, and light from the side would be bent to come in from above, but as you got closer to the singularity, the cone would shrink and get narrower until just at the singularity, all light (well, radiation, well beyond gama-ray energies) would come from a single ultra-concentrated spot directly above you.

At the singularity itself, of course, the spot would be multiplied by every direction, and the entire sky would be lit.

All that assumes that black holes have no quantum structure. If they do, only half a dozen people in the world have any idea what that would be like, and even they're not too sure about it yet.

[1] Aren't you glad I didn't say butt-crack?

Re:The burst is a signal!!!

[teknopagan]

Meat Lover's is from Pizza Hut, not Domino's, you insensitive clod!