Most Extreme Gamma-Ray Blast Yet Detected

Flash me? by Z00L00K · 2009-02-20 19:09 · Score: 1

And this isn't a Men in Black flashing device?

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Re:Flash me? by Tubal-Cain · 2009-02-20 19:24 · Score: 2, Funny

No, just some swamp gas.

WHAT'S THE SCOUTER SAY ABOUT THIS SUPERNOVA? by Anonymous Coward · 2009-02-20 19:09 · Score: 5, Funny

"Fermi team members calculated that the blast exceeded the power of approximately 9,000 ordinary supernovae, if the energy was emitted equally in all directions."

IT'S OVER NINE THOUSAAAAAND~

Re:WHAT'S THE SCOUTER SAY ABOUT THIS SUPERNOVA? by Anonymous Coward · 2009-02-20 19:37 · Score: 2, Funny

best dbz call ever
Re:WHAT'S THE SCOUTER SAY ABOUT THIS SUPERNOVA? by KibibyteBrain · 2009-02-21 03:02 · Score: 1

I was confused by this though. Usually explosive yields and such impulsive events are given in terms of energy. I'm not sure what to make of the power of a burst. After all, the power of a pulse is zero except when integrated over a limited time range, and without being given an interaction time, this claim is sort of ambiguous.
Re:WHAT'S THE SCOUTER SAY ABOUT THIS SUPERNOVA? by Kagura · 2009-02-21 05:09 · Score: 2, Interesting

"Fermi team members calculated that the blast exceeded the power of approximately 9,000 ordinary supernovae, if the energy was emitted equally in all directions." IT'S OVER NINE THOUSAAAAAND~
I was hoping for a great set of comments to read, but now I have to pick and choose to get to the informative comments--all because of this number. ;(
Re:WHAT'S THE SCOUTER SAY ABOUT THIS SUPERNOVA? by conureman · 2009-02-21 14:29 · Score: 1

This seems several orders of magnitude beyond most of the energy measurement terms I'm familiar with. One could use scientific notation, but for a few of us, X to the Xtillionth GigaJoules is a little too abstract. This is not too ambiguous for me.

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coloured dots!!! by enter+to+exit · 2009-02-20 19:15 · Score: 1

The website comes with a gif animation of coloured dots!!!

WOAHH!!!

This is called humour, oh Spock descendant mods

yes i see the time problem in my statement

Re:coloured dots!!! by MichaelSmith · 2009-02-20 20:07 · Score: 3, Insightful

What I wanted to see was a graph with time on the horizontal axis and energy on the vertical axis. That would give me a better feel of what the burst actually did.

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Re:coloured dots!!! by hwyhobo · 2009-02-20 20:09 · Score: 2, Informative

gif animation
Actually, it is worse. It is a 6-second .mov Quicktime movie, all 7 MB of it. Considering it is a 6-second movie of colored dots, it would have been a lot more efficient to represent it in a different format. Perhaps an animated GIF?

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Re:coloured dots!!! by MadnessASAP · 2009-02-20 20:23 · Score: 1

Your tax dollars at work eh? Paying for NASAs servers to withstand a Slashdotting of an excessively large movie.

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Re:coloured dots!!! by daemonburrito · 2009-02-20 20:56 · Score: 1

http://arxiv.org/abs/0902.0761
Submitted by the leader of the team working with GROND.
Re:coloured dots!!! by MichaelSmith · 2009-02-20 22:12 · Score: 1

Thanks.

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Re:coloured dots!!! by boot_img · 2009-02-20 23:39 · Score: 2, Interesting

"9,000 ordinary supernovae" = 9000 x 10^44 Joules =~ 10^48 Joules.
According to Wikipedia, 1 ton (do they mean tonne) of TNT = 4 x 10^9 Joules, so this makes 2 x 10^38 tons of TNT equivalent.
And the largest bomb ever exploded is 5x10^8 tons of TNT.
So this would be ~ 10^30 of those, or around a million Yotta-bombs.
Not sure if that helps.
Re:coloured dots!!! by History's+Coming+To · 2009-02-21 01:32 · Score: 1

Ok, lets try this....

If a tonne of TNT goes "Boom!", and six tonnes goes "Booooooom!" (etc) then to type this noise out would take 1,000,000,000,000,000,000,000,000,000,001 o's.

Nope. Doesn't help either.

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Re:coloured dots!!! by RicktheBrick · 2009-02-21 02:54 · Score: 1

This numbers are way to large to mean anything to me. What interests me is if this explosion had occurred anywhere in the milky way galaxy and the energy was directed at earth, would we still be here discussing the matter?
Re:coloured dots!!! by the_other_chewey · 2009-02-21 03:03 · Score: 2, Informative

And the largest bomb ever exploded is 5x10^8 tons of TNT.
Not quite. You are thinking of the sowjet "Tsar Bomba" - with an estimated
blast of about 50Mt TNT-equivalent. That would be 50e6, or 5*10^7.

This factor of ten of yours of course doesn't change the fact that the amounts of energy involved in cosmic
explosions are mindbogglingly huge.
Re:coloured dots!!! by the_other_chewey · 2009-02-21 03:06 · Score: 1

What interests me is if this explosion had occurred anywhere in the milky way galaxy and the energy was directed at earth, would we still be here discussing the matter?
Depends. Is slashdot accessible from the afterlife?

how do they know by timmarhy · 2009-02-20 19:41 · Score: 1

i've always wondered how they know the size and distance of these objects. short of running a tape measure out, how the hell do you calculate the size of something an unknown distance away?

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Re:how do they know by Anonymous Coward · 2009-02-20 19:51 · Score: 1, Informative

Parallax and red shift, I would imagine. They know the speed of light, and the rate (roughly) that red-shifting happens. Parallax measurements allow them to determine how far away it is to at least a modicum of accuracy.
Note: The above is a guess, but it seems plausible.
Re:how do they know by Sorny · 2009-02-20 19:51 · Score: 1

Parallax and redshift perhaps?

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Re:how do they know by robbiedo · 2009-02-20 19:55 · Score: 2, Interesting

There are an awful lot of assumptions made in astronomical measurements. Numbers that are bandied about have huge margins for error based on a series of interdependent assumptions. Not only is this estimated to be 12 billion light years distant; obviously, this event occurred in the distant past near the beginning of the Universe itself.
Re:how do they know by MichaelSmith · 2009-02-20 20:01 · Score: 2, Informative

One of the articles I read about this event talks about a technique which relies on the way light between the source and us is absorbed by dust along the path which the light traverses. Low energy photons are absorbed at a different rate to high energy photons. Measuring the spectrum at our end can tell you how much dust is between us and the light source. This gives astronomers an estimate of distance.

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Re:how do they know by Snowblindeye · 2009-02-20 20:15 · Score: 2, Interesting

Parallax and redshift perhaps?
Parallax only works to about 1600 light years, which is aprox 1% of the diameter of our Galaxy. And that is with a specialized satellite doing the measurement. There is no way parallax is going to work for something that is 12.2 billion light-years away.
Re:how do they know by Spy+Handler · 2009-02-20 20:22 · Score: 2, Informative

parallax only works for stars very close (astronomically speaking) to us... few dozen light-years at most. Even then they have to use the whole width of earth's orbit around the sun, taken 6 months apart, to calculate the parallax.... closing your left eye then your right eye aint gonna cut it for measuring light-year distances :P
Redshift is how they measure galaxy distances, and by some process they determine that this gamma ray burst occurred in galaxy X, so that's how far they come up with the distance here. I think, I haven't RTFA :-/
Re:how do they know by DamienRBlack · 2009-02-20 20:57 · Score: 5, Informative

i've always wondered how they know the size and distance of these objects. short of running a tape measure out, how the hell do you calculate the size of something an unknown distance away?
The chain of logic is vast and complex, but I'll try to summarize:
1) First, we used radar and the speed of light to figure out the distances of things in our solar system. These calculations helped us figure out the diameter of the Earth's orbit, which is used in the next step, parallax.
2) Once we know the diameter of Earth's orbit, we used parallax to determine the distance to nearby stars. Parallax is a process of triangulation, where we use the earth at two extremes and the star we are looking at as the three points of a triangle. Knowing two angles and one side lets us solve for the distance to the star. But the resolution of our telescopes only lets us use this method with any accuracy for stars in our immediate vicinity.
3) Once we could figure our how far away nearby stars are, we began focusing in on types of stars that have fairly consistent outputs of energy in comparison to their other measurable traits, such as color. We call these consistent types of stars (and other astronomical objects) standard candles.
4) Once we are sure that these standard candles do indeed have consistently predictable outputs, we can guess how far away stars of these types are by noting that luminosity (total light output) and apparent brightness are related by a simple inverse distance squared relationship. This lets us estimate the distance to any type of star that has a fairly estimable luminosity.
5) After we have our standard candles mapped out in space, we can note the absorption lines in the light spectrum which indicates various types of dust and gasses. With this data we can make a rough map of where dust and gasses are floating around. This map will let us look at light from stars and objects that aren't standard candles and figure out how far away they should be to account for the absorption lines we see in their light spectrum.
6) After mapping out many of the nearby galaxies using supernovae as our key standard candle, we notices that is seems that there is a linear correlation between how far away an object is and how fast it is moving away from us (we can tell how fast an object is moving away from us using red-shift). This observation seems to show that the universe is expanding, but more important to the discussion at hand, it gives us another tool with which to estimate and map the distances of objects -- this time at any arbitrary distance.
Using the many of the above methods we can get estimates for how far away objects are, but the margin of error is huge because of all of the assumptions we've made. Plus of minus a magnitude or two is considered fairly precise in astronomical terms. This might have been more of an answer than you bargained for, but there you have it.
Re:how do they know by daemonburrito · 2009-02-20 21:45 · Score: 1

The spectrum shape and afterglow over time are predicted by models. Here's one cited by the J. Grenier et al. paper on arxiv: http://www.journals.uchicago.edu/doi/abs/10.1086/518996.
Here's the J. Grenier (the GROND leader) paper on arxiv: http://arxiv.org/abs/0902.0761
Re:how do they know by ergean · 2009-02-20 22:05 · Score: 5, Insightful

This is why I come to /. once in a thousand comments there is one like this. Thank you!
Re:how do they know by daemonburrito · 2009-02-20 22:10 · Score: 3, Informative

The host or counterpart galaxy was too faint (the GRB was 12.8Gly away, and models predict that the host galaxy wouldn't be detectable). But apparently, there is now enough confidence in the models for GRBs to get a good fix on the distance anyway. It's awesome that they can do this without observing a host galaxy now.
The same team that measured this also confirmed the most distant GRB to date last September, and this is within the most distant 5% of observed GRBs.
Arxiv paper
Re:how do they know by ConanG · 2009-02-20 22:11 · Score: 4, Informative

I don't think you made the part about standard candles very clear, so I'll elaborate on that point.
The term doesn't refer to a specific type of star. Standard candles are any stellar objects that have some quality that allows them to be used to measure distance.
One of the most famous examples are Cepheid variable stars. These stars all vary in brightness over some predictable period of time. There is a relationship between how fast they "pulse" and how bright they are. The faster they pulse, the dimmer they are (in absolute terms). If one is pulsing really slow, and it looks dim (relatively speaking), it's probably very far away since it should be relatively bright. If it looks bright and pulses quickly, it's probably close by since they don't get very bright (absolutely speaking).
Other standard candles include planetary nebula, supergiants, globular clusters, H II regions, and supernova. Each of them has a different maximum range over which they can be detected, but there is some overlap. The ones in the overlapping regions are used to calibrate the distances for the rest.
Re:how do they know by Janek+Kozicki · 2009-02-20 22:12 · Score: 1

yep, thank you! ...and I wonder why this story is tagged !etacarinae

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Re:how do they know by daemonburrito · 2009-02-20 22:53 · Score: 1

I hope I won't get whooshed for this, but the !etacarinae tag is because the popular science articles said it was in the direction of the constellation Carina. There is a famous hypergiant in that direction, about 7.5Kly away from us called Eta Carinae, which is expected to supernova in the near future (astronomically near, anyway) and produce a GRB.
GP's post is fine and all, but the determination of the distance of this is just as interesting as its extreme intensity. The host galaxy was too faint to be detectable. That they can determine the distance is due to the predictive power of the current models for GRBs and the network of instruments on earth and in space that can quickly focus on an event.
The determination of the distance and intensity is the actual accomplishment here. http://arxiv.org/abs/0902.0761
Re:how do they know by doti · 2009-02-20 23:19 · Score: 1

So is the weather, and the stock market.

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Re:how do they know by boot_img · 2009-02-20 23:46 · Score: 1

The observed redshift (4.5 in this case) and the Friedmann equation.
Re:how do they know by Genda · 2009-02-21 00:20 · Score: 1

For those not familiar with Eta Carinae, you need to check out the Eta Carinae nebulae (one of the largest nebulae of it's kind in our neck of the galaxy, and the star itself which puffs out huge amounts of gas and dust. The current dual lobed cloud surrounding the star if brightly illuminated by it, and referred by astronomers as the Homunculus (latin for little human or puppet.) Because the cloud seen through a telescpe looks vaguely like a little doll.
If this star does go with a gamma ray burst, and if one of the beams is pointed directly at earth, it will cause us to have a very bad day.
Re:how do they know by ArmchairGeneral · 2009-02-21 00:58 · Score: 1

Damn, well put. I've indeed learned something useful today, thank you very much.
Re:how do they know by syousef · 2009-02-21 01:57 · Score: 1

Parent is essentially correct and thorough but one thing I'll add is the importance of supernova as standard candles.
A certain type of supernova - Type Ia is always going to peak at the same absolute brightness because of the physical process involved. It is the result of one star - a white draw - drawing in matter from another star until the white dwarf reaches a mass where it can no longer keep itself from collapsing. As a result it implodes and bounces back as a spectacular supernova explosion. Since the point at which this mass is too much for the star to hold itself up against gravity is consistent (determined by the physics) the brightness of each type Ia is almost exactly the same.
So now we just need to measure the apparent brightness of one type Ia supernova, and knowing the distance by other means we work out it's absolute brightness. If we see another type Ia (and we can tell the type by looking at the spectra) we know it's absolute brightness, measure it's apparent brightness, and with a simple calculation we get a pretty good estimate of how far away it is. We can now work out the distance to incredibly distant objects because the supernova explosions are so big they're seen clearly in distant galaxies.

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Re:how do they know by John+Hasler · 2009-02-21 02:03 · Score: 1

> 1) First, we used radar and the speed of light to figure out the distances of things in
> our solar system. These calculations helped us figure out the diameter of the Earth's
> orbit, which is used in the next step, parallax.
No. First we used Newton's laws and geometry to figure out the distances of things in our solar system. No radar needed. The first quantitative estimates of the speed of light were made using the known motion of and distance to Jupiter's moon Io.

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Re:how do they know by Guido+von+Guido · 2009-02-21 02:32 · Score: 2, Interesting

So is the weather, and the stock market.
Bad analogy. We're using these models to do something more along the lines of looking at all that standing water in somebody's backyard about three states away and saying, ah yes, it rained there last night. In other words, they're looking at something that's already happened and attempting to figure out what has already happened. I think we can do this at least reasonably well for both the weather and (to a lesser extent, I suspect) the stock market.
Re:how do they know by jo42 · 2009-02-21 03:52 · Score: 1

WAG - Wild Arsed Guess.
Re:how do they know by Almost-Retired · 2009-02-21 05:56 · Score: 1

Correction, a very bad LAST day. I for one am damned glad we are looking at that thing from the angle we are. And I hope it or we don't move so that when it does blow, we are looking down the gun barrel. The GRB will be here from that distance, probably within a few days of seeing it go supernova. The question that runs in the back of my alleged mind is: Are these GRB's beamed, or isotopic. If beamed, and we are in the beam...
Not much we can do but make our peace.
Re:how do they know by the+donner+party · 2009-02-21 06:40 · Score: 1

What's even more amazing is how they know all their names! I think this is the most direct evidence we have of aliens secretly visiting Earth - they must be telling the government all kinds of things, but the names of the stars is the only thing the government hasn't held away from us, and even there they don't admit where they got all that data from.
Re:how do they know by Kagura · 2009-02-21 08:04 · Score: 1

We will have only a few hours' warning after the neutron detectors on earth all detect less than a hundred or thousand or so neutrinos.

The gamma rays will be the first thing to arrive after the neutrinos.

http://en.wikipedia.org/wiki/SN1987A#Neutrino_emissions
Re:how do they know by IndustrialComplex · 2009-02-21 09:04 · Score: 1

Correction, a very bad LAST day. I for one am damned glad we are looking at that thing from the angle we are. And I hope it or we don't move so that when it does blow, we are looking down the gun barrel. The GRB will be here from that distance, probably within a few days of seeing it go supernova. The question that runs in the back of my alleged mind is: Are these GRB's beamed, or isotopic. If beamed, and we are in the beam...
Not much we can do but make our peace.
Wouldn't the GRB be here at the exact same moment we see it go supernova? Depends on how long it takes a supernova to generate the burst. Of course, assuming that it hasn't yet gone supernova, the instant it does, we would have several thousand years of 'making our peace'.
The good news is that we tend to know fairly accurately (in astronomical scales) when such an event would occur depending on what the star is currently using as fuel. The other good news is that we are moving away from the star as well.

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Re:how do they know by dotancohen · 2009-02-22 10:10 · Score: 1

Thank you! This may be the single most informative post in /. history.

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alternate... by 800DeadCCs · 2009-02-20 19:54 · Score: 2, Funny

In an alternate galaxy long long ago...

Emperor palpatine went senile, and every time they fired the death star superlaser, insisted that darth vader pull his finger.

Re:alternate... by MichaelSmith · 2009-02-20 20:04 · Score: 1

Personally I wonder if somebody was fighting a hot war 12 billion years ago, and occasionally a weapon gets pointed in our direction.

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Re:alternate... by Criliric · 2009-02-20 20:12 · Score: 1

i've always pondered that myself, even just a stray shot from a stellar dog fight, it would be rather interesting and answer some questions for sure
Re:alternate... by Artraze · 2009-02-20 20:52 · Score: 1

It's a fun idea, but practically speaking, this is just far too powerful. A handful of supernovae worth of energy could fairly easily destroy an entire solar system, so a weapon yielding OVER 9000!!! (sorry) would be severe overkill. And not the fun sort of 'why not' overkill, but the inter-solar equivalent of nuking it from orbit: for when you have to be sure nothing within several hundred light-years survives (and another few thousand ltyr are devastated).
So maybe it'd be more accurate to think of these as a civilization's last ditch effort to take out a horrible nemesis, rather than a simple weapon.
Re:alternate... by bingoathome · 2009-02-20 21:40 · Score: 1

Yes but if it was a tightly focused weapon that missed its target 12 billion years ago then it might have only needed to be half a super nova (which is equal to 20 LoC raised to the power of a slashdot meme). Any hooos if you can decimate someone else's 2000 light years of space why not - teach a lesson an' all that.
Re:alternate... by ConanG · 2009-02-20 22:22 · Score: 1

The 9000 figure is assuming that the radiation is spread equally in every direction. A "stellar dog fight" weapon might not work that way. Think of a laser. Focus a lot of energy into a fairly tight beam. It would look a hell of a lot more powerful if someone assumed that same amount of energy was being spread in every direction.

Power of Gamma Ray Bursts by Snowblindeye · 2009-02-20 20:01 · Score: 4, Informative

My favorite comparison to illustrate the power of Gamma Ray Bursts: A Gamma Ray Burst puts out the same amount of power (while it is bursting) as all the stars in the universe together.

(Usually comparisons made in the media are rather lame, i.e. Libraries of Congress, but this one really impressed me)

Alien Hulk Incoming by V50 · 2009-02-20 20:07 · Score: 1

Bah, all that star talk mumbo-jumbo. We all know what really happened.

A bunch of aliens just created the Hulk.

Kaboom by Dracophile · 2009-02-20 20:23 · Score: 5, Funny

Great shot, kid! That was one in a million!

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GROND by daemonburrito · 2009-02-20 20:25 · Score: 2, Informative

In this particular case, it was this.

Method is explained a little in the eso.org link, but here's a wikipedia article, too: http://en.wikipedia.org/wiki/Photometric_redshift.

Also, awesome Tolkien reference apparently acknowledged by Jochen Greiner.

Re:GROND by NewbieProgrammerMan · 2009-02-21 01:02 · Score: 1

Wow, that's obscure!

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question by binaryseraph · 2009-02-20 20:26 · Score: 3, Funny

Soooo should I put on the tin foil hat again?

Re:question by mail2345 · 2009-02-20 20:31 · Score: 1

Tin foil hats don't shield from gamma ray bursts.
Their unique properties deflect only mind control rays.
Everyone knows that.

To deflect gamma rays, you really need these magnetic bracelets! Only 19.99! They use the power of magnets to deflect the bad stuff in your body!
Re:question by PPH · 2009-02-21 06:52 · Score: 2, Insightful

Yes. And at these energy levels, make sure its shiny side out.

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And make it relative! by Gazzonyx · 2009-02-20 20:33 · Score: 1

I'm assuming you'd like the logarithmic scaled version! :)
I'd go one further. That very same graph with a third axis (axee? axen? Arg!) that shows this burst/time graph relative to an energy source I can somewhat comprehend. Maybe the projected output of an average star over that same time frame.

P.S. - Great sig. I actually LOL'ed.

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Re:And make it relative! by yotto · 2009-02-20 20:50 · Score: 3, Informative

That very same graph with a third axis (axee? axen? Arg!) that shows this burst/time graph relative to an energy source I can somewhat comprehend.
The plural of axis is axes.
That said, you're talking about a single one (the third in a set, but it's still singular) so axis is correct.

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Re:And make it relative! by MichaelSmith · 2009-02-20 20:58 · Score: 2, Interesting
P.S. - Great sig. I actually LOL'ed.
Its not mine though. Years ago there was a magazine called Kilobaud Microcomputing. In one issue they ran a funny graphic story called "The man from CPU". It was a detective story built around computer jargon. By the time I realised the value of it my Dad had cleared out the attic and all the old magazines were gone. From time to time I google a few choice keywords in the hope that somebody has put their archives on line and I can recover the article.

So far it has been no go but I put that line in my sig in the hope it would jog someone's memory and they would have a copy they could put on line for me.

From memory: few choice lines:
- That must be the same massive compiler which executed Object ProgRam, our Indian agent.
- He picked up a nearby filing cabinet and tried to delete me.
- I flipped the Matre D' two bits. Parity checked out and I was good to go.
- In a couple of microseconds I was on the other side of town.
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Re:And make it relative! by Antique+Geekmeister · 2009-02-21 03:47 · Score: 5, Funny

And the plural of axes is chainsaw.
Re:And make it relative! by conureman · 2009-02-21 14:33 · Score: 1

More like narrow chisels.

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Re:And make it relative! by shadowbearer · 2009-02-23 06:23 · Score: 1

I remember that magazine, although I never saw that particular article. Sounds like a real gem.
You ought to contribute that to the wiki article on KM. Perhaps somewhere out there someone still has some old mags... I've seen a few issues for sale on ebay from time to time.
Cheers,
SB

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Let me be the first to say.. by RichiH · 2009-02-20 20:42 · Score: 1, Interesting

..why is this not moderated over9000 (yet)? ;)

Yah, yah, it's old, but hey. It fits :)

Re:And no-one knows why they go bang. by Xiroth · 2009-02-20 20:46 · Score: 1

But Gamma Ray bursts are a mystery. Actually 3 mysteries, because they been classed into three types the fastest a 1000 times faster than the slower type.

Uh, what? Last I checked, there's only one speed that gamma rays can go in a given medium - the speed of light. Are you perhaps referring to frequency differences?

Kai Hansen commented the news as by toriver · 2009-02-20 20:48 · Score: 2, Funny

"awesome!"

nice summary by circletimessquare · 2009-02-20 20:52 · Score: 1

all i can think is

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Re:Big Bang by symbolset · 2009-02-20 20:52 · Score: 1

Not even close. The universe extends so far in every direction that no matter where you look, you get objects receding from you at the speed of light.

On the upside though, congratulations! You are once again at the center of the known universe.

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Re:And no-one knows why they go bang. by Bazman · 2009-02-20 21:03 · Score: 2, Informative

The "speed" is how long the burst lasts for - not how fast the gamma rays go!

Alien industrial accident by TapeCutter · 2009-02-20 21:54 · Score: 1

IIRC it was Arthur C Clarke who, with tounge firmly in cheek, suggested such blasts were in fact alien industrial accidents.

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We have witnessed the death of several evolved by assemblerex · 2009-02-20 22:43 · Score: 3, Interesting

civilizations, if the odds of other life evolving to advanced civilizations is taken seriously.

Re:We have witnessed the death of several evolved by JamesP · 2009-02-21 01:11 · Score: 1

I wish I had mod points for this, so true.
They say if a supernova (does its thing) in (apparently very far distance) from earth, we'll all be wiped out.
But again, we're in the urban sprawl of the milky way,

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Re:We have witnessed the death of several evolved by Anonymous Coward · 2009-02-21 03:19 · Score: 2, Insightful

Since the explosion was 12.2 billion light years away, and the age of the universe is 13.7 billion years, the objects around it would have got a maximum 1.5 billion years to nurture.
Now, considering the fact that the universe was very violent at that time, there might not have been any possibility of any civilization at all.
Also considering the fact that after sun came into being, life (basic proto microbial) took almost 1.5 billion years, and from there almost 2.5 billion years to reach the current stage, the possibility of any civilization being extinguished by the burst does seem remote.
Re:We have witnessed the death of several evolved by jschen · 2009-02-21 04:29 · Score: 2, Insightful

Furthermore, the early universe was much less rich in elements other than hydrogen and helium. Anything we might recognize as an advanced life form almost certainly would require a few generations of star formation to go by first before there's enough heavier elements given off by all the supernovas out there (admittedly, a lot more back then) to give them a chance. That said, it's not out of the question that something evolved that quickly. Sure, it wasn't so fast on earth, but one data point hardly makes for a rule.
Re:We have witnessed the death of several evolved by glitch23 · 2009-02-21 08:28 · Score: 1

Why do you assume they had to evolve? You do know what assuming does, right?

--
this nation, under God, shall have a new birth of freedom. -- Lincoln, Gettysburg Address
Re:We have witnessed the death of several evolved by assemblerex · 2009-02-21 22:21 · Score: 1

Sure do, it gets you a giant collider under switzerland that may/may not destroy the earth. Very few things are certain, the rest is agreed observation and theory.

It's called "EIRP" by mangu · 2009-02-20 22:59 · Score: 2, Informative

A common acronym you'll find in engineering and physics texts is EIRP, which stands for equivalent isotropic radiated power. This means you take the direction with the highest intensity of radiation and calculate what would be the total power if it was radiated with equal intensity in all directions.

This system of calculation is very convenient in communications engineering, because you buy amplifiers and antennas separately. Antennas which emit tighter beams are called "high gain", because using one such antenna allows you to use a smaller amplifier to get the same effect at one direction.

In microwaves it's very common to trade off the cost of a smaller antenna against the higher cost of a more powerful amplifier when designing a point to point link. When you calculate the needed signal intensity at the receiver, you represent the result as an EIRP and calculate the loss due to the signal spreading out to get the needed EIRP at the transmitter. Then you check out how much different antennas and amplifiers cost to get the cheapest combination that gives the needed EIRP.

Since radio astronomy uses basically the same formulas, it only stands to reason that astronomers would use the same terminology.

Re:It's called "EIRP" by Muad'Dave · 2009-02-23 05:50 · Score: 1

Part Two: Decibels for Dummies - how to add gain, loss, and EIRP figures.
EIRP is typically measured in Decibels referenced to a standard power level. Decibels are a logarithmic scale that is used to compare different power or voltage levels. For power levels, the decibel ratio is 10 * log (p/p0), where p0 is the reference power. For instance, if I have a 2 Watt transmitter, its power output is approximately 3dBW (decibels referred to 1 Watt), or 33 dBm (decibels referred to 1 mW).
Antenna gain and cable loss are also measured in dB. Antennas are usually referenced to either an isotropic radiator (dBi), or a dipole antenna (dBd). Cable losses are given in dB at a specific frequency.
For example, a 3dBW transmitter connected to a 6 dBi antenna with a cable that has 2 dB loss at the operating frequency yields an EIRP of 3 + 6 - 2 = 7 dBW, or about 5W.

--
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.

Re:Big Bang by boot_img · 2009-02-20 23:43 · Score: 3, Informative

No, this was just a little Bang. The big one, we had already found. You can see a picture here.

Don't forget about SN_1987 by NotSoHeavyD3 · 2009-02-21 01:47 · Score: 1

Basically this wikipedia article talks about a specific instance of using geometry to figure out how far a supernova was. http://en.wikipedia.org/wiki/SN_1987A#SN1987A_distance_and_the_speed_of_light

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Did you know 80 to 90% of the moderators on slashdot wouldn't recognize a troll even if one dragged them under a bridge.

Big Bangs... by Talkischeap · 2009-02-21 02:23 · Score: 1

They are Big Bangs "leaking" into our universe from another.

Like the one the bore our universe.

Betcha'.

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If it don't GO... chrome it. ~ Frank Banks

Need for a bigger parallax? by tjstork · 2009-02-21 02:53 · Score: 3, Interesting

That's enormously interesting.

It seems to me that, if funding were available, one of the most useful things for astronomy then would be a set of ships sent to "opposite" orbits in the solar system, extremely far from the sun. Given today's technology, the farther you could get a pair of ships orbiting at an extreme distance from the sun - out past jupiter and farther, then, you could extend the range of your parallax measurements, which are fairly direct. You'll never obviously be able to get the whole universe, but you would be able to get more standard candles. Or, are there already enough stars within a thousand light years that you don't need that? A thousand light years is a pretty good chunk of space.

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This is my sig.

Re:Need for a bigger parallax? by andersa · 2009-02-21 09:09 · Score: 1

Far too expensive and completely unnecessary. A much cheaper solution is already in the implementation phase. Ready my post below about Gaia.

That was no collapsing star... by Strake · 2009-02-21 03:06 · Score: 1

I was just changing my shirt.

Re: 3d map of the galaxy by andersa · 2009-02-21 04:48 · Score: 3, Interesting

2) Once we know the diameter of Earth's orbit, we used parallax to determine the distance to nearby stars. Parallax is a process of triangulation, where we use the earth at two extremes and the star we are looking at as the three points of a triangle. Knowing two angles and one side lets us solve for the distance to the star. But the resolution of our telescopes only lets us use this method with any accuracy for stars in our immediate vicinity.

This is where the Gaia mission will step in and improve things drastically.

Using distant quasars as fixed beacons, Gaia will collect paralax data to all of the brightest starts in our galaxy and for a huge number of closer stars. With this data we will be able to produce a precise 3d map of our entire galaxy. We will finally be able to see it as a distant observer will see it. It will revolutionise our knowledge of space. I personally think this is the coolest astrophysics project being developed right now.

Total Recall, Chapter 25 by HTH+NE1 · 2009-02-21 07:30 · Score: 1

She stopped at a news station. "...results of the special election will be announced as they occur," the announcer said. "Meanwhile on the science front: astronomers report another `inexplicable nova' discovered. That makes seven so far. According to scientists, these novas shouldn't be happening, because they aren't the right type of stars. They--"

Something connected in Quaid's mind. "Oh, my God!" he breathed.

Melina looked at him again. "Something wrong?"

"That news item--those novas--I just realized--" He choked off, not wanting to believe it.

"What's the matter, Doug?" she asked, alarmed.

"Those novas--they're artificial," he said. "That's why they don't seem to make sense. They're seeded, same way as the No'ui seed species."

"I suppose, if the aliens are as powerful as you say," she said doubtfully. "But I can't believe that--"

"Believe it!" he said. "You haven't seen the sheer scale of that reactor! If they can build something like that, and use alien science to make air in a way we couldn't, they can seed a star to go nova!"

"Well, maybe so, if you say so. But what has that to do with this?"

"I told you, they don't pussyfoot! It's all or nothing with them. No second chance."

"Yes, but--"

"The destruct symbol," he said, feeling the horror rise as he spoke. "It was a nova."

Melina shrugged. "Why not? We put a skull and crossbones to indicate poison. We don't mean it literally. It's figurative."

"They don't know figurative. They're a literal species, maybe because of the way they come genetically preprogrammed, like ants. To them, something either is or it isn't, or it is ignored. It can't be partway, unless it's something under construction. So when they use a nova symbol--"

Now the horror came to her face too. "You mean--?"

"I mean that when they say nova, they mean nova! If we abuse the reactor--"

"Our sun will go nova," she said.

"It must be keyed in. The moment the reactor starts to go wrong, it sends the destruct signal to the sun. The sun flares up and takes everything out, maybe through the orbit of Jupiter. Just a little flare, on the galactic scale, but our species will be gone. Just as those other species went, thousands of years ago when they didn't pass the test, and now we're seeing their novas. There are three requirements, one being that we achieve limited space travel on our own, another that we are able to recognize the nature of the artifact, and the third is undefined--but now we know that it means to do it right, or else."

"No second chance," she agreed, staring straight ahead.

"We're shooting for all the marbles!" His face felt frozen. He remembered the dream he had had, of mankind ending. No dream, but an alien warning!

"All the marbles," she echoed hollowly. "God, Doug--"

"Yeah." He arrowed on down the passage, feeling numb.

--
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?

Re:Big Bang by Doctor+Morbius · 2009-02-21 09:37 · Score: 2, Insightful

You're a moron. Take your crank science and go talk about it on the "electric universe" site.

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If I disagree with you it's because you are wrong.

Re:Big Bang by geekboy642 · 2009-02-21 09:42 · Score: 3, Insightful

"quantized" red shift.
You don't even know enough to know you don't know what the hell you're talking about.

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Just another "DOJ fascist authoritarian totalitarian bootlicker" -- Zeio

Pass me the Sunscreen... by ColonelBlinky · 2009-02-21 10:29 · Score: 1

can someone pass me the SPF9000000000+ sunscreen please.

Re:Big Bang by franl · 2009-02-23 05:24 · Score: 1

The universe extends so far in every direction that no matter where you look, you get objects receding from you at the speed of light.

Just to be clear, the highest redshift object is galaxy IOK-1 with a redshift of z = 6.96, which is nowhere near high enough for the object to be moving away from us at nearly the speed of light.

Re:Big Bang by symbolset · 2009-02-23 14:37 · Score: 1

That light left that galaxy 12.88 billion years ago, when the universe was 750 million years old. The universe is expanding, and has been for all of those nearly 13 billion years. Whatever distance this object was then, it's a good country mile further down the road now. It's reasonable to expect that light leaving it today will never arrive here because the relative vectors currently exceed the speed of light, or will before it arrives here. The Y'krith of IOK-1/septus/keorf/3 have left our light cone. No doubt if they knew, they would flutter their gelsacs with relief.

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Re:Big Bang by arminw · 2009-02-24 11:23 · Score: 1

...You're a moron....

In any discussion on any subject, the party that resorts to personal attack and name calling is automatically admitting defeat.

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All theory is gray

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