Scientists Forced To Reexamine Theories In Light of Massive Gamma-Ray Burst 128
cold fjord writes "Earlier this year we discussed news of a shockingly powerful gamma-ray burst. Scientists have had time to study the phenomenon, but it's not offering up any easy answers. The Christian Science Monitor reports, 'An exploded star some 3.8 billion light-years away is forcing scientists to overhaul much of what they thought they knew about gamma-ray bursts – intense blasts of radiation triggered, in this case, by a star tens of times more massive than the sun that exhausted its nuclear fuel, exploded, then collapsed to form a black hole. Last April, gamma rays from the blast struck detectors in gamma-ray observatories orbiting Earth, triggering a frenzy of space- and ground-based observations. Many of them fly in the face of explanations researchers have developed during the past 30 years ... "Some of our theories are just going down the drain," said Charles Dermer, an astrophysicist at the Los Alamos National Laboratory in New Mexico ... while typical long-duration bursts last from a few seconds to a few minutes, GRB 130427A put on its display for 20 hours. ... [W]ith GRB 130427A, some of the highest energy photons, including the new record-holder, appeared hours after the blast. "This is hard to explain with our current models," Dermer said. In addition, gamma rays and emissions at visible wavelengths brightened and dimmed in tandem, quite unexpected because theory suggested they come from different regions of the expanding shells of material and thus should have peaked and dimmed at different times. Finally, theorists had posited different mechanisms for generating gamma rays and X-rays that are part of the light show a long-duration gamma-ray burst puts on. The result should have been a fadeout for the two forms of light punctuated by periods where emissions were interrupted. Instead, the two dimmed smoothly. The theoretical edifice GRB 130427A is eroding has been 46 years in the making.' — The 21 November 2013 Science Express has abstracts for four related papers (first, second, third, fourth). More at Sky & Telescope and NASA."
Re:Question (Score:5, Informative)
http://news.discovery.com/space/why-does-a-star-explode.htm [discovery.com]
This is the first result for the Google search "Why do stars explode".
Re:Question (Score:5, Funny)
From what I remember from 6th grade science class:
Stars mainly use hydrogen/helium as nuclear fuel. However, once those run out, it begins to collapse as gravity takes over. The compression forces it to begin fusing heavier elements, which gives it a renewed burst of energy, thus causing it to explode outwards. You could argue that the heavier elements are still nuclear fuel, but it's not the primary fuel of the star throughout its life so that's basically just an argument of semantics.
Alternative explanation: Hollywood has taught us that random objects may explode at any moment, even in the absence of combustibles or pressure.
Re:Question (Score:5, Funny)
Alternative explanation: Hollywood has taught us that random objects may explode at any moment, even in the absence of combustibles or pressure.
Certain aspects of quantum theory teach us the same thing.
Almost, quantum theory explicitly requires an observer. Hollywood implicitly assumes observers paying $15 a ticket and another $40 for the BlurRay in 3 months. In fact, Hollywood assumes all possible observers will be observing and paying the full rates, so anything short of those predictions are losses due to piracy.
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"quantum theory explicitly requires an observer."
Entirely wrong.
Quantum theory does not require an observer any more than fish require aqualungs.
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Well, as normally stated, quantum theory DOES require an observer. It does not require that the observer be sentient. Any electromagnetic interaction will do. Also strong or weak force interactions. Probably gravity, too, but that's just a bit difficult to observe.
Typically experiments use electrons or photons as the primary observers, but nearly anything will work, with varying degrees of sensitivity.
OTOH, as a believer in the Many-Worlds interpretation, I think that the observation just details which
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Quantum physics is indeed absurd, but do read up on the observer effect [wikipedia.org]; there's very little fundamental difference between observing a quantum phenomenon and interacting with it. 'Infinite are the arguments of sages'*, but for the purposes of the layman, not only is an observer a requirement of quantum physics, but before you observe things, they are not just in one state or the other (but unknown to you), they are in a state of superposition, i.e. simultaneously occupying both states. This superposition i
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The compression forces it to begin fusing heavier elements, which gives it a renewed burst of energy, thus causing it to explode outwards.
As I recall, stars will continue fusing elements up iron fairly happily. Elements heavier than iron are synthesised during the core collapse of a supernova. Probably someone will correct me, but I think that explosion is just release of gravitational potential energy.
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A gravitational collapse's release of energy doesn't need any nuclear reactions. Stuff simply falls down, so it converts gravitational potential energy into kinetic energy. Eventually it hits some other stuff hard, releasing said energy as photons.
Re:Question (Score:4, Informative)
When this fuel is exhausted, the star collapses under its own gravity. This can be extremely sudden (even in human terms).
The collapse can only go so far before the star is compressed to its limit. Where this limit is depends on how massive the star is. Unless the star is massive enough to crush right into a black hole, the collapse will also stop suddenly and "bounce back" as the core instantly reheats from the compression. This is the supernova explosion as all the stuff that normally wouldn't fuse goes and fuses anyway (this is where elements past iron come from).
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Re:Question (Score:4, Informative)
...what mass does a star have besides the helium and hydrogen that should be all gone at this point?
The hydrogen and helium are not gone, they're just converted (via fusion) to higher number elements which require more extreme conditions to be used as fuel. The fusion reaction is what releases the energy in a star, not a pure conversion of hydrogen to energy.
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The Sun is still mostly hydrogen and helium but there are trrace amounts of other elements: http://csep10.phys.utk.edu/astr162/lect/sun/composition.html [utk.edu]
Since the Earth has elements that aren't hydrogen and helium, we know our Sun isn't a
Re:Question (Score:4, Interesting)
Which is where that whole bit about us being made of star dust comes from. It is not that we are formed of the same stuff that constitutes stars but that literally the atoms that make up our bodies, and most of our world were at some point formed inside a star.
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Whats even more interesting is that even the least dense gas in the sun, Hydrogen plasma, is compressed so ridiculously high because of the intense gravity that it's denser than lead. Think about that, and then think what the iron in the star must be like.
If you want to understand the process, read this:
http://abyss.uoregon.edu/~js/ast122/lectures/lec18.html [uoregon.edu]
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You do realize that burning gasoline in your car engine doesn't change the mass of anything, right? That the mass of gas burned + mass of intake air = mass of exhaust?
And must like a catalytic converter will "burn" exhaust further, by subjecting it to different conditions, a star will briefly burn its own exhaust in the immense energy density that briefly exists as the star falls in on itself and reaches peak pressure before rebounding. All elements heavier than iron come from these brief moments in the l
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You do realize that burning gasoline in your car engine doesn't change the mass of anything, right? That the mass of gas burned + mass of intake air = mass of exhaust?
... = mass of exhaust + mass equivalent of energy released
That's tiny in the case of gasoline in a car, but far from negligible for the sun:
The sun loses about four million tons [anl.gov] per second this way.
(Although, in relative terms, it's negligible for the sun as well...)
Re:Question (Score:5, Informative)
First of all, I'm not a physicist.
But, the fusion happening in a star means it's taking the hydrogen and helium and turning it into heavier elements like iron and the like. It's not "burning" fuel in the sense of consuming it and leaving smoke, but crazy big nuclear reactions are energetically making heavier kinds of matter (that's what fusion means, things are getting stuck together, as opposed to fission which is ripping things apart).
Once the crazy big nuclear reaction runs out, the forces keeping the star occupying a larger volume stop, and everything collapses in on itself.
Once that happens, it makes a really really big boom. Because eleventy zillion tons of hot iron and other stuff collapsing onto itself is, to make a huge understatement, exceedingly energetic -- to the point that it can briefly kick out things like gamma rays. (Because, as far as I understand, the magnitude of the collapse is well beyond anything we could even ponder and has a mass likely millions or billions of times that of the Earth.)
So the star hasn't exhausted its mass, it has exhausted its fuel. And then a really vast amount of mass collapses in on itself under its own gravity. And then we see some of the most energetic events we can even fathom. And the crazy collapse under gravity pushes matter to even more ridiculous levels of density, and then releases even more energy.
At least, that's my best understanding of it. I'm sure several people will tell me how horribly wrong I am. I already know it's horribly simplified.
Re:Question (Score:4, Informative)
At least, that's my best understanding of it. I'm sure several people will tell me how horribly wrong I am. I already know it's horribly simplified.
I am a physicist, and no: As simplified explanations go, yours is a pretty good one.
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Pedantically, 0.7% of mass is lost, converted to energy by the proton-proton chain process. But your point stands.
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Hydrogen fuses to Helium. Helium fuses to Beryllium then Carbon. Carbon can fuse to numerous other elements - Oxygen, Neon, Magnesium, etc.
The problem is that fusing heavier elements gives less and less energy, and require more and more energy to trigger. Sol, for instance, will never start fusing Carbon into heavier elements. This causes the star to form distinct layers, as only deep within large stars does sufficient pressure exist to trigger heavier and heavier fusion.
Once you hit Iron*, it's a net negat
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That is at least my layman's understanding of approximately how it works.
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If it exhausted its "nuclear fuel," how could it explode?
Briefly, (and I'm not an expert) a star is a balance of inward gravitational pull and fusion-generated thermal energy pushing out. If the fuel runs out the balance is disturbed, stuff falls inwards at vast speeds and a very impressive bang ensues. There are also other ways a star can go nova (e.g involving a small, dense, companion star). Details here: http://en.wikipedia.org/wiki/Supernova [wikipedia.org]
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Once you're heavy enough, you're not statically stable. Without a source of energy, you collapse, and soon thereafter release the gravitational energy as photons.
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I'm by no way an expert, but I thought supernovas happen because a star runs out of the the lighter elements (Hydrogen, Helium, etc) which are easy to fuse. When this happens, the star collapses upon itself, greatly increasing internal pressure which causes the heavier elements to undergo fusion. It is this second level of fusion that causes the explosion, since it releases a lot more energy. Only really massive stars can go supernova because only they have enough mass to reach some sort of critical pres
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The fusion of heavier elements actually liberates less energy, and above some point (iron?) fusion of nuclei is a net loss of energy, which is why heavy elements are so much rarer than the lighter elements. They are all 'parasitic' losses of energy that are only produced during supernova.
A "binding energy" chart shows that light elements should be fused to release energy and heavy elements should be split to release energy. https://en.wikipedia.org/wiki/File:Binding_energy_curve_-_common_isotopes.svg [wikipedia.org]
A less doomed one [Douglas Adams] (Score:2)
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a star tens of times more massive than the sun that exhausted its nuclear fuel, exploded, then collapsed to form a black hole.
If it exhausted its "nuclear fuel," how could it explode?
When they say the fuel is "exhausted", what they really mean is that there is no longer enough to maintain an equilibrium with gravity. There is still a lot left. As gravity sucks down the remaining fuel it increases the pressure, heating it up enough for a big fusion reaction.
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a star tens of times more massive than the sun that exhausted its nuclear fuel, exploded, then collapsed to form a black hole.
If it exhausted its "nuclear fuel," how could it explode?
Warning, I could have a few things wrong, but the idea is correct
Stars start fusion hydrogen, which turns into helium. Eventually the star starts to run low on hydrogen and starts to collapse. The collapse increases pressure, which then starts the fusion of helium. This releases even more energy than hydrogen, which causes the star to swell into a red giant. Helium starts to run low, and iron starts to form. This is an endothermic process, meaning it absorbs more energy that it emits.
The star starts to
Re:Question (Score:5, Informative)
You might then want to read up on it. The Christian Science Monitor has been around for a long time and has a strong record of integrity and high quality reporting. While owned by the CS the news side is segregated from the editorial side like most reputable newspapers. And the news side dominates. One of the better national newspapers of the US.
Re:yeah, newspaper of a child-killing cult (Score:5, Informative)
Handily, there's a name for your post. It's called the Genetic Fallacy.
While it is true that the person starting the publication was roundly dismissed for her "science" (and for that matter, roundly dismissed by mainstream Christianity for her "Christianity")... that is completely irrelevant to the quality of the publication today. In spite of, or perhaps even attributable to extra scientific caution in a "defensive" reaction to that history, it is now quite highly-regarded for the scientific soundness of its articles.
Henry Ford was virulently antisemitic. Do you attack acquaintances today who own Ford cars? No need to answer. If (when) we reviewed your daily life, we'd undoubtedly find there is one and only one issue to which you apply this "logic"--religion.
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mod this up.
(i would, but i already commented)
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While I do like the reporting from the CSM, I don't think your logical analysis here is up to snuff.
GP made the claim that supporting the CSM, by buying it or giving them pageviews, supports an organization that is actively promoting harm. To follow your analogy, if Ford Motor Company today were actively promoting an anti-Semitic (or anti-Christian) agenda, you can bet that people buying their cars would catch grief for it.
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Handily, there's a name for your post. It's called the Genetic Fallacy.
While it is true that the person starting the publication was roundly dismissed for her "science" (and for that matter, roundly dismissed by mainstream Christianity for her "Christianity")... that is completely irrelevant to the quality of the publication today. In spite of, or perhaps even attributable to extra scientific caution in a "defensive" reaction to that history, it is now quite highly-regarded for the scientific soundness of its articles.
Henry Ford was virulently antisemitic. Do you attack acquaintances today who own Ford cars? No need to answer. If (when) we reviewed your daily life, we'd undoubtedly find there is one and only one issue to which you apply this "logic"--religion.
If Ford called his cars Jew Haters then you'd have a point. But Ford didn't include his beliefs in his choice of car names. Christian Science Monitor title states it has something to do with a religion, hence the Christian part. If it has nothing to do with the christian religion, then maybe they should go by Science Monitor. or a new name. But thinking people shouldn't associate it with Christians is stupid, as that is part of it's name.
And when I think of Christians and science, I think of the
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again: you know nothing about the paper itself, other than its origin, and you are attacking it based on that, and that alone. you can hate the religious sect all you want, but the paper is SEPERATE and DISTINCT from the religious group. it'd be like hating an internationally recognized and award winning newspaper...because it was owned by L Ron Hubbard who also started scientology. Just because she started both things, does not make one invalid simply becaus eyou consider the other invalid.
and in fact, the
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also, supporting the paper, DOES NOT SUPPORT THE CHURCH. again. seperate. one does not fund or publish the other, or vice versa.
MONEY FROM THE CSM GOES TO CS (Score:2)
How many times does this need to be said?
When you give advertising or subscription money to CSM, that's money going to CS.
These days the CSM is just another way they establish themselves as legit; it's branding, pure and simple.
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When you give advertising or subscription money to CSM, that's money going to CS.
That's the point of paying for a good service. You want the money to go to who is providing the service.
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Wait, I thought prescribing antibiotics is killing children by breeding superrestistant bacterial strains
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Everyone knows Lara Logan is the most credible!
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The Christian Science Monitor is owned by the 'Church of Christ, Scientist'; however the church doesn't interfere with the magazine.
Despite it's name and provenience, it's actually a well respected and credible organization.
No creationism or other superstitious nonsense there.
Comment removed (Score:5, Informative)
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I actually loaded up the story just to see how many comments it would take this time before someone blasted it as untrustworthy on account of its name. Happens every time CSM comes up. You didn't disappoint.
And yeah, as others have said, they're extremely reputable and have essentially nothing to do with Christian Science, other than carrying their name.
On the up side ... (Score:4, Funny)
this is what happens... (Score:2)
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Maybe it's a Birthstar. It creates spocks.
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Dispersion, anyone? (Score:2)
some of the highest energy photons, including the new record-holder, appeared hours after the blast
One explanation is that the star is "weird" that way. Another explanation is dispersion in the interstellar- and intergalactic medium between the star and us. I mean, come on, we don't really know much about the intergalactic medium's dispersion for such energetic photons, since the only way to observe it would be via gamma ray bursts, right? I know zilch about the subject, so I'd really like to hear from an astrophysicist or two who happen upon this. As far as I'm concerned, the star could be weird, or th
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Let's face it: over 3 billion light years, it doesn't take much dispersion for things to arrive with a 20 hour delay. We're talking parts-per-trillion here.
Lensing (Score:3)
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IANAAP, but impedance is a better word than dispersion. Much like the speed of light through a prism varies by frequency, the speed of light through the interstellar medium (which is called vacuum, but is not some Platonic ideal of vacuum) should vary just a bit by frequency. Of course, that's not going to surprise anyone in the filed, so presumably the numbers aren't quite as expected even accounting for that.
The effect is very small, and I agree this could be telling us about the "vacuum" as easily as i
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Let's not forget that dispersion is solely due to interaction of photons with electrons in atoms. In ideal vacuum, there's no "small" effect to observe, since there's no electrons (atom-bound or otherwise) for photons to interact with. Case closed.
Of course, back in the real world, over 3 billion years, there's no such thing as a vacuum. There's stuff in there all right. Even the best pseudo-vacuum the universe can throw at us becomes very much non-vacuumy over such distances. Since you're shooting those x-
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Impedance, in the abstract, is that factor that limits the speed that a wave propagates. If light at one frequency (e.g., gamma) is slower than light at another (e.g. visible), then impedance differs by frequency. The speed light moves is limits by (ideal) vacuum impedance, by the absorption and re-emission due to electron interaction (dispersive or otherwise), and by interaction with virtual electron-positron pairs and other vacuum quantum effects. All of these contribute to impedance, dispersion is a s
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Yes, but are they the same across all wavelengths? I believe this GRB included the current record for shortest wavelength ever observed in a photon. I don't know how much this-scale-GRB data we have to compare this against.
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Try reading the thread? The whole discussion is about the facts that "vacuum" isn't vacuum, and what affects the speed of light because it's not just a travelling photon.
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You could see correlations with distance or how much stuff is in between you and the source if that was the case. GRB 130427A they are talking about in this case is in the top 5 closest GRBs seen list, so it can't be an effect just from vacuum, and would come down to if there is a lot of stuff in the way.
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The "a lot of stuff in the way" is a one part-per-trillion effect [google.com], so it's not all that easy to tell if there "is" a lot of stuff other than by dispersion! You'll not see it in purely transmissive/absorptive spectral properties unless we have spectrometers that good - ones that have to work from optical all the way to gamma rays, by the way.
My crack-brained theory: (Score:1)
Someone blew it up on purpose.
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Yep, we may be looking at the results of a long ago war or terrible accident. Of course, maybe we don't know Jack.
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I mean they have a planets with oxygen count for about a 1000 light year radius and can't even tell what's in the atmosphere on a moon inside our own solar system
What moon can't they determine the atmospheric makeup of? It's a pretty straight forward and well understood process...I think most of us learn about it around the age of 10. The light from the sun is reflected off the moon's atmosphere, picked up by a telescope and run through a prism. Certain elements absorb specific wavelengths of light. So you look at the spectrum and see which wavelengths are missing and you know what elements are in the atmosphere.
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So they're wrong about well established fact again. Wonderful.
The theory here was never well established fact. It was a long standing theory, because we've only recently had the tools to test it.
Re:not unusual (Score:5, Informative)
"Scientists Forced To Reexamine Theories" (Score:1)
Seriously? Like they'd sit around in their labs all day doing nothing but now! - oh noes, they are forced to reexamine theories! Yup, that's not at all what science is about.
In other news: Programmers forced to refactor ancient code!
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In the light... (Score:2)
They won't be reexamining much for very long if they keep standing in the light of a massive gamma-ray burst (by which, of course, I mean that it's hard to take the time to examine anything if you're constantly flipping out and going on green-skinned rampages).
Hangout (Score:2)
we've just learned to walk (Score:1)
the model for GRB's is not one that's been carved in stone. to be honest, GRB's are not very well understood. the reason for this is that you have to be lucky to detect one AND then be fast enough to point enough telescopes at it to gather enough data for a somewhat stable mathematical model. not so long ago, we didn't really have any clue WTF happened, so I'm not surprised that the models fall short to explain rare occurrences. i've had gamma ray astronomers in the offices next door using satellites like G
Ultimate Kickstarter (Score:1)
We are developing this exciting new energy source and will continue testing it in the outer spiral arms of the Milky Way, where there's no intelligent life.
For one: (Score:2)
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Just wait for Thanksgiving/Black Friday, they're not under stress yet.
Also...I for one welcome our green testosterone filled overlords.
Down the drain (Score:2)
With Adam, Noach (rhymes with Coach?) and the whole
Christian Science monitored lot.
3.8 billion light-years away (Score:1)
While typical long-duration bursts last from a few seconds to a few minutes, GRB 130427A put on its display for 20 hours. ... [W]ith GRB 130427A, some of the highest energy photons, including the new record-holder, appeared hours after the blast.
Maybe light speed varied for particles that arrived here so that "typical" couple minute burst now looks like 20 hour burst ? Reason for that could be particles crossed some dust clowd or some other fenomen.
God damned reality (Score:2)
Always proving our theories wrong and making mankind look dumb.
Heaven forbid our scientific community should just admit 90% of what they "know" is nothing more than a reasonable guess based on virtually no evidence on the cosmological scale.
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Obelisk from beyond!
Answer the phone (Score:1)
It's clear that our failure to respond to the extraterrestrials shorter burst of gamma rays have led them to try to get our attention with much bigger and more powerful technology.
Will someone please answer that phone?!
Oddball? (Score:1)
Do other distant gamma ray bursts display these odd characteristics, or just this one?
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Taxes are unnecessary. Fund the govt with Treasury bills. Imagine: instead of paying taxes, you have a free choice to buy t-bills that pay you interest.
Also, how come your taxes argument isn't used against the big corporations that get money from the govt? "Hey, I got money for creating toxic assets!"