Short Gamma-ray Bursts Traced to Colliding Stars 135
Astervitude writes "Collisions of the cosmic kind could be the source of one of nature's most lethal explosions. Astronomers have traced the origin of short-duration gamma-ray bursts, or GRBs, to the merger of neutron stars or other dense bodies. Space.com has a report on the scientific detective work that led to the solution of what has been described as a 35-year-old mystery. "Our observations do not prove the coalescence model, but we surely have found a lady with a smoking gun next to a dead body," said Shri Kulkarni, one of over two dozen astronomers who discovered and investigated two short-duration bursts that took place last May and July. Unlike short-duration GRBs, long-duration GRBs are believed to be produced when extremely massive stars collapse and explode as supernovas."
The Science Channel (Score:4, Interesting)
I just think it's weird how some things seem like a trend some times.
The idea of neutron stars colliding is a very old theory but this seems to shed new light on the possibility of it being the main cause.
Correction... (Score:2, Interesting)
Anyway, it is curious that no gamma-ray bursts occured in our galaxy (yet). It is supposed that such an even would generate enough gamma rays to wipe out the ozone layer, and cause life extinction on earth.
Wait... why dinosaurs dissapeared again?
You're right, they're massive enough. (Score:4, Interesting)
Actually, that's an understatement.
According to the wikipedia [wikipedia.org], a neutron star is about 1.5 times massive as the sun... and that would be about 1.5 × 2x10^30 kg = 3x10^30kg, but ONLY 12 miles in diameter. One can just imagine the gravitational force these things have.
I'd appreciate it if someone made calculation: If two neutron stars are say, 10,000 km far from each other, what will be the acceleration? (remember, the greater the mass, the greater the acceleration). And what speed will they have when they collide? Finally, what will be the kinetic force at the time of impact?
Re:The Science Channel (Score:2, Interesting)
Re:They explode, hence blackholes are a impossibil (Score:3, Interesting)
Despite what you may believe, physicists will listen to challenges to almost any theory (and are proven wrong on a regular basis, science advances!). However, if you just say something can't happen because it is patently silly, without providing a compelling alternative explanation of loads of experemental results, you will be dismissed out of hand. Also, the longer and more successfully a theory has been used, the more substantial evidence against it you will need. Black holes have only been accepted for a short period of time, but if you challenge conservation of energy be prepared. Extraodinary claims require extraodinary evidence.
Also, frequently an outsider to a field will have an alternate theory rejected immediately not because it is absurd but because the experts have already thought of it, done the calculations, and shown that that explanation is inadequate.
Of course, scientists make mistakes, too, but not usually for long in the face of strong evidence.
A few questions about GRBs (Score:3, Interesting)
What is a typical duration?
How close would you have to be to one to receive a lethal radiation dose?
The summary (Score:2, Interesting)
http://www.astro.caltech.edu/~ejb/faq.html [caltech.edu]
especially the portion that said ...."
In practice, over the few seconds that a gamma ray burst occurs, it releases almost the same amount of energy as the entire Universe! "
The article posted on Slashdot is on the short and hard type