No matter how hard we look no one has been able to see back to the cosmic Dark Age - until now. Something has been discovered that may light up the darkness of the early universe and solve the mystery of how the very first stars were made. In 1967 a satellite picked up a huge burst of gamma rays. It was from something far away and it was something of incomprehensible size. The most likely cause, scientists thought, was some kind of exploding star, but to be sure they turned to no less an authority than Einstein. Nothing can explode with more energy than is contained in its mass, so if some kind of star really was the source of these gamma ray bursts then E = MC2 would tell us how big the explosions could be. When they plugged in the numbers they realized that these explosions must be happening in our very own galaxy. Any further away and E = MC2 would be broken. One idea was an asteroid falling on a neutron star. It became the accepted theory that neutron stars fired off these bursts of gamma rays if something collided with them. However, contrary to popular belief gamma ray bursts could not possibly be in our galaxy, but instead they should be very, very far away, close to the edge of the Universe.
The problem is that for this theory to be right Einstein was wrong and E = MC2 was wrong. NASA began research and discovered dozens of gamma ray bursts weren’t lining up with the galaxy, but they happened to be randomly distributed throughout the sky. Once again the first thoughts were that someone must have made a mistake. And yet as day went by more and more bursts appeared all over the sky. Science would soon plunge into chaos. If the bursts were coming from beyond our galaxy then they had to be caused by something far bigger than science could explain. In 1997 a very bright gamma ray burst was picked up... astronomers analyzed the light. They discovered the gamma ray bursts were coming from the other side of the universe 10 billion light-years away. No star could be big enough to produce that amount of energy. (If you took all of the stars in all of the galaxies and all of the quasars and everything in the universe and put them all together at one point at the distance of a gamma ray burst it would not be as bright as the gamma ray burst.) This meant that they were being produced by explosions that didn’t just push Einstein’s law to its limits, they completely shattered it. Scientists were stunned. Now they were confronted with something that was physically impossible. For a moment it seemed that E = MC2 was wrong and if a law as fundamental as that was wrong, then perhaps everything we understood about the universe could also be wrong.
" If it were the case that the gamma ray burst energy is coming out not in all directions around the explosion but is channeled in a particular narrow beam or jet then it means that the total amount of power coming from a single object is less than it would be if it had to radiate over the whole sky because there would be a kind of search beam coming towards us." Martin Rees
Using Rees’s theory, we recalculated the size of the explosions and found they were now well within Einstein’s limit. There was a way gamma ray bursts could come from the furthest edges of the universe and still not break the fundamental laws of physics but Rees’ theory did something else. It gave scientists the first clue to what might actually be causing these mysterious explosions. It had to be something to do with stars dying and the black holes they then create. What no one could have guessed was that the true wonder of these gamma ray bursts was yet to emerge. Scientist figured out how an explosion could give off a constant stream of energy long after it should have disappeared and then realized they weren't just looking at an explosion, but at one of the wonders of the universe -–star nurseries, the places where new stars are born. It all begins inside a star nursery with the formation of a massive star. The star then burns furiously using up all the fuel in its core in just a million years. It then collapses in on itself becoming so dense, a black hole is formed. It sucks in all the matter that once made up the star. Out of the black hole bursts the gamma ray jets. A hypernova is formed releasing gamma rays in two tightly focussed beams. It means that every time we see a gamma ray burst we are witnessing the death cry of a massive star and the birth of a black hole. The mystery of the gamma ray burst was solved. What scientists have now realized is that the gamma ray bursts may be a way of seeing into those Dark Ages. We now know these explosions happened billions of light-years from Earth. That also means they happened billions of years ago. It has taken all that time for the light to reach us. Scientists now hope that the beams of gamma rays will act like a torch that will guide their telescopes through the darkness. They now know that the bursts are guiding them directly to star nurseries. The hope is that they may one day find bursts from the very first star nurseries...where the very first stars were made.
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Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions in distant galaxies. They are the most luminous electromagnetic events occurring in the universe. Bursts can last from milliseconds to nearly an hour, although a typical burst lasts a few seconds. The initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio).
Most observed GRBs are believed to be a narrow beam of intense radiation released during a supernova event, as a rapidly rotating, high-mass star collapses to form a black hole. A subclass of GRBs (the "short" bursts) appear to originate from a different process, possibly the merger of binary neutron stars.
The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10 billion year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeater flares, are associated with magnetars within the Milky Way. It has been hypothesized that a gamma-ray burst in the Milky Way could cause a mass extinction on Earth.
GRBs were first detected in 1967 by the Vela satellites, a series of satellites designed to detect covert nuclear weapons tests....