A gamma ray burst from a powerful stellar explosion was aimed nearly directly at the Earth from the constellation Bootes. The dying star was 7.5 billion light-years from Earth.
If it was 7.5 billion light-years from Earth, then that means that it happened 7.5 billion years ago and we are just now seeing the results. Does that mean that the gamma rays, which I believe travel near the speed of light, are now striking the Earth?
Gamma rays are produced constantly and occasionlly huge bursts of gamma rays come from other galaxies.
Gamma rays are deadly. We use gamma rays to destroy cancer but since they are ionizing radation they can destroy the molecules that support any life.
Luckily the strength of gamma rays declines at the square of the distance so bursts of gamma rays from far away are weak by the time they reach the Earth. Also, our atmosphere absorbs gamma rays and protects us. A strong burst of gamma rays from a nearby source (perhaps a star in our own milky way going supernova) could literally fry the Earth though.
Did you know that with a Supa Nova that it sends out tinny molecules that travel straight through solid objects and can start.. stop.. or even change evolution.. Who knows.. in years to come we might end up with powers like the X-Men
Gamma rays travel at exactly the speed of light - they are EM waves, just like light is. So yes, they are now striking the earth. In fact, that's the only way we could know that such a thing happened in the first place.
"Did you know that with a Supa Nova that it sends out tinny molecules that travel straight through solid objects and can start.. stop.. or even change evolution."
Er, what? None of that makes any sense.