- #1
ashwin
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Hi, I am currently an A Level student and we today begun to discuss fields. We were discussing the four different types of forces and my teacher asked me to name one difference between electromagnetic and gravitational forces. I said that gravitational forces are always attractive whereas EM can be either- this led onto the interesting discussion of a new theory that at long distances, gravity can be a repulsive force. He said that there has been evidence from a certain type of supernova which always explodes with the same intrinsic brightness, which can be used to show that the universe is actually expanding at an increasing rate!
Now from my previous readings on this subject, (which haven't been all that extensive) i had understood that gravity was always an attractive force caused by the exchange of gravitons between particles.
Can anyone help to explain possible explanations for this phenomena. There seems to be extensive material on the topic available, but none which is very succinct or easy to follow. Any light that you could shed on the matter would be greatly appreciated.
Thank you very much
-ashwin
Now from my previous readings on this subject, (which haven't been all that extensive) i had understood that gravity was always an attractive force caused by the exchange of gravitons between particles.
Can anyone help to explain possible explanations for this phenomena. There seems to be extensive material on the topic available, but none which is very succinct or easy to follow. Any light that you could shed on the matter would be greatly appreciated.
Thank you very much
-ashwin