empty head Posted October 4, 2009 Share Posted October 4, 2009 Hello all non empty heads. As a layman I was wondering. If light is both a wave and a partical. Does it also exert a gravitational pull however small. and if so might this go some way to explaining why the universe holds together? Dumb question may be. but hey. Dumb guy. Link to comment Share on other sites More sharing options...
dr.syntax Posted October 4, 2009 Share Posted October 4, 2009 Hello all non empty heads. As a layman I was wondering. If light is both a wave and a partical. Does it also exert a gravitational pull however small. and if so might this go some way to explaining why the universe holds together?Dumb question may be. but hey. Dumb guy. Reply: I say it has no gravity and no mass. I seem to recall that it is said to: behave as both a partical and a wave. That is not the same as saying it is a particle and is a wave. This is from way back when. What are they teaching nowdays. Did they figure all that out. What are some of the new theories being kicked around. ...Dr.Syntax Link to comment Share on other sites More sharing options...
insane_alien Posted October 4, 2009 Share Posted October 4, 2009 well, its neither particle nor wave, just like everything else really. they all have bot hparticle properties and wave properties. there isn't really anything on a macroscopic scale that is analogous to it so it is a very difficult concept for most people to grasp as it isn't intuitive. but what we do know is that light has no rest mass at all. and gravity is related to rest mass so this means no gravity. -1 Link to comment Share on other sites More sharing options...
ajb Posted October 4, 2009 Share Posted October 4, 2009 and gravity is related to rest mass so this means no gravity. The energy-momentum tensor is the source of the gravitational field in general relativity. Is the opening question a) is light effected by gravity? answer yes. In general relativity gravity is understood as the local curvature of space-time. Thinking of a photon as a test particle, it follows what we call null geodesics. These are the "straightest possible curves". b) is light a source of gravity? answer yes. The energy-momentum tensor in Einstein-Maxwell theory is in general non-trivial and thus light can be a source of the gravitational field. Link to comment Share on other sites More sharing options...
Dave Cell Posted October 8, 2009 Share Posted October 8, 2009 Light is a wave but the waves can only move in little packets called quanta, which we can treat as a particle at times since the wave would then only have a certain length. What I just said is not really true but if you accept it you will sleep well at night and have more time to watch TV. Link to comment Share on other sites More sharing options...
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