RE: Is there something that is not affected by gravity?
May 7, 2013 at 9:10 am
(This post was last modified: May 7, 2013 at 10:06 am by Anomalocaris.)
(May 7, 2013 at 3:52 am)KichigaiNeko Wrote:(May 7, 2013 at 3:48 am)A_Nony_Mouse Wrote: They travel through distorted space therefore they are affected by gravity which is distorted space. Pretty straight forward actually.
OK thanks Nony!
Current thinking is particles are effected by gravity if they interact with the messenger particle of gravity, called gravitons, similar to how the other three elementary forces - the electromagnetic, the nuclear weak, and nuclear strong forces - excerts their effects through their respective messenger particles.
Neutrinos, for example, does not interact with photons, the messenger particle of electromagnetic force. This is why it can zip through solid matter as if it were not there because it does not feel the presence of electron cloud around atoms, which makes up 99.99% of the volume solid matter. But both neutrino and even photons interact with gravitons. So no neutrinos or light would be coming out of blackholes.
AFAIK, we've not yet observed anything that would make us suspect it does not interact with gravitons. While the standard model gives solid working descriptions of the property and behavior of the messenger particles of those other three particles, it does not do so for gavitons. So within the context of any theory which deserves the name, we have no basis to really speculate whether anything exists that does not interact with gravitons.
String "theory" does postulates something about gravitons. In many different varieties of string theory there ought to be room for stuff to exist that does not interact with gravity. But those stuff must exist only in spatial dimensions beside the 3 we know that string theory postulate to exist but hitherto has not even suggested any practical means to test or to falsify. So it can say anything it likes, but it can't demonstrate anything, much less prove anything.
