====== Gravity ====== Although three of the four (known) fundamental forces have been unified by one paradigm called the [[http://en.wikipedia.org/wiki/Standard_Model|Standard Model]] (SM) //Gravity// remains outside. This doesn't necessarily mean that //Standard Model// has failed in some way. Perhaps //Gravity// is independent from and incompatible with the other three forces. ( //viz.// the //Electromagnetic force//, the //Strong force// and the //Weak force//.) Unlike the other three forces, which have all had their force-transmitting particles detected and measured by experiment, the //[[https://en.wikipedia.org/wiki/Graviton|Graviton]]// has not yet been detected - and theory suggests that it would probably require a particle accelerator the size of the solar system to do so. (For a 45 min. podcast discussion about the graviton, listen to the BBC's [[https://open.live.bbc.co.uk/mediaselector/6/redir/version/2.0/mediaset/audio-nondrm-download/proto/https/vpid/p02q5xc0.mp3|In Out Time]] programme on the subject) Other unanswered questions about //Gravity// :\\ • Why is so weak compared to the other forces - some 1040 times weaker than the electromagnetic force?\\ • Why is there apparently no //'AntiGravity'?// //See:// [[http://en.wikipedia.org/wiki/Gravity|Gravity]] in //Wikipedia// ---- Also see [[content:physics:cosmology:gravitational_constant]] ~~stars>4/5~~