general relativity - What is the likelihood of ever discovering the graviton?

How would one look for and confirm existence of a graviton?

Someone was speaking to me about perhaps one day discovering the graviton, but to me it seems unlikely, although I'm young and essentially quite naive, so am coming to you physicists to ask

1. What actually is the likelihood of finding it?


2. How would we find it?

Answer

Unfortunately, no physically reasonable detector could ever detect gravitons. For example, a detector with the mass of Jupiter placed in close orbit around a neutron star would only be expected to observe one graviton every 10 years (see the below paper). The few that would be detected would be indistinguishable from the background 'noise', i.e. neutrinos.

See here:

http://arxiv.org/abs/gr-qc/0601043

Even though we can't detect individual gravitons, gravitational wave detectors may shed some light on them, since the graviton is the quantum of the gravitational wave (similar to how early 20th century physicists studied the nature of the photon based on properties of light, such as the photoelectric effect.).