# What is the relationship between a gravitational wave and a graviton? [duplicate]

Gravitational waves were theorized a century ago and recently discovered, leading to the awarding of the 2017 Nobel Prize in Physics. According to Wikipedia:

The comparison to electromagnetic radiation makes me think that gravitational waves must be describable in particle terms as well. It also makes me think that the particle form must be the long-rumored graviton. Yet, about the graviton, Wikipedia has to say:

the graviton is a hypothetical elementary particle

I understand that relativity and quantum mechanics are not well integrated, and that this gravitational wave is a macro-scale phenomenon that, experimentally, doesn't have much to do with particles. But I have basically no understanding of how gravity is interpreted in quantum mechanics (it seems like you can ignore it at such small scales).

Shouldn't the detection of a gravitational wave be evidence in favor of the existence of its corresponding particle? Can gravitational waves be used to 'prove' the existence of the graviton particle?

## marked as duplicate by David Hammen, Cosmas Zachos, Community♦Dec 18 '17 at 15:13

• Gravity waves are detected only from very large cosmic occurrences. They are non-detectable on a small scale. – Douglas D. Beatenhead Dec 18 '17 at 15:13

The relation is the same as the one between a electromagnetic wave and a photon. And it is not true that one can ignore gravity at small distances. In fact, at very small distances of the order of the Planck length ($\sim10^{-35}\,$m), gravity becomes very strong. The Planck length is given by the square root of Newton's constant.

• Dear marmot, you mean 10^-35m and do you have a link where you read this? – Árpád Szendrei Apr 23 '18 at 18:40
• @ÁrpádSzendrei Yes, I meant to write $10^{-35} m$, which corresponds to $\sim 1/(10^{18}\text{GeV})$, i.e. $1/M_\text{P}$. – marmot Apr 23 '18 at 18:49