# Why are Gravitational Waves so small? [duplicate]

I'm sure you've all seen the diagrams and/or 3D visualizations of gravity; the ball sitting on a piece of fabric which makes it sink down. They've also started using it in the videos that explain gravitational waves. Two objects will be circling each other on the fabric and will emit waves.

I know this is an oversimplification of what's going on, but it is quite misleading and has left me a little bit puzzled as to why gravitational waves are infact the size of protons, not the size of planets like the videos suggest.

So I guess my question is, why are they in fact so small, and why can't we detect them from astral bodies in our solar system that we can actually detect a physical force from?

Actually the wavelengths often are the sizes of planets. If the period of something moving at $c = 3\times10^5\ \mathrm{km/s}$ is $1\ \mathrm{s}$ (similar to the recent LIGO discovery), its wavelength is $\lambda = 3\times10^5\ \mathrm{km}$. Other phenomena could well produce waves with wavelengths larger than the solar system.
What is small is the amplitude of the waves. The recently detected waves had amplitudes of $10^{-21}$. This means that they stretched spatial lengths by one part in a thousand billion billion. LIGO in particular has interferometer arms that are a few thousand meters in length, so these arms were stretched by a few parts in a billion billion.