# What effects could/can gravitational waves have on us?

Are gravitational waves something a human beeing could notice if it were powerful enough? Or would it be more like a higher dimensional force, since it would alter us in the sameway as our surroundings so as my eye deforms in the same relation to the enviroment it would anyway the enviroment capture like we are used to?

To calrify what I'm interested in:

Let us assume our earth wouldn't be orbiting sun, but instead be orbiting (or what ever it would be) 2 merging black holes with each of mass ~501 solar masses with earth having a distance of lets say 5000 kilometers when the merging occurs.

Please just ignore all other none GW caused effects that would have extinguished earth allready anyway.

So when this merging event occurs:

Would we be able to notice2 the shapeshifting caused by the waves or would it be in an higherdimensional sense not be notable for us as it is not changing shape in any irregular manner?

1I used this figure in hope it would cause an effect strong enough to express what I'm interested in.

2May it be pain caused by the deforming of our body or altered vision by seeing the objects stretching happen.

1 light year is approx. 63000 astronomical units. The recently recorded event happened some 1.3 billion light years away, which makes it approx. $10^{14}$ AU away. Since the peak strain in the detector was approx. $10^{-21}$ in relative units, even at the distance of the Earth it wouldn't be more than approx. $10^{-7}$, which IMHO would be barely detectable. Having said that, it would deform the planet by about 1m... and my guess would be that it may trigger some earthquakes... but I don't have a good intuition for that. The daily tidal motion is certainly on that order of magnitude... it's just much slower.
• I think it wasn't clear that you meant the strain would be $10^{-7}$ if you were to replace the sun with the source of the GW150914 event, because the strain amplitude scales as $1/r$. – Mike Aug 28 '16 at 16:45