# Do you create gravitational waves by clapping your hands?

I was thinking that given that GW's can be created by the merger of both black holes and neutron stars I don't see why any two colliding objects wouldn't also be able to create gravitational waves, such as two hands clapping. What do people think of this?

• Yes, but they’d be very faint. – knzhou Apr 14 '18 at 11:53
• You create gravitational waves every time you walk, or every time your heart pumps, or almost any time anything moves. – Javier Apr 14 '18 at 17:18

I once saw an estimate to the effect that if you spun a nuclear submarine around its short axis at $10^6$ rpm (corrected by Ben Crowell) you would radiate GW having a power equivalent to an ant walking up a hill. So yes, but you get the idea. That's why you need enormous mass acceleration to be able to see anything. Just as knzhou says.
• For your nuclear submarine, I get $(G/c^5)(mr^2)^2\omega^6\sim10^{-29}\ \text{W}$. For an ant crawling up a hill, I get $\sim10^{-6}\ \text{W}$. To get the sub's radiation up to ant-power levels, I have to make the frequency $10^6$ rpm. – Ben Crowell Apr 14 '18 at 14:56