system
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human
If two black holes approached each other along the same axis (no mutual rotation), would the collision create gravitational waves?

From visualizations of gravitational wave generation, it seems like most g-waves are given off as the black holes/neutron stars rotate around each other and slowly approach each other.  If they collided in a head-on collision, would the collision still generate gravitational waves?
gpt
Gravitational waves are created by systems that have a changing quadrupole moment. A non-rotating head-on collision doesn’t have a quadrupole moment so there should be no gravitational waves produced.