Record black hole merger may be optical illusion caused by gravitational lensing

In November 2023, gravitational wave detectors registered what seemed to be the most massive black hole collision ever witnessed — an event so extreme it strained the boundaries of known physics. Now, scientists are entertaining a humbling possibility: that the universe itself may have bent the signal on its long journey to us, making a more ordinary merger appear extraordinary. The phenomenon known as gravitational lensing, a consequence of Einstein's insight that mass warps spacetime, may have acted as a cosmic magnifying glass, amplifying what we received into something that never quite was