LIGO Detects Gravitational Waves from Merging Black Holes . ... The measured gravitational waves match those expected from two large black holes merging after a death spiral in a distant galaxy, with the resulting new black hole momentarily vibrating in a rapid ringdown . ... The featured illustration depicts the two merging black holes with the signal strength of the two detectors over 0.3 seconds superimposed across the bottom. ... NASA Web Site Statements, Warnings, and Disclaimers . ...