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How can gravitational-wave astronomy reveal events that ordinary light telescopes cannot observe?

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gravitational lens — gravity A galactic cluster, about five billion light-years away, produces a tremendous gravitational field that “bends” light around it. This lens produces multiple copies of a blue galaxy about twice as distant. Four images are visible in a circle surrounding the lens; a fifth is visible near the center of the picture, which was taken by the Hubble Space Telescope.

Gravitational-wave astronomy allows scientists to observe phenomena that are invisible to traditional telescopes because it detects ripples in space-time rather than electromagnetic radiation (light).12

While conventional astronomy relies on the electromagnetic spectrum—ranging from gamma rays to radio waves—to study the universe, gravitational-wave astronomy monitors the physical distortions caused by the acceleration of massive objects. This capability provides several unique advantages:12

Observing Dark Objects: It enables the detection of events involving black holes, which do not emit light and are therefore invisible to optical instruments.13
Probing Internal Structures: By observing gravitational waves from neutron stars, scientists can gain insights into the stars' internal structures and compositions that might otherwise remain hidden.1
Uncovering the Unexpected: Historically, every new method of observing the universe has revealed unforeseen phenomena; gravitational-wave astronomy is expected to uncover entirely new aspects of the cosmos that have not yet been theorized.1

By measuring these minute changes in distance using the Laser Interferometer Gravitational-Wave Observatory (LIGO), researchers can study high-energy events, such as binary mergers, that release vast amounts of energy without relying on light emission.123