Gravitational waves are ‘ripples’ in the fabric of space-time caused by some of the most violent and energetic processes in the Universe.
The strongest gravitational waves are produced by catastrophic events such as colliding black holes, the collapse of stellar cores (supernovae), coalescing neutron stars or white dwarf stars and the remnants of gravitational radiation created by the birth of the Universe itself.
Historically, scientists have relied primarily on observations with electromagnetic radiation (visible light, x-rays, radio waves, microwaves, etc.) to learn about and understand objects and phenomena in the Universe.
But now gravitational waves will open up a new window of study on the Universe, give us a deeper understanding of these cataclysmic events, and usher in cutting-edge research in physics, astronomy, and astrophysics.
Gravitational waves carry information about cosmic objects and events that is not carried by electromagnetic radiation.
Since gravitational waves interact very weakly with matter (unlike electromagnetic radiation), they travel through the Universe virtually unimpeded giving us a clear view of the gravitational-wave Universe.
They carry information about their origins that is free of the kinds of distortion or alteration suffered by electromagnetic radiation as it traverses intergalactic space.
- A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
- Because no light can get out, people can’t see black holes. They are invisible.
- Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.