The LIGO Collaboration is a scientific collaboration of over 1,300 scientists from universities and research institutions around the world.

The first direct detection of gravitational waves was announced on February 11, 2015.

The gravitational waves detected in 2015 were produced by the collision of two black holes with masses of 36 and 29 solar masses, respectively.

Advanced LIGO is a pair of large-scale interferometers that are used to detect gravitational waves.

The two LIGO detectors are located 3,000 kilometers apart, one in Hanford, Washington, and the other in Livingston, Louisiana.

Advanced LIGO is sensitive to gravitational waves with a strain amplitude of 10^-22 meters.

Advanced LIGO is sensitive to gravitational waves with frequencies between 10 Hz and 100 Hz.

Einstein's Theory of General Relativity predicted the existence of gravitational waves.

Gravitational waves travel at the speed of light.

The discovery of gravitational waves has confirmed Einstein's Theory of General Relativity, opened up a new window on the universe, and allowed us to study the properties of black holes and neutron stars.

Gravitational wave astronomy has the potential to study the early universe, detect black holes and neutron stars, and measure the properties of dark matter and dark energy.

Gravitational wave astronomy faces challenges such as the sensitivity of gravitational wave detectors, the distance to gravitational wave sources, and the background noise from other sources.

Cosmic Explorer, Einstein Telescope, and LISA are all next-generation gravitational wave detectors that are currently being built.

The expected sensitivity of the next-generation gravitational wave detectors is 10^-24 meters.

The expected frequency range of the next-generation gravitational wave detectors is 1 Hz to 10 Hz.