What are gravitational waves?
When massive black holes collide, they create ripples in space-time that physically stretch and squeeze the entire universe.
Known as gravitational waves, these ripples travel at the speed of light and distort the fabric of reality. When they pass through Earth, they cause everything—including you—to tiny, invisible shifts in size. These distortions are so small that scientists need ultra-sensitive lasers to detect them. This breakthrough allows us to 'hear' cosmic events that were once completely invisible.
Nerd Mode
On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) made history by detecting gravitational waves for the first time. This event, known as GW150914, was caused by the collision of two black holes located about 1.3 billion light-years away. One black hole was roughly 29 times the mass of the Sun, while the other was 36 times the Sun's mass.Albert Einstein first predicted these waves in 1916 as part of his General Theory of Relativity. He theorized that massive accelerating objects would disrupt space-time like a stone thrown into a pond. However, he believed the signals would be too weak for humans to ever detect. The ripples from the 2015 collision changed the length of LIGO's 4-kilometer arms by a distance 1,000 times smaller than a proton.LIGO uses L-shaped detectors with laser beams that bounce between mirrors to measure these infinitesimal changes. When a wave passes, one arm stretches while the other shrinks, altering the interference pattern of the light. This discovery earned Rainer Weiss, Kip Thorne, and Barry Barish the Nobel Prize in Physics in 2017. It opened a new era of 'multi-messenger astronomy' where we can study the universe using gravity instead of just light.
Verified Fact
FP-0001959 · Feb 16, 2026