The universe is rumbling, and we finally learned how to listen

Science · Published 22 October 2026 Swipe more like this →

In short: Imagine a ripple moving across a pond, but instead of water, it's the very fabric of space and time stretching and squeezing. These are gravitational waves—invisible signals from the cosmos' most violent events that were predicted a century ago but only detected in 2015.

For centuries, humanity understood gravity through Isaac Newton's Law of Universal Gravitation. Newton correctly identified that mass exerts a gravitational field, but his theory had a glaring flaw: it couldn't explain how gravity traveled between objects. It implied that if one mass moved, the other would react instantly, suggesting information traveled faster than light. This paradox remained until Albert Einstein published his Theory of General Relativity in 1916. Einstein reimagined gravity not as a mysterious invisible tug, but as a geometric distortion. John Wheeler, a renowned physicist, once remarked that the movement of mass is dictated by space-time's curvature, while the shape of space-time is determined by the presence of mass.

When massive objects—like black holes or neutron stars—accelerate or collide, they create ripples in this curvature. These gravitational waves travel at the speed of light, spreading across the universe like waves in a pond. However, because gravity is the weakest of the four fundamental forces and space-time is incredibly 'stiff,' these ripples are infinitesimally small. By the time they reach Earth from billions of light-years away, the distortions are smaller than the width of a proton. To capture them, scientists built LIGO, a laser interferometer that uses light interference to measure these microscopic changes in space-time.

On 14 September 2015, scientists first directly observed a pair of black holes, both exceeding 30 solar masses, crashing into one another. This discovery confirmed a century of theory and earned a Nobel Prize in 2017. Since then, the LIGO, Virgo, and KAGRA detectors have observed over 300 signals. These waves allow us to 'hear' the universe's most violent secrets—from the energetic collapse of stars to the gravitational echoes of the Big Bang—providing a new way to observe the cosmos that doesn't rely on light alone.

A recent discovery, GW250114, provides a striking comparison to the first detection, GW150914. The new signal is described as an almost carbon copy of the original, produced by two orbiting black holes. This consistency helps scientists refine their theoretical models and test the limits of our understanding of the universe's most extreme environments.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The universe is vibrating, but we are almost too small to feel it
• The universe is vibrating with ripples in the fabric of time
• Space is a choppy sea, and we are sailing through its gravitational ripples
• We live on a choppy sea of space, roiled by distant, violent cosmic collisions.
• How ripples in spacetime allow us to hear the universe
• When your immune system mistakes blood vessels for enemies
• Does history belong to the few or the masses?
• How neural networks use gradient descent to minimize error
• The smaller shark may have outcompeted the ocean's largest predator
• Why your stomach acid is migrating into your lungs
• The deaf composer who couldn't hear his own masterpiece's premiere
• How does Google Maps calculate the fastest route across the country in milliseconds?

More in Science · Latest · A–Z · All topics