Between 2002 and 2025, upgrades have increased LIGO's detection range tenfold

LIGO is part of the advanced gravitational wave detector network

Like the Laser Interferometer Gravitational-wave Observatory, Europe's Virgo Gravitational Wave Interferometer and Japan's Kamioka Gravitational Wave Detector reflect laser beams down perpendicular tunnels to detect gravitational waves in the patterns created by the recombined waves. Future observatories are expected to contribute to this network, further improving gravitational wave detections.

LIGO made the first detection of gravitational waves

On February 11, 2016, scientists at the Laser Interferometer Gravitational-Wave Observatory announced the confirmed detection of ripples in spacetime, which were produced from the collision of two black holes 36 and 29 times the mass of the sun. The detection confirmed that gravitational waves travel at the speed of light, as predicted by Albert Einstein in 1915.

Gravitational waves are detected at LIGO by measuring shifts in interfering lasers

The instruments at each site send lasers down equally long arms, which should take the same amount of time to travel between suspended mirrors. Passing gravitational waves alter the shape of space—lengthening one arm and shrinking the other—altering how long it takes the lasers to complete their path, which scientists can measure.

Potential LIGO sites were selected in pairs, approximately 3,000 kilometers apart

The 1,864-mile distance meant gravitational wave signals would be detected no more than 10 milliseconds apart, ruling out many background signals. The sites needed sufficient plots of nearly flat land, proximity to infrastructure (e.g., electricity), and adequate distance from urban areas and geologically active areas to reduce environmental noise.

Since 2017, Virgo has helped LIGO localize astronomical phenomena

The detector near Pisa, Italy, coordinates its experimental runs with those in Hanford, Washington, and Livingston, Louisiana. Scientists can triangulate the locations of celestial events that generate gravitational waves using signal arrival times, just as earthquake locations can be determined from measurements at three seismic stations.

The NSF funded the design and construction of LIGO by MIT and Caltech

The 1992 Cooperative Agreement between the National Science Foundation and both research institutions came twelve years after funding 1.5-meter (4.9-foot) and 40-meter (131-foot) prototypes. With a 1992 budget of $395M, LIGO was once one of the largest NSF-funded projects in history

LIGO boosts its signal sensitivity by manipulating quantum uncertainty

According to the uncertainty principle, the amplitude, or height of a wave's peak, and its phase—the point in time when the first peak is observed—are inversely linked. Based on the frequency of the gravitational waves of interest, scientists sacrifice precision in one optical property to reduce noise in another.

Watch the director's cut of the award-winning documentary about LIGO

Production on the film began in August 2015, shortly before the facilities detected gravitational waves for the first time on September 14. Those interviewed, including future Nobel Laureates Kip Thorne and Barry Barish, provide their accounts of the discovery as events unfold in real time.

The 2017 Nobel Prize in physics was awarded to LIGO's founders

Rainer Weiss, Kip Thorne, and Barry Barish won the award for their contributions to the detector a year after the discovery of gravitational waves was announced. Acknowledging the Nobel statutes limited the prize to no more than three people, Thorne stated, "our marvelous discovery is the work of more than a thousand."

The construction of LIGO needed to compensate for Earth's curvature

Across the 4-kilometer (2.5-mile) arms, the height of Earth's surface falls by almost a meter, preventing the lasers traveling within the arms from meeting the mirror at the end of each. Concrete slabs built beneath the arms help keep them level and provide structural support against seismic vibrations.

The first interferometric gravitational wave detector was invented in 1972

Robert Weiss completed the designs after his students asked about an earlier apparatus that used stretched aluminum cylinders to detect passing gravitational waves. Unfamiliar with general relativity and hoping to keep the course focused on experimental tests rather than mathematics, Reiss later asked his students to consider his device for homework. (Some readers may experience a paywall.)

LIGO can detect changes in spacetime one ten-thousandth the width of a proton

Gravity is the weakest of the fundamental forces in nature, meaning the length of objects only changes by minuscule amounts as gravitational waves ripple through space from distant, albeit massive, cosmic events. LIGO's sensitivity can measure an object shifting its position by one seven-hundred-trillionth of the width of a human hair.

The next generation of gravitational wave detectors may include a triangular design

The Einstein Telescope will use three pairs of underground detectors—each with arms separated by 60 degrees—arranged in an equilateral triangle. The European observatory will work alongside the Cosmic Explorer, a pair of new US detectors, to provide an eightfold increase in sensitivity over LIGO and extend the current detection frequency range.

Help scientists at LIGO train AI to resolve glitches in observational data

Volunteers are provided with visual representations of signal abnormalities at various frequencies and tasked with categorizing them based on reference examples. Progressing through the tool unlocks more difficult images and additional features. Categorized images will be used to train machine learning algorithms for automated future classification.

Between 1993 and 2009, Hubble was serviced for repairs and upgrades 5 times

Across 21 space walks totaling 144 hours, replacement instruments, gyroscopes, solar arrays, batteries, and computer systems have helped extend the Hubble Space Telescope's operational lifetime beyond its planned 15 years.

Take a 360-degree tour of the particle detector at the Large Hadron Collider

The ATLAS experiment integrates concentric layers of sensors to analyze the properties of particles that emerge from the collisions of accelerated matter. More than 3 petabytes of data—equivalent to 600 years of music—can be expected to be collected from this experiment yearly (VR device-compatible).

The James Webb Space Telescope is rewriting what we know about the early universe

Thanks to its advanced infrared sensors and massive mirror, the James Webb Space Telescope can see farther back in cosmic history than Hubble, revealing galaxies formed just 500 million years after the Big Bang.

As of 2025, LUX-ZEPLIN is the world's most sensitive dark matter experiment

The experiment is designed to indirectly detect WIMPs—weakly interacting massive particles and a candidate for what dark matter is made of—by looking for light produced when they collide with xenon atoms. Such collisions would also release electrons, which are then manipulated to produce a secondary light signal that helps rule out background effects.

Through 2025, two-thirds of known exoplanets have been detected via transits

This technique involves observing periodic, consistent dips in a star's brightness caused by an exoplanet passing in front of it. Observing wobbles in a star as it is pulled by an orbiting exoplanet's gravity has become the second most common detection method, followed by microlensing and direct exoplanet observation.

DESI is mapping the universe's expansion over the last 11 billion years

The Dark Energy Spectroscopic Instrument is conducting a five-year redshift survey of over one-third of the sky, measuring the receding motions and locations of about 35 million galaxies and millions of stars using light captured by 5,000 optical fibers.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

Laser technology powers communication, medical and manufacturing tools

Lasers are used when scanning groceries, printing documents or undergoing cosmetic procedures to enhance efficiency, precision and accuracy. Missile defense, targeting and optical communication systems have made using laser technology habitual in the military.

Global life expectancy has more than doubled since the 1850s

The human species experienced a dramatic increase in expected lifespan over the past 150 years. Antibiotics, improved sanitation, and better worldwide food distribution are a few factors contributing to this rapid transformation. Use this interactive resource to explore longevity gains over time and compare these improvements across the globe.

View a timeline of AI deployments from 2017 to 2025

The development of transformer architecture and the release of GPTs across AI labs led to rapid changes in LLM scale and power. Companies like OpenAI, Google, Meta, Microsoft, and Anthropic have invested billions of dollars to develop reliable, versatile models.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

In 2023, there were nearly as many payloads in LOE as trackable pieces of debris

In 2021, the European Space Agency estimated that more than 130 million space debris objects larger than 1 millimeter were in low Earth orbit, though only about 22,000 were being tracked. As of late 2025, the tracked total exceeds 49,000.

Nineteen years after its conclusion, scientists finish what the HGP started

The Human Genome Project mapped 92% of the human genome sequence upon its completion in 2003, leaving unreachable DNA regions unmapped. PacBio HiFi DNA sequencing allowed its completion 19 years later, with the additional mapping of 200 million DNA letters.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

See the evolution of Ebola vaccine and treatment development.

'Silent' fireworks have gained more interest in recent years as a quieter celebratory option.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

Before the current East Wing ballroom project, only two White House renovations in the past 100 years cost more than $10M.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

Domino's Pizza's 30-minute delivery guarantee was responsible for the chain's 1980s surge, but it was discontinued after the company was found liable for delivery driver accidents.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states