LIGO boosts its signal sensitivity by manipulating quantum uncertainty

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.

In LIGO's interferometers, light cancels itself out in the absence of gravitational waves

The devices are designed so that a laser is split into two beams that later recombine, canceling each other out and producing no signal. Changes in the lengths of the arms due to passing gravitational waves result in an interference pattern whose properties reveal features of the objects that created the waves.

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.

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

After the construction of Initial LIGO was completed in 1999, no gravitational waves were detected during operations between 2002 and 2010. Instrument redesigns and significant technological improvements brought about Advanced LIGO, which began observations in 2015. Continued upgrades between continuous laser runs have improved detection sensitivity and stability.

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.

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.

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 uncertainty principle prevents measuring position and momentum at the same time

In quantum physics, objects behave like particles and waves, meaning they can’t simultaneously have a definite position and speed. This isn’t due to flawed measurement, since combining waves to localize a particle always adds uncertainty to momentum, and vice versa.

How neutron stars serve as laboratories for testing Einstein's theory of gravity

Data from a 16-year study of an orbiting pair of spinning neutron stars showed that measurements of gravitational wave energy and the bending of light around the system were consistent with predictions made by general relativity to an accuracy of at least 99.99% across seven tests. (Some readers may experience a paywall.)

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.

Lasers, semiconductors, medical imaging, and atomic clocks rely on quantum mechanics

Semiconductors, crucial in electronics, operate based on quantum superposition. Lasers use stimulated emission, a quantum process, and MRI machines leverage the quantum spin of hydrogen atoms for imaging. Atomic clocks measure time with unprecedented precision using quantum transitions.

The extreme precision of atomic clocks highlights gravitational time dilation

Scientists at the National Institute of Standards and Technology have constructed clocks made out of stacked strontium atoms, which show differences in the passage of time across just a millimeter of height consistent with predictions from general relativity, where atoms closer to Earth's center tick off time more slowly.

Try to catch the 'sound' of black holes in gravitational wave detector data

In "Black Hole Hunter," users try to listen for gravitational wave signals from black holes in four sample data files that include substantial background noise. With each level, learn more about black holes while being faced with ever-quieter signals.

LIGO confirmed Stephen Hawking's theorem about black hole surface areas

Black holes are known to grow with increased mass but lose energy during mergers through the emission of gravitational waves. Amid these competing factors, the black hole area theorem—confirmed in 2021 using LIGO data—states that a merged black hole's size cannot be smaller than the combined surface area of its progenitors.

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.

Light waves can interfere and cancel each other out

When light waves travel past one another, their peaks and valleys combine, just as overlapping ripples in water can combine to form a larger ripple. When the peak of a light wave meets the valley of another of the same wavelength and brightness, the waves combine to produce no light.

Some founders of quantum mechanics thought consciousness could influence phenomena

Since quantum systems exist as a superposition of states before producing a definitive outcome, some quantum pioneers wondered if the act of conscious observation was what collapsed the wave function of possibilities into one state.

String theory replaces black hole singularities with fuzzballs of tangled strings

Black holes contain singularities where information about the material that fell in is lost, violating quantum mechanics. Instead, modeled as a bundle of strings, information is stored and slowly released as the black hole evaporates.

Quantum mechanics-based technology may explain the Fermi paradox

It describes the discrepancy between the high likelihood of life beyond Earth given the vastness of the universe and the lack of evidence for such life, since extraterrestrial civilizations have not communicated with us. However, quantum communication—a more information-dense and effective method than classical means—requires massive receivers and very narrow signals, which would easily miss Earth, making a lack of signals expected.

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

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

Science is rarely a linear progression of understanding

Particularly at the frontiers, investigations conducted based on established knowledge can provide unexpected results. This opens the door to revising existing models, inspiring new lines of research, and ultimately leading to better future comprehension. For instance, experiments on the speed of light and the expansion of the universe yielded then-confusing data that led to revolutionary insights.

Researchers identify a hidden instability pattern in simple ocean wave models

Stokes waves—a solution to the mathematics of water waves—were once assumed to be stable. Italian mathematicians have proven disturbances cause these waves to collapse and such collapses follow an infinite repeating pattern. To complete the proof, the team offered a $100 donation to solicit online help.

Google chose Santa Barbara to host its Quantum AI computing project

The project seeks to reduce errors within its quantum computer and integrate 1 million physical qubits (or quantum bits) into the room-sized computer. This powerful device will attempt to solve complex problems in medicine, computing, and more.

Hubble's first light test produced an underwhelming photograph

This test represents the first time light travels entirely through an observatory's optical system and reaches its detectors, producing an image. Although the telescope's warped mirror was not discovered and announced until a month after first light, the issue was not responsible for the simplicity of the first light image.

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.

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

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Watch how algorithms can be designed to train themselves and self-improve without human input, to the point where the optimized code is too complex for programmers to understand.

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

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

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.

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.

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

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

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

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

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

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

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.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Walt Disney's early film 'Alice's Wonderland' was a groundbreaking innovation in the silent film era

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.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.