Trump's Budget Reductions Endanger Nobel Prize-Winning Observatory That Identified Merging Black Holes

Nearly 10 years ago, scientists observed ripples in spacetime created by the collision of two black holes that took place 1.3 billion years ago. The first direct detection of gravitational waves opened up an entirely new way of seeing the universe, allowing us to observe a once invisible side of the cosmos. Today, the ability to track the frequencies produced by the most notable events that shape our surrounding cosmos is at risk due to drastic budget cuts targeting a breakthrough observatory.

In late May, the U.S. administration released a so-called skinny budget that highlighted the proposed funds allocated to NASA and the National Science Foundation in 2026. As part of several monstrosities committed against ongoing science programs, the proposed budget would gut the funding for the Laser Interferometer Gravitational-Wave Observatory (LIGO) by 39.6%. The budget request allocates $29 million instead of $48 million for LIGO, and shuts down one of its two interferometers.

The twin interferometers are situated 1,865 miles apart (3,002 kilometers), with one facility in Washington State and another in Louisiana. The enormous research facilities operate in unison as a single observatory designed to detect gravitational waves, ripples in spacetime that travel at the speed of light.

Unlike other telescopes, LIGO is blind. It detects gravitational waves by measuring incredibly small distortions in spacetime. Using its laser interferometers, it splits a laser beam into two and sends each of them down two long vacuum-sealed arms. The beams travel back and forth through each arm, bouncing between precisely configured mirrors. Each beam monitors the distance between the mirrors and detects tiny changes caused by gravitational waves, which can stretch space in one direction and compress it in the other. The lasers can discern movements between their mirrors with an accuracy of 1/10,000th the width of a proton.

Researchers from Caltech and MIT, with funding and oversight from the National Science Foundation, completed construction of LIGO—one of the world’s most sophisticated scientific observatories—in 1999. Scientists spent years searching for gravitational waves and coming up empty. Finally, on September 14, 2015, the observatory began picking up the signal of its first gravitational waves. The groundbreaking detection provided scientists with a brand new way of observing the universe, allowing them to trace the waves back to events that had long remained hidden in the cosmos. Gravitational waves are caused by the merger of black holes, the collision of neutron stars, and asymmetric supernovae. Some may have also been produced in the early universe, moments after the Big Bang.

Three researchers behind LIGO’s discovery were awarded the Nobel Prize in Physics in 2017 for their role in the detection of gravitational waves: physicists Rainer Weiss, Barry Barish, and Kip Thorne. These ripples in spacetime were first predicted by Albert Einstein in 1916, and could only be confirmed decades later. The first discovery was confirmed because the signal was observed by both LIGO detectors. Since then, the twin LIGO interferometers—sometimes in coordination with the Virgo observatory in Italy—have detected hundreds of additional gravitational wave signals.

Gravitational waves produce a high-pitched chirp when translated to audio, beginning at a low frequency. The two interferometers, and sometimes three, need to work in unison to confirm these faint signals. If one of LIGO’s twin interferometers is shut down, as is suggested by the proposed budget, researchers would have trouble distinguishing between a black hole collision and a nearby seismic tremor, according to Science.

The field of gravitational waves is only just getting started thanks to the twin LIGO detectors. Killing off one of the laser interferometers would hinder our newfound ability to listen in to the soft ripples of spacetime that echo through the cosmos.