Three years ago, a little-known telescope made waves with an incredible discovery, or rather, detected some waves. In 2015, the LIGO telescope became the first to detect gravitational waves, first hypothesized by Einstein over a hundred years ago. Now, after nearly a dozen gravitational wave detections over the past few years, the telescope is getting a significant upgrade that will let it peer even deeper into the universe.
LIGO is technically a telescope, but it doesn’t look like any telescope you’ve ever seen. Instead of a giant mirror or radio dish, LIGO features two long tunnels that run for miles at right angles to each other. A laser is sent down each tunnel, and at the end of each a giant mirror reflects the laser pulse back to the start.
This might seem like a weird look for a telescope, but it’s essential for detecting gravitational waves. Gravitational waves are essentially ripples in the fabric of space-time, caused when stuff with mass moves around. These gravitational waves are indescribably tiny, but for very large objects like black holes the waves are just barely big enough to be detectable.
When a gravitational wave passes by the LIGO observatory, it causes space itself to contract and expand ever so slightly. Under the influence of a gravitational wave, one of LIGO’s two tunnels gets almost imperceptibly shorter, while the other one lengthens by the same amount. By using the most precise equipment ever manufactured, including the largest vacuum chamber and most polished mirrors in the world, LIGO astronomers are capable of picking up some of these minuscule vibrations.
Now, thanks to a $34 million investment from the U.S., the U.K., and Australia, LIGO will be even more sensitive. The money will go toward upgrading the equipment, including adapting techniques from quantum mechanics to improve the lasers and taking advantage of new mirror coating technologies. With these upgrades LIGO will be able to detect gravitational waves that are much fainter.
This means LIGO will be able to pick up waves from less massive objects, including smaller black holes and neutron stars as well as nearby supernovas and star collisions. But most importantly, LIGO will be able to pick up gravitational waves from much farther away. The upgrade will be able to extend LIGO’s range by almost seven times, which should make picking up a gravitational wave event an almost daily occurrence.
The upgrade is scheduled to be complete by 2024. In the meantime, LIGO is expected to continue in its current configuration starting this spring.
Origiannly posted on Popular Mechanics