How can scientists detect gravitational waves?

Introduction

Gravitational waves are phenomena that were once thought to be merely a fantasy of Einstein, but after their discovery, two methods have emerged for detecting them. Scientists are now working to find new ways to discover gravitational waves. The study of gravitational waves is one of the most advanced fields in fundamental physics.

Going to Deep Space

The “Laser Interferometer Space Antenna” or LISA mission is an amazing endeavor. LISA consists of three spacecraft located in a triangle with sides measuring 2.5 million kilometers, sending lasers between them as they orbit the sun. This mission is expected to be the best hope for scientists to discover more gravitational waves.

Going to the Moon

Thanks to NASA’s Artemis program, which aims to return to the Moon, scientists are currently seeking inspiration from our earthly neighbor. The “Lunar Laser Interferometer Observatory” or LILA is one of the proposals aimed at placing a gravitational wave detector on the Moon’s surface. It is expected to be easier to detect gravitational waves on the Moon due to the absence of vibrations caused by human activity and other factors. This device could detect gravitational waves with wavelengths reaching tens or hundreds of thousands of kilometers.

Going to the Atomic Level

Observatories such as LISA and LIGO measure the stretching and squeezing of gravitational waves by observing how the laser beam interferes after passing through the long arms of the observatories. However, a proposed technique relies on monitoring the distance between clouds of atoms instead of the length of the observatories’ arms. Thanks to the quantum properties of atoms, scientists can use this technique to detect gravitational waves with wavelengths that fall between those of LIGO and LISA.

Going to the Past

Other efforts aim to identify gravitational waves from the earliest moments of the universe. It is believed that these waves may have been produced during the inflationary period after the Big Bang when the universe expanded in size. These waves are expected to have longer wavelengths than ever before – up to 10²¹ kilometers or 1 sextillion kilometers. However, the search for these waves faces significant challenges and they have not yet been found.

Searching for the Unknown

For most types of gravitational waves that scientists are searching for, they know some information about their sources. Known objects such as black holes or neutron stars can produce these waves. However, scientists wish to verify whether short-wavelength gravitational waves exist. These waves might result from violent events in the early history of the universe, such as phase transitions or primordial black holes that cannot be formed by standard means. These gravitational waves are extremely mysterious, and detection techniques are still under investigation.

Exploring the Unknown

Gravitational waves are an extremely challenging discovery, but they are worth the effort made to find them. Gravitational waves have already helped confirm Einstein’s general theory of relativity, discover a new class of moderately massive black holes, and unveil the fireworks that occur when two super-dense objects known as neutron stars collide. There is still much to discover in the field of gravitational wave detection, and it is sure to be exciting.
Source: https://www.sciencenews.org/article/gravitational-waves-detection-lasers-atoms