February 1, 2023

Soon, it would be possible to hear the buzzing from the bottom of the universe

For those who don’t know, all neutron star mergers or black holesEvery supernova and even individual, rapidly spinning neutron stars can be the source of gravitational waves.

The rapid inflation event of space after the Big Bang, which occurred 13.8 billion years ago, should have created a series of gravitational waves.


In 2015, the first gravitational waves could be detected, the result of a collision of two black holes 1.4 billion years ago and combined ripples that propagated at the same speed of light on Earth. a land.

The recognition was able to clearly confirm the existence of black holes. He stated that the prediction made by the “general theory of relativity” 100 years ago that gravitational waves were correct.

This means that this instrument, the gravitational wave interferometer, that scientists have been working on for years, will revolutionize our understanding of black holes.

In contrast, the Ligo and Virgo 100 interferometers found strong gravitational wave events capable of shaking the signal in the data. In the composition of these interferometers there is a laser that shines in tunnels many kilometers long.

The space-time created by the waves is what affects them, generating interference and giving scientists the opportunity to measure things that generate large signals.

According to research, interferometers use bright lasers in special kilometer-long tunnels.

The laser experiences the expansion and compression of space-time by gravitational waves, which creates an interference pattern.

“The astrophysical background arises from the confusing noise of many weak, independent, and unresolved astrophysical sources,” Scott said.

“The Earth’s gravitational-wave detectors LIGO and Virgo have already detected gravitational waves from dozens of mergers of individual pairs of black holes, but the astrophysical background from mergers of binary stellar-mass black holes is expected to be a major source of background gravitational waves for this current generation of detectors.

“We know that there are a large number of these mergers that cannot be resolved individually, and together they produce random noise in the detectors.”

Scientists revealed they believed it to be about one merger per minute and several per hour.

The random signals are individual and may be too faint to find, but to create consistent background noise, astrophysicists would liken them to the sound of popcorn.

The LIGO and Virgo interferometers are instruments currently undergoing maintenance and setup and will be accompanied by a third observatory, KAGRA in Japan.

This will happen in a new process in March 2023. These are not the only gravitational wave instruments.

In addition, more other instruments will have the ability to investigate other background sources of gravitational waves.

One such instrument, which is still 15 years away, is the Laser Interferometer Space Antenna (LISA), scheduled for launch in 2037.

Image: Caltech/R. Hirt/IPAC

“The background of a gravitational wave doesn’t always look like popcorn,” Scott told ScienceAlert.

“It can also consist of individual imperative signals that overlap in time, producing a noise of disorientation, similar to background conversations at a party.”

An example of confusing noise is the gravitational radiation generated by galaxy clusters of merged binary white dwarfs. This will be a major source of confusing noise for LISA.

In this case, the random signal is so strong that it becomes a foreground, acting as an additional source of noise when trying to detect other weak gravitational wave signals in the same frequency band.

Image: Caltech/R. Hirt/IPAC

Like any stone thrown into water, these massive events send ripples that reverberate through the fabric of “space-time”.

Forced expansions and contractions of Void We can detect them as differences that should be taken as strictly timed signals.

knowledge expansion

Theoretical physicist Susan Scott, of the ARC Center of Excellence for gravitational wave detection, reports that identifying the random background of gravitational radiation can provide important information.

This information relates to populations, sources, and astrophysical processes in the early universe that cannot be accessed anywhere.

For example, electromagnetic radiation does not provide a picture of the universe prior to the time of the last scattering (about 400,000 years after the Big Bang). However, gravitational waves can give us information from the beginning of inflation, only ~10-32 seconds after the Big Bang.

Physics also stated that gravitational waves send us data from the beginning of inflation, only ~10-32 seconds after the Big Bang.

cosmic background radiation

After the universe began and space cooled, the rising foam that was present throughout space froze.

Any kind of radiation that could arise was scattered along with it, causing impediment to travel great distances.

After the Big Bang, the first flash of light appeared in space. In turn, this light was thrown at all angles, but it was very weak, like microwaves.

The asymmetry of this light, called anisotropy, is shaped by small fluctuations in temperature that are the first light.

The discovery was remarkable, as they discovered that the cosmic microwave background is one of the only investigations of the state of the early universe.

The discovery of the gravitational wave background would be a stunning refutation of this victory.

“We hope that detection and analysis of the gravitational wave background will revolutionize our understanding of the universe, in the same groundbreaking way that was through observations of the cosmic microwave background and its anisotropy,” Scott said.

Photo: NAOJ