KAGRA, a facility that aims to elucidate the mysteries of the universe by detecting space-time distortions "gravitational waves" caused by the merger of black holes, has not been able to capture "gravitational waves" due to insufficient sensitivity. Hmm.

Regarding this "KAGRA", it was found that the government has approved a two-year extension of the plan, which was originally until this year, and observation will be carried out for the first time in three years next year.

What is "KAGRA"

KAGRA is a large-scale observation facility built underground in a mine in Gifu Prefecture at a cost of 16.4 billion yen led by the University of Tokyo. We aim to elucidate the origin of various elements brought into the universe by capturing the distorted "gravitational waves".



It was planned as a large-scale national project, and in 2020, we conducted observations for the first time together with overseas research institutes.

Observed for the first time in three years since May this year

Professor Takaaki Kajita of the Institute for Cosmic Ray Research, the University of Tokyo, who was awarded the Nobel Prize in Physics and is the principal researcher, responded to an interview, saying that due to the influence of the new coronavirus, the equipment adjustment and observation necessary to increase the sensitivity could not be performed sufficiently. After that, he announced that he is expected to make observations for the first time in three years from May this year.



The observation will be conducted jointly with overseas facilities that have a track record of capturing "gravitational waves." The period is planned to be one and a half years. ” is the aim.



The period as a large-scale national project was originally until this fiscal year, but the impact of the new corona was considered, and an extension of two years was approved.



Professor Kajita said, "Now that we have identified the factors that limited the sensitivity, we are aiming for a level of sensitivity that would allow us to finally capture 'gravitational waves' in our next observation. I want to get everyone's understanding," he said.

The history of gravitational wave observation is

Gravitational waves were predicted by Einstein in 1916.



About 100 years later, in 2015, the American observation facility `` LIGO '' succeeded in directly capturing it, confirming the existence of `` gravitational waves '', and three members of the research team won the Nobel Prize in Physics.



There is also an observation facility "Virgo" in Europe, and it has already detected "gravitational waves".

What is the significance of observing in Japan?

Professor Takaaki Kajita of the University of Tokyo, who is the principal investigator of the construction and observation of KAGRA in Japan while overseas is leading the way, says, "With only one gravitational wave, it is difficult to know which direction the signal came from. If you want to determine it accurately, you need three or more devices that are as far apart as possible.It is important to have it in Japan in the Far East in addition to the United States and Europe."



In addition, the sapphire mirror, which is the heart of "KAGRA", aims to improve sensitivity by using a new technology that cools it to minus 253 degrees, and it is also meaningful to contribute to the development of next-generation equipment.



Since the national government has decided to extend the project, it is expected that KAGRA will receive a budget until FY2024, but in order to continue the plan after that, it will be necessary to receive an evaluation from the national working group in two years, which is the final year of the plan. , it will be a critical moment to see if the expected results can be achieved.