A laser interferometer is one of the most precise instruments used for physics and
astronomy. One famous example is a gravitational wave observatory. In addition to that,
nowadays, there are many proposals of the application of the laser interferometric
precise measurement technology for various physical and astronomical purposes, such as
dark matter search, test of the quantum mechanics, measurement of physical constants,
and so on. In this talk, these physical and astronomical topics will be introduced in
association with laser interferometry and my research experience.