By Jeannie Chung
Duke Physics hosted Ronald Walsworth of Harvard last week to hear about his use of something called an “astrocomb,” a tool that could help astronomers make more precise measurements of distant astronomical objects, including planets like Earth.
An astrocomb uses a a laser and an atomic clock to improve the calibrations on the instruments astronomers use to measure tiny shifts in the spectra of a star. The shifts can indicate if a star has a planet.
Currently, astrophysicists cannot measure the minute shifts of planets the size of Earth, or other cosmological phenomena, with these spectrographs. The shifts are too tiny. But this laser calibration astrocomb could be seen as the sunrise on a bright future.
Walsworth said that in five years, discovery and characterization of Earth-like planets would be possible, and that in 10-20 years, direct measurement of cosmological dynamics — the change and characteristics of celestial bodies – may be possible. He said the laser frequency comb will allow us to see a live feed of the expansion of the universe, instead of looking at hindsight and making inferences from snapshots of a past universe.