A cartoon illustrates results from the MICROSCOPE satellite mission, which has measured with astronomical sensitivity the falling rate of different objects under gravity.
Observing gravitational-wave memory may help physicists test general relativity predictions about large-scale symmetries in the fabric of spacetime. Read More »
Some ultralight black holes that formed soon after the big bang might have been exotic objects with a net “color charge” that left potentially observable signatures. Read More »
Spacetime wrinkles known as cosmic strings, which might have formed in the early Universe, could be a dominant source of gravitational waves at ultrahigh frequencies, according to new calculations. Read More »