Can Space Time Keep Memory?

Thank you to Raycon for supporting PBS. Go to https://www.buyraycon.com/spacetime for up to 30% off your order, plus free shipping! Brought to you by Raycon. There are cosmic events so powerful that they leave permanent marks on the fabric of the universe itself. Imagine two colossal black holes spiraling into each other, yes they send ripples in the fabric of spacetime—gravitational waves that we’ve only recently learned to sense. Ripples pass, leaving the pond … or the universe … unchanged when they’re gone. But ripples aren’t the only type of wave. There’s another type of wave that l...