Is it possible that dark energy is not a constant, but rather is changing over time? Sean Carroll talks to us about how our understanding of dark energy evolved in recent history, and what is still left unknown.For exclusive ask-us-anything episodes, join us for just $3 a month on Patreon: https://patreon.com/whythisuniverse. Our merch is available here: https://www.shalmawegsman.com/why-this-universe Support the show