The Universal Death Clock In short, this video displays a 43-part clock in Minecraft which pulses once every 1.3 googol years, and uses that to talk about universal heat death and deep time. It's somewhat chilling to watch, and provides a nice system of units to use for talking about really long times. 3 trillion years is 8 Death Clock Units (DCU's).

Also, figuring out how long energy could be generated in the universe is an interesting mental exercise. I think I figured out how to generate power until 15 DCU's.