Condensed matter lessons about the origin of time

Understand

It is widely hoped that quantum gravity will shed light on the question of the origin of time in physics.

• The currently dominant approaches to a candidate quantum theory of gravity have naturally evolved from general relativity, on the one hand, and from particle physics, on the other hand.
• A third important branch of 20th century `fundamental' physics, condensed-matter physics, also offers an interesting perspective on quantum gravity, and thereby on the problem of time.
• The bottomline might sound disappointing: to understand the origin of time, much more experimental input is needed than what is available today.