Classical aspects of Hawking radiation verified in analogue gravity experiment

Understand

There is an analogy between the propagation of fields on a curved spacetime and shallow water waves in an open channel flow.

• By placing a streamlined obstacle into an open channel flow we create a region of high velocity over the obstacle that can include wave horizons.
• Long (shallow water) waves propagating upstream towards this region are blocked and converted into short (deep water) waves.
• This is the analogue of the stimulated Hawking emission by a white hole (the time inverse of a black hole).