FEATURED IMAGE: 10 Dec 2019, 14:00 UTC | How to Shape a Spiral Galaxy 10 December 2019, 8:01:36UTC RSS RSS | About | Contact | Site Map
Home » News & Blogs » Thermal spectrum of analogue black hole puts Hawking radiation in a new light
Bookmark and Share
Physics World Blog

Thermal spectrum of analogue black hole puts Hawking radiation in a new light

29 May 2019, 17:00 UTC
Thermal spectrum of analogue black hole puts Hawking radiation in a new light
(200 words excerpt, click title or image to see full post)

Physicists in Israel have shown that radiation from an analogue black hole has a thermal spectrum. This allows them to assign the “black hole” a temperature, providing indirect experimental evidence for the existence of Hawking radiation.

The popular conception of a black hole is a remorseless cosmic vacuum cleaner that sucks everything in and lets nothing – not even light – escape. When quantum mechanics is added to the mix, however, things get more complicated. In 1974, Stephen Hawking showed theoretically that pairs of photons are created at a black hole’s event horizon – one with positive energy and one with negative energy. The negative energy photon is drawn into the black hole, whereas the positive energy photon is emitted into space. This provides a steady energy flux from the black hole.
The theoretical implications of this are revolutionary, because it suggests that black holes have temperatures. Temperature is defined in statistical mechanics by the average energy in a system that has a large number of degrees of freedom (such as a gas comprising many molecules). In Einstein’s general theory of relativity, however, a black hole is defined purely by its mass, charge and spin. Assigning a black hole a ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day

astronomy_pod