Planck density in physics is a unit of density in the Planck system of units ; denoted by ρ P. Planck density is defined as:
- 5.1⋅10 96 kg / m³ ,
Where:
- m P - Planck mass ,
- l P - Planck length ,
- Is the reduced Planck constant ,
- G is the gravitational constant
- c is the speed of light in vacuum .
- l P - Planck length ,
This is a very high density, approximately equivalent to 10 23 solar masses compressed in the space of one atomic nucleus. The density of the universe was equal to one unit of Planck density at the end of the Planck era after the Big Bang .
It is the ultimate density of matter [1] . Any attempt to give any matter a higher density value will inevitably result in the birth of a black hole. A Planck mass having Planck density will have a Planck volume, and it will inevitably be turned into a Planck black hole, which after one Planck time will annihilate due to Hawking radiation with the release of Planck energy in the form of light quanta.
However, this does not mean that matter must have Planck density in order to become a black hole; Planck density is only the upper limit. So, many supermassive black holes have a density comparable to that of water or even air, which is explained by the fact that the density is inversely proportional to the volume, i.e. cube of length.
Notes
- ↑ Tomilin K.A. Planck quantities // 100 years of quantum theory. Story. Physics. Philosophy: Proceedings of an international conference. - M .: NIA-Priroda, 2002 .-- S. 11 .