Wednesday 24 September 2014

thermodynamics - Do all massive bodies emit Hawking or Unruh radiation?


It is known that any accelerated observer is subject to a heat bath due to Unruh radiation. The principle of equivalence suggests that any stationary observer on the surface of a massive body should also experience heat bath. Indeed by substituting surface gravity g into the formula for Unruh radiation one can find the black body temperature for a hypothetical hyper-cool planet:


$$T = \frac{\hbar g}{2\pi c k}$$


which is $3.9766×10^{-20}\,\rm{K}$ for Earth


one even can find the time which it will take for Earth to evaporate: $5.69×10^{50}$ years.



Since the heat in the super-cold Earth cannot come out of nothing one should assume that it will come from decay of particles due to a certain mechanism.


Sometimes I heared an argument that an event horizon is needed for Hawking radiation to exist. But this can be countered by assumption of possibility of decay due to quantum virtual black holes (which inevitably should appear due to uncertainty principle, and the more massive and dense body is the greather concentration of virtual black holes inside it will be, eventually becoming similar to the concentration of bobbles inside a body of boiling water). Or just suggest that any massive body due to uncertainty principle can quantum tunnel into a black hole state so to emit Hawking radiation.


So what is the conclusion here?



  • Can we say that all massive bodies are surrounded by the atmosphere of heated vacuum?


This is a weaker preposition: thermal state of surrounding vacuum does not mean energy transfer if the system is in thermodynamic equilibrium.



  • Any body gradually evaporates, i.e. transfers its energy to the surrounding vacuum until completely vanishes?



This is a stronger preposition and suggests emission of radiation al loss of mass.




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