Quote:
Originally Posted by dipayankar  Good way of putting it across. However since we do see the propagation of EM waves, therefore the detrius from Big Bang does exist in the form of space time, and yes probably EM waves uses these mediums... |
Hi Dipayankar; I believe Jeff was refering to Hawkings Black Hole Formula;
Black hole entropy
Black hole entropy is the
entropy carried by a
black hole.
If black holes carried no entropy, it would be possible to violate the
second law of thermodynamics by throwing mass into the black hole. The only way to satisfy the second law is to admit that the black holes have entropy whose increase more than compensates for the decrease of the entropy carried by the object that was swallowed.
Starting from theorems proved by
Stephen Hawking,
Jacob Bekenstein conjectured that the black hole entropy was proportional to the area of its
event horizon divided by the Planck area. Later, Stephen Hawking showed that black holes emit thermal
Hawking radiation corresponding to a certain temperature (Hawking temperature). Using the
thermodynamic relationship between energy, temperature and entropy, Hawking was able to confirm Bekenstein's conjecture and fix the constant of proportionality at 1/4:
where
k is
Boltzmann's constant, and is the
Planck length. The black hole entropy is proportional to its area
A. The fact that the black hole entropy is also the maximal entropy that can be squeezed within a fixed volume was the main observation that led to the
holographic principle. The subscript BH either stands for "black hole" or "Bekenstein-Hawking".
Although Hawking's calculations gave further thermodynamic evidence for black hole entropy, until 1995 no one was able to make a controlled calculation of black hole entropy based on
statistical mechanics, which associates entropy with a large number of microstates. In fact, so called "
no hair" theorems appeared to suggest that black holes could have only a single microstate. The situation changed in 1995 when
Andrew Strominger and
Cumrun Vafa calculated the right Bekenstein-Hawking entropy of a
supersymmetric black hole in
string theory, using methods based on
D-branes. Their calculation was followed by many similar computations of entropy of large classes of other
extremal and
near-extremal black holes, and the result always agreed with the Bekenstein-Hawking formula.
Best to all, Pat