Expert: Jayendra Upadhye - 7/31/2004

Question
I have a set of question which are not of high intellect primarily because i never care to understand these things in school . Please excuse me if you find them stupid.

1. I read in a book that when it comes to Black holes Newton's theory does not hold good. According to his theory the black hole should not collapse further. I could not understand the explaination. Please help me out.

2. The book also mentioned that Einstein's theory said that energy and mass can be converted into each other. I know that E=mc^2 (for an object at rest), which i understand that energy and mass are related but is it true that it they can be converted into each other.

3. In E=mc^2 what kind of energy is it?

Answer
Hi Achint!
Not being interested in school does not qualify one to be called Dull or stupid!
If that were true, I would have qualified for both long ago!
So take heart!
1 - I do not know in what context the book said that, but Newton's theory has some basic flaws and these appear magnified in the presence of strong gravitational fields.
That was why Newton's theory failed to explain properly, why the perihelion of mercury's orbit (rather the major axis of its orbit, undergoes a "precession". ie the axis points in a new direction with each pass of mercury near the sun. The flaws are nicely enumerated at the site:
http://theory.uwinnipeg.ca/users/gabor/black_holes/slide3.html

2 - Yes! It has been checked out in high energy partcle accelerators. The Cern Laboratory actually came up with about 10 hydrogen anti-matter atoms that underwent annihilation by conversion to pure energy!
The sun is powered by fusion. The creation of the helium nucleus from hydrogen nucleii actually entails a "mass-defect". Its mass is slightly lower than than what went into making it. The equivalent energy as predicted by E = M*C*C then appears as high energy Gamma radiation and a neutrino. The neutrino streams out effortlessly through the dense solar core. however the gamma ray suffers multiple absorptuions and re-emissions and loss of energy.(That is the energy that keeps the sun from collapsing due to its gravity, and which heats up the matter to billion degrees at the core and 6000 deg.c. at the surface. A sudden loss of this energy , as happens in supernovas, is the trigger that starts the supernova. without which you and me and most of the higher elements of the periodic table would not have existed!) :)
Eventually after a million years or so, it emerges as a low energy photon (ultra violet thru visible thru infra red thru radio) covering the low energy end of the spectrum.

3 - Radiant energy. Generally Gamma radiation.
The suns energy is derived by the Neutron Gamma re-action.
the mass-defect matches the radiatied energy.
Jayen