Negative Energy Near Black Hole
I have recently been reading "A Brief History of
Time" in which Hawking talks about how a particle can have a
negative energy when it gets close to a black hole. I am
interested as to how this can happen.
I do not understand this either. We are in good company. Dr.
Richard Feynman, in his Lectures on Physics, says (and I paraphrase)
that one cannot understand Quantum effects in the way that one can
understand normal physical entities. One has to learn the physics
and math and then be careful to verify any conclusions one draws by
experiment. To my knowledge, no-one has been able to perform a
laboratory verification of this particular negative energy.
Here is an interestingly written essay from which I have extracted
one paragraph. You may find the remainder of the essay at
"Near the event horizon of a black hole, virtual
particle-antiparticle pairs are being created all the time. Every
now and then, half of one of those pairs falls into the hole and
cannot get out to recombine with its partner. If the partner outside
the hole has sufficiently high energy, it can escape the
gravitational pull of the hole and thus create the illusion that the
hole is radiating. Entanglement then demands that the partner that
does not escape the black hole has negative energy. Because of
Einstein's relation between mass and energy, E = mc2, the
negative-energy partner effectively has a negative mass, so when it
falls into the hole it causes the mass of the hole to decrease."
Best wishes on your studies. Stay curious! But; be careful what
you believe; particularly where Quantum is concerned.
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Update: June 2012