nce upon a time it was thought
nothing could escape a black hole,
including light. This is, of course,
the origin of their blackness. Then along
came Stephen Hawking, who stunned the
world of physics by showing that the space
around a black hole emits photons of light
and other subatomic particles. Now, more
than four decades after the bombshell of
‘Hawking radiation’, the world-renowned
Cambridge physicist may have done it
again. In a new paper, Hawking claims that
stuff can actually leak out of a black hole.
If he is right, black holes are not what we
thought they were. In fact, in the strictest
sense, they may not even exist.
A common way a black hole forms is
when a massive star runs out of fuel to
burn in its core. With insufficient heat to
oppose the gravity trying to crush the star,
the core shrinks catastrophically down to
a point-like ‘singularity’. The singularity is
cloaked by an ‘event horizon’, an imaginary
spherical surface that marks the point of no
return for in-falling material. The existence
of such a horizon was first deduced in 1916
by Karl Schwarzschild, using Einstein’s
brand new theory of gravity. The first realStephen Hawking has once again shocked the world of physics by casting into doubt how ‘black’ black
holes really areAn artist’s impression of Cygnus X-1, a black hole that leaches material off a neighbouring supergiant star. The material heats up as it nears the black hole, giving off
PHOTO: GETTY, NASA/ESA, NASA/HUBBLE SPACE TELESCOPEpowerful x-raysO
ASTROPHYSICS