Do White Holes Exists on Space. How they are created?
A new study explains why astronomers have never seen one of these weird
objects.
Black
holes are among the most exotic of astrophysical objects and consequently one
of the most deeply studied. White holes, on the other hand, are largely ignored
by astrophysicists. So it’s time, therefore, to change the balance with some
deeper theoretical development of the properties of these objects, says Stephen
Hsu at the University of Oregon in Eugene.
White
holes are closely linked with black holes, being their time-reversed
equivalent. The thinking is that whatever black holes can do, white holes also
do in reverse.
That
leads to an odd conclusion. In the 1970s, Stephen Hawking showed that in
certain circumstances black and white holes become identical. When they are in
thermal equilibrium with their surroundings, he said, they ought to absorb and
emit the same amount of radiation and therefore be indistinguishable.
But
what of black and white holes in other circumstances? Nobody has been quite
sure, until now. Hsu tackles this question by examining how white holes would
behave in isolation, surrounded by empty vacuum.
He
points out that the time reversal symmetry of black and white holes only works
when they are in equilibrium with their surroundings. But when they are in
isolation, they are not in equilibrium. In this case, a black hole emits radiation
in the form of hawking radiation. However, the white hole does not behave in a
time reversed fashion; it does not absorb any radiation because it is isolated
in space.
So the
black hole gradually evaporates as it emits Hawking radiation, but the white
hole cannot perform the time reversed operation which would be to absorb
radiation because there is none to absorb. Instead, it is forced to explode,
releasing large amounts of thermal energy, concludes Hsu. “Isolated white holes
explode into quasithermal radiation,” he says.
He also
says that while it is possible to construct an eternal black hole that lasts
forever (as long as it isn’t disturbed), a similar state does not appear to be
possible to white holes.
Which
may mean that stable white holes cannot exist in empty space. A conclusion that
appears to be backed up by the fact that a white hole or anything like has
never been spotted in space.
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