a celebrated astrophysicist is intently
studying the skies in search of his
elusive quarry combing through the
thousands of images coming to him from
the state-of-the-art international event
horizon telescope finally after months
and months of searching he thinks he may
have found what he's been looking for
all this time in the images he sees the
tell-tale signs of a mysterious
phenomenon called a black hole but as he
scrutinizes the images captured by the
powerful telescope something doesn't
seem quite right there right in front of
his very eyes the black hole appears to
be burping the scientist knows this
should be impossible nothing can escape
from a black hole not even light that's
why they're so hard to find but here's
photographic evidence of matter coming
out of a black hole could it be that
this is not a black hole at all but the
black hole's neglected twin a white hole
could this be his chance to once and for
all answer the questions that might have
been nagging him through his whole
career what is a white hole how do they
form how do they work and do they even
exist at all in 1915 einstein's field
equations turned the world of physics on
its head his theory of relativity
described the force of gravity and
shattered the prevailing paradigm of the
nature of reality rather than being
rigid space and time can actually bend
and fold along with the mass of stars
and planets within a year scientists
calculated how spacetime curves around a
single ball of mass the seeds of what
today is called the singularity
physicists were able to describe how a
spherical mass shrunken down to an
infinitely dense point could wrap space
around it so tightly that a region of
space is effectively pinched off from
the rest of the universe creating a no
man's land beyond the event horizon
where the laws of physics no longer
apply and the link between cause and
effect is shattered a black hole is an
incredibly dense area of space where all
matter has been squeezed into an
impossibly tiny space called the
singularity this creates such an intense
gravitational pull that nothing not even
light can escape from the black hole's
clutches a tiny black hole might be the
size of a single atom but have a mass
equal to a large mountain stellar black
holes formed when a dying star collapses
in on itself in a supernova can have a
mass of up to 20 times greater than our
sun the largest black holes are called
supermassive black holes and they can be
found at the center of every galaxy in
our universe the supermassive black hole
at the center of our milky way galaxy
named sagittarius a star has as much
mass as four million of our suns all
condensed into a tiny ball only as big
as a few million earths a black hole's
event horizon is what we would consider
the surface of the black hole although
it's not a surface in the true sense of
the word it's not a membrane or a
barrier but rather the threshold beyond
which there is no going back the event
horizon is the point of no return
nothing that crosses the event horizon
can ever come back even light cannot
escape the black hole once it's past the
event horizon once something or someone
has crossed the event horizon they will
begin the inevitable process of falling
toward the black hole singularity
eventually dissolving into the
singularity itself we can only guess
what happens after that physicists have
been studying black holes for decades
and are only just beginning to
understand them only recently have they
turned their attention to the black
hole's neglected twin the white hole
from afar the white hole would appear
identical to its better known cousin a
black hole like a black hole a white
hole might be big or small might spin or
remain stationary and might be
electrically charged a white hole would
also be surrounded by a ring of dust and
a cloud of gas and debris would gather
at its event horizon the key difference
between a black hole and a white hole is
that white holes burp yes burp unlike a
black hole from which nothing can escape
matter actually can cross the event
horizon and come out of a white hole
it's only in these moments when objects
emerge from the white hole that
scientists can definitively say that
what they're looking at is a white hole
and not a black hole if a black hole's
event horizon is the point of no return
then the event horizon of a white hole
could be described as the point of no
admission nothing can ever cross the
event horizon of a white hole and reach
the interior in a black hole objects in
the space outside can cross the event
horizon and affect the interior of the
black hole but matter inside the black
hole can never again interact with space
outside in a white hole the reverse
holds true objects from inside the white
hole can cross the event horizon and
interact with objects in the space
outside of it but nothing on the outside
can ever enter the white hole or affect
the inside this is because a white hole
is a black hole's time reversal
according to physicists a black hole
singularity exists in the future whereas
a white hole singularity exists in the
past since the interior of a white hole
is cut off from the universe's past via
its event horizon no outside object or
event will ever affect the inside of a
white hole james bardeen a black hole
pioneer and professor emeritus at the
university of washington explains the
magnitude of this difference somehow
it's more disturbing to have a
singularity in the past that can affect
everything in the outside world he said
scientists had theorized about the
existence of black holes for hundreds of
years before einstein's theory of
relativity paved the way for physicists
to prove their existence theoretically
at least since no light escapes from a
black hole they are invisible to the
naked eye until very recently the only
way scientists have been able to find
evidence of black holes has been to look
for signs of their impact on the
surrounding universe stars gases and
other space objects behave differently
near a black hole than they do elsewhere
in the universe as the black hole's
intense gravity pulls on them using
telescopes equipped with special tools
scientists can pick up a type of
high-energy light emitted by objects
that interact with the black hole's
gravitational forces and reverberation
mapping can measure the radiation given
off by the ring of debris that surrounds
the black hole helping physicists
pinpoint the location of a black hole
even if they can't see the black hole
itself finally in 2019 scientists made a
stunning breakthrough in the study of
black holes when the international event
horizon telescope captured the world's
first image of a black hole technically
what they captured was the black hole
shadow since the absence of light
reflecting from a black hole makes the
black hole itself impossible to see but
nevertheless this was the world's first
solid photographic proof of the
existence of black holes if black holes
have finally been proven to be real does
that mean that white holes are a proven
fact of the universe too well not
exactly while einstein's theory of
general relativity does describe the
existence of both black and white holes
it doesn't explain how a white hole
might actually form in space a black
hole forms when a dying star implodes in
a supernova collapsing all the star's
matter into an impossibly tiny area
cordoned off from the rest of space the
reverse doesn't quite make sense the
idea of a white hole exploding into a
fully functioning star would be a bit
like unscrambling an egg it just
wouldn't work this idea also violates
the statistical law that entropy must
increase over time furthermore if a
white hole did form the matter it
releases when it burps would collide
with the matter in orbit around the
white hole these collisions would cause
the entire system to collapse into a
black hole perhaps if white holes do
exist they don't remain as a white hole
for long hal haggard a theoretical
physicist at bard college in new york
has said that a long-lived white hole i
think is very unlikely other scientists
have different theories about white
holes that help explain some of the
inconsistencies stephen hawking
discovered back in the 70s that black
holes leak energy which led him to
wonder how do black holes die and what
happens to everything that's been
trapped inside of a black hole when it
dies the theory of general relativity
holds that nothing can get out of a
black hole but quantum mechanics
prevents any information inside a black
hole from being deleted so where does it
go some have taken this to mean that a
white hole is actually the result of a
death of a black hole as a black hole
dies it may become so small as small as
one microgram in size about the mass of
a human hair that it would no longer
obey the laws of physics as we know them
this infinitesimally small object would
be so small that it would defy gravity
but inside it would hide a cavernous
interior full of everything it swallowed
in its previous life as a black hole its
small size and gravity-defying behavior
could allow it to remain stable enough
to eventually spit out information and
matter that had been swallowed by the
black hole becoming a burping white hole
instead if this theory holds true the
universe could one day come to be
dominated by white holes after all of
the stars in the universe had been burnt
out and imploded into black holes and
then after all those black holes
themselves have all died the universe
might be nothing but a set of burping
white holes thankfully this could only
happen in a universe countless trillions
of times older than our universe is
currently so it's not a scenario we need
to worry about anytime soon there are
many more questions than answers when it
comes to white holes and that leaves
room for plenty of imaginative theories
about what a white hole actually is some
scientists actually think that we're
currently living inside the ultimate
white hole to these black hole
physicists the behavior of a white hole
looks suspiciously similar to a little
thing we call the big bang the explosion
of matter and energy resulting from the
big bang that created our universe is
remarkably similar to the way theorists
suspect that white holes release matter
the geometry is very similar in the two
cases how haggard the physicist from
bard college has said even to the point
of being mathematically identical at
times this theory has attracted plenty
of criticism but haggard intends to
follow this rabbit hole to the very end
saying why wouldn't you investigate
whether white holes have interesting
consequences it may be that these
consequences aren't what you'd expect
but it would be foolhardy to ignore them
we may still be a long way off from
being able to look into a telescope and
watch with our own eyes as a white hole
burps out matter into the surrounding
universe although we've only just gotten
our first glimpse of a black hole and
though we have yet to even lay eyes on a
white hole scientists will undoubtedly
discover more about these mysterious
phenomena in the future if the past has
taught us anything it's that just
because we can't see something doesn't
mean it's not there only time will tell
which theory about white holes were
proved to be correct or if we had it
completely all wrong one day we may get
an answer to the question what is a
white hole but until then it remains yet
another of the countless says yet
unsolved mysteries of our vast and
unknowable universe if you thought this
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