General relativity says that white holes are mathematically feasible. But
does that imply that they are genuinely present?
All the focus seems to be on black holes. But what about the white holes,
their mirror-image twins? Are they real? If so, where are they right
now?
We must first look at the far more well-known black holes in order to
comprehend the characteristics of white holes. Black holes are areas of
total gravitational collapse, when gravity has completely surpassed all
other cosmic forces and compacted a collection of matter into an infinitely
small point called a singularity. An event horizon, which is just the limit
around a singularity where the gravity is so intense that nothing, not even
light, can escape, surrounds that singularity. This event horizon is not a
real, solid boundary.
We understand how black holes are created in the cosmos. When a large star
dies, the core is crushed by the star's vast weight, creating a black hole.
Any particles or radiation that go too close to the black hole are drawn to
their ultimate demise beneath the event horizon by the powerful gravity that
surrounds it.
Einstein's theory of general relativity helps us to comprehend how black
holes are created as well as how they interact with their surroundings. It
is important to understand that general relativity disregards the passage of
time in order to arrive at the idea of a white hole. Since the equations are
symmetric with respect to time, they may be solved either by moving ahead or
backward in time.
Therefore, if we reversed a video of a black hole's creation, we would
discover a source of radiation and particles. It would eventually blow up,
leaving a huge star in its wake. Since this is a white hole, general
relativity says that everything is OK as it is.
Black holes are unusual, but white holes would be much stranger.
Singularities and event horizons would still be present at their centers and
edges, respectively. Even then, they would be enormous gravitational
objects. The white glow, however, shone violently because any material that
entered a white hole would quickly be expelled at a speed faster than the
speed of light. Anything outside of a white hole would be unable to enter it
since doing so would require traveling faster than the speed of light past
the event horizon.
But why don't we think that white holes exist in the real world if general
relativity's logic allows them? The explanation is that there are other
theories of the universe besides general relativity. We may learn about the
underlying workings of the cosmos through other fields of physics, such as
our ideas of electromagnetic and thermodynamics.
Entropy, which is, generally speaking, a measure of the disorder in a
system, is a notion found in thermodynamics. According to the second rule of
thermodynamics, the entropy of closed systems can never decrease. To put it
another way, instability always spreads.
Consider the scenario when a piano is thrown into a wood chipper. A large
amount of ground-up trash emerges. The second law of thermodynamics has been
met and the system is now more chaotic. However, you won't get a completely
formed piano out of that same wood chipper if you just put a bunch of random
pieces into it, as that would lessen chaos. (Highly structured systems, like
life, can develop on Earth, but doing so results in the sun becoming more
entropic. No matter how you set up your system, you still won't pull pianos
out of wood chippers.)
Stars don't just come out of massive cosmic explosions, thus we can't just
reverse the process of black hole development and produce a white hole.
Entropy wouldn't increase. White holes may or may not exist, according to
general relativity, but thermodynamics is categorically opposed to the
idea.
A white hole could only have formed if some unusual mechanism had been at
work in the early cosmos and baked the concept of a white hole into the very
structure of space-time. In this scenario, the problem of reducing entropy
would not be a factor in the genesis of white holes; instead, the white hole
would have existed from the beginning of time.
White holes would unfortunately also be extremely unstable. Nothing would
be able to traverse the event horizons, but they would still attract matter
and tug it toward them. Any anything that came close to a white hole, not
even a single photon, would be doomed. The particle would be unable to cross
the event horizon if it came close to it, which would cause the system's
energy to soar. The particle would eventually possess enough energy to cause
the white hole to turn into a black hole, terminating the particle's
existence.
White holes therefore do not seem to be characteristics of the real
universe; rather, they appear to be ghosts haunting general relativity's
equations, amusing and mind-bending as they may be.
