The general theory of relativity was published by the physics genius more than a century ago, to refine Isaac Newton’s law of universal gravitation.

Providing a unified description of gravity as a geometric
property of space and time, or spacetime, this model is still currently used by
scientists as an explanation of gravitation in modern physics.

Einstein’s theory has important astrophysical implications
as it alludes to the existence of black holes – cosmic phenomenons in which
space and time are distorted in such a way that nothing, not even light, can
escape.

At the center of a black hole, as described by general
relativity, may lie a gravitational singularity, a region where the spacetime
curvature becomes infinite.

But while mathematics says a singularity is possible, nature
apparently proves these do not exist, Discovery Channel’s ‘How the Universe
Works’ exposed.

The series explained: “When a giant dying star collapses,
the mass of the star falls in and keeps falling in crushing down into an
infinitely small point.

“This is called the singularity.”

But physicist Max Tegmark believes the “singularity” is
“just a fancy way of saying ‘we have no idea what is happening here’.”

Astronomer Phil Plait explained why some experts have an
issue with using this theory.

He said: “The way our physics describes black holes when
they form is you’re taking a finite amount of mass and you’re collapsing it
down.

“Its volume should shrink all the way down to zero, but that
means it has infinite density and infinite gravity.

“That doesn’t make sense.”

Theoretical physics Lawrence Krauss then explained why some
are questioning Einstein’s theory.

He added: “If you make a prediction and the answer is
infinite, then it tells you that there is something wrong with your prediction.

“We have never seen infinity in the universe.

“Maybe a black hole with an event horizon described by
general relativity just isn’t the proper description of the physics.”

Quantum mechanics is a fundamental theory in physics that
provides a description of the physical properties of nature at the scale of
atoms and subatomic particles.

Leading astronomer and assistant director for Science
Communication at NASA’s Goddard Space Flight Centre, Michelle Thaller,
explained why it is key to the debate.

She said in 2018: “Have you ever thought about the term
quantum mechanics and what those terms actually mean?

“Everything in the universe is broken up into tiny units and
there is a basic unit of energy, time and space that cannot be divided any
smaller.

“There is a limit to how small those things can be.”

The smallest unit in the universe is what is known as a
Planck Length to physicists.

But if there is a universal limit on the smallest size, then
something infinitely small cannot exist, according to some scientists.

Quantum mechanics expert Sean Carroll explained: “If infinity
doesn’t exist, then singularities don’t exist.

“And if singularities don’t exist, then Einstein’s theory of
General Relativity is not correct.

“The simplest thing we can do is change some equations,
change his theory of gravity.

“Let’s invent what we would call exotic speculative
physics.”

This has led scientists to invent the theory of the Planck
Star.

Passing one in space would look like a black hole, but
without a point of singularity at its core.

The star is just like a black hole, but it obeys the rules
of quantum mechanics.

Physicist Max Tegmark detailed the new theory that has been
proposed.

He said: “Maybe things can be collapsed down to less than
the Planck Length, or maybe you get stuck with a Planck-sized nugget.

“It stabilizes everything, keeps everything finite.

“The reason why there are so many alternatives to black
holes is because you can write down a gazillion different postulated mysterious
new kinds of matter and say ‘this exists, so maybe that explains the data’.

“The problem is there is no evidence that any of that kind
of stuff exists.”