Quantum Gravity: A physicist explains how black holes could lead to a theory of everything.

String theory is considered the best candidate for a theory of everything, which aims to unify the subatomic realm described by quantum physics and the vast universe explained by Einstein's general theory of relativity. Currently, these two theories do not align, and the conflict arises from gravity. In an effort to integrate gravity, which is weak in the subatomic world, string theory posits that the universe consists of tiny one-dimensional strings, whose vibrations produce the particles we observe. The challenge is that many predictions of string theory are difficult to test. However, theoretical physicist Marika Taylor from the University of Birmingham in the UK believes that through string theory and observations of black holes, a theory of quantum gravity or a theory of everything can be developed, as reported by Live Science.

According to Taylor, string theory unifies all the fundamental forces of the universe and allows for a description of the force of gravity. Yet, there are numerous observations and physical phenomena that we cannot adequately explain using existing theories, particularly quantum mechanics and Einstein's theory of relativity. Therefore, it is essential to create a theory of everything that reconciles the conflicting fundamental theories of physics.

String theory examines the dynamics of interactions not as point particles but as one-dimensional extended quantum strings. It combines ideas from quantum mechanics and Einstein's theory of relativity, leading physicists to believe that a theory of quantum gravity can be formulated based on it.

The central tenet of string theory, which actually integrates several different theories, is that each particle is fundamentally a tiny string, and the vibrations of these strings correspond to various elementary particles.

"We tend to think of the forces of gravity and the physics of elementary particles as conceptually distinct. Now we see that they are actually connected," says Taylor.

The scientist believes that the validity of string theory's assumptions can be tested by studying black holes and their mergers, during which gravitational waves are produced.

"As we begin to gather more data on black hole mergers, it becomes a good way to detect unknown new physics," Taylor states.

According to the scientist, a black hole behaves like a very efficient quantum computer. When something falls into a black hole, the information about that object is preserved, similar to data stored on a quantum computer's hard drive. The evaporation of a black hole via Hawking radiation can be likened to executing a quantum computational process.

"One should think of the surface of a black hole as the disks of a quantum computer. It's hard for people to visualize, but information is stored on the surface of the black hole," explains Taylor.

The scientist asserts that string theory is a collection of fundamental physics ideas. It is very unlikely that there will be irrefutable evidence proving it wrong. This theory may lead to the development of a theory of quantum gravity or a theory of everything.