From: mk_thisisit
Physicists face significant challenges in reconciling quantum mechanics with gravity, particularly in developing a unified theory of quantum gravity [00:00:00]. Traditional methods of applying quantum mechanics to gravitational interactions have led to impasses [00:00:00].
The Problem of Unification
The primary goal of quantum gravity is to create a model that integrates both classical and quantum physics [00:09:13]. Currently, Einstein’s equations perfectly describe the universe on a macro scale, including galaxies and black holes, while quantum theory describes elementary particles on a microscopic scale [00:10:04]. There is no single theory that unifies these two descriptions [00:10:27].
Attempts to build such a unified theory using the laws of quantization for gravity, starting from the 1920s and 1930s, have consistently failed [00:10:29]. Calculations repeatedly resulted in infinities, a problem physicists refer to as a “lack of renormalization,” indicating that the approach of building a quantum theory of gravity like other theories is flawed [00:10:45], [00:11:10], [00:11:13]. It seems necessary to return to fundamental principles [00:11:18].
The Standard Approach vs. An Alternative
Most physicists believe that to achieve unification, quantum mechanics should remain unchanged as established by figures like Dirac and Heisenberg, while the theory of gravity should be modified or considered valid only at low energies [00:11:35]. This approach has led to persistent problems [00:11:59].
An alternative idea proposes keeping gravity at the level of Einstein’s equations largely unchanged, and instead, reformulating quantum mechanics to address its paradoxes by incorporating gravitational effects [00:12:06]. This perspective suggests that quantum mechanics itself might need revision, especially concerning its non-locality [00:12:17], [00:12:22].
Twistor Theory
The Twistor theory, nearly 50 years old and developed by Roger Penrose, was initially conceived to provide a mathematical formalism describing both classical and quantum physics in a similar way [00:06:04], [00:06:08]. This theory departs from the fundamental concept of points in space-time, which are considered the building blocks in most other models of the universe [00:04:50], [00:05:04]. Instead, the Twistor theory posits that a light ray is a more elementary object, and “twist space” is the space of all such rays with an additional degree of freedom [00:05:11], [00:05:17], [00:05:23]. A point in space-time emerges only at a higher level [00:05:45].
The Twistor theory aims to reformulate most of classical and quantum physics using the language of these light rays [00:05:32]. While the physics derived from the Twistor theory was initially unclear, it has proven successful in solving numerous problems in pure mathematics, multidimensional geometry, and differential equations [00:06:30].
Recent Breakthroughs
In recent years, there have been breakthroughs in the Twistor theory [00:12:40]:
- Particle Scattering Calculations: String theorists and elementary particle physicists have begun to learn Twistor theory because it allows for calculations of particle interactions, such as photon and gluon collisions or quark-photon scatterings, which were previously impossible or extremely difficult using conventional methods [00:06:52], [00:07:12], [00:07:25], [00:12:52], [00:13:00].
- Reforming Quantum Mechanics: Researchers believe they now understand how to reformulate quantum mechanics using simple Newtonian gravity to explain the collapse (reduction) of the wave function [00:13:20], [00:13:32]. This involves understanding the non-locality inherent in both Twistor theory (at a classical level) and quantum theory [00:14:01], [00:14:43], [00:14:48], [00:14:51].
Non-Locality in Physics
Quantum theory exhibits non-locality: when a particle’s position is measured, its wave function instantaneously changes its state across the entire universe [00:14:03], [00:14:08], [00:14:31], [00:14:39]. The Twistor theory also possesses a non-local property, but at the level of classical physics [00:14:48]. In Twistor theory, a point does not correspond to a localized region but to an infinitely long line or sphere [00:13:45], [00:13:50].
Experimental Verification
Despite its mathematical elegance, the Twistor theory faces a significant hurdle: experimental verification [00:07:41], [00:07:43]. Current experiments can only confirm or refute ideas from the 1960s [00:08:01]. Observing the predictions of quantum gravity theory, which Twistor theory purports to address, is currently impossible under conditions in our galaxy [00:08:15], [00:08:23], [00:08:25]. Without experimental clues, theoretical physics is “walking blindly” [00:08:35].
Cosmological Constant and Quantum Effects
A proposed hypothesis connects the cosmological constant (dark energy), which drives the accelerating expansion of the universe, with quantum effects at the level of elementary particles [02:07:05], [02:11:15], [02:12:21]. The cosmological constant is a very small constant that can only be measured at the edges of the universe, which has a diameter of slightly less than 100 billion light-years [02:21:26], [02:26:00], [02:29:00]. Another very small constant in physics is the Planck constant, which describes how quantum effects become dominant over classical ones at the scale of a hydrogen atom (10-10 meters) [02:01:00], [02:06:00].
The idea suggests that the existence of the cosmological constant at the universe’s edge should modify the Schrödinger equation at the atomic level [00:00:31], [00:34:00], [00:37:00]. This “crazy idea” posits that phenomena at cosmic scales could influence elementary particles [02:41:00], [02:44:00], [02:46:00]. While counter-intuitive, mathematical analysis of the Schrödinger equation with gravitational effects supports this hypothesis, which has been presented within the framework of Twistor theory [02:54:00], [02:58:00].