The multiverse theory has its roots in ancient philosophy and religion, but it was first proposed as a scientific theory in the early 20th century by astronomers such as Fred Hoyle and George Lemaitre. In recent years, the multiverse theory has gained traction among physicists as method to explain the observed properties of our universe, such as the value of the cosmological constant.
The multiverse theory is the idea that there are an infinite number of universes, each with its own set of physical laws. According to this theory, our universe is just one of an infinite number of universes, each of these universes has its own set of physical laws. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them. The different universes within the multiverse are called “parallel universes”, “other universes”, “alternate universes”, or “many worlds”.
Scientists argue that the multiverse is a necessary consequence of certain physical laws, while others contend that there is no scientific evidence to support the existence of multiple universes.
There are a variety of multiverse theories currently being debated by physicists, these include quantum theory, string theory, inflationary cosmology, and M-theory.
Quantum theory is the branch of physics that studies the behaviour of matter and energy in the presence of an observer. It is the foundation of modern physics and the theory of the wave-particle duality.
Quantum theory has its roots in the work of Max Planck, who proposed that energy is emitted and absorbed in discrete packets, or quanta. In the early 1900s, Albert Einstein used quantum theory to explain the photoelectric effect. Quantum theory was further developed by Niels Bohr, who proposed that electrons orbit the nucleus of an atom in certain discrete energy levels. Quantum theory has since been applied to a wide range of physical phenomena, including nuclear reactions, superconductivity, and lasers.
Quantum mechanics supports the multiverse theory. According to quantum mechanics, particles can be in multiple states simultaneously. This means that there could be an infinite number of universes, each with different versions of you and me!
The Duel Slit Experiment
In quantum theory, the dual slit experiment is a thought experiment that demonstrates the principle of wave–particle duality. It shows that a wave-like behaviour and a particle-like behaviour can coexist. The experiment is performed by firing particles (such as electrons) at a screen with two slits. The waves from each slit interfere with each other, producing a pattern of light and dark bands on the screen. However, if the particles are fired one at a time, they will produce a different pattern on the screen—a series of dots corresponding to where each particle hits. This second pattern is what would be expected if the particles were behaving like bullets, rather than waves. The dual slit experiment shows that particles can exhibit both wave-like and particle-like behaviour, depending on how they are observed.
String theory is a branch of physics that attempts to explain the fundamental nature of matter and energy. According to string theory, all particles are fundamentally vibrating strings. Different vibrations correspond to different particles. Some researchers believe that string theory implies the existence of multiple universes, often referred to as the multiverse. This is because string theory allows for the possibility of multiple universe solutions, each with its own unique set of physical laws.
In the 1960s, US physicists John Schwarz and Joel Scherk independently came-up with an early form of string theory. However, it was not until the 1970s that string theory began to be developed into a full-fledged physical theory. In the 1980s and 1990s, string theory underwent a major revival, culminating in the discovery of a new class of solutions called “string vacua.” These solutions led to the development of the currently favoured version of string theory, known as M-theory.
Most string theories require ten or eleven dimensions of space-time in order to be consistent with experimental observations. In other words, string theory predicts that there must be several additional dimensions that are “curled up” too small for us to currently detect or observe. Some string theories require as many as twenty-six dimensions, but most versions of the theory favour 10 or 11 dimensions. The extra dimensions predicted by string theory are very different from the three spatial dimensions that we experience in our everyday lives. In string theory, the extra dimensions are not just empty space – they are an active, integral part of the theory and play a crucial role in its predictions.
M-theory is a multiverse theory that suggests our universe is just one among an infinite number of others. The “M” stands for “mother,” as this multiverse is purported to be the ultimate origin of all other universes.
M-theory is an extension of string theory that incorporates eleven dimensions of space-time, rather than the ten dimensions predicted by earlier string theory hypothesis. These extra dimensions are thought to be curled up and hidden from view, except at very small scales.
According to Edward Witten, M should stand for “magic”, “mystery”, or “membrane” according to taste, and the true meaning of the title should be decided when a more fundamental formulation of the theory is known.
Investigations of the mathematical structure of M-theory have spawned important theoretical results in physics and mathematics. “More speculatively, M-theory may provide a framework for developing a unified theory of all of the fundamental forces of nature. Attempts to connect M-theory to experiment typically focus on compactifying its extra dimensions to construct candidate models of the four-dimensional world, although so far none has been verified to give rise to physics as observed in high-energy physics experiments.” (Wikipedia)
Inflationary cosmology is another theory that suggests the existence of multiple universes. This theory states that our universe is just one bubble in an infinite sea of bubbles. Each bubble contains its own universe with different physical laws. This theory was first proposed by Alan Guth, in the early 1980s.
Inflationary cosmology suggests that our universe went through a period of rapid expansion shortly after it was first created. This period of inflationary growth is thought to have created many parallel universes, each with its own set of physical laws.
Inflationary cosmology is thought to be supported by observations of the cosmic microwave background (CMB), which is a map of the leftover radiation from the Big Bang. These observations show that the universe appears to be uniform on large scales, which can only be explained if there was a period of inflationary growth.
While there is no definitive proof that parallel universes exist, many scientists believe that the multiverse is a necessary consequence of the laws of physics. Some even argue that there is evidence for the existence of other universes.
The multiverse is a fascinating concept that continues to be studied by scientists all over the world.