Summary of Where Are All The Hidden Dimensions?

00:00:00 - 00:40:00

In this video, researchers discuss the idea that there may be extra dimensions that we are unable to detect. However, if they do exist, they would have a significant impact on the physics of the universe. Although the idea is still theoretical, it remains an interesting possibility.

• 00:00:00 In 1927, Albert Einstein was successful in extending his special theory of relativity to include gravity. His general theory of relativity turned gravity into geometry, which was a beautiful theory but a hard one to understand.
• 00:05:00 In the 1920s, physicists Theodore Kaluza and Albert Einstein worked on a new theory of gravity that included an extra dimension. For years, few people cared about the theory, and it was largely forgotten until the 1980s when physicists began to experiment with it again. Today, the theory is still being explored, and some scientists believe it could help us understand the universe in a deeper way.
• 00:10:00 In 1984, two physicists at a conference in Aspen, Colorado, found a way to solve a problem with string theory that had been plaguing the theory for years. The solution was a bit of a surprise, as it required the existence of extra dimensions. Despite the excitement this discovery sparked, the idea quickly went out of fashion, and the field largely ignored it until the early 2000s. Since then, string theory has been gaining renewed interest, but the theory still faces many theoretical and experimental challenges.
• 00:15:00 In 1984, two physicists, Andrew Strominger and Gary Horowitz, discovered that the equations of Einstein's theory of gravity are also valid in six additional dimensions. This resulted in a "thunderous storm" of interest in the subject, which has since been dubbed "quantum gravity." Collaborators have since explored the potential shapes that these extra dimensions could take, with the most popular idea being "calabial manifolds," which are named after the Italian-American mathematician Eugenio Kalabi and the Chinese geometer Ching Tang Yao. These spaces have already attracted interest from mathematicians due to their complex geometry, and they are topologically complex - having hundreds and hundreds of the higher-dimensional equivalents of holes. Additionally, they satisfy the equations of general relativity, which gives them extra protection from quantum effects.
• 00:20:00 Supersymmetry is a form of extra symmetry that is especially good at taming the most dangerous effects of quantum physics. However, some physicists believe that supersymmetry may be part of the true theory of the world, and that when it is discovered, it will be one of the greatest moments in all of physics. So far, however, the number of such collaborates spaces has just kept growing, and though they sound deliciously exotic, they have yet to be enumerated manually by a lone mathematician.
• 00:25:00 In this video, researchers discuss the idea that there may be "legacy particles" that remain after a theory with extra dimensions is reduced to a lower dimension. They suggest that these particles may be similar to photons and electromagnetism in that they are the minimal quantum excitation of the extra dimensional geometry.
• 00:30:00 Where Are All The Hidden Dimensions? examines the possibility that extra dimensions may exist, but that we may never be able to detect them because they are too weakly interacting. However, if they do exist, they would live for a long time and may be part of the particle strum during the end of inflationary epoch.
• 00:35:00 This video discusses the possibility that dimensions other than the three we know exist may exist, and that if they do, they would dominate the energy density of the universe Eventually, all energy in the universe would be in the form of moduli. If this scenario is true, it would change the way we detect moduli from the outer realms of possibility into a more conventional hard physics problem. However, moduli do eventually decay, and their gravitational strength interactions give them longer lives than other particles.
• 00:40:00 In this video, the presenter discusses the possibility that extra dimensions exist and that they may be detected through the study of the physics of moduli. Although the idea is still theoretical, it remains tantalizing.