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Gravity in Particle Physics

One of the Biggest Problems in Modern Physics is creating a model which can accurately describe the Universe on the largest and smallest scales. Notably, no current theories are able to explain the role of Gravity on Quantum scales. While Gravity is well explained by Einstein's General Relativity on universal sizes, it is so weak compared to the other Fundamental Forces that its effect cannot be described on atomic scales. Quantum Field Theory (QFT) and the Standard Model of Particle Physics is our current best way of modelling particle decays and interactions. This involves Feynman Diagrams to show decay routes and the idea of coupling constants (such as the fine structure constant) to predict probabilities. Fermions or matter particles exert forces on each other via the exchange of Bosons or force carrying particles. The gauge boson for Electromagnetism is the (virtual) photon. For the Strong Nuclear Force it's the Gluon, and for the Weak Nuclear Force it's the W+, W- and Z0 Bosons. For gravity, theoretical physicists predict the existence of the Graviton in order to quantise the force's action. Although Gravitons haven't been detected, we can use QFT to derive their properties such as quantum spin, charge, color-charge and weak charge. This video discusses how the idea of gravitons is not complete and shows other ideas for quantum gravity beyond the standard model such as string theory. But will any of these be capable of replacing General Relativity as the best way to model gravity? (as the bending of spacetime instead of a classical force) 0:00 - Fundamental Forces of Nature and Gravity 0:41 - Relative Strength of Gravity with Electromagnetism between Protons 1:42 - The Strong and Weak Nuclear Forces and Coupling Constants 3:17 - Fermions and Bosons in Particle Physics 4:32 - Exchange of Gauge Bosons as Forces 5:24 - The Graviton: Initial Idea 5:50 - Probability of Decay Routes and Conservation Laws 7:42 - Electric Charge, Color Charge and Quantum Chromodynamics (QCD) 8:49 - Gravitational Charge, Mass, Energy and Einstein 9:36 - Gravitons: Further Properties 10:01 - Problems with QFT and Quantum Gravity Theories 10:40 - String Theory and new ideas necessary 11:00 - General Relativity, Bending of Spacetime and Gravitational Lensing 12:11 - Gravity within the Universe: Outlook