It is difficult to overstate the importance (not to speak of the beauty) of what we have learned: The exchange of a spin 0 particle produces an attractive force, of a spin 1 particle a repulsive force, and of a spin 2 particle an attractive force, realized in the hadronic strong interaction, the electromagnetic interaction, and the gravitational interaction, respectively. The universal attraction of gravity produces an instability that drives the formation of structure in the early universe. ... Denser regions become denser yet. The attractive nuclear force mediated by the spin 0 particle eventually ignites the stars. Furthermore, the attractive force between protons and neutrons mediated by the spin 0 particle is able to overcome the repulsive electric force between protons mediated by the spin 1 particle to form a variety of nuclei without which the world would certainly be rather boring. The repulsion between likes and hence attraction between opposites generated by the spin 1 particle allow electrically neutral atoms to form.
The world results from a subtle interplay among spin 0, 1, and 2.
In this lightning tour of the universe, we did not mention the weak interaction. In fact, the weak interaction plays a crucial role in keeping stars such as our sun burning at a steady rate.
American physicist
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Electromagnetism becomes stronger as we go to higher energies, or equivalently shorter distances.
Physically, the origin of this phenomenon is closely related to the physics of dielectrics. Consider a photon interacting with an electron, which we will call the test electron to avoid confusion in what follows. Due to quantum fluctuations ... , spacetime is full of electron-positron pairs, popping in and out of existence. Near the test electron, the electrons in these virtual pairs are repelled by the test electron and thus tend to move away from the test electron while the positrons tend to move toward the test electron. Thus, at long distances, the charge of the test electron is shielded to some extent by the cloud of positrons, causing a weaker coupling to the photon, while at short distances the coupling to the photon becomes stronger. The quantum vacuum is just as much a dielectric as a lump of actual material.