What is the Relationship between Particle Physics and Cosmology?
There is an intimate relationship between the fields of particle physics and cosmology, which been exemplified by a long line of physicists working in both simultaneously: Albert Einstein, Stephen Hawking, Kip Thorne, and many others. Cosmology is the study of the universe and its structure, whereas particle physics is the study of fundamental particles such as quarks and photons, the smallest known objects. Although at first they may seem as unconnected as anything can be, cosmology and particle physics are in fact closely linked. Unlike the complex systems on Earth, which much be described using higher-level explanations rather than properties emerging from the lowest levels, intergalactic and cosmological phenomena are comparatively simpler. For instance, in the vast distances of space, only one of the four forces of nature has any real influence: gravity. Although stars and galaxies are very far away and many times larger than ourselves, we have a remarkably accurate picture of how
