ABSTRACT
The biggest achievements of 20th and 21st century physics are quantum mechanics, which led to the Standard Model that describes the behavior of elementary particles such as quarks, protons, and electrons; and general relativity, Einstein’s theory of gravity that explains the interactions between large cosmic bodies. The basic quantum gravity experiment uses entangled pairs of photons. Entanglement is a quantum effect where two photons, once created as a pair, remain forever linked even if far apart. In 2018, Siddarth Joshi of the Austrian Academy of Sciences and 44 international colleagues proposed a project they called QUEST. In a broad view of the value of space science and technology as outgrowths of space exploration, these efforts to shed light on quantum gravity add to a growing list of varied and sometimes unexpected benefits such as improved astronomical observation, and closer to home, quantum communication and insights into human health and longevity.
