Physics Articles

Learn about the many kinds of stars that populate the cosmos, from red dwarfs to blue giants, and the physical features that distinguish them. Discover what it takes for a star to become a neutron star or a black hole, and what the fate of our Sun will be.

Learn about how stars are born, evolve, and die, becoming either white dwarfs, neutron stars, or black holes. Discover the physics of protostars, hydrostatic equilibrium, nuclear fusion, red giants, and the helium flash by understanding Hertzsprung-Russell diagrams and the physical laws that govern the universe.

Learn about the shape and fundamental features of black holes—the event horizon, ergosphere, photon sphere, accretion disk, and relativistic jets—and how to classify them. Discover how five types of black holes—from primordial to supermassive—differ in terms of their mass, prevalence, and method of formation. 

Learn about gamma rays and their spectroscopic measurement with semiconductor detectors. In this guide, the energy and intensity of gamma rays from a europium-152 source are measured. Measurements also include a background spectrum, x-ray emission, x-ray escape peaks, peak summing, annihilation photons, dead time, shaping time, and three different kinds of detector efficiency.

Nuclear isomers may sound boring, but they could be the key to revolutionary advances in nanotechnology, fusion energy, and Star Trek style weapons like phasers. Indeed, nuclear isomers store energy in extreme concentrations, making nuclear batteries a real possibility. Furthermore, this energy could be released in the form of "gamma ray lasers".

The Hubble Telescope has been in operation for decades, taking spectacular images of the cosmos. It has helped us to discover the age and expansion of the universe, the existence of extrasolar planets, and the supermassive black holes at the cores of galaxies. This article presents ten of the most beautiful Hubble images of nebulae and galaxies and explains the physics behind them.