Physics Talk

Credit - ParallelVision: https://pixabay.com/illustrations/black-hole-nebula-space-eye-5868615/ Black holes are usually defined as regions of space-time that are so dense that nothing, not even light can escape from it. However, this is not quite true. It turns out that black holes could be evaporating, losing mass, and shrinking in the process. This phenomenon, proposed by Stephen Hawking in 1974, is called Hawking radiation.   “Black holes ain’t as black as they are painted” – Stephen Hawking, August 2015   In empty space, pair production and annihilation occur spontaneously. Pair production describes the formation of a particle and its corresponding antiparticle, normally from the interaction of a high energy photon with a heavier particle. For example, an electron and a positron (antiparticle of the electron) can be formed when a high energy photon interacts with an atomic nucleus. Pair annihilation is essentially the reverse of this process: a particle colli...

Backward Black Hole (Artist's Concept); Credit - NASA/JPL:  https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA13168 You have probably heard of black holes: incredibly dense regions of space-time with such strong gravitational attraction that not even light can escape from them. They were first predicted by general relativity, but Einstein’s famous theory does not stop there. The same equations that revealed the presence of black holes point to an equally fascinating phenomenon – white holes. [1] Black holes in reverse While black holes are notoriously known for pulling matter inward, white holes do the opposite, ‘spewing [it] out.’ [2] Black holes are extraordinarily massive, with supermassive black holes ranging from ‘millions to billions of times the mass of the Sun.’ [3] White holes are born when you consider what would happen if a black hole singularity had no mass. They have not yet been discovered by astronomers and are currently just a mathematical prediction. H...

Picture credits: X-ray: NASA/CXC/Naval Research Lab/Giacintucci, S.; XMM:ESA/XMM; Radio: NCRA/TIFR/GMRTN; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF Astronomers have detected the 'biggest explosion since the big bang' using high power telescopes: NASA's Chandra X-ray Observatory, the ESA's XMM-Newton, the Giant Metrewave Radio Telescope in India and the Murchison Widefield Array in Australia. This explosion has easily surpassed the previous record held by an eruption from a cluster named MS 0735.6+7421 in which 'a mass of about 300 million Suns was swallowed'. This latest outburst is said to be 'five times bigger than any other known explosion'. Calculations suggest that approximately 5 x 10 54  Joules of energy would be required to cause an explosion of this magnitude. The calculated amount of energy involved is around 9 x 10 33  times more than annual global energy consumption (5.8 x 10 20  Joules). The explosion was ...