{"id":375,"date":"2020-09-11T12:00:00","date_gmt":"2020-09-11T16:00:00","guid":{"rendered":"https:\/\/anyonecanscience.com\/?p=375"},"modified":"2021-02-28T16:00:21","modified_gmt":"2021-02-28T21:00:21","slug":"hawking-radiation-and-the-rise-and-fall-of-the-black-hole-era","status":"publish","type":"post","link":"https:\/\/anyonecanscience.com\/index.php\/2020\/09\/11\/hawking-radiation-and-the-rise-and-fall-of-the-black-hole-era\/","title":{"rendered":"How the Universe Will End \u2014 Hawking Radiation and the Rise and Fall of the Black Hole Era"},"content":{"rendered":"\n

In last week\u2019s post on entropy<\/a>, I blithely referred to black holes<\/a> as spontaneously increasing in entropy. This may seem counterintuitive (as much as anybody can have \u201cintuition\u201d about black holes). If we view the increase in entropy as a system moving from order to disorder, how would a singularity become more disordered? How could the contents of a black hole spread out in a more disordered manner if they are supposed to take up an infinitely small amount of space? If we use the other definition of entropy, the dispersal of energy, then that would imply that a black hole leaks energy into the surrounding void of space. But nothing is supposed to escape the black hole\u2019s event horizon\u2014not even light. The second law of thermodynamics<\/a> demands that entropy increases, but for a long time even scientists could not determine how that would happen in a black hole. The problem was cracked in the 1970s by Stephen Hawking, who proposed that black holes have a set temperature <\/a>proportional to their surface area that disperses into the surrounding void in the form of Hawking radiation. Hawking radiation explains how black holes increase in entropy over time, but it also presents a whole new set of questions that physicists continue to grapple with today. Hawking radiation also sets the scene for how the universe may die in the far, far future. It seems not even black holes are safe from the ravages of time.<\/p>\n\n\n\n

The common, simplified description of Hawking radiation explains the phenomenon in terms of \u201cvirtual particles.\u201d These are small particles of matter and anti-matter that spontaneously pop into existence and immediately annihilate each other. But at the edge of a black hole, one of these virtual particles may appear inside the event horizon. The particle, like light, cannot escape the singularity\u2019s gravitational pull. As the particle is swallowed by the black hole, its opposing twin radiates away from the black hole with nothing to annihilate it. Positive energy from this jilted virtual particle appears to leak out of the black hole as radiation. Simultaneously, the particle that fell into the black hole imparts negative energy, reducing the surface area of the event horizon. Small black holes leak their energy faster than big black holes, meaning that small black holes appear much \u201chotter.\u201d But, over time, black holes evaporate completely into nothing but random energy.<\/p>\n\n\n