Blog Post 4: End of the Universe

Welcome back everyone,

Many amateur physicists have asked the question, if large black holes suck in more energy than they output (and then convert that into mass) will these black holes continue to operate forever. And the short answer is, no.

The reason is extremely fascinating and is related to my favorite topic in chemistry, thermodynamics; although we physicists know that in reality this principle belongs to physics. The reason a black hole becomes a net negative energy black hole or a net positive energy black hole is not actually related to the characteristics of a black hole, but it indirectly linked to the characteristics of cosmic background radiation. A black hole becomes a net negative energy or a net negative positive energy black hole depending on whether or not it is currently hotter than the cosmic background radiation. As of right now, the end of the world is predicted through universal expansion, which will lower cosmic background temperatures to near absolute zero (Right now, they are about 2.7 Kelvin). If the universe expands, like it currently predicted to, cosmic background radiation will become spread over an increasingly larger area, which means that the temperature of space will approach absolute zero and even the coldest black hole, will be warmer than the surrounding cosmic background radiation; making all black holes become net positive energy emitters and start to lose mass, until they lose all their mass. Thus, black holes will be gone before the universe’s predicted end due to the great expansion theory.

"The universe won't go out with a bang, but a whimper" - Neil DeGrasse Tyson

Dr. Chinmay Patel (PhD in Astrophysics)

Professor at Stanford University

Links:

Ball, Philip (Dec 3, 2013). Could we harness energy from black holes? Retrieved From: <http://www.bbc.com/future/story/20131203-could-black-holes-provide-energy>

Anderson, Ryan (November 19, 2009). Black Hole Drive could power future Starships. Retrieved From: <http://www.universetoday.com/45571/black-hole-drive-could-power-future-starships/>

Jones, Zimmerman, Andrew (2010). What is Hawking Radiation? Retrieved From: < http://physics.about.com/od/astronomy/f/hawkrad.htm>

123HelpMe.com. "Black Holes: The Power Source for Future Space Travel?" Retrieved From: <http://www.123helpme.com/view.asp?id=43865>

Whiting, Jim. (2011). Mysteries of the universe: Black Holes. New York, USA. Publisher: Creative Education. Book.

DeGrasse, Tyson. (2007). Galactic Engines. Death by Black Hole and Other Cosmic Quandaries. (pg. 268-274). New York, USA. Publisher: Norton. Book.

Begelman, Mitchell. (2010). Gravity Triumphant. Gravity’s Fatal Attraction: Black Holes in the Universe. (pg. 1-22). New York, USA. Publisher: Cambridge University Press. Book.

#Chinmay