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New section: white holes
Matter coming close to the event horizon of a small black hole undergoes a process called spaghettification, a term coined by Stephen Hawking in his book ''A Brief History of Time'' to describe extraordinarily strong tidal forces. Because the mass at the center of the black hole is so dense, the gravitational pull on the near end of an object is much greater than the pull on the object’s far end. This causes the object to be stretched out in a way resembling a piece of spaghetti, and generally torn in two.
Matter coming close to the event horizon of a small black hole undergoes a process called spaghettification, a term coined by Stephen Hawking in his book ''A Brief History of Time'' to describe extraordinarily strong tidal forces. Because the mass at the center of the black hole is so dense, the gravitational pull on the near end of an object is much greater than the pull on the object’s far end. This causes the object to be stretched out in a way resembling a piece of spaghetti, and generally torn in two.
==White Holes==
Because the [[Quantitative Introduction to General Relativity|general relativity equations]] are symmetric with respect to time, one can take a negative square root instead of positive to yield an equation describing a hypothetical object which expels, rather than attracts, matter and energy.<ref>http://cosmology.berkeley.edu/Education/BHfaq.html#q10</ref> As this is the exact opposite of a black hole, it is called a '''white hole'''.
However, there is no evidence white holes actually exist. If they generate new matter and energy, this would violate the [[Law of the conservation of mass]]. Therefore, some scientists have proposed that matter falling into black holes goes through a [[wormhole]] to emerge at a white hole. While such wormholes are allowed by general relativity, they would be extremely unstable<ref>http://casa.colorado.edu/~ajsh/schww.html</ref>, and there is no evidence that they exist.
Dr. [[Russell Humphreys]] used a white hole in his model of the universe during [[Creation week]] to allow millions of years to pass in outer space while only three days passed on Earth.
==In Popular Culture==
==In Popular Culture==