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Black holes have been a device in science fiction ever since their prediction. Many sci-fi books, movies, and television shows use black holes as a method of travel (see the Potential Future Exploration section above) or as a threat to a space-going vessel.  In at least one season of the show ''Star Trek: the Next Generation'' by Gene Roddenberry, artificially created miniature black holes are used as power sources for spaceships and natural ones as incubators for the young of an alien race.  Neither of these uses has much of a basis in reality, of course.

Black holes have been a device in science fiction ever since their prediction. Many sci-fi books, movies, and television shows use black holes as a method of travel (see the Potential Future Exploration section above) or as a threat to a space-going vessel.  In at least one season of the show ''Star Trek: the Next Generation'' by Gene Roddenberry, artificially created miniature black holes are used as power sources for spaceships and natural ones as incubators for the young of an alien race.  Neither of these uses has much of a basis in reality, of course.

Contrary to popular myth, a black hole is not a cosmic vacuum cleaner. In other words, a one-solar-mass black hole is no better than any other one-solar-mass object (such as, for example, the Sun) at "sucking in" distant objects. However, a one-solar-mass black hole has the same amount of matter as any other one-solar-mass object but compressed into a much smaller space, making it impossible to move fast enough to leave a black hole once there.  If a spaceship could land on a black hole, it would never be able to take off again.

Contrary to popular myth, a black hole is not a cosmic vacuum cleaner. In other words, a one-solar-mass black hole is no better than any other one-solar-mass object (such as, for example, the Sun) at "sucking in" distant objects. However, a one-solar-mass black hole has the same amount of matter as any other one-solar-mass object but compressed into a much smaller space, making it impossible to move fast enough to leave a black hole once inside the event horizon. If all of the Earth's matter could be compressed down to a radius of one centimeter at the center of the Earth's present configuration, it would become a black hole, but gravity at normal distances would be unchanged.  The Moon would still orbit the Earth, as would all artificial satellites (International Space Station, GPS satellites, communications satellites, etc.) If a spherical platform could be constructed at an altitude of 4000 miles above the black hole, we could walk around on it and not notice anything unusual.  (But if you dropped a nickel through a hole in the platform, you would never see it again.)

The term "black hole" is also used as a metaphor for a place that it is hard to get out of, generally containing a high concentration of something unpleasant.  Ex: "The inner city is a black hole of crime and drug use."  The "Black Hole of Calcutta" long predates the celestial use of the term; it was a horrible underground prison in [[Calcutta]], India.

The term "black hole" is also used as a metaphor for a place that it is hard to get out of, generally containing a high concentration of something unpleasant.  Ex: "The inner city is a black hole of crime and drug use."  The "Black Hole of Calcutta" long predates the celestial use of the term; it was a horrible underground prison in [[Calcutta]], India.

==Are Black Holes Falsifiable?==

==Are Black Holes Falsifiable?==

''Things'' cannot be judged [[falsifiable]] or non-falsifiable.  The concept of being falsifiable only applies to theories or hypotheses.  One can't say the unicorns are falsifiable, but the hypothesis "there are no unicorns" is.  The imagined experiment would consist of finding a unicorn.  If one were found, the hypothesis would be refuted.  None has ever been found, but that's not germane to the question of falsifiability.  Similarly, the hypothesis "there are no black holes" is falsifiable.  The test would be to find one.  (Many have been found, perhaps the most notable being the ones involved in the discovery of [[gravitational waves]].)

''Things'' cannot be judged [[falsifiable]] or non-falsifiable.  The concept of being falsifiable only applies to theories or hypotheses.  One can't say the unicorns are falsifiable, but the hypothesis "there are no unicorns" is.  The imagined experiment would consist of finding a unicorn.  If one were found, the hypothesis would be refuted.  None has ever been found, but that's not germane to the question of falsifiability.  Similarly, the hypothesis "there are no black holes" is falsifiable.  The test would be to find one.  (Many have been found, perhaps the most notable being the ones involved in the discovery of [[gravitational waves]].)