Question: What is meant by the term spaghettification?

Chris Kettle answered on 14 Jun 2012:

Wiki: In astrophysics, spaghettification (sometimes referred to as the noodle effect[1]) is the vertical stretching and horizontal compression of objects into long thin shapes (rather like spaghetti) in a very strong gravitational field, and is caused by extreme tidal forces. In the most extreme cases, near black holes, the stretching is so powerful that no object can withstand it, no matter how strong its components. Within a small region the horizontal compression balances the vertical stretching so that small objects being spaghettified experience no net change in volume.

In his book A Brief History of Time (1988), Stephen Hawking describes the flight of a fictional astronaut who, passing within a black hole’s event horizon, is “stretched like spaghetti” by the gravitational gradient (difference in strength) from head to toe. However, the term “spaghettification” was established well before this; Nigel Calder, for example, uses it in his book The Key to the Universe: A Report on the New Physics (Viking Press, 1977), a companion to a one-off BBC TV documentary: The Key to the Universe