Could tidal effects make matter hot enough for nuclear fusion?

Question

There was a recent question about cosmological firewalls. Putting aside questions of entanglement and information and looking at the problem from a pure mechanical viewpoint, we know that although there is little perceptible radiation emitted from the blackhole, the tidal forces approaching the event horizon are enormous leading to spaghettificaton. Although the tensile forces will eventually tear a person apart, there are also compressive forces for material located in the same plane.

A human body contains a considerable amount of hydrogen and other lighter elements. Would the compressive effects of spaghettification be sufficiently high to cause any of the hydrogen or other elements to fuse prior to reaching the event horizon?

Answer 1

Tidal effects are not necessarily large at the event horizon. The tidal forces decrease as the black hole gets bigger, so for a big enough black hole the tidal forces at the event horizon can be insignificant. However the tidal forces always become infinitely large as you approach the singularity.

But I can answer a slight variation of your question. The accretion disk round a black hole gets heated by frictional interactions and can become hot enough for atoms to fuse. This isn't sustained fusion as happens in a the core of a star because the density is too low for that. However fusion can occur leading to nucleosynthesis. See for example http://arxiv.org/abs/1112.2673.