Question

What is there in the black hole

Answer 1

Nothing is present in black hole but
it has highest gravitational attraction which pull the object towards the hole.

Answer 2

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. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars by Jocelyn Bell Burnell in 1967 sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality. The first black hole known as such was Cygnus X-1, identified by several researchers independently in 1971.