Planets Could Orbit Singularities Inside Black Holes

Planets Could Orbit Singularities Inside Black Holes

The discovery of stable orbits inside certain kinds of black hole implies that planets and perhaps even life could survive inside these weird objects, says one cosmologist

It's easy to imagine that black holes gobble up everything they encounter, consigning this stuff to eternal oblivion. Right?

Well, not quite. Today, Vyacheslav Dokuchaev at the Institute for Nuclear Research of the Russian Academy of Sciences in Moscow points out that certain black holes can have a complex internal structure. And that this structure ought to allow photons, particles and perhaps even planets to orbit the central singularity without ever getting sucked all the way in.

A black hole is a region of space where gravity is so strong that nothing can escape, not even light. However, cosmologists have known for some time that there are regions inside charged, rotating black holes where objects such as photons can survive in stable periodic orbits.

Dokuchaev's contribution is to study these orbits in detail and to explore their dynamics. One of the problems that would at first seem to scupper any chance of planetary orbits inside a black hole is the way that the dimensions of space and time behave.

It's well known that a traveller passing through a black hole's event horizon arrives in a region in which the radial dimension becomes time-like, rather than space-like. Conventional orbits are clearly impossible here.