The concept of a singularity, particularly in the context of black holes, is a complex and poorly understood phenomenon. Our current understanding of physics breaks down at the singularity, and we don't have a complete theory that can accurately describe what happens within it.
According to general relativity, which is the theory of gravity proposed by Albert Einstein, a singularity is a region of spacetime where the gravitational field becomes infinitely strong and the density becomes infinite. However, the laws of physics, as we currently understand them, cannot explain the physics of the singularity itself.
At the singularity, the known laws of nature, including those governing the behavior of atoms and particles, break down. Therefore, it's not meaningful to speak of extreme heat or the source of heat at the singularity in the conventional sense. Our current understanding of physics cannot adequately describe the conditions within the singularity, and it's an area of active research and speculation.
It's worth noting that the laws of nature, as we understand them, may not be applicable to the extreme conditions near the singularity. To obtain a complete theory of quantum gravity, which could potentially describe the behavior of spacetime at the singularity, scientists are actively exploring various approaches, such as string theory, loop quantum gravity, and others. However, these theories are still under development, and a consensus has not yet been reached.