A singularity, as described in the context of physics and general relativity, refers to a point in space where certain quantities (like density and curvature of spacetime) become infinite or undefined. This phenomenon is typically found in the center of black holes.
On the other hand, the Planck length, approximately 1.6 x 10-35 meters, is considered the smallest measurable length in the universe according to quantum mechanics. It represents a scale at which classical notions of gravity and space break down and quantum effects dominate.
In theory, a singularity is thought to be a point of infinite density, which means it occupies zero volume. Therefore, it’s often said that a singularity could be considered ‘smaller’ than the Planck length as it does not have a defined size in the way we typically understand dimensions. However, it’s important to note that our current understanding of physics, especially when combining general relativity and quantum mechanics, is still incomplete. The true nature of singularities and whether they can be situated meaningfully in relation to the Planck length remains a topic of ongoing research in theoretical physics.