The "singularity" can be decomposed into 2 mutually-supportive feedback loops - the digital and the physical.

With frontier LLM agents, the digital loop is happening now to an extent (on inference code, harnesses, etc), and that extent probably grows larger (research automation) soon.

Pertinent to your point, however, is the physical feedback loop of robots making better robots/factories/compute/energy. This is an aspect of singularity scenarios like ai-2027.

In these scenarios, these robots will be the control mechanism that the digital uses to bootstrap itself faster, through experimentation and exploration. The usual constraints of physical law still apply, but it feels "unbounded" relative to normal human constraints and timescales.

A separate point: there's also deductive exploration (pure math) as distinct from empirical exploration (physics), which is not bounded by any physical constraints except for those that bound computation itself.