The abstract notion of a Universal Turing machine cannot exist as a physical subsystem without the introduction of noise from an external energy source. The mathematical paradoxes uncovered by Turing and Godel do not bear any consequence on physical world because they can never be truly realised in physics. Like many other mathematical anomalies arising in the realm of Platonic forms, they are denied a physical existence by the laws of thermodynamics.
Michael James Kewming