Can Physics Explain Its Own Laws?

Physics faces a fundamental challenge in explaining the origins and nature of its own laws, as any explanation typically presupposes the existence of other laws, leading to logical paradoxes like infinite regress, circularity, or foundationalism.

• Physics' standard explanations for laws often lead to deeper, unresolved questions.

• Philosophical theories on laws and explanation highlight inherent logical limits in self-explanation.

• The inability of physics to explain its own laws may reveal fundamental limits of explanation, not a scientific failure.

The question of why physical laws exist in their particular form is complex and treacherous, as traditional physics explanations often rely on symmetries or deeper mathematical structures that only push the problem further back. Philosophers highlight that 'explanation' itself relies on 'law-like' regularities, making it inherently difficult for laws to explain themselves without circularity or an infinite regress. This challenge suggests that explanation might have inherent limits.

Limitations of Physical Explanations

• 00:01:11 Physicists often attribute particle properties to spacetime symmetries and conserved quantities to Noether's theorem, but these explanations face issues, such as the non-invertibility of the map from symmetries to conservation laws and the existence of conservation laws without variational principles. This reveals that the explanatory successes of physics do not fully address the foundational question of why laws have their specific form.

Philosophical Theories of Laws

• 00:02:18 Attempts to explain the origin of physical laws often retreat to grander theories like Tegmark's mathematical universe hypothesis, Smolin's cosmological natural selection, or Wheeler's 'it from bit,' where laws emerge from information. However, each of these theories pushes the explanatory burden back, requiring further explanation for the underlying mathematical structures, meta-laws, or the nature of information itself. The very definition of a 'law' is debated, ranging from Humean views of laws as mere patterns to non-Humean views where laws are prescriptive constraints on reality.

The Agrippan Trilemma

• 00:09:08 Any justification for physical laws typically falls into one of three problems from Agrippa's Trilemma: infinite regress, where each law is explained by a deeper one; circular reasoning, where laws explain themselves; or foundationalism, where some facts are asserted dogmatically without further justification. Most physicists, consciously or unconsciously, adopt foundationalism, accepting certain symmetries as brute facts, which is seen as an admission of explanatory defeat rather than a true explanation.

Limits of Explanation Itself

• 00:12:12 Asking physics to explain its own laws is akin to asking a system to justify its own foundations, as the concept of explanation inherently presupposes 'law-hood' or regularities. If explanation means subsuming phenomena under laws, then asking for an explanation of laws requires laws to subsume themselves, leading to a logical impasse. This suggests that the seeming impossibility of physics explaining its own laws is not a failure of physics, but rather a profound insight into the inherent limits and nature of explanation itself.