366 | Jim Al-Khalili on Time, Quantum, Biology, and Cosmology

Time functions as a fundamental, four-dimensional reality rather than a mere psychological construct or measurement tool. While fundamental dynamical equations of physics are time-symmetric, the observed arrow of time emerges from the behavior of open systems and the increase of entropy. The universe’s initial low-entropy state, often framed as the past hypothesis, provides the necessary conditions for this irreversibility. Beyond cosmology, quantum biology investigates whether living organisms have evolved to exploit quantum phenomena like entanglement and tunneling to maintain structural integrity far from equilibrium. These processes suggest that life may actively utilize quantum mechanics, potentially challenging the assumption that biological environments are too warm and wet to sustain non-trivial quantum effects. Reconciling these physical laws with the subjective experience of time remains a central, unresolved challenge in modern theoretical physics.