Physicists have found a way to certify time-entanglement using the imaginary part of heat capacity, measurable via calorimetry. This quantity, like an echo delay, points to temporal quantum connections. Linking to the pseudo-density matrix revealed nonclassical correlations through negativity and violation of temporal CHSH inequalities. Experimentally achievable bounds guaranteeing time-entanglement at the macrolevel have been found. This opens a straightforward path to searching for temporal quantum effects in condensed matter systems.
A pot of soup remembers being stirred. When heated, the temperature rises with a lag—the soup seems to glance back at the past. This thermal inertia opens a window into quantum connections between events at different times. At its root lies entropy, but the quantum world adds a layer of memory where particles influence each other across time.
Physicists found a way to decode this memory by adapting the criterion from the Clauser–Aspect–Zeilinger inequality for time. When thermal lag becomes large and uneven, it proves temporal quantum entanglement. Surprisingly, detecting it doesn't require microscopic particles—even ordinary water will do. This method takes quantum physics beyond the standard models of the microworld.
🎯 Usually heat capacity is just a number, but with uneven heating an imaginary component appears—a sign that the material is "oscillating" between past and present. A familiar kitchen experience: a cast-iron skillet responds slowly to the flame, and hidden in that lag is a quantum subtext.
🎬 The thermal memory of soup isn't a metaphor, but a physical bridge between "before" and "after," like in the best science fiction novels.