Quantum Steampunk Is a Real, Retrofuturistic Field of Physics

  • The real field of quantum steampunk is cutting-edge science.
  • Entropy explains why time moves forward and first emerged in thermodynamics.
  • Any closed system of any size or scale can exhibit entropies that are meaningful.

Scientists are mashing up steamy old thermodynamics and cutting-edge quantum mechanics into a new field they’re calling quantum steampunk. By combining some of the most established 19th-century science with nano-scale quantum technology, researchers say they can solve complex problems that require versatility and skill in both fields.

Writing for Scientific American, theoretical physicist Nicole Yunger Halpern explains that one of the key concepts shared by both kinds of science is entropy. “Entropy quantifies our uncertainty,” she writes. “According to the second law of thermodynamics, the entropy of a closed, isolated system cannot shrink. This fact underlies the reality that time flows in a single direction.”

New technologies like quantum computers and quantum-based information security end up using physics as much as they use the typical programming ideas of traditional barriers like firewalls or complex passwords. Because of that, entropy is back in the picture as a way to measure unknown quantities in these quantum systems.

“Entropy is often thought of as a single entity, but in fact, many breeds of entropy exist in the form of different mathematical functions that describe different situations,” Yunger Halpern explains. She says the overarching idea of entropy and its application as functions and equations means it’s a good model for a variety of other situations, too. Quantum systems down to the nano-scale level can still be closed in the sense of the definition of entropy.

“Suppose we are trying to use entanglement to share information in a certain channel,” Yunger Halpern muses. “We might ask, Is there a theoretical limit to how efficiently we can perform this task? The answer will likely depend on an entropy.” Instead of an idea like bandwidth over a cable, quantum systems deal directly with how electrons are moving. The speeds or capacities can be pure physics.