Quantum mechanics marks a century as a platform for new technologies
A Science perspective traces how quantum theory moved from early disputes to lasers, secure communications, precision tools and quantum computing.
By Lucas Ferreira · Science & Environment Writer
3 min read
Quantum mechanics has moved from a disputed theory about subatomic behavior to a working base for major technologies, according to Texas A&M University. A new perspective in Science argues that the same ideas that challenged early 20th-century physicists now support tools used in computing, medicine, communications and physics research.
The article, by Marlan O. Scully of Texas A&M University and Princeton University and William G. Unruh, reviews 100 years of quantum mechanics. Texas A&M said Scully traces the field from its origins in explaining tiny particles to current work on quantum computers, quantum heat engines, gravitational-wave detection and biology.
From theory to hardware
Texas A&M said quantum mechanics began as a way to describe behavior that classical physics could not explain. Erwin Schrödinger and Werner Heisenberg built separate mathematical approaches, wave mechanics and matrix mechanics, that later became part of a broader framework for describing quantum systems.
The university said those ideas developed beyond Niels Bohr’s early model of the atom, which pictured electrons moving around a nucleus in a planet-like arrangement. Later research changed that picture, but Texas A&M said Bohr’s model helped open the route to modern quantum theory.
Schrödinger’s 1935 cat thought experiment remains one of the best-known attempts to show how strange quantum theory appeared, according to the university. The paradox described a cat treated as both alive and dead until observed, a scenario meant to expose the difficulty of applying quantum rules to everyday objects.
Coherence, lasers and entanglement
Texas A&M said quantum coherence, in which atoms or photons can stay coordinated as part of a shared quantum state, became one of the field’s most useful concepts. That principle helped make lasers possible, even though the university said many researchers once doubted such devices could work.
Lasers now appear in barcode scanners, eye surgery and scientific instruments, according to Texas A&M. The university also linked coherence to quantum entanglement, the effect Albert Einstein described as “spooky action at a distance.”
Entanglement allows particles to share information through quantum properties, Texas A&M said. Those effects support quantum cryptography and help improve advanced instruments, including the Laser Interferometer Gravitational-Wave Observatory, which measures small distortions in spacetime.
Energy, biology and open questions
Scully’s work has included coherent nanoscale laser spectroscopy, which Texas A&M said helps researchers study molecules with atomic-scale precision. The university also said he has worked on quantum heat engines, which use coherence to test classical assumptions about thermodynamic efficiency.
According to Texas A&M, classical engines are bounded by the Carnot limit, a maximum efficiency set by thermodynamics. Researchers are investigating whether quantum coherence could allow heat engines to exceed those classical constraints.
The university said quantum methods are also being applied in biology through techniques such as coherent Raman spectroscopy, which can examine viruses and other nanoscale structures. In physics, researchers are using quantum ideas in efforts to connect quantum mechanics with Einstein’s relativity through fields such as string theory and quantum gravity.
Texas A&M said quantum concepts are also being used to study turbulence, a problem tied to weather, climate systems and aircraft performance. Work with superfluid helium, which shows unusual quantum behavior, could help reveal patterns relevant to climate modeling, storm prediction and aviation safety, according to the university.
The Science perspective presents quantum mechanics as both a mature theory and an unfinished research program. Texas A&M said unresolved questions include whether gravity can be described quantum mechanically and how far quantum computers may reach in medicine and materials science.
This story draws on original reporting from ScienceDaily.