Two Quantum Quirks Become One

Physicists have determined that two long-standing concepts of quantum physics - Wave Particle Duality and the Uncertainty Principle - are not separate entities but manifestations of the same quantum quirk.

The discovery of the relationship between these two concepts, fundamentals of quantum physics since its inception a century ago, enhances our understanding of this weird counter-intuitive that is the heart of reality. Mathematical equations that describe wave-particle duality can be reformulated to express information gathered on the properties of particles affected by the uncertainty principle.

Wave Particle Duality is the idea that a particle can behave like a wave, at least untilyou perform a measurement on it. This effect is famously demonstrated in the Double Slit Experiment. Single particles, which can be electrons or photons, are sent one-by-one towards a screen with two narrow slits in it, which they pass through and hit a secondary screen.

The pattern of where the particles hit the second screen is observed. Instead of seeing two distinct stripes on the screen in line with the slits, as would be expected from particle-like behavior, there is a pattern of stripes across the width of the screen, showing that the particles are exhibiting wave-like behavior.

To make it even stranger, if you try to detect which slit the particles pass through, then the pattern seen is instead that produced by particles exhibiting particle-like nature.

The Uncertainty Principle states that it is impossible to know at the same time information about certain pairs of properties of a particle. The most commonly known example of this is that the more precisely you know the position of a particle, the less well you can determine the speed that it is moving. This isn't an issue with how well experiments can measure, but rather a fundamental property of nature. There is a trade off between the amount that can be known about the wave-like behavior and the particle-like behavior of a system.

The next goal for physicists is to study further these intertwined concepts, and their links with other concepts such as quantum nonlocality, to futher unravel the mysteries of quantum physics and gain a deeper insight into the fundamental physics governing reality.

Image credit:

Double Slit Experiment. University of Oregon. URL: http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec13.html