rhamphotheca:

New Uncertainty About the Uncertainty Principle

by Clara Moskowitz

One of the most often quoted, yet least understood, tenets of physics is the uncertainty principle. Formulated by German physicist, Werner Heisenberg, in 1927, the rule states that the more precisely you measure a particle’s position, the less precisely you will be able to determine its momentum, and vice versa.

The principle is often invoked outside the realm of physics to describe how the act of observing something changes the thing being observed, or to point out that there’s a limit to how well we can ever really understand the universe. While the subtleties of the uncertainty principle are often lost on nonphysicists, it turns out the idea is frequently misunderstood by experts, too. But a recent experiment shed new light on the maxim and led to a novel formula describing how the uncertainty principle really works.

The uncertainty principle only applies in the quantum mechanical realm of the very small, on scales of subatomic particles. Its logic is perplexing to the human mind, which is acclimated to the macroscopic world, where measurements are only limited by the quality of our instruments. But in the microscopic world, there truly is a limit to how much information we can ever glean about an object. For example, if you make a measurement to find out exactly where an electron is, you will only be able to get a hazy idea of how fast it’s moving. Or you might choose to determine an electron’s momentum fairly precisely, but then you will have only a vague idea of its location…

(read more: Live Science)        (image: Dreamstime)