“The Curious Observer’s Guide to Quantum Mechanics”, Part 1?

Practical perspective in this first part of a seven part “mathless” series. Some humor and clever analogies get the knowledge across of the complex world of quantum mechanics. Recommend reading from *ars TECHNICA*, the source. Link is below. Because Quantum is Coming. Qubit.

**A “no math” (but seven-part) guide to modern quantum mechanics**

+ In many ways, the role of quantum mechanics can be understood in analogy with Newtonian gravity and Einstein’s general relativity. Both describe gravity, but general relativity is more correct—it describes how the Universe works in every situation we’ve managed to test. But 99.99 percent of the time, Newtonian gravity and general relativity give the same answer, and Newtonian gravity is much easier to use. So unless we’re near a black hole, or making precision measurements of time with an optical clock, Newtonian gravity is good enough.

+ Similarly classical mechanics and quantum mechanics both describe motions and interactions. Quantum mechanics is more right, but most of the time classical mechanics is good enough.

+ What I find fascinating is that “good enough” increasingly isn’t. Much of the technology developed in this century is starting to rely on quantum mechanics—classical mechanics is no longer accurate enough to understand how these inventions work.

*My [Miguel F. Morales’] goal in this seven(!)-part series is to introduce the strangely beautiful effects of quantum mechanics and explain how they’ve come to influence our everyday world. Each edition will include a guided hike into the quantum mechanical woods where we’ll admire a new—and often surprising—effect. Once back at the visitor’s center, we’ll talk about how that effect is used in technology and where to look for it.*

+ But which path did the particle really take? The experiments show that the particles really take both paths. Despite much confusion (even among some physicists), this is the answer. But the question is based on a faulty mental image. The question assumes that a particle is really a little ball bearing, and thus must have chosen one path or the other. But this mental image is wrong. Particles really behave like waves when in motion. Asking which path a tsunami wave took when traveling between Hawaii and California really makes no sense—it is spread out. Similarly, asking which path the particle really takes makes no sense; it moves like a wave so it naturally takes all of the available paths.

+ But isn’t the stripy pattern we see with light a classical effect? Yes and no. In quantum mechanics, there is nothing special about a photon of light vs. any other kind of particle—they all move like waves and hit like particles and they will all make interference stripes. What is different is the history of our understanding. Before the invention of quantum mechanics there was a wave-theory of light—Maxwell’s electrodynamics.

Source:* ars TECHNICA. Miguel F. Morales, A “no math” (but seven-part) guide to modern quantum mechanics… *

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