IDGI — A guide to (not) understanding quantum mechanics How can we come to grips with a theory that doesnt explain how anything works?
Paul Sutter – Feb 13, 2023 12:30 pm UTC Enlarge / According to Werner Heisenberg and Niels Bohr, when it comes to the subatomic world, were just goldfish.Aurich Lawson | Getty Images reader comments 170 with Share this story Share on Facebook Share on Twitter Share on Reddit
Quantum mechanics is simultaneously beautiful and frustrating.
Its explanatory power is unmatched. Armed with the machinery of quantum theory, we have unlocked the secrets of atomic power, divined the inner workings of chemistry, built sophisticated electronics, discovered the power of entanglement, and so much more. According to some estimates, roughly a quarter of our worlds GDP relies on quantum mechanics.
Yet despite its overwhelming success as a framework for understanding what nature does, quantum mechanics tells us very little about how nature works. Quantum mechanics provides a powerful set of tools for successfully making predictions about what subatomic particles will do, but the theory itself is relatively silent about how those subatomic particles actually go about their lives.
For example, take the familiar concept of a quantum jump. An electron in an atom changes energy levels and thus either absorbs or emits energy in the form of one photon of radiation. No big deal, right? But how does the electron jump from one energy level to another? If it moves smoothly, like literally everything else in the Universe, we would see the energy involved change smoothly as well. But we dont.
So does the electron magically disappear from one energy level and magically reappear in another? If it does, name one other physical object in the Universe that acts like that. While youre at it, please give me a physical description of the unfolding of this magic act. I’ll wait. Advertisement
Quantum mechanics is completely silent on how the electron changes orbitals; it just blandly states that it does and tells us what outcomes to expect when that happens.
How are we supposed to wrap our heads around that? How can we possibly come to grips with a theory that doesnt explain how anything works? People have struggled with these questions ever since quantum mechanics was developed, and theyve come up with a number of ways to make sense of the processes involved in quantum behavior. Lets explore three of these interpretations of quantum mechanics to see if any of them satisfy our cravings for a “why” behind all this odd phenomenology. The Copenhagen interpretation
Enlarge / The participants of the Copenhagen Conference in 1930. Niels Bohr is second from the left in the front row, and Werner Heisenberg is beside him on the right.SSPL/Getty ImagesIf youre not the kind of person to sweat the small stuff, the Copenhagen interpretation is for you. Like the other two interpretations well explore in this article (and the many more we wont), there isnt one precise, definitive Copenhagen interpretationrather, its a collection of ideas that share a similar set of values.
In this case, those values are best expressed as shut up and calculate.
The Copenhagen interpretation was named in the 1950s, but it traces its lineage to some of quantum theory’s founding figures who were based in that city in the early 20th century: Werner Heisenberg and Niels Bohr. Page: 1 2 3 4 Next → reader comments 170 with Share this story Share on Facebook Share on Twitter Share on Reddit Advertisement Promoted Comments Thakk Great article. Helpful explanations. Yup, I’m a goldfish. February 13, 2023 at 12:49 pm Channel Ars Technica ← Previous story Next story → Related Stories Today on Ars