Wednesday, August 04, 2021

Quantum Mechanics and the Double-Slit Experiment

The double-slit experiment continues to be of interest with respect to quantum mechanics, even after so many years. I've mentioned about this many times, with this one being the most relevant here to this particular post. And note that I made that blog entry back in 2013!

This time, Don Lincoln of Fermilab has released a video on the topic of the double-slit experiment and how it is relevant to QM.


BTW, has he lost weight? If he has, I hope it is on purpose and not due to an illness.

In any case, watch the video and check out the link that I gave. This issue doesn't look like it will be resolved anytime soon unless some new experiment comes up.

Zz.

2 comments:

Howard Gary said...

Always great to hear from experimental particle physicist Don Lincoln. He has a special knack for simplifying complex concepts in particle physics and quantum mechanics, while entertaining us at the same time. Of the four options he listed for what story is the data telling us about the double-slit experiment:
1. Shut up and calculate
2. Pilot wave theory
3. Many Worlds
4. Others
I think my favorite is the Many Worlds Interpretation of quantum mechanics.

The video posted below: 'The Many Worlds of the Quantum Multiverse |Space Time| PBS Digital Studios' gives a pretty good explanation of what Many Worlds is all about.

https://www.youtube.com/watch?v=dzKWfw68M5U

Andrei said...

This is from the video's transcript:

"So, what would we expect if light acted like a particle when it went through the double slits? Well a particle is like a BB or a marble or something. The particle would go through one slit or the other, but not both. The resulting pattern on a distant screen would be two patches where the particles hit, and the rest of the screen would have no hits."

A BB or a marble behaves almost as a neutral object since it contains a very large number of charges (electrons and nuclei). Its motion would be described by Newtonian mechanics with contact forces only.

An electron, an atom or a molecule interacts electromagnetically with the barrier. It's trajectory should be calculated based on classical electromagnetism, not on Newtonian mechanics. So, in this case, there is no reason to believe that "the resulting pattern on a distant screen would be two patches where the particles hit".

Electromagnetic phenomena, even classical ones, like induction, cannot be described by Newtonian mechanics. So, there is no mystery that Newtonian mechanics fails to replicate quantum phenomena.