How Cheap Cigars Legitimized Quantum Mechanics

The Stern-Gerlach Experiment in lauded in textbooks around the world for its contributions to the world of quantum physics. But for a few years, scientists unknowingly praised it for proving the wrong thing! Because instead of proving an established hypothesis about how electrons work, it had actually discovered an entirely unexpected phenomenon (called spin).

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Sources:

[NikhillRao]

"Imagine a ball that's spinning. Only it's not a ball and it's not spinning"

[chasenthedragon]

"Gatterman recommends that the operator smoke during the preparation, for he found that a trace of hydrogen cyanide is sufficient to give the tobacco smoke a highly characteristic flavor. This preliminary warning is useful in case of leaky apparatus or a faulty hood."

[brigidtheirish]

When my paternal grandpa was in high school, one of the math problems on a test required finding the volume of the intersection of two cylinders. He pictured the cylinders in his head and came up with the answer. Thing is, the test required that he show his work, so he scribbled down what he though *might* be the equation before moving on.

The next day, the teacher asked to speak with him. Turns out, he was the only student in the class to get that particular question rigth, but his equation was *all wrong.*

[nigeldepledge]

Just to clarify a point with the historical context, Hank : the Weimar republic instituted in 1919 did indeed have a problem with inflation, but *hyperinflation* only reared its ugly head in 1923 (triggered by France occupying the Ruhr Valley where almost all of Germany's manufacturing industries were located, as a punitive measure when Germany stopped paying the reparations stipulated in the treaty of Versailles). By your account, the experiment was successfully performed in 1922, at least several months before hyperinflation kicked in.

I don't know if there's a technical distinction between severe inflation and actual hyperinflation, but 1923 was the year in which the cost of basic subsistence was increasing so fast that you had to spend all your money on pay-day because it might buy only half as much food a few days later. More specifically, this was the latter half of 1923. Up until perhaps May of 1923, there was still some hope that inflation could be reined in before the currency crashed.

[generaledelogu]

At least there's no confirmation bias since he's trying to prove it wrong initially 😂

[grndy]

I understood every word you just said completely and also still have no idea how any of this works.

[matthewkolb]

"Have even gotten a math test back and found you got a tricky question right?" No

[rayneweber]

Man that chemo perm is always surprising.

[colddogs]

smoking in the lab, the famous follow-up song to smoking in the boys room

[dysonkennedy]

physics student here! I never knew there was that lil whoopsie period with Bohr's angular momentum. it's easier to teach some basic spin than it is atomic oriental angular momentum so it makes sense but this is delightful

[josephhargrove]

I'm just amazed that the quantitative relationship between the two angular momenta was ½ and not some seemingly random but close value like √3/𝜋 or some other random, difficult to pin down irrational value. Measurements from nature may appear to relate to each other by (the incredibly convenient) powers of 2, but they rarely actually do. Close may be good enough for the abstract cigar, but not close enough for lab work.
richard
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[sarahleonard]

My entire career has been based on the spin of unpaired electrons. So, thank you, Stern & Gerlach!

[SlowToe]

If I've learnt anything from this video it's to take up cigars. Thanks Crash Course ❤

[GSBarlev]

Physics PhD here—Stern's initial reaction is entirely understandable. When a modern-day physics major learns about quantum mechanics, one of three thing happen:

1. They have a crisis of faith upon learning that microscopic particles behave deeply "unphysically"
2. They see how quantum laws align with classical mechanics principles as the number of particles goes to infinity and think, "Wow, neat! I'm one step closer to understanding the universe's 'source code'"
3. They decide that it's all _useful math_ and decide not to take any of it too seriously beyond its ability to make predictions.

Broadly generalizing:
- People in the third group go on to have long, productive careers in physics
- People in the first group switch to engineering
- People in the second group go on to *become crackpots.*

[BrownP]

Generations will truly remember the Stern-Gerlach Experiment as the first scientific implementation of the "task failed successfully" meme.

[davido]

Love the 90s / early 00s aesthetic of the background and some instances of the camera work.
Also, look into the "discovery" of potassium flare stars, another incident in science (astronomy) involving smoking.

[rosskappa]

Beautifully explained a somewhat complex story. I love this channel. Hope I can have the economic power to support you guys in the future !

[terrafirma]

When you stare into the quantum void, it... panics.

[QuintonMurdock]

This is comedic in such a nerdy way. The story has comedy to it that only some people would be able to appreciate the impressiveness and the comedy

[aliciakidd]

Look at that curly hair coming in! Lol just a reminder how lucky we are to still have you on this Earth. Thank you for being you.