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How Cheap Cigars Legitimized Quantum Mechanics
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- čas přidán 12. 07. 2024
- 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).
Hosted by: Hank Green (he/him)
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"Imagine a ball that's spinning. Only it's not a ball and it's not spinning"
Electron spin
"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."
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.*
I had this issue too, I knew what the answer was for questions, but I hated showing my work cause.. I couldn't. I knew it was right, but I couldn't explain how I knew it was right.
@@SeraphRyan My father is a master estimator. I did not inherit all his talents, but I'm really good at estimating area and volume.
It's really eerie watching my dad do math in his head. He's never "right" but he's like 3 decimal places right 90% of the time.
@@SeraphRyan I generally suck at math, but I drove my mom *nuts* because I'd get word problems right and equations *wrong.* Somehow, the word problems made more sense.
I remember a HS Statewide test where I looked at the graphic where they wanted us to calculate a distantance and it looked to scale to me. So I just measured the answer distance and gave the answer.
Some questions I just did in my head.
I was questioned because I hardly used the paper they gave us to do our calulations.
My son could spout off the answer to any math question, no matter how complicated, but could never tell you how he reached his conclusion. It turned out to be his particular thought process. As he described it, the average person might see green but doesn’t think blue and yellow. They think green. That’s how he saw math.
At least there's no confirmation bias since he's trying to prove it wrong initially 😂
A much more reliable way of testing.
Task failed successfully!
Someone - maybe Feynman - said that when an experiment is verified, you learn something. And when an experiment is refuted, you also learn something.
This is such a healthy take, it's joyful, and I shall endeavour to carry it with me, for the next time I am very wrong about something!!
@@baruchben-david4196 it's an unfortunate fact that most people don't understand that the experiments that fail are often the most important ones.
I'm b@@katbairwellnd😂b ed Know what I mean
Oxymoron XD
"Have even gotten a math test back and found you got a tricky question right?" No
Thenn you need to smoke more cheap cigars
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.
I understood every word you just said completely and also still have no idea how any of this works.
Congratulations! You're ready for a career in physics.
Nobody understands "how it works," and anyone who claims to is trying to sell you something. QM is *deeply weird,* and, unlike classical mechanics and relativity, which can be derived, more or less, from pure logic, quantum mechanics requires complex and expensive experiments to determine which "solutions" it produces are "physical" (see the other video on: "Does antimatter fall up?").
As a serious reply:
Imagine a spinning ball that is magnetic, with one half being positive and one half being negative. It is shot through a strong magnet and lands on a surface behind it. To make it more visual, you can also imagine a ball with a light at either end.
The old theory was that the ball was magnetic all the time, so if it spins, the magnetic field constantly changes direction in relation to its movement. Imagine the ball with lights being thrown with spin and how wildly the direction of the light would vary.
The new theory was that the ball wasn't magnetic all the time, so if it spins, it is only affected by the magnetic at intervals. This would be like the ball with lights flashing instead of being constantly on.
The result of the old theory is a random, linear pattern as the ball can have the magnetic field be in every direction.
The result of the new theory is a specific pattern as the ball has a known spin and known interval in which it is magnetic.
This makes the pattern predictable as there is a constant instead of absolute randomness, proving that particles act in the way quantum physics describes.
You must be a physicist!
Breaking the IRL fourth wall.
Congratulations, you understand quantum mechanics as well as any expert. Which is to say we dont understand it, but we're starting to figure out a number of facts, even if we cannot fully comprehend those facts.
Man that chemo perm is always surprising.
It also happens from some anti-epileptics like Depakote.
smoking in the lab, the famous follow-up song to smoking in the boys room
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
Bohr's idea was better than what was before him I believe and serves well to get some idea.. We keep on learning things better and more accurate but I don't think we have come to the end of it.
@@leonhardtkristensen4093 of course, we probably wouldn't know his name if he was conpletely wrong. And (to my knowledge) his model is still useful for some applications, in a "use the simplest tool that does the job" kind of way - like Newton's laws of motion don’t completely accurately describe forces, masses and acceleration, but we don't bring out relativity to calculate how a car accelerates
10:51
Nolan: hold my joint
Cigar*
If I've learnt anything from this video it's to take up cigars. Thanks Crash Course ❤
My entire career has been based on the spin of unpaired electrons. So, thank you, Stern & Gerlach!
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.
My mom's hair came back curly after her chemo for breast cancer some 8-9 years ago. Greyer than before but thicker and much more curly.
@@Pow3llMorgan My cousin’s previously thick and curly hair came very thin and straight. The fact that she dyes her hair a dark brown colour makes her scalp stand out more than if she didn’t dye it.
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
--
in this case they do, because both values are determined by the same thing: symmetry under rotations and the special angle of 360°
Interestingly enough, that extra factor of 2 that the electrons pick up in their magnetic moments isn't actually 2, but around 2.00231930436092. The extra contribution comes from interactions between the electrons and the quantum electromagnetic field.
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.
Beautifully explained a somewhat complex story. I love this channel. Hope I can have the economic power to support you guys in the future !
Generations will truly remember the Stern-Gerlach Experiment as the first scientific implementation of the "task failed successfully" meme.
The Michelson-Morley experiment did it earlier.
When you stare into the quantum void, it... panics.
Using silver during hyperinflation is dedication.
they snuck this one in right before hyperinflation
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
Still getting used to curly-haired Hank. Not like it's a bad thing, just "oh yeah he underwent a transformation because of murdering cancer"
tbf, it's not generally permanent. Give it a few years, he'll likely have his old hair type back.
the epitome of " it's going to be okay, but it's going to be different"
@@matheussanthiago9685 For the record I think he looks great but I had similar hair in HS (when the hormones chilled out it got straighter)
I think this is easily my favourite Sci-Show episode ever.. not only is it educational, but funny, its advanced quantum theory dramatically - discovering 'spin'..
And, you can tell how smart these people are, because I got to the middle of the video and was like "cool, so, that makes sense" but no.. even smarter people later, picked it apart and discovered it was right, for the wrong reasons.. and one of the craziest things about spin is that you can have ½ spin, where you have to rotate the particle 720⁰ (twice all the way round) just to get back to its starting point.
I can't believe we have worked any of this stuff out because it is a hard combination of nonsense and counter intuitive facts.
Oh, and the cherry on top was Hank. Looking great and radiating enthusiasm!
This episode is surprisingly good!
There are so many great physics stories from the early 20th century. I haven’t this one before.
5:55 the left picture says "WITHOUT magnetic field" and the right "WITH magnetic field"
The text roughly says "Dear Mr. Bohr, here are the results of our tests of the directional quantisation. Congratulations to the confirmation of your theory!"
Wow this was a super interesting video, never heard of this mixup! Crazy that it all worked out how it did
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.*
What category are the three Nobel 2022 physicists Clauser, Aspect, Zeilinger for quantum entanglement, quantum teleportation and their applications?
I can confirm this. I was in the second group. I'm currently researching the corelation of the raise of crime with the decline of spirographs.
Think about it
"They see how quantum laws align with classical mechanics principles as the number of particles goes to infinity"
Huh? This doesn't work in many cases, e. g. in metals, you have a very large number of electrons which don't behave classically at all.
also a physics PHD here, im off that good kush and alachol
H-bar? Are you serious? Scientists named something normal ONE TIME and I struggle to grasp the concept of it. Yet when they want to name an everyday medication EVERYONE uses they use the most random jumble of letters to be thought of.
Scientists don't really name medications anymore, marketing teams do.
@@AxyzGridWell said. There's an entire study on the name of diseases/disorders and their subsequent medication, and what key additions to the name make it more appealing to consumers
Isn't h-bar the Planck's constant?
@@porcorosso4330 _Reduced_ Planck's constant (it's basically Planck's constant divided by 2*Pi).
@@AxyzGrid"The bell doesn't dismiss you, I do!"
Nuance time! It is understandable why it didn't make the script, though. The earth also has momentum the sun's orbit around the galaxy, and the galaxy's trajectory toward the Andromeda galaxy.
eh, nothing Hank said discounts that.
Tbf all motion is relative
Those components are negligible. "Nuance" doesn't mean including things that are irrelevant. Same reason he says it's not worth discussing why planets orbit on a roughly flat plane.
And don't forget the angular momentum from the rotation with the moon.
@@mailcs06Rotation is an accelerated motion. So it is not relative as only one frame of reference is free of centrifugal forces.
Thanks for making a video on these early quantum physics people - I love the stories of these sorts of experiments from the time of the ultraviolet catastrophe to the end of wwii, when scientists didn't have any computers or huge particle accelerators or anything like that, just hilarious contraptions and cigar smoke and yet they were making all these counterintuitive discoveries about the smallest parts of the universe.
I've never heard of Stern before, but him sending a photo and congratulating Bohr on confirming his theory sounds like a class act.
Love this video that’s somewhat deeper than many scishow videos (also super like the quick ones I watch while wolfing down lunch 😋 )
What a perfect story for understanding how the scientific method works.
Best class I took in college was the History and Philosophy of Science!
I never knew about the cigar smoke part of the experiment! Much of the rest is taught in many intro quantum courses but the fun cigar smoke information is really interesting!
Sometimes a cigar is just cigar. And apparently sometimes a cigar also accidentally leads to great scientific discovery.
We got cheap cigars legitimizing quantum mechanics before GTA 6
Please do more long form videos like this ...
Absolutely wild that two men that worked so much together on things I don’t understand wound up on opposite sides of history
1:13 Um, why is there a little "Credit:" on Hank's chest?
I think that was supposed to name the creators of those two images, but now it's a typo!
"Spooky action, at a distance..."
The question this video left me with is how do scientists collect a single atom for those types of experiments? With the way search engines work now I can't seem to find an answer
They don't really collect individual atoms. The way it's done nowadays is different, but the way it was done in that experiment is heating a chunk of silver in an oven so it emitted silver particles, and then passing these particles through a series of slits in order to only keep the ones going in a specific direction.
with really tiny tweezers
@@MalcolmCooks thought so
@@RedHair651 yes after doing much more research I saw that it's more a "stream" of particles per se
Either magnetic fields or lasers sort of like how you can make a ping pong ball hover with air the pressure from lasers can move a single atom around
One mistake I think is worh noting, in quantum physics lingo it's not the magnetic moment that is two, it's the so called g-factor (or Landé factor depending on who you ask) for the electron that is two.
For as many times as I've heard of Stern-Gerlach machines (thanks PBS Space Time!) this is the first time I've heard the whole story.
I just watched the CSI episode the Theory of Everything which included the Mythbuster’s String Theory and Characters named Bohr, Planck and a cat named Schrödinger.
At what speed would a hydron collider need to move/spin to cause noticable change in its normal operation?
Smoking in the lab is also how cyclamate was discovered as an artificial sweetener
Never know what you'll discover when you set your ciggie on some chemicals ... and then resume smoking it like nothing happened!
Proving yourself wrong is a glorious moment for any serious scientist 🥰
hell yea, great episode with hank with the coolest topic in a while
Hank is looking great! Especially the hair!
In quantum physics, the Stern-Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized. Thus an atomic-scale system was shown to have intrinsically quantum properties.
Soon as I heard the words "The Stern-Gerlach Experiment" I thought this was PBS Space time for a hot moment lol
I had a feeling that we are still working with a wrong or more likely incomplete model of quantum physics
yes of course. The amount of energy we need to really test out the multiple models is litterally astronomical.
We *need* a space based economy.
Not just for the energy collection required for the science either. We need to end scarcity for people, and accept that it wont be profitable, it will end the idea of profit as a motive at all.
Fame, Fun, Helping each other, and Exploration. Not profit will be the currencies of the future and we have to switch it up, or accept the inevitable, and terrible wars we will cause otherwise.
A lot of very smart people have thought quantum mechanics might be incomplete, but the ways people try to complete it tend to be incompatible with the original theory. See Bell's theorem for an example.
You're right that we don't have a full model of quantum gravity yet.
Buuuuuuut we can't discount the successes of QFT. Just look at the device you watched this video on. The results speak for themselves.
I will never forget one time in my sophomore year math class we were competing with other students in groups of 4. I was the de facto leader of my group because I was well regarded as one of the best math guys in our class, and on one particular problem I got the answer 15. Now a member of my group who was the only other person that decided to complete this problem as well looked at my work and noticed a few logical errors, while their own work appeared to have no issues. Begrudgingly the group decided to go with his answer.
The correct answer to that problem was in fact 15, and had we gone with that answer we would’ve one the competition with a perfect score. Alas we did not go with that answer and came in second.
Man, I am so glad you're doing well. I missed your science sass.
I noticed the curls are slowly going back to straight!!!
Yup! He did a great Sci Show about it!
Not me thinking we’d go away knowing how to extract quantum particles from cigars 😂
Thank god for this. I was reading the history trying to wrap my head around this and couldn’t figure out what the hell happened
Smokin’ in the Bohrs room!
I am not a student in the field but I called that it was spin before it was mentioned in the video.. I never really understood what that meant but now I have a better idea of it (as better an idea one can have about quantum anything without a full education that is)
Loved it! more videos like this please💛💛
Smoking in the lab was also how the first artificial sweetener was found.
Would the Earth also have angular momentum from its orbit about the galactic center? I wonder if it would be more or less than it gets from orbiting the Sun.
Yes it does. The scales aren't going to match.
I sometimes wonder if the sciences have been more progressed by people who were willing to be wrong, than by those who were right. As someone that is wrong , like a whole heckin' lot (for a wild variety of neurodivergent, and disability reasons), it brings me a sense of peace, that maybe wrongness isn't inherently bad, and be something I can learn to sit comfortably with. I've not got there yet, but lessons in the history of science, like this one, are boeth educationally, and emotionally, edifying for me. Thank you SciShow, for giving me a healthier perspective on both the universe that exists all around us, and also the microuniverse that exists between my ears!
Different is not wrong. Solidarity.
Is they audio not perfectly synchronized on this video? or is it youtube being screwy again
This is the silliest thing about physics I've ever heard and I love it 😂
What's with that eyeball shape on the photographic plate, though? I've never heard anyone talk about anything other than the two piles at +/- h-bar. What happened with the ones on the sides?
The magnetic field is weaker towards the edges, so the silver atoms get deflected less and less the more close they are to the edges. This results in this eye-like shape.
Earth has a third source of angular momentum - Earth revolves around the “barycenter” for the Earth-Moon system.
I love Dirac. What an interesting and amazing human being.
To me it's phenomenal how little time it's been since we developed these theories - what, a hundred years or so?
It's amazing how in science, two wrongs can sometimes make a right.
How did Quantum Physics give us micro chip and laser ?
Microchips utilize semiconductors, which only exist because of the quantum band gap structure of such materials. Lasers function because atoms absorb and emit light at only fixed energies, and interacting with a photon of one of those energies can stimulate the emission of another.
Excellent, thank you!
Physicists have always had a weird thing with smoking historically
Take a drink for every "Stern" and "Gerlach" and a shot for every "h-bar"
You'll be discovering your own definition of spin after that
He was in a superposition of being right and wrong at the same time.
Great video! Thanks :)
The last math class I took...I'd get the tricky problems very surprisingly right and make a mess of the basic operations!🤦♀️
I especially liked this one. Unfortunately I can't really say why. If I could so I would say, do "this" again.
This is why science works, because if you carefully set out to prove someone else wrong you will often end up proving yourself wrong instead.
Nicely done. 😊
10:00 I think they just repeated the experiment so they had a valid reason to be allowed to smoke cigars in the lab. That's what I would have done.
cigarette ash also played a role in the discovery of cilia on the lungs.
Why does the mark on the silver look like a line and not two blobs in the photo???
This is a helluva great story!
Love how this set of anecdotes shows us that science is tricky, quantum physics is WEIRD, and Hank has very strong opinions about best practices in the laboratory!
Also that important knowledge is created not by lone geniuses (with or without cigars), but by MANY brilliant minds, and MANY long and frustrating hours of thought, experiment, rethinking, and debate. (Debate meaning, arguing without coming to blows about it, an art that seems to be vanishing these days)
I like the stories behind the discoveries. You always present them in a very impressive and detailed way. But can you please clarify the pronunciation of the names of the people you are talking about? Google Translate in German certainly gets it right with the names Stern and Gerlach.
Am I wrong or do all planets not rotate on their axis? Yes they spin around the sun but they all freely spin on their own as they rotate the sun correct?
Yes and no. Ideally, they all _should_ rotate in the same plane as their orbits, just because they all got their angular momentum from the same place. However, other events like collisions can turn the axis of rotation, causing it to precess thereafter. Earth's orbit has a small but notable tilt that causes seasonal weather in part because of the collision that gave us the moon. I believe Uranus (could be a different planet, but I think it's Uranus) is all the way on its side.
A great reminder of how multiple errors can sometimes lead to the right answer.
Looking good Hank 💛🙏
Those scientist guys n gals were rippin blunts…….
I clicked on this informative video to try and justify my enjoyable habit of smoking cheap cigars.
A note; I do not inhale, however, there is a substance called second-hand smoke!
mike
Thanks!
That's actually crazy that Einstein and Max plank were at the same table
They were friends of course. What's surprising?
What until you hear about the Solvay conferences. ;)
Looking good in your new hair!
Moment doesn't sound like moment. One has the emphasis on the first sylllable the other on the last.
For disambiguity we say momentum in English.
I think it’s the gyromagnetic ratio that is (close to) 2, not the magnetic moment. The magnetic moment has units…gyro magnetic ratio does not.
Thanks a lot 👍
The beginnings of Quantum Theory were just a bit meta.
Interesting stuff 🙂
I used to smoke in the lab all the time. Usually transformers and rectifiers. And yes, it was a bad idea.