A Brief History Of Quantum Mechanics
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- เผยแพร่เมื่อ 27 ก.ย. 2024
- / sciencereason ... Quantum Mechanics (Chapter 1): A Brief History Of Quantum Mechanics.
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1. A Brief History Of Quantum Mechanics
• A Brief History Of Qua...
2. The Structure Of Atoms
• Quantum Mechanics: The...
3. Wave Function And Wave-Particle Duality
• Wave Function And Wave...
4. The Uncertainty Principle
• Quantum Mechanics: The...
5. The Spin Of Fundamental Particles
6. Quantum Entanglement
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The history of quantum mechanics began essentially with the 1838 discovery of cathode rays by Michael Faraday, the 1859 statement of the black body radiation problem by Gustav Kirchhoff, the 1877 suggestion by Ludwig Boltzmann that the energy states of a physical system could be discrete, and the 1900 quantum hypothesis by Max Planck that any energy is radiated and absorbed in quantities divisible by discrete energy elements, E, such that each of these energy elements is proportional to the frequency ν with which they each individually radiate energy.
Planck insisted that this was simply an aspect of the processes of absorption and emission of radiation and had nothing to do with the physical reality of the radiation itself.
However, at that time, this appeared not to explain the photoelectric effect (1839), i.e. that shining light on certain materials can function to eject electrons from the material.
In 1905, basing his work on Plancks quantum hypothesis, Albert Einstein postulated that light itself consists of individual quanta. These later came to be called photons (1926). From Einstein's simple postulation was born a flurry of debating, theorizing and testing, and thus, the entire field of quantum physics.
• en.wikipedia.or...
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Quantum mechanics (QM) is a set of principles describing the physical reality at the atomic level of matter (molecules and atoms) and the subatomic (electrons, protons, and even smaller particles). These descriptions include the simultaneous wave-like and particle-like behavior of both matter and radiation ("waveparticle duality").
Quantum Mechanics is a mathematical description of reality, like any scientific model. Some of its predictions and implications go against the "common sense" of how humans see a set of bodies (a system) behave. This isn't necessarily a failure of Quantum mechanics - it's more of a reflection of how humans understand space and time on larger scales (e.g., centimetres, seconds) rather than much smaller.
Quantum mechanics says that the most complete description of a system is its wavefunction, which is just a number varying between time and place. One can derive things from the wavefunction, such as the position of a particle, or its momentum. Yet the wavefunction describes probabilities, and some physical quantities which classical physics would assume are both fully defined together simultaneously for a system are not simultaneously given definite values in Quantum mechanics.
It is not that the experimental equipment is not precise enough - the two quantities in question just are not defined at the same time by the Universe. For instance, location and velocity do not exist simultaneously for a body (this is called the Heisenberg uncertainty principle)
Certain systems, however, do exhibit quantum mechanical effects on a larger scale; superfluidity (the frictionless flow of a liquid at temperatures near absolute zero) is one well-known example. Quantum theory also provides accurate descriptions for many previously unexplained phenomena such as black body radiation and the stability of electron orbitals. It has also given insight into the workings of many different biological systems, including smell receptors and protein structures.
Even so, classical physics often can be a good approximation to results otherwise obtained by quantum physics, typically in circumstances with large numbers of particles or large quantum numbers. (However, some open questions remain in the field of quantum chaos.)
• en.wikipedia.or...
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Thank you so much for your videos - I have a chemistry test tomorrow and my instructor does not explain anything very well. These videos have really helped!
How did it go?
Hi, May I please use your videos and put their links on Blackboard for my class?
Could the difference between quantum and classical physics be because quantum physics represents the passage of time itself?
This theory is based on just two postulates,
1. The first is that the quantum wave particle function explained by Schrödinger’s wave equation represents the forward passage of time or Arrow of Time photon by photon.
2. The second is that Heisenberg’s Uncertainty Principle that is formed by the wave function is the same uncertainty we have with any future event.
Is Cassiopeia still producing videos? I've enjoyed watching them, they've radically changed my map of the world. I want more!
i love history! wish i loved it this much in school.
Extremely helpful. I really like the diagram indicating how the different colors of light contribute to the changing color of the heated object and how we get white light from the others. Thank you very, very much!!!
thanks for the backup! I wasn't expecting such a heavy lashing for bringing this up :)
Brilliant effort.
@Sardanapalus96 Its called a kiln its used to heat up clay to harden it. If you have ever been to a arts and crafts place its will look like this very large metal container.
It has been 10 years since the upload.. Who's on 2020?
@EezySource I see, and how many years of experience do you have in the fields of neurology and quantum mechanics? Have you ever solved the Schrodinger equation before? Are you a regular subscriber to the Journal of Cognitive Neuroscience? On what neuro-physical basis do you claim this? And what happens when the brain decays after death? Does our consciousness get "blocked" completely? What's the difference between a fully "blocked" consciousness versus no consciousness at all?
You can actually perform the double-slit experiment using one photon at a time. Each photon will actually "land" in a random point in space. The *probability* of finding the photon is the physical thing that "diffracts." Each photon is still a particle, but the probability density telling them where to land is the thing that "waves." This is the essence of duality. Discrete particles governed by a wave equation.
@tomo25252 I was just answering someone's question, they wanted to know what the "oven" thing was. It's called a kiln
@Exmech2:
Sure, they're called "fundamental PARTICLES". But the point is that we don't really know what they really are. We only know how they behave.
Sometimes photons behave like a particle and sometimes like a wave. Therefore the statement "light is most definitely a particle" is most definitely wrong. ;-)
According to String Theory the so called "Fundmental Particles" are vibrating strings.
Thankyou ACX,you are helping me get my head around such counter intuitive concepts a lil' bit easier.
I would love to be able to make such nice videos. I'm a physicists who unfortunately has no artistic skills. With new media we could clarify so many difficult concepts, but there is still a divide....
Can someone please explain to me why why they thought it would keep going to infinity as the frequency rose? I know it has something to do with the energy being equal to kb x ν thank you!
@Shawnbfromsd Not quite true. For example, when you turn on a light bulb, for a fraction of a second, while it's colder, it shines red-ish light, but the next moment it's spectrum gets shifted to yellow, according to Wien's displacement law as the bulb's temperature goes higher.
This is the best video on quantum mechanics I've ever seen. I couldn't guess why it has less than 2000 thumbs up.
I gave up trying to make sense of wave-particle duality and other ideas of quantum mechanics. Even with a good grade in quantum mechanics and further independent studying by looking stuff up online, I came to realize that I don't understand ANYTHING in quantum mechanics!
@schnauzelbif
While there's no reason to link quantum mechanics to consciousness, the context of the statement, alongside what we know is effected by chemicals, demonstrates it probably means what we experience. Damage to the brain resulting in behavioral defects, and the effects of diet on experience, show the same thing. What definition of state of consciousness isn't altered by these things?
@MaitreyaRocket,
Parts of quantum mechanics are accurate, but the idea of quantized space can't be accurate. It's very simple. You can't use calculus if space isn't continuous.
Did you notice that background sound in 6:41 with the military guy photo?
5:46 this statement is the crux of quantum mechanics (from my impression)
Hey guys,. does anyknow of any good documentarys about this subject available on dvd, internet or something?
Thanks!
from 2:22 he said that the hot gases emitted by buring substance emit different colours
Extremely helpful . Thank you very, very much!!!
Excellent series. Highly recommended.
the music makes it like a spooky film
1961 is only the first edition. The latest edition on Amazon is from 1998. This is the first one I learned from when I took my first grad-level course in 2005. Even the "Modern Quantum Mechanics" text I studied in my second grad course last year is dated 1994.
I promise, I'm not trying to be controversial. I really have studied this stuff. I even have a published paper on numerical simulation of quantum systems. I'm not making this stuff up.
best explanation by far
true
@THEFLESHMANN1 When you quote part of someone's post TH-cam sometimes automatically regards it as spam.
what is the relationship between light and electrons? is light a beam of electrons? or are electrons the fuel for light? i was really confused when i heard of electron microscopes :(
Very nice. It was interesting to learn about the science of these things in Chemistry.
But it also is quite fascinating to learn about the history of the theory. The problem solving that went into it and the people who did the problem solving.
These are awesone
I love this channel, even that I am to stupid to understand a lot of it. Thank you for breaking it down as much as you can.
@xKingPola3ux
that's how solar panels work, sun hits the panel which releases electrons and creates a circuit (this is a very simplified version)
Wait, so how can the Photons release the Electrons, if the Electron appears in its wave state?
@boblafro I know what you mean.
But it's like dropping a marble into water, it might disturb the 'water', or wave, but it won't actually release the electron..
But maybe you're right, but it's not how i would have imagined it O_o.
@RevJohn I'm sorry, I don't see what radio stations have to do with limits of consciousness.
Never regretted hitting that "Subscribe" button.
I highly recommend everything on this channel for anyone intrested in learning more about the wonders of this cosmos!
Its like free college, education really is free!
zasabiibasaz
If you're ignorant and have access to the internet, you really have no excuse, save your own sloth.
Prince Istalri Seriously I'm turning into a theoretical physicist while people are watching the kardasians.
+zasabiibasaz
both a computer and an internet connection cost money.
Because he says "In GENERAL, the energy of a photon = n (quantum number) times h (Planck's constant) multiplied by the frequency of the photon."
So, there you go. The military guy appeals to the word "general" in that sentence, even though it's totally irrelevant! :P
@schnauzelbif 'no reason to assume that drugs alter one's "state of consciousness"' What do suppose LSD does?
I suppose our disagreement comes from consciousness is defined. I would define it as how we interpret the ongoing stream of information from the senses, coupled with an internal process for analysis.
Straight to the point. Awesome!
What's the music at the very beginning called? :)
What's the song at the very beginning called?
love this video thank u for such a beautiful demonstration
@CHIPSTERO7 Kind of strange but makes sense , thank you for clarifying that .
Quantum Physics is AWESOME!
@Omega5001x hooray for Quantum Mysticism, eh?
maybe we are just one's whom experience. Our brain observes the world via the senses and the brain does all the thinking and we experience all the brain's actions including what it observes thus we get the illusion we are the brain when we are just observing the brain :)
Very nice presentation and vedio. Thank u sir
Thank you so much
why is there a random military dude in the background at 6:41 ?
Here from BME 135
Two slits.
The universe knows you're watching.
Created observer to be observed. Extrapolate.
@mindvox626 I'm sorry, I don't even remember what this video was about and I'm not about to spend time watching it again so I can defend something I said in passing however many months ago. Thanks.
"Shown" is spelled "shown." Duh.
"Shone" rhymes with "one." The number.
And "center" has a T in the middle. I don't know what a "senner" is.
@charkopolis It's called an analogy. And of course you wouldn't understand, being an old school classical materialist. However, let me get back to you thirty years from now. Quantum consciousness is not merely a fad, it is a paradigm shift that will drag you kicking and screaming into the 21st century.
That periodic table is awesome xD
Very good explanation
To be honest, the scientific community really needs to "sell" its research projects/agendas a bit better. For example, if we said the LHC was going to find the God particle the initial machine would be much larger than what we have now in Switzerland and we would get a lot more funding. I have no idea how CERN screwed up on that question.
To be honest, LHC produced enough collisions to detect Higgs particle. It was all according to a plan. Almost ten years passed since. You had no idea what you are talking in your assessment.
@SinnFein4ever This is just a 10 minute thing to whet your apetite. If you are interested, you should dig further into it!
Awesome TY
So, light behaves like a wave, light only travels with certain amounts of energy, only certain wavelenghts interfere with the entity called electron.
And the conclusion is that light is small particle-waves that hit electrons?
What great "conclusion" ! Those "scientists" must've been geniuses.
Too bad they had no idea what wave, energy and electrons are.
@cooldaddyjames
I have one in my text book, it's called 'Chemistry matter and change' it's similar to that, but not exact.
I wonder why fcdog555's comment was marked as spam , it answers one of the top rated comments questions. Makes no sense whatsoever.
Fantastic. 5 Stars
I love your channel, awesome.
I have that "the elements" chart.
Thanks
Well, that escalated quickly.
@EXALTEDDIRT im absolutely not shure if this is a poes law case or not
look it up!
btw nice vid bu ultraviolet catastrophy could have been cleared up
can anyone please explain me from 5:09 to 9:37
[Sometimes photons behave like a particle and sometimes like a wave.]
Photons never behave like waves. The thing that behaves like a wave is the PROBABILITY DENSITY FUNCTION (solve the Schordinger equation sometime and you'll see what this means). Even the vibrating strings of String Theory are discrete little packets. A single photon does not radiate or diffract in any sense. Only the likelihood of finding the photon may be described in such terms.
Fantastic! thanks!
Huppy the Hippy said "GROOVY!"
You are awesome. Thank You!
@seethruable I don't even know what you're talking about. I have no idea if QM has to do with consciousness or not. I just don't think there has been presented any legit arguments or evidence for it yet. Am I dogmatic in my desire for evidence? Sure, I'll take that title.
The over like thing is called a Kiln
@bigg132
You are everything you exclaim in other words. You've apparently done it all. Thanks for concluding that I'm right. No argument here. There is no win or lose. You may believe something or anothers way that you haven't looked at before. A different perspective so to type. That is what all the difference in opinions are. You point out the reason you believe something and someone else either does or doesn't have to. It is just differences not wins and losses.
The echo and the background music were distracting.
Good work 👏👏
0:57
some people were flamed too....
Which one should we thank? I like thor best
amazing, thanks
Aaaaa this video is awesome
StarOfSaggitarius that is correct.
thanks great upload
@RevJohn Yet here we are, and it seems to be this way. Go fig.
it was interesting, thanks
I'd really like to say your explanation helped a lot but Im afraid it didnt. I have indeed watched the video you mentioned. Thats easy to understand, but the terminology here is just maybe too complicated. Thanks for trying to help tho!
@charkopolis If the brain produced consciousness, we wouldn't be capable of abstract thought -- seeing ourselves in the third person -- evaluating our own thoughts and actions. Consciousness and instinct would be undifferentiated. All our actions would be predictable, programmed, robotic. If the brain produced consciousness, there would be no free will, and nobody could be held accountable. The sole purpose of consciousness would be to service the needs of the organism, the machine. Period.
Great layman's level explanation of the 'ultra violet' catastrophe and it's solution, by way of the beginning of QM.
awesome vid
Sir,I like to know you.Who are you? A university student
@DecentralizedByGuilt i just saw the first page, i didnt know it ended, chill out
Just found a johnny hangong outta my arse with a KC mongram on it?
IT'S A SIGN!
I dont mind his voice so much more the way he says plonc not Planck!
Far from being an expert, I am pretty well versed in the conceptual side of quantum mechanics. It just sounds to me like you've fallen victim to psuedoscience parading around in the guise of legitimate quantum physics. It's quite common, particularly with "what the bleep" running around out there. Any legit textbook on quantum mechanics leads to no such fancy new agey conclusions. Sure, QM is weird. But no where does it require that consciousness be disembodied.