3. Wave-Particle Duality of Light

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  • Опубліковано 19 січ 2025

КОМЕНТАРІ • 134

  • @lucasm4299
    @lucasm4299 7 років тому +88

    Omg. These are good. You don’t just throw equations, but explain where they come from and why they make sense in a simple manner.

    • @NazriB
      @NazriB 3 роки тому

      Lies again? Hello Whatsapp

    • @quasa0
      @quasa0 2 роки тому

      @@NazriB hello hello lies again!!!

  • @LostAlienOnEarth
    @LostAlienOnEarth 9 місяців тому

    The creativity in play here is stunning!

  • @medicinalis9642
    @medicinalis9642 2 роки тому +19

    I'm not from the us but you can't imagine how helpful was that for me, to see the greatest educational institution offers the help hand to all students from all countries and for free. thank you MIT on behalf of all the students

  • @mohammedbadra8797
    @mohammedbadra8797 6 років тому +121

    The more I see these videos, the more I realize that what I receive at school isn't really an education...

    • @miyamotomusashi4556
      @miyamotomusashi4556 4 роки тому +4

      Considering your name, you are probably an Arab, and so am I. Here in Algeria we have the worst educational system you can think of.

    • @jaykay2218
      @jaykay2218 4 роки тому +6

      Shinobi San here in America we have an “educational system” but it’s no good.

    • @miyamotomusashi4556
      @miyamotomusashi4556 4 роки тому +3

      @@jaykay2218 Compared to ours. Yours is good.

    • @mohammedbadra8797
      @mohammedbadra8797 4 роки тому +8

      @@jaykay2218 It all depends on the teacher. Physics is the same everywhere, but when I wrote that comment, I was comparing the professor to my high-school physics teacher. My teacher only knew what it takes to solve a problem and that's what he only cared about. But this professor was much much more knowledgeable and that was visible in her teaching. I know that not all teachers in the US are like that, but at least you can find them somewhere. But here, they're very very rare

    • @theheadscout4356
      @theheadscout4356 4 роки тому +3

      I am South African. I fully agree with you!!!! My country has been ranked last in the world in 2020 in science education.. Do the math.. (Most in my country cant...)

  • @calengr1
    @calengr1 2 роки тому +11

    15:50 Roy G Biv; 27:48 duality ; PE effect; 30:20 Graph freq vs KE; 31:18 Int vs KE; 33:20 h Planck constant

  • @tolulopeadeliyi9242
    @tolulopeadeliyi9242 3 роки тому +3

    This is an excellent lecture. Thanks, Prof. Drennan. You made me understand the wave-particle duality of light so easily.

    • @schmetterling4477
      @schmetterling4477 2 роки тому

      That's cool, except that there is no such duality. :-)

  • @9241716399
    @9241716399 6 років тому +8

    This makes a lot of sense to me.
    I got a clear picture when she explained the graph of KE vs Frequency

  • @shb8651
    @shb8651 6 років тому +24

    Thanks a ton Prof. Drennan & MIT, these lectures are really helpful for my high school chemistry back here in India, and yes I promise 23:04

  • @Adharsh774
    @Adharsh774 4 роки тому +9

    While watching the video I have a same feeling that of sitting in MIT.

  • @kallmekrissarchivetiktoks8012
    @kallmekrissarchivetiktoks8012 7 років тому +30

    This lectures are really good!! Thank you!!!

  • @donboscongwina1479
    @donboscongwina1479 3 роки тому +3

    Thank You Dr. Drenna. Your lectures help me understand General Chemistry better.

  • @mojtabafarahani3553
    @mojtabafarahani3553 Рік тому +1

    Best professor of all times☢

  • @helicalactual
    @helicalactual 5 років тому +4

    that was so dope!!!!!! YOUR THE BEST PROF DOC DRENNAN!!

  • @agabriela1
    @agabriela1 4 роки тому +2

    Wow, these are phenomenal. I wish I had these videos when I was in highschool

  • @natashashvetz405
    @natashashvetz405 4 роки тому

    Thank you for revealing the truth. E = hf shenanigan is not the "internal" energy of electron. From KE = hf - hf0 we see that speed of the ejected electron depends on the frequency of light.

  • @samuelwamwere4867
    @samuelwamwere4867 Рік тому

    I literally came to the US after following her classes!

  • @Spacexioms
    @Spacexioms 3 роки тому

    Even in 1.5 speed, it’s fairly easy to follow this teacher

  • @fantoom88
    @fantoom88 4 роки тому +1

    I love these lectures, and I love professor Drennan!!!

  • @nathanielreichert4638
    @nathanielreichert4638 Рік тому

    No kidding, at Towson university, we didn’t start doing mole calculations until the last month of the course.😂

  • @paul_lewallen
    @paul_lewallen 6 років тому +1

    This lecture is a great supplement to my courses at community college.

  • @adarshyadav5985
    @adarshyadav5985 8 місяців тому

    The ejected electrons from the metal surface are also called [ Photoelectrons ]

  • @dancooper8551
    @dancooper8551 Рік тому +1

    Excellent lecture!

  • @ruellerz
    @ruellerz 5 років тому

    Maybe I'm just stubborn but I dont understand why we need to think of light as a packet after introducing E=hv. I visualize wave peaks propelling the electron instead of packets. If the frequency is too low the wave peak can't quite hit the electron in the electron shell. I should do more research about that v0. Is v0 where is becomes 100% efficient? Visualizing a beach ball tied to a buoy "x" amount of feet away in the ocean. The wave peak needs to be just right at which it breaks the rope and the beach ball/electron goes flying.

  • @jorgemeruane
    @jorgemeruane Рік тому

    muy muy MUY BUENA PROFESORA, SIMPATICA Y BELLA, BUENAS CLASES SUPERRRRR ELLA.

  • @Josephteles
    @Josephteles 7 років тому +5

    Mais uma aula fantástica.

  • @maxwell3814
    @maxwell3814 4 роки тому +2

    Cooler than a Rockstar🙌🏿

  • @kamilziemian995
    @kamilziemian995 16 днів тому

    I have more question about quantized nature of light, that I have two days ago. Maybe I will be able to solve some of them, maybe not?

  • @Dark-tk9xu
    @Dark-tk9xu 2 роки тому

    It is not clear to me as to how classical mechanics says that energy of a wave has no relationship with it's frequency. 30:24 Can someone help?

    • @schmetterling4477
      @schmetterling4477 2 роки тому

      Because the energy of a classical wave is proportional to the square of the amplitude. It is also not quite proper to say that in quantum mechanics the energy of a wave is proportional to the frequency. The energy of the quanta that form a classical wave is proportional to the frequency of that classical wave. It is not proper to say that quanta have a frequency, though. One has to have a narrow distribution of quanta with nearly equal energies to form something like a classical wave packet with an identifiable frequency.

  • @Blade_Music2049
    @Blade_Music2049 5 місяців тому

    Why did you tell me about ROY G BIV. What have you done.

  • @sitaramar13
    @sitaramar13 3 роки тому

    I have a doubt madam. In wave propagation water or sound , how individual particle vibrations are transmitted from particle to particle in the direction of wave propagation? There are gaps between particles in solids, liquids and gases. Is this not against principle of locality?

  • @practice6566
    @practice6566 3 роки тому

    it is so figurative teaching system you used

  • @sanjuansteve
    @sanjuansteve 7 років тому +1

    It seems the most obvious & logical explanation for a #particle acting like an #AxialWave when moving thru space is that it's orbiting something (a dark matter particle perhaps) or visa versa.
    It's not unlike Earth being pulled into a wobble by the moon, or a distant star's wobble evidencing planet orbits making our trajectory as we fly thru space have an axial wave (packet) as well.
    And since we think we know undetectable dark matter exists but don't yet know where it's distributed, this seems the most logical possibility. What do you think?
    This could explain the double slit experiment results, including with a detector with some interaction between the dark matter and the detector.

    • @kallmekrissarchivetiktoks8012
      @kallmekrissarchivetiktoks8012 7 років тому

      sanjuansteve I would HIGHLY doubt that's the case

    • @sanjuansteve
      @sanjuansteve 7 років тому

      Which particle physics or QM theory do you believe best explains the universe?

    • @joeseppe1398
      @joeseppe1398 6 років тому

      i think if we can see spectrum of an atom then we can assume its change it orbital via force.

  • @mahbubaaktary2593
    @mahbubaaktary2593 6 років тому +4

    That was really impressive.Thank you very much!

  • @eshwarray3993
    @eshwarray3993 5 років тому +2

    Thank you this vedio is extremely helpful

  • @spencerhahn1635
    @spencerhahn1635 4 місяці тому

    I remember being taught that intensity of light is related to the energy of photons through their frequency, or something like that. And I can find info saying similar things online. But here it sounds like intensity is measuring the amount of photons only? I'm sure the professor is right, but I think I'm misunderstanding something, or different people are conveying this information in different ways that is confusing me.

    • @lepidoptera9337
      @lepidoptera9337 3 місяці тому

      Intensity is the power per unit area. This is a completely classical quantity and it's valid for any spectrum. The energy of a photon, which is the quantum of energy of the electromagnetic field is proportional to the frequency of monochromatic light. The latter relationship links a quantum mechanical quantity (photon energy) to a classical quantity (frequency).

  • @banduraleeroyt4364
    @banduraleeroyt4364 Місяць тому

    many thanks ,,,the topic is now easy🙏🙏

  • @RedNomster
    @RedNomster 3 роки тому +2

    Using the popcorn button on the microwave is some of the worst advice, I thought she was smart
    /s
    Seriously though, don't use the popcorn button, it even says on most bags that the popcorn button will burn your popcorn, which is the opposite of what she says in the video.

  • @moulikkhanna8746
    @moulikkhanna8746 3 роки тому +1

    thanks a lot for video it is extremely helpful.

  • @ED99LAM
    @ED99LAM 2 роки тому

    I am unclear why photons loss all the energy to the ejected electrons ( when Ei > workfunction) - can photons lost part of the energy to the electrons? thanks in advance for answering.

    • @schmetterling4477
      @schmetterling4477 2 роки тому +1

      Yes, an electron can absorb part of a photon's energy. That's called inelastic scattering. It's not really proper to talk about "the outgoing photon" as the same as "the incoming photon", though. And, no, in case of the photoelectric effect not all of the photon's energy is imparted on the electron. Much of it goes to the metal's lattice.

    • @ED99LAM
      @ED99LAM 2 роки тому

      @@schmetterling4477 thanks. This bring me to another question of this lecture> is it assuming all photons energy is fully transferred to the ejected electrons K.E. = Ei- workfunction ? am I misunderstood ?

    • @schmetterling4477
      @schmetterling4477 2 роки тому +2

      @@ED99LAM That's correct. If the electron gets all of the photon energy, then the remaining kinetic energy is still reduced by the work function (which is basically just the electrostatic potential energy of the electrons inside the metal). At least that's the simplified theory. In practice there is also a thermodynamic component, which is why thermal emission is possible even without external sources of energy like in case of the photoelectric effect and then we can also lower the work function with an additional electrostatic field, which leads to field emission. And finally the work function can be greatly modified by surface contaminants, leading to both a suppression of emission and active emission centers. And now things get really complicated (and interesting for physicists who like to work on surface physics).

    • @ED99LAM
      @ED99LAM 2 роки тому

      @@schmetterling4477 thanks for taking the time to answer my questions. There are more to learn in Quantum physics.

  • @surajpaswan7456
    @surajpaswan7456 5 років тому

    What is the work function here mean? (38:00)

    • @chiklachikla7641
      @chiklachikla7641 2 роки тому

      Planck constant(h) ×treshold frequency of the metal(v0)

  • @l1h4x0r
    @l1h4x0r 4 роки тому +2

    Misconceptions about photons. What if I told you photons don't actually move. They allow photonic energy to travel in the same way air allows sound to travel. Duality of light is a misconception, particle and a wave. Speed of Light is another misconception or worded incorrectly. It's actually the Speed of Energy. Take picture of a pendulum and see what it does (transfer of kinetic energy from one end of the pendulum to the other) and you'll have a better understanding of why/how light/energy travels so fast. The word you need to get familiar with is propagation.
    Photon is the particle and the energy is the wave. Photon doesn't actually travel the whole distance, that is the whole misconception.

    • @samuelallan7452
      @samuelallan7452 3 роки тому +2

      No photons can absolutely travel the "whole" distance. In fact you can get an interference pattern on a screen (an experiment reproduced multiple times) by firing individual photons

  • @gyro5d
    @gyro5d 3 роки тому +1

    Light does not have a speed, it has a rate of induction. Light does not exist, it's perturbations of the Aether field. Until it hits a 3D vortex, so called particle, creates a hysteresis of Illumination.
    Visible light is at phi:1 on the EM spectrum. Magnetism is phi:1.
    Photons and electrons are not particles, they are Vortices.
    e- >~< p+ = Aether's Hyperboloid, ~ = Inertial Plane = Infinite Capacitance. The smaller the Spacial footprint, the higher the capacitance. Aether's Hyperboloid Apex.
    Aether decays into e-, ~, p+. p+ enters Counterspace, 1836 p+ in Counterspace = 1 Proton as seen from Space. 1836 e- in Space.
    Blackhole/Counterspacial Sink is Aether's Hyperboloid into Counterspace.
    Stars are Aether's Hyperboloid into Space.
    Space was created for Aether to exist in.
    Aether was created for Space to exist in.
    Empty Space does not exist.

  • @state8458
    @state8458 4 роки тому +1

    that was nice.thanks

  • @codingWorld709
    @codingWorld709 3 роки тому

    Thanks

  • @hsjoo9734
    @hsjoo9734 7 років тому +4

    OMG I would have so answered that question....!! I want want want that Lego DX

  • @not_amanullah
    @not_amanullah 5 місяців тому

    Thanks 🤍❤️

  • @lindseybrummert8068
    @lindseybrummert8068 2 роки тому

    I actually understand wavelength and frequency 😮

  • @adrianwright8685
    @adrianwright8685 4 роки тому +1

    1:08 1% got 24 moles - well, 12+ 12 = 24 so I guess that's their logic!

    • @duraace6511
      @duraace6511 3 роки тому

      That’s pretty scary considering they are MIT students. I hope it was a troll or a technical failure.

    • @dontdisturbimstudying6944
      @dontdisturbimstudying6944 3 роки тому

      well i got 2 moles . and my logic is very complex.

  • @the.abdullah.nouman
    @the.abdullah.nouman 10 місяців тому

    7126D

  • @exactspace
    @exactspace 5 років тому +3

    The students that refuse to clap have some personal issues.

  • @bymanshi
    @bymanshi 4 місяці тому

    12:02

  • @MrHenkfromHolland
    @MrHenkfromHolland 7 років тому +1

    I'm Dutch, but this lecture is easy stuff for people how got electronics education
    This glass is very simple

    • @lucasm4299
      @lucasm4299 7 років тому +3

      Henk ten Dolle
      What?

    • @navarrogomezfernando2693
      @navarrogomezfernando2693 5 років тому +2

      completely agree with you I find this quite easy.

    • @Colonies_Dev
      @Colonies_Dev 5 років тому

      Hello dutch

    • @love1algeria785
      @love1algeria785 3 роки тому

      I know for European people this stuff is very easy. This is America education is very easy and all get As

  • @rememberme8632
    @rememberme8632 3 роки тому +1

    roy g biv common its
    VIBGYOR

  • @santushtiranjan5831
    @santushtiranjan5831 6 років тому +4

    instead of ROY G BIV, we can memorize VIBGYOR!!!!!!!!!!!!!!!!!

  • @CaptainCalculus
    @CaptainCalculus 7 років тому +2

    I don't see the point of the clickers, it just seems like a time padder

    • @mitocw
      @mitocw  7 років тому +9

      It gives an instructor realtime feedback on how their lesson is going. She is able to see where there is confusion on a particular subject and cover it more. Here's an educator video on it: ua-cam.com/video/VXeTfT8JL0Q/v-deo.html

    • @alial-musawi9898
      @alial-musawi9898 6 років тому +1

      @mit
      They're an excellent idea!

  • @laurenc5054
    @laurenc5054 3 роки тому

    do molecules ever do game theory?

  • @TheJohnmuniz
    @TheJohnmuniz 5 років тому +1

    It maybe that it becomes a wave do to the weight or interference of shadows or electromagnetic field or dark matter energy event!

  • @anilmaurya9072
    @anilmaurya9072 3 роки тому

    Great

  • @donutzzs
    @donutzzs 3 роки тому +1

    Stop typin' "our education system is poor". If u had good education system and a great teacher why would u come here?

  • @matthewgale6560
    @matthewgale6560 2 роки тому

    The human body is also considered continuous overlaps
    And sectors
    that really relate
    to the factor being round
    We are round until
    Applicated shape.
    The desire will be met by the maker.

  • @carlasouza5194
    @carlasouza5194 3 роки тому

    she seems soooooo nice

  • @kiyoponnn
    @kiyoponnn 5 років тому +9

    lol that first question is something I learnt in grade 10

    • @frank-ek4cy
      @frank-ek4cy 4 роки тому

      Oo the classic, I LEARNED THIS AT GRADE .....

    • @GameOnBeast
      @GameOnBeast 4 роки тому

      Im sure everyone did lol

    • @jameseames4754
      @jameseames4754 4 роки тому

      I skipped ten grades. I basically learnt in the womb. No, I learnt it as a sex gamete.

    • @YISTECH
      @YISTECH 2 роки тому

      😨😨😨😨😨scary

    • @kiyoponnn
      @kiyoponnn 2 роки тому

      @@frank-ek4cy dude, I am not american so pipe down. We actually learn things in school in the rest of the world instead of having gun violence

  • @drewmetra
    @drewmetra 6 років тому

    RESPECT

  • @love1algeria785
    @love1algeria785 3 роки тому +2

    Really many concepts were not well explained. For example waves were badly explained as she did not explain what really a wave is? as a traveling pulse not a motion of matter. Also she always taking waves as periodic while it could be just pulses (like Tsunami) generated by an earthquake (the source) in oceans that then propagate in the medium (water). A wave is created by a source of pulses that propagate because there is a medium. The sound is a longitudinal wave where the source is your tongue moving the air and these perturbations propagate in air (the medium): sound waves cannot propagate in vacuum it need a medium. All waves need a medium to propagate except electromagnetic waves they can propagate in vacuum: Light reach earth even if almost all the distance between sun and earth is empty space except the earth atmosphere. She seems young and she should read more about physics. Also saying the wavelength is the distance between two maximums in a periodic wave which is rather a consequence of the true definition of the wavelength: "The wavelength is the distance traveled by the wave during a period of time" so is: lambda = v*T (v: wave speed and T the period). So because the time between two maximums is T and the x axis is the direction of the wave propagation, it matches the definition of the wavelength.
    Teaching at MIT does nit mean you really understand physics.

    • @antoniokambire2271
      @antoniokambire2271 3 роки тому +2

      I mean this is an intro class that is also taught in high school... Judging to this extent just because of simplifications is kind of weird lol.

    • @dontdisturbimstudying6944
      @dontdisturbimstudying6944 3 роки тому

      *BRUH* people don't have the time to read your little essay . if she has got anything wrong in the subject go to another channel . if don't understand . *MIT DOES'NT HAVE TIME TO READ YOUR ESSAY ABOUT WHAT'S RIGHT OR WHAT'S WRONG*

  • @calengr1
    @calengr1 2 роки тому

    4 min energy quantized into bundles called photons; speed 186K miles /s

  • @YoshiShairy
    @YoshiShairy 7 років тому +6

    12:56 The asian girl sleeping

    • @nahidparvez9010
      @nahidparvez9010 5 років тому +2

      where was that Asian girl? In first bench, she was searching for something in her bag. Not sleeping.

    • @youngjim7987
      @youngjim7987 4 роки тому +1

      @@nahidparvez9010 row 2 on the right side of the asian boy.
      but I reckon that this may be too simple for her so she got bored as it's actually taught in high school

    • @thomasthornton5478
      @thomasthornton5478 3 роки тому

      She wasn't sleeping. You can see her eyes open and she is wide awake a moment before.

  • @jasonr.7887
    @jasonr.7887 Рік тому

    They "Must" Be Giants....really?

  • @deborahrhoades7544
    @deborahrhoades7544 3 роки тому

    👍🏾👍🏾👍🏾💙💙💙

  • @emanraafat4380
    @emanraafat4380 6 років тому

    💗

  • @user-be4yc2vr5c
    @user-be4yc2vr5c 5 років тому

    Either my eyes are super bad or 1 is deff the.... *me squinting super damn hard, with my bad glasses of which I cannot afford new ones, noticing there is actually a variable height throughout the chart and you could infact fit pretty much two of a into b*
    ... nvm.

  • @Shosho_shamma
    @Shosho_shamma 2 роки тому

    Ytdgg

  • @Roy-el7yf
    @Roy-el7yf 4 роки тому

    VIBGYOR is better then your song.😀🤣

  • @kenciolek843
    @kenciolek843 7 років тому

    wow...you just gotta know this...this is in line with scripture...Bible makes claims and statements about Bible and bibles....pure Bible vs.perverted Bibles...light and darkness....spirit and truth....father and son...and all kinds of proclamations of truth...

  • @conesillyvalley7182
    @conesillyvalley7182 2 роки тому +1

    Very average instructor