De Broglie wavelength | Physics | Khan Academy

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  • เผยแพร่เมื่อ 15 ธ.ค. 2024

ความคิดเห็น • 291

  • @ankitaaarya
    @ankitaaarya 5 ปีที่แล้ว +74

    "Luey deBroy"
    Gotchya!

  • @PhilMoskowitz
    @PhilMoskowitz ปีที่แล้ว +2

    No one initially performed an experiment to test De Broglie's hypothesis. Instead there was an experiment that had unexpected results. De Broglie's paper was used as the explanation for those unexpected results.

  • @VG__
    @VG__ 2 ปีที่แล้ว +11

    You won't even realise how many more major concepts of physics he has explained just in 10min of video that would actually take you 10years to comprehend =D
    Simply aesthetic 🌺🌺

  • @astro.5oh
    @astro.5oh 4 ปีที่แล้ว +22

    This is absolutely amazing. Physics has always interested me but is not my best subject. I came here because my Modern Physics professor suggested this video. I see why he did so--this video does not only make this concept extremely easy to understand, it made it interesting. I wish all my professors could make difficult topics such as Modern Physics and Quantum Mechanics so enjoyable. Thank you!

  • @tanmaygarg_9025
    @tanmaygarg_9025 7 ปีที่แล้ว +196

    after searching thousands​ of websites and seeing hundreds of videos this video was one the cleared every little thought in my mind. HATS OFF to you. you are terrific!!!!!❤❤

  • @colinsilver1041
    @colinsilver1041 6 ปีที่แล้ว +171

    Just an awesome video. I read the textbooks, I understand the books, but I just didn't get the big deal until this explanation. Thank you!

  • @aishwaryajangir2909
    @aishwaryajangir2909 6 ปีที่แล้ว +46

    That's the explanation I wanted to know!
    Thanks a ton for not only spreading knowledge but spreading it in explicit manner.
    PS - This is the top channel for us(students) to learn :))

  • @nymphaea888
    @nymphaea888 ปีที่แล้ว +2

    This was the most well explained resource of the De Broglie wavelength that I’ve come across. Thank you!

  • @sanchisingh5117
    @sanchisingh5117 5 ปีที่แล้ว +8

    this is one the best videos that explains this concept so beautifully WOW

  • @mahdibakkar7446
    @mahdibakkar7446 4 ปีที่แล้ว +17

    De Beoglie's new discovery had a big importance . It is the pillar of the Heisenberg Uncertainty principle

    • @utahimeiori8739
      @utahimeiori8739 3 ปีที่แล้ว

      The heinz what 🤠

    • @nmarbletoe8210
      @nmarbletoe8210 2 ปีที่แล้ว +1

      @@utahimeiori8739 uncertainty in mustard x uncertainty in ketchup = relish

    • @PhilMoskowitz
      @PhilMoskowitz ปีที่แล้ว

      By way of Schrodinger's equation. Also, if it were only Schrodinger's equation, I don't Heisenberg would have developed the Uncertainty Principle. He would have just called Schrodinger's equation- bad math. It was only through seeing this same uncertainty in Heisenberg's Matrix Mechanics (a rival and equivalent theory to Schrodinger's) that led Heisenberg to develop The Uncertainty Principle.

  • @papangkonninarundech2562
    @papangkonninarundech2562 4 ปีที่แล้ว +132

    It's been three years and i'm still pronoucing the guy's name Broglie.

    • @WeAreShowboat
      @WeAreShowboat 4 ปีที่แล้ว +9

      Me too, and I made this video :)

    • @hadmeinthefirsthalfngl2717
      @hadmeinthefirsthalfngl2717 4 ปีที่แล้ว +2

      @@WeAreShowboat Really?

    • @WeAreShowboat
      @WeAreShowboat 4 ปีที่แล้ว +4

      @@hadmeinthefirsthalfngl2717 💯

    • @pranjalkohli183
      @pranjalkohli183 3 ปีที่แล้ว

      Ya

    • @Scarabola
      @Scarabola 3 ปีที่แล้ว +2

      but it always is pronounced Broglie.
      depending on how you pronounce the name "Broglie".

  • @jessereiner5401
    @jessereiner5401 4 ปีที่แล้ว +11

    Excellent job framing an important idea that's hard to get a foothold on! How about making another one on the Davisson-Germer experiment itself?

  • @Llllllllllllxjxn
    @Llllllllllllxjxn 11 หลายเดือนก่อน +1

    This channel is a huge disservice to physics and the next generation

  • @RichardDLewis41
    @RichardDLewis41 6 ปีที่แล้ว +14

    This video highlights the important point about the quantum nature of light and wave particle duality. There is a somewhat different way of explaining the physical nature of light and the photoelectric effect by following the Spacetime Wave theory.
    In the Spacetime Wave theory, light is described as a real physical wave disturbance of spacetime moving through space. This is like a gravitational wave but at a higher frequency. In the Spacetime Wave theory light exists in discrete quanta of energy because of the way that light is emitted by a change in energy level of an atomic electron. Light waves are not inherently quantised but are quantised due to the way they are emitted.
    So we abandon the concept of wave / particle duality and instead consider the photon to always be a wave quantum. In the experiment to demonstrate the photoelectric effect the wave quantum is the perfect description because the wave part describes the energy (E=hf) in each quantum.
    The Spacetime Wave theory goes further by describing electrons, protons and neutrons as looped wave disturbances of spacetime in spacetime travelling at speed c in the loop. This provides a similar model to the de Broglie model where there must be an integer number of wavelengths in the loop and this provides the correct results for the emission of a wave quantum (photon) when an electron changes energy level.
    The advantage of the Spacetime Wave theory is that it provides a deeper understanding of the real physical processes taking place when looped waves in spacetime change state.
    For more detail see:
    www.academia.edu/5927513/The_Spacetime_Wave_Theory
    www.academia.edu/5038836/The_Unification_of_Physics
    Richard

  • @sakinahdil6060
    @sakinahdil6060 ปีที่แล้ว +1

    okay so this is basically the first video which made me understand the De Broglie Wavelength. I didn't even know that it was about electrons working as waves

  • @gautomdeka581
    @gautomdeka581 3 ปีที่แล้ว +1

    That's great what debroglie found , he didn't get the formula for matter using mathematics, he just predicted that might be true as it is valid for light

  • @hasansaleem4983
    @hasansaleem4983 3 ปีที่แล้ว +1

    2:15. Because of you now I have to cramm some questions and answers!!

  • @shivensaini3643
    @shivensaini3643 2 ปีที่แล้ว +1

    Nice explanation, BTW We can also derive this expression from equating energy from
    1. E=hf(Wave nature)
    2. E=mc^2(Particle Nature)

  • @vineetasharma3722
    @vineetasharma3722 5 ปีที่แล้ว +30

    When is your birthday David?
    We are celebrating teacher's day 2.0 on the day your birthday falls.
    Period.

  • @priyank5161
    @priyank5161 6 หลายเดือนก่อน +1

    2:43 heres come my boy...
    None other than... LUI DE BROY

  • @albijos2684
    @albijos2684 2 ปีที่แล้ว +2

    just great ! this piece is a real gem.

  • @AfsanaKhan-hm8zr
    @AfsanaKhan-hm8zr 3 ปีที่แล้ว +2

    Really found your channel with the best explanation…hope you upload more related videos

  • @thenaughty5441
    @thenaughty5441 5 ปีที่แล้ว +4

    man! i'm in love with you ! thankyou so much

  • @suipheng1322
    @suipheng1322 5 ปีที่แล้ว +2

    Wow, you explained it so well, I think its the best explanation video regarding this topic on TH-cam.

  • @srinivasankv2964
    @srinivasankv2964 2 ปีที่แล้ว

    Tomorrow is my final exams and now i am confident , thanks to your channel.

  • @adityapendyala1413
    @adityapendyala1413 5 ปีที่แล้ว

    Best class ever.....doesn’t even sound like a class!!!!!

  • @abdurrafay6150
    @abdurrafay6150 ปีที่แล้ว

    This guy is hands down the best physics teacher

  • @Chris-wh3yz
    @Chris-wh3yz 6 ปีที่แล้ว

    Yuri Ivannov’s revolutionary discovery concerning standing waves and a new concept that fully explains gravity, probably in its truest most complete theorem, and not the past goody explanations and work around in science that has never truly captured what mechanisms by which gravity works. It’s really more basic than they thought.

  • @talhaansari3140
    @talhaansari3140 7 ปีที่แล้ว +14

    Anyone know this software which is in this video for writing please i wanna know please

    • @MsQuikly
      @MsQuikly 6 ปีที่แล้ว +8

      it's been 10 months, but it's called smoothdraw

    • @_Thoughtful_Aquarius_
      @_Thoughtful_Aquarius_ 5 ปีที่แล้ว +1

      @@MsQuikly , thank you very much. ☺️

  • @haroldbog9137
    @haroldbog9137 2 ปีที่แล้ว

    Damn. He teaches soo well, not even tryin to sound like a cringe comment, but each of his lectures is so good.

  • @manjulapriyadarshani8291
    @manjulapriyadarshani8291 4 ปีที่แล้ว +1

    Thanks . I was able to learn clearly with this video .

  • @hamidthephysicist6376
    @hamidthephysicist6376 6 ปีที่แล้ว +15

    Thank you very much . The weird thing is I was so happy watching the video ! I lived the video second by second .. I think I should specialize in Quantum Physics .

  • @CACBCCCU
    @CACBCCCU 2 ปีที่แล้ว

    My apologies in advance if you enjoy spookiness.
    Dipoles interfere, massless or not.
    A dipole does not interfere with itself. Dipoles tend to be overlooked when they pair up 180 degrees out of phase with each other, with consequent signal drop out.
    Photons are extended polarized electromagnetic dipoles. Polarizers are re-polarizers. Opposing helicities of polarization can be induced by a linear polarizer.
    Electrons are magnetic dipoles due to their spin. Their spin is both quantized and tied to their speed. As matter dipoles they like to pair up 180 degrees out of phase.
    Ions are electric dipoles and spinning ions are magnetic dipoles, their spinning involves contact with surroundings and can be synchronized.

  • @paulg444
    @paulg444 5 ปีที่แล้ว +1

    David, this is a fantastic presentation.

  • @mohammadrezaeisapour6613
    @mohammadrezaeisapour6613 หลายเดือนก่อน

    Great and simple explanation! Thanks!

  • @michaelgonzalez9058
    @michaelgonzalez9058 ปีที่แล้ว +1

    By the outcome of source h is available

  • @GlynWilliams1950
    @GlynWilliams1950 7 ปีที่แล้ว +4

    Wow.
    Amazing and great explanation.

  • @kokomokid4006
    @kokomokid4006 2 ปีที่แล้ว

    I had no idea wtf he was talking about...but i shur enjoyed it!!!

  • @keywordmcat2256
    @keywordmcat2256 6 ปีที่แล้ว

    best physics teacher ever...down with this expensive and inefficient u.s. university system..

  • @jaahid08088
    @jaahid08088 9 หลายเดือนก่อน

    Thanks for this explanation.

  • @hasansaleem4983
    @hasansaleem4983 3 ปีที่แล้ว +1

    Thankyou I finally understood it

  • @zhraisjoy
    @zhraisjoy ปีที่แล้ว

    Really great
    U make the idea very easy to understand
    I can't know how much I can thank you

  • @aminsa9392
    @aminsa9392 2 ปีที่แล้ว

    Amazing video you made. I was not understanding this case but your video made it more easy for me to understand. Thank you

  • @keysangyonthan
    @keysangyonthan 6 ปีที่แล้ว +3

    so does that means that everything in this universe can act as a wave as well as a particle depending on the experiment we are subjecting the object to?

    • @samihaislam9147
      @samihaislam9147 4 ปีที่แล้ว +1

      I guess. My physics teacher told me even the particles in our bodies spread a very miniscule amount when we go through doorways... Donno if its true though, it's really weird and hard to believe

    • @DapaChrons
      @DapaChrons 4 ปีที่แล้ว +1

      yes, everything has a wavelength

  • @AM-es7of
    @AM-es7of 9 หลายเดือนก่อน

    Beautiful lesson. Thank you!!!!!!

  • @tomnoyb8301
    @tomnoyb8301 6 ปีที่แล้ว

    Quantization always arises from boundary conditions. It's not a "particle nature" of light quantizing the photoelectric effect, rather the boundary conditions upon the electron that prevent it from accepting low energy waves. Light is always a wave and may always be calculated as a wave. Particle models are always simplifications of the more accurate wave calculation. "Wave" is always correct, "particle" might sometimes be correct.

    • @aaroncurtis8545
      @aaroncurtis8545 5 ปีที่แล้ว

      But... We hypothesized the photoelectric because treating light as a wave doesn't work; it leads to the ultraviolet catastrophe, even without electrons getting involved.

  • @kalarani6682
    @kalarani6682 3 ปีที่แล้ว +2

    Khan academy is the best. Do you agree?

  • @lilitek8001
    @lilitek8001 2 ปีที่แล้ว

    This explanation was amazing. Thanks

  • @swapanmanjhi
    @swapanmanjhi 2 ปีที่แล้ว

    Great Explaination sir,
    Thanku 💐

  • @qurrotatechnology2073
    @qurrotatechnology2073 4 ปีที่แล้ว

    The explanation is just amazing

  • @dabanfarad8756
    @dabanfarad8756 7 ปีที่แล้ว +5

    Great video thanks

  • @avezl
    @avezl ปีที่แล้ว

    Thank you so much, finally i could understand it

  • @iaminevitable1651
    @iaminevitable1651 3 ปีที่แล้ว +2

    Danielle Bregolie Wavelength

    • @viktoriaaureliaa
      @viktoriaaureliaa 8 หลายเดือนก่อน

      this made me laugh out loud😂

  • @randallmcgrath9345
    @randallmcgrath9345 6 หลายเดือนก่อน

    Khan Academy is also nice for math practice as many know.

  • @afzalhakim4681
    @afzalhakim4681 3 ปีที่แล้ว

    Understood every part of it !!

  • @ashishfargade1393
    @ashishfargade1393 6 ปีที่แล้ว

    9 dislikes,,,, i mean why would people give it,, this video cleared every doubt in my mind,,, what more do these people want,,, why would they dislike it without any reason, they are cruel af!

  • @meghnameghna1498
    @meghnameghna1498 3 ปีที่แล้ว

    Thank you so much for such a elaborated and good explanation

  • @nazneenali3628
    @nazneenali3628 6 ปีที่แล้ว +2

    Double slits cause interference of light waves whereas diffraction pattern results from a single slit.

    • @ronasmatyar5642
      @ronasmatyar5642 5 ปีที่แล้ว

      The light diffracts at both slits thats what causes the interference.

  • @NimrodTargaryen
    @NimrodTargaryen ปีที่แล้ว

    Wonderful commentary, thank you🎉❤

  • @michaelgonzalez9058
    @michaelgonzalez9058 ปีที่แล้ว +1

    6.626.4 h constant(photons)

  • @AfsanaKhan-hm8zr
    @AfsanaKhan-hm8zr 3 ปีที่แล้ว

    Are you not posting any more videos…

  • @ZwiffleOwnsU
    @ZwiffleOwnsU ปีที่แล้ว

    Incredible explanation

  • @fstopPhotography
    @fstopPhotography 2 ปีที่แล้ว

    That was fascinating.
    Thank you.

  • @tiagotassinari1435
    @tiagotassinari1435 2 ปีที่แล้ว

    Awesome video !!! Thank you!

  • @hasnainiqbal4870
    @hasnainiqbal4870 7 ปีที่แล้ว +1

    Is the equation only true when the particle is travelling very closer to 'c'?
    Or, at any velocity?

    • @antoniovianaaa
      @antoniovianaaa 7 ปีที่แล้ว

      Hasnain Iqbal, i'm probably too late, but i'll try to answer. This equation is valid for "any" value of speed. You can see in books some exercises of calculation of a baseball wavelength, for example.

  • @ambreshbakshi8648
    @ambreshbakshi8648 5 ปีที่แล้ว +3

    But this equation is derived for massless particle
    How can we use mass of electron

    • @bananabird7584
      @bananabird7584 4 ปีที่แล้ว

      I think it's because the mass of an electron is ~0 kg, but there is still a mass.

  • @mariaporras1864
    @mariaporras1864 3 ปีที่แล้ว +1

    Hi! where can i read the paper of De Broglie?

  • @ayushsharma0324
    @ayushsharma0324 6 ปีที่แล้ว +1

    truly, thank you.

  • @antoniovianaaa
    @antoniovianaaa 7 ปีที่แล้ว +6

    That dislike is so unfair. I think this lecture is very interesting for a beginner on quantum mechanics.

  • @internationalremixes6440
    @internationalremixes6440 7 ปีที่แล้ว

    fabulous video...it's like crystal clear

  • @qrthack
    @qrthack 3 ปีที่แล้ว

    What tablet are you using?

  • @VG__
    @VG__ 2 ปีที่แล้ว

    1:56
    4:46

  • @bhavanikasiviswanathan3707
    @bhavanikasiviswanathan3707 4 ปีที่แล้ว

    It is very useful. Thank you!

  • @c260sadiaafrin2
    @c260sadiaafrin2 3 ปีที่แล้ว

    This video is great!!!

  • @jackiec.acosta9929
    @jackiec.acosta9929 4 ปีที่แล้ว +3

    Hahaha thought it was "lu-wis de brog-lee"

  • @EricTheJester
    @EricTheJester หลายเดือนก่อน

    8:03 balloons filled with marbles can bounce around like a wave. the ballon is a packet of energy. Would this exemple make sense to see how a super stretchable balloon could be made to look like a wave? do I get an award or im I totally off.

  • @விகாஷ்வர்தன்
    @விகாஷ்வர்தன் 3 ปีที่แล้ว

    I would like to see his paper. But will i understand it or even if i don't where do i get it?

  • @imafan555
    @imafan555 3 ปีที่แล้ว

    david's voice is so smooth.

    • @gorilladesu
      @gorilladesu หลายเดือนก่อน

      Do yk his full name?

  • @amyralove6109
    @amyralove6109 5 ปีที่แล้ว +16

    As a french speaker I think we spell it " De Brogg_ly "

    • @carl6167
      @carl6167 5 ปีที่แล้ว +3

      C'est une exception.
      Les Ducs de Broglie sont d'origine italienne et c'est en françisant leur nom quand ils ont émigré vers la France que c'est devenue Broglie.
      La prononciation d'origine a cependant été gardée.

  • @aritrabhattacharyya2374
    @aritrabhattacharyya2374 8 หลายเดือนก่อน

    Awesome class sir

  • @thenuyogi5751
    @thenuyogi5751 6 ปีที่แล้ว

    THANK YOU!

  • @beyourself8085
    @beyourself8085 ปีที่แล้ว

    Thanks sir!!

  • @vijgenboom2843
    @vijgenboom2843 2 ปีที่แล้ว

    Excellent! Thank you. ❤️❤️

  • @jayjain1033
    @jayjain1033 2 ปีที่แล้ว

    yow this guy can explain stuff!!

  • @physics-theworkingofeveryt6086
    @physics-theworkingofeveryt6086 3 ปีที่แล้ว +1

    I am 11 years old but still I understood every word you said
    Thank you sir

  • @noemotions4251
    @noemotions4251 4 ปีที่แล้ว

    Sir kindly help me. I won't lecture on mie-gruneisen equation.

  • @keshanisakunthala8600
    @keshanisakunthala8600 ปีที่แล้ว

    Thank you so much

  • @naturegirl1999
    @naturegirl1999 5 ปีที่แล้ว +3

    What if what we’ve always called particles are always just waves with super small wavelengths?

  • @TheLivirus
    @TheLivirus 4 ปีที่แล้ว

    So the particle nature of light was shown by light knocking away electrons in metals, but then electrons were shown to also be waves. It seems to follow naturally that one would then try to explain the photoelectric effect by considering both light and electrons as a wave. I'm sure someone tried this, but does anyone know what was the conclusion? Does the photoelectric effect not work considering both light and electrons as waves? Why?

  • @dodoahmed3121
    @dodoahmed3121 3 ปีที่แล้ว

    Awesome video thank you sooo much

  • @thunder_0997
    @thunder_0997 6 ปีที่แล้ว

    Good explanation bro!!

  • @jessz-4453
    @jessz-4453 ปีที่แล้ว

    better than college chem lecture ngl...

  • @jmac6653
    @jmac6653 ปีที่แล้ว +1

    I feel both 100x smarter and 100x more dumb from this video. Thank you.

  • @chrisklenke9681
    @chrisklenke9681 4 ปีที่แล้ว

    Anyone know where I can find his paper?

  • @kartikeykakaria9a180
    @kartikeykakaria9a180 2 ปีที่แล้ว

    Sir but I have a question like we are always taught e=mc² if we square that we get e²=m²c⁴ but here you showed that e²=m²c⁴+p²c² how can that be true? This just unbalances an equation?

    • @lepidoptera9337
      @lepidoptera9337 8 หลายเดือนก่อน

      The correct formula is the one that includes the momentum term. The simplified formula should not be taught as fundamental. It's a specialization of the full formula for p=0 (i.e. it is only valid in the rest system of the body).

  • @nurulshamchannel9307
    @nurulshamchannel9307 2 ปีที่แล้ว

    Thank you sir

  • @haseeb6053
    @haseeb6053 5 ปีที่แล้ว

    Thank you! Really, Thank you!!

  • @kevinmanganini544
    @kevinmanganini544 7 ปีที่แล้ว +1

    If matter particles have a wavelength, does this mean all condensed matter bodies, such as a human body, behave as a wavelength as well? Or is this just relevant to each individual electron particle?

    • @legalgamers59
      @legalgamers59 6 ปีที่แล้ว +1

      Kevin Manganini everything behaves as a wave. But wavelength is very very very small for human body

    • @PeterBaumgart1a
      @PeterBaumgart1a 6 ปีที่แล้ว

      But what happens if v goes to zero. With momentum (p=mv) going towards zero lambda would get very large, no?

    • @goodn1051
      @goodn1051 6 ปีที่แล้ว +1

      Then you won't exist.....no matter has zero velocity.... If so your wavelength goes to infinity

    • @aaroncurtis8545
      @aaroncurtis8545 5 ปีที่แล้ว

      @@goodn1051 then you're Everywhere!

    • @sonarbangla8711
      @sonarbangla8711 2 ปีที่แล้ว

      Good question, De Broglie's wane nature of particles shows all particles you are made of are waves, proving something even basic. It proves all quantum fields are basic, particles are secondary. Similarly the whole universe is an evolution of the Schrodinger's wave function. But sadly we don't know the infinite axiom algorithm, how quantum states produce classical objects, like stars, planets BH etc. Einstein craved to improve QM, but failed, because this algorithm is known only to God. Mankind can at best arrive at a finite axiom algorithm.

  • @tusharpal5431
    @tusharpal5431 6 ปีที่แล้ว +2

    I still have the question 7:54

  • @soul5626
    @soul5626 6 ปีที่แล้ว

    Thank you