What is the Bohr model of the atom?

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  • Опубликовано: 24 дек 2024

Комментарии • 695

  • @supreetsahu1964
    @supreetsahu1964 4 года назад +330

    Dude you're pumping out quality stuff

  • @underpowerjet
    @underpowerjet 4 года назад +524

    I am calling it right now. You are the 3Blue1Brown of Physics! This channel is going to get big. I am loving going through your videos to get a a better understanding of physics in this universe. This is fantastic source material of the future when I do decided to start studying physics seriously. Getting to conceptually understand the struggles that past scientists had to deal with when confronted observational data is turly eye-opening. We are standing on the shoulders of giants, and most individuals in our species are unware of their existance. Our modern society exists because of them, and their contributions to the field of phyiscs.
    KEEP UP THE GREAT WORK!

    • @oumuamua12
      @oumuamua12 4 года назад +30

      Although 3B1B has some beautiful animatons and sourceful content, this channel is way better in terms of quality and approach to viewers, at least for now. Hoping to see much more from this amazing guy. :-)

    • @underpowerjet
      @underpowerjet 4 года назад +5

      ​@@oumuamua12 Agreed.

    •  4 года назад +12

      @@oumuamua12 I've got a feeling that your opinion on this may change when this channel gets older. Stuff is going to ramp up in complexity, and some people will get lost along the way. Zach Star (formerly 3Blue1Brown) is doing an _incredible_ job with the stuff he is dealing with at this point.
      If Physics Explained can match him when he gets as far into things, everyone is in for a treat. This video is definitely fantastic but there's still a long way to go until all of physics is covered. I just hope that he keeps the level of detail as high as this one throughout. Equations is what I''m missing more of on RUclips - there is plenty of the handwavy stuff.
      @Physics Explained: Thanks for sharing, I really appreciate your work. 👍

    • @underpowerjet
      @underpowerjet 4 года назад +3

      @ I have some understanding of linear algebra, calculus and integrals from university + using it on many projects. Plus having taken physics in highshcool and once in unviersity. I don't feel like I am completely lost. However, I see what you mean about when the completexity ramps up. It certainly could become off putting for some.

    • @oumuamua12
      @oumuamua12 4 года назад +1

      @ That being said, you should definetly check out Michel van Beizen's channel.

  • @vincentd1120
    @vincentd1120 4 года назад +45

    I am very engrossed in the minimalist style that you present these concepts. The quotes from the scientists are well appreciated. I want to see this channel to grow in to something great.

  • @eiskaffe0
    @eiskaffe0 Год назад +4

    I might have spotted a typo at 13:33. The orbital speed of an electron is v = (e^2)/(2ϵnh). You can see that by substituting in:
    v^2 = (e^2)/{4πϵm*[(n^2)*(h^2)*ϵ]/[πm*(e^2)]} = (e^4)/[4*(n^2)*(h^2)*(ϵ^2) -> v = (e^2)/(2ϵnh). So its not divided by h, not π.

    • @cristofermarti
      @cristofermarti 19 дней назад

      i notice the same right now that i'm learning this!

  • @metal_brrr_2005
    @metal_brrr_2005 4 года назад +161

    At high school I never learnt the derivation of the Bohr model. Physics curriculum should be less about exercise and worksheet, more about derivation and a little bit of history.

    • @christophermckay7082
      @christophermckay7082 3 года назад +14

      Couldn't agree more. The history makes it real.

    • @stpirate89
      @stpirate89 3 года назад +5

      In the UK at A level physics, your school chooses a module for you, and by far the best one to choose is Turning Points in Physics, as it gives a nice overview of the differences and similarities between theories before and after some great discovery (obviously not in as much detail as this video - high school physics isn't really like proper physics, as it needs to be accessible to someone who isn't doing A level maths)

    • @theophrastusvonhoenheim4022
      @theophrastusvonhoenheim4022 2 года назад +2

      I just wish theyd have like a problem solving lab in a derivation based class like they do for expirimental labs

    • @Classical741
      @Classical741 Год назад +1

      @@stpirate89 I'm a wee bit confused. Is it true that A level physics doesn't rely on knowing A level maths? Asking for an American friend.🤔

    • @stpirate89
      @stpirate89 Год назад +2

      @BeachesRuS that is true yes. Its one of the reasons I hated teaching A level physics. It ruins the physics syllabus because of it, and realistically, nearly all students take A level maths anyway if they're going to take physics. In my 6th form, we had a lot of people take physics in year 12, around 60 to 70 people, and only 3 of them didn't also do maths. I don't think any of them carried physics on to year 13 either.

  • @j.abrahamhernandez3629
    @j.abrahamhernandez3629 4 года назад +83

    from one physicist to another, amazing work! this is so very useful to both the laymen and professional scientists themselves!
    please do keep up the good work

  • @jimcarpenter965
    @jimcarpenter965 4 года назад +70

    From content to presentation this was an absolutely outstanding production. Very well done!

  • @evilotis01
    @evilotis01 4 года назад +23

    i really enjoy the way you go into the nuts and bolts of how the concepts you explain actually work. i've seen this subject matter addressed on various other channels, but the actual math is often glossed over or said to be "too hard", etc. i'm glad that you're willing to go into detail, and the clear, concise way in which you go through the details step-by-step make them easy to follow. please keep doing what you do! it's really great!

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +7

      Thanks for the detailed feedback. My philosophy is to try and convey the thought process behind the ideas, so I am glad you have picked up on this and find it helpful

  • @potawatomi100
    @potawatomi100 4 года назад +87

    Outstanding video and very well narrated.

  • @tensevo
    @tensevo 4 года назад +2

    I have only watched this vid but I think you have nailed the vibe that, the map is not the territory. Physics is the map, whilst base reality is the territory. Physics models reality. So many physicists take that step too far, over-reach and proclaim, Physics is reality. The true greats such as Einstein and Newton were careful to respect that physics is not reality. As Bohr said, 26:48 physics is not about what the world is, but what we can say about the world.

  • @cosmicnomad8575
    @cosmicnomad8575 2 года назад +7

    As a young aspiring Physicist, I must say, finding your channel is amazing! Watching these videos and then trying to work them out on my own again later and trying my own stuff is always helpful. Thanks for this!

  • @Nietzsche_K_Gote
    @Nietzsche_K_Gote 4 года назад +130

    First time I encountered this was 14 years back in school and today is when I can say I kind of have a grasp of it,thanks to you .
    I am an art director at a small agency but people like you online keep feeding my thirst for curiosity. Thank you for doing what you do.

  • @dariushimani8956
    @dariushimani8956 4 года назад +6

    I’m very glad I found your channel when I did. I’m a physics major in university and just started taking modern physics. Watching your videos in Compton scattering, the ultraviolet catastrophe, and now the Bohr model have helped me immensely. I’m so glad you don’t skip the deep and thorough math either, it only serves to drive home the conceptual explanation you put together.
    Anyway, just wanted to thanks very much, keep doing what you’re doing!

  • @abdirazaqali8921
    @abdirazaqali8921 3 года назад +1

    I am at a very local university in kenya but i am learning physics like as if i am in world class university because of this youtube channel. Thank you so much❤❤❤🇰🇪🇰🇪😘

  • @sandipanhazra5510
    @sandipanhazra5510 2 года назад +1

    First of all, Thank you very very much for these videos. This type of videos are the reasons for me to get motivated to understand the majestic beauty of nature/physics rather than running behind marks/degree.
    At 9:50 I think angular momentum vector would be equal to m(r vector crossed with v), not the other way around.

  • @st3althyone
    @st3althyone 3 года назад +5

    Amazing how you’re able to breakdown the monumental achievements of Niels Bohr in such an eloquent yet easy to understand manner. I’ve always loved physics since learning about it in high school, but I never understood why it bewildered so many of my peers. I guess it all depends on the way you view and breakdown information and I was blessed with an exceptional teacher whom guided me through tackling everything that is elementary physics. It would be wonderful if all teachers had the language to make learning fun instead of what they are for the most part information dumps that tend to overwhelm most students.

  • @urquizagabe
    @urquizagabe 4 года назад +1

    I really, really enjoy your videos. I am a post-doctoral researcher in atomic and molecular physics. I work with quantum mechanics, molecular simulations and all sorts of things related to the atomic structure of materials and stuff. These things that you have been teaching are the bedrock upon which my entire field of research rests (apart from that one where you compute the distance between the Sun and the Moon) and you still managed to make me look at those things with fresh eyes. You have a good educational method, keep up the good work, we need communicators like you.

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад

      I really appreciate your feedback. Thanks for taking the time to leave such a positive and encouraging message. Best of luck with your post doc!

    • @urquizagabe
      @urquizagabe 4 года назад

      @@PhysicsExplainedVideos Thanks a lot. I mean it. It is hard making things sound as clear and easy as you do. The work you put on making everything obvious shows, I bet that takes A LOT of research and banging your head on the wall. I found myself binging the videos as if my life depended on it. Not only they have good, clear content, they are also a treat to watch. I agree with "The One" on this one, you have the potential to become the 3Blue1Brown of physics. I really want to see that happening.

  • @jakublizon6375
    @jakublizon6375 2 года назад +1

    I watch one of these every morning as I sip coffee and hope that by some miracle, I don't have to come into work today.

  • @skypickle29
    @skypickle29 4 года назад +5

    Thank you again for a clear account of the Bohr model. You also made it clear to me that higher energy level electrons gain more potential energy than they lose kinetic energy. I never thought of higher energy electrons moving more slowly. Also that the radius of an orbital increases as the square of n suggests that higher orbitals should be more further apart.

  • @petermferguson
    @petermferguson 4 года назад +1

    The most clear, concise, and joined up explanation of this topic I have encountered. This is the first time I have understood this clearly, and I have a Physics degree.

  • @skypickle29
    @skypickle29 4 года назад +1

    I SO admire your regard for the young students who thought about these things a hundred years ago. Yes they were students, unknowns. They spent decades cogitating. And we are spoon fed this stuff in minutes. And back then, to engage in this endeavor had no promise of economic success. No VCs, no patreon, no kickstarter. No promise of applicability or consideration of market. I wonder what motivated people like Maxwell, Bohr, Thomson, Rutherford,etc.. Your presentation is so engaging. Someday, perhaps an AI will weave these you tube videos into threads and tapestries so we can understand the human dimension as well as the abstract. But until then we only have a few people like you.

  • @naoufelelhadrati
    @naoufelelhadrati 3 года назад +4

    a well-made explanation
    P.S: 13:16 I think you made a typo in the expression of the speed. We must replace pi by the planck constant

  • @salvatronprime9882
    @salvatronprime9882 4 года назад

    This is definitely the best new science series on youtube!

  • @MrEmrys24
    @MrEmrys24 4 года назад +1

    I hope you can make series about the progress of physics from the development of classical physics up to the modern physics the way you did here

  • @jonvance69
    @jonvance69 4 года назад +1

    These really are some of the best physics videos out there. Love how you don't shy away from the math. You can't fully understand physics without the math!

  • @SteveHaslamUK
    @SteveHaslamUK Год назад

    One thing I particularly like about these videos is they tie the reasonably-detailed algebra to experimental results. In this case, including the photograph of the spectral emission lines from hydrogen really brings home that all the maths leading up to that point is describing a real, testable phenomenon.

  • @MorbusCQ
    @MorbusCQ 4 года назад +38

    Is this my new favorite science channel? I think it is

  • @romeshsrivastava2474
    @romeshsrivastava2474 11 месяцев назад

    I always wanted to be a physicist.. did my masters too.. but couldn’t pursue it further. Your videos exactly explaining not only the results and the flashy headlines but also the mathematics of how to get there make me relive my love for physics. Thank you so much for making them. Please keep making them.

  • @zeynep-ho9kv
    @zeynep-ho9kv 3 года назад +1

    thank you for this content, this is the first time i felt a need to directly appreciate the content creator, have a good day lol

  • @TanCoul
    @TanCoul 4 года назад +22

    I love RUclips science videos, but they usually either remind me of things I already knew, or leave me somewhat baffled. This time I learned something new and understood what I was learning - nice one.

  • @n4rzul
    @n4rzul 4 года назад +9

    Subscribed. Beautifully articulated and factually correct. Rare in a world dominated by disinformation. Bravo.

  • @StuartJuggernaut
    @StuartJuggernaut 4 года назад +1

    this is lowkey my favorite physics channel now

  • @RK-li7bk
    @RK-li7bk 4 года назад +2

    I have been waiting for this clear explanation so long.

  • @TheShovelKiller
    @TheShovelKiller 4 года назад +2

    Your enthusiasm and passion for physics are clearly seen in these videos of yours. Thanks for reigniting the spark in an otherwise disengaged undergrad.

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +1

      My pleasure, it really makes me happy to think that this helped reignite the spark. Don't give up! The hard work will pay off when you begin to see the world differently through the eyes of a physicist

  • @ElZafro_
    @ElZafro_ 4 года назад +3

    I really love these videos because you don't explain the topic and call it a day, but also you do it just like the physicists form then developed their theories. This way it's so much more logical and understandable to arrive at those concepts and formulas. Thanks!

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +4

      I am really glad you like the approach taken in these videos. When I was a student, I used to like understanding the historical context of the ideas.

  • @jpm3616
    @jpm3616 4 года назад +2

    This is great stuff - both from a technical and historical point of view. Very entertaining too - I often remember Bohr as "that guy who was always arguing with Einstein" but forget the brilliant early work that catapulted him to fame...

  • @Stejarulpufos70
    @Stejarulpufos70 4 года назад +1

    Best presentation on this subject on youtube so far

  • @ahmedafifkhan
    @ahmedafifkhan 4 года назад +2

    Do you have a reddit? I strongly recommend you to have one.
    You have just combined what I always wanted how these classes should be.
    • These classes should sound like good researched 'history' (or story) classes rather than simply jotting down equations of abcd.
    • No background music. Oh! So, soothing to hear!
    • Clean visuals, esp @4:45. This really punched my intuition! Just loved it.
    Subbed your channel within one minute into this video! Well RUclips recommendations are really doing a good job.

  • @lucamiccinilli1426
    @lucamiccinilli1426 4 года назад +15

    This is really great content, it is clean, well explained and very usefull.
    I hope you keep work on this type of video

  • @abj358
    @abj358 4 года назад +1

    I'm a math dud. No, I wasn't trying to say dude. Dud. For sure. Yet, I have known conceptually about each of the elements of this story for ages. But I could never see how they all fit together until now. I also see, and this is the most impactful revelation for me here, that, by the math, the path to understanding such things is cleared of it's thatch and toe-bruising stones. One thing neatly fits with another. I will spend more time here. And, thank you.

  • @MrMegaL0N3
    @MrMegaL0N3 4 года назад +1

    Excellent video. The straightforward calculations and succinct explanations are much appreciated. Keep up the good work.

  • @sachinsrb
    @sachinsrb 2 года назад

    I must say this is the best explanation I have seen on RUclips or for that matter any other documentary/educational service of the atomic model as conceived by Bohr. Outstanding and kudos to you, Keep up the awesome work.

  • @germangonzalez3063
    @germangonzalez3063 4 года назад +2

    Yes. You are the 3Blue1Brown of Physics! Thank you both

  • @EMC273
    @EMC273 2 года назад +2

    I'm really pleased to watch great content in this channel. Keep recording videos about the beauty of physics.

  • @kylerathert7742
    @kylerathert7742 3 года назад +2

    Thank you for making this understandable.

  • @samlloyd8582
    @samlloyd8582 4 года назад +1

    These physics videos are among the best I've seen. I admit the maths gets a bit beyond me, but I remember enough High School maths to at least understand what is going on. It is the explanatory diagrams and the helpful narration that I like; I feel I understand and gain insights into the big questions being asked. Thank You!

  • @mikeseufert9473
    @mikeseufert9473 4 года назад +4

    Great video! I've got a minor correction. Angular momentum, L, is actually defined as r cross momentum , that is, r x p. At 10:01 you show L = p x r. This matters because the vector cross product is anti-commutative and so your L is actually in the opposite direction to what it should be. In the picture on the right at that time, you've got it correct with the L vector directed towards the viewer. Keep up the great work!

    • @gabrielhoyos45
      @gabrielhoyos45 Год назад

      Considering the cross product is orthogonal to both elements, does it really matter? Or is it that direction is changed due to the interchanging of elements?

    • @phenax1144
      @phenax1144 Год назад

      @@gabrielhoyos45it is definition we could have chosen to do it the orher way around bur we didn’t

  • @vasantphadke3913
    @vasantphadke3913 4 года назад

    No 1 video indeed , gift to Mankind

  • @dafdaf4052
    @dafdaf4052 4 года назад +4

    1, Do not stop doing this.
    2. Your handwriting is beautiful as well, apart from the pictures used I believe it would take less time to produce videos with handwriting.
    3. You may not do this a full-time job, but what you are doing is valuable and if you can mass produce these videos I am sure people will notice soon.
    4. I don't know your education level, but if you can touch more advanced subjects it would be really nice.
    Keep up the good work.

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +1

      Thanks for your feedback. You are right, videos with hand-writing are far less time consuming. I will probably produce a mixture of videos in the future. I have a PhD in theoretical physics and have considered doing a series of videos on quantum field theory and string theory, but first I am going to cover the basics of quantum mechanics and special relativity

    • @dafdaf4052
      @dafdaf4052 4 года назад +1

      @@PhysicsExplainedVideos I could tell you know a lot on the subject, now I know it. You could do series like DrPhysicsA, which are basically a summary of Susskind's Theoretical Minimum. You have really nice dots as well, on your 'Estimating the number of atoms in the observable universe' video your dots are making me feel comfortable. So touching some Boltzmann subjects would be eye candy (with a lot of dots involved obviously!!!).
      Also, your video titles are really nice; everybody is into well-delivered clickbait videos. Like 3b1b's hardest question on the hardest test, or most of the quantum mechanic videos.
      I would say there are not that many string theory videos that are visually satisfying, given the complexity and math required to understand the topic (and it always feels like string theory is built upon the idea of unreasonable efficacy of mathematics, which is why its probably very promising theory as well.)
      I feel like expanding this channel (which you should be doing given you are one of few physicists with good handwriting and deep knowledge on the subject) relies on well-delivered quantum mechanics videos. Not so surprisingly quantum videos are getting millions of views (probably due to magical interpretation of the subject by popular science), a well-delivered video explaining everything that led the development and implications of the subject will be well appreciated by the public.
      Clearly getting clicks is not the main purpose of making educational videos. Learning more about the subject while delivering, teaching and ego-boosting are probably the main reasons behind it; but at the end of the day, we are animals that love positive feedback and social acceptance. So getting more views will ensure you will deliver more videos with higher quality.
      Please use more handwriting and never shy away from diving deep into mathematics. Teach the rules and apply them to problems like how can you calculate gravitational constant, what really is an electron, infinite slit experiment or whatever comes to your mind. Keep it clickbaity, equation filled and comprehensive. Good luck!

  • @qwerty90615
    @qwerty90615 4 года назад +1

    Excellent pronunciation, pace quick enough to remain stimulating, while not jumping or skipping. Graphics are simple and clear. Length of lesson per video appropriate. Worth repeated viewing. About the only suggestion I can imagine is a reference to some book with solved examples and homework assignment. I wish I had you as an undergraduate professor in EE.

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад

      Thanks for the feedback and suggestion. I think putting in some links to questions is an excellent idea. I will see what I can do

  • @Beeonnet-ur4ul
    @Beeonnet-ur4ul 4 года назад

    After 20+ years I finally understand how spectral analysis works. Thank you!

  • @williamli0722
    @williamli0722 4 года назад +1

    Thanks Dr. Rod for making us watch this, very cool!

  • @rajarshisen1631
    @rajarshisen1631 4 года назад +1

    I'm just becoming a fan of your simplistic explanation. You are doing a great job carry on.....wanna see more videos asap

  • @elle-hk
    @elle-hk 4 года назад +1

    I wish you'd have a separate video on the story of the electron and Thomson's experiments. It rarely gets a lot of attention, if any, but sometimes it feels like it is what actually triggered the quantum revolution. In any case, thank you so much for such clear and detailed explanations, with maths included!

    • @SpectatorAlius
      @SpectatorAlius 4 года назад

      How do you get the 'trigger' out of that? Historically, it is pretty clear that it was Planck's bold quantum hypothesis for the Planck Radiation Law that triggered it. And he was considering a blackbody, no atomic hypothesis required at all. It is only late commentators who claimed the quantum oscillators where atoms. Planck did not actually need this hypothesis to explain the oscillators and their quantization.

  • @sathearn
    @sathearn 4 года назад +3

    I found your ultraviolet catastrophe video excellent as well as this one, and look forward to continuing to learn from your videos. It always helps to see things presented in several slightly different ways. I've been trying to make beginner's headway in MCQuarrie and Simon's _Physical Chemistry: A Molecular Approach_ as well as White's _Introduction to Atomic Spectra_ , having completed Chapter 1 of the former and being in the middle of Chapter 1 (devoted to pre-Bohr spectroscopy) in the other. Having viewed your latest video a couple times casually when it came out, I dedicated yesterday to reviewing the relevant section of McQuarrie and Simon and then looking ahead to part of White's treatment of the Bohr atom, before devoting a couple hours last night and this morning to reviewing your video in detail, checking everything.
    I did notice a couple of errors in the expressions that appear. @13:25 the video has v = e^2/2πε_0n, whereas the actual expression that follows from the substitution shown should be v = e^2/2hε_0n. @15:05 the expression given to substitute for v^2, is the first such expression from earlier in the video, namely v^2 = e^2/4πε_0m_er, rather than the one actually needed for the substitution: v^2 = e^4/4ε_0^2h^2n^2.
    I must confess being driven in my desire to learn more by criticisms which have been leveled against the nuclear theory itself, as well as interest in a related non-standard theory. Those criticisms remain almost unknown due to the historical fact that Bohr's contribution (in part due to its striking initial success) has been the focus of subsequent modifications, in effect shielding the nuclear concept itself from critical scrutiny. A brief-but-cogent presentation of the reasons may be found here: philpapers.org/rec/LARJHM-3
    To the point here, the conclusion that "the basic idea of energy levels and electron transitions would ultimately account for the emission spectra of all the known elements," is marred by the lack of discrimination between the sound pedigree of the energy levels concept itself, and the historical predisposition to describe them in terms of "electron transitions."
    To underscore this point, I'll close with an extended quotation from Larson's neglected classic _The Case Against the Nuclear Atom_ (1963). Would it not be healthy for physics if these criticisms were more widely appreciated?
    The most astounding feature of this whole situation is that after having thrown the only connection between the atomic energy levels and the nuclear atom to the wolves, and putting nothing in its place - even going to the extent of contending that nothing _can_ be put in its place - the physicists still insist on using the genuine successes of the theory of atomic energy levels as evidence of the validity of the nuclear theory to which it is no longer even distantly related. Furthermore, the whole jargon of spectroscopy is based on the features of the original theory that have now been repudiated. While Schrödinger tells us that there really are no electrons in orbit, Heisenberg says that there actually is no physical electron at all, only a “symbol,” and the whole Copenhagen school insists that we cannot conceive of the atom or any of its parts in anything but purely mathematical terms, the spectroscopists tell us just how many electrons there are in the atom and exactly how they are arranged in “shells,” etc., and proceed on this basis with the calculation of spectroscopic terms to an accuracy of eight or nine significant figures. “The terms result from definite configurations and motions of the outer electrons of the atom and are explained by a well-established theory of spectral structure,” [Citation omitted] says the National Bureau of Standards.
    This utterly ridiculous situation in which one group of physicists is defining specifically and in great detail the properties of entities which, according to an even more eminent group of physicists, have “no immediate and direct properties at all ” and do not even “exist objectively” is another example of the same confusion that was pointed out in connection with Moseley’s Law. Here again, as in the Moseley case, a name derived from currently popular theory has been arbitrarily attached to a particular physical phenomenon, and the scientific profession has fallen into the habit of accepting the connotations of that arbitrary nomenclature on the same basis as the observed properties of the phenomenon itself. The Bureau of Standards tells us, “…the atoms of a gas or vapor, when excited by radiation, absorb certain wavelengths corresponding to transitions of their outer electrons from lower energy levels to higher ones.” Here we have an assertion which contains three statements of totally different origin, all lumped together as if they were equally authoritative. The statement that the atoms absorb certain wavelengths when excited by radiation is a description of an observed fact. The statement that these particular wavelengths correspond to transitions from lower to higher energy levels is a theoretical conclusion which is strongly backed by evidence from experimental sources. The further statement that these energy levels are energies of electrons is pure hypothesis without the least vestige of experimental support. These levels are “Atomic Energy Levels” - the title of the Bureau of Standards publication from which the foregoing statement was taken - and that is all we know. Evidently some kind of units enter into the situation, but applying the name “electrons” to these units is pure guesswork.
    Similarly the same N.B.S. circular says, “Each chemical element can emit as many atomic spectra as it has electrons,” but what is actually known is that the number of different spectra is equal to the atomic number; the further conclusion that this represents a number of electrons is wholly gratuitous, and the use of the name “electron” serves no purpose that would not be fulfilled equally well by any other name. As pointed out earlier, any theory of atomic structure that could be given any serious consideration at all must necessarily make some provision for a quantity corresponding to the atomic number, and the name of this “something,” whatever it may be, can be substituted for “electron” in the language of spectroscopy without affecting spectroscopic theory in the least. The current contention that the successful application of the theory of energy levels to the study of spectra constitutes an argument in favor of the nuclear theory of the atom is therefore pure fantasy.

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +1

      sathearn thanks for the detailed comment and feedback, much appreciated. Thanks for spotting the typo involving epsilon nought. And yes, for simplicity I should have written an expression for v squared which did not involve r but hopefully anyone working through this will just substitute for r to get the correct expression. I really like the quote by the way, certainly something to think about

  • @banibalyonadam5371
    @banibalyonadam5371 4 года назад +2

    I really love your explanations! You don’t skip Important parts!

  • @black_pantheon
    @black_pantheon 3 года назад

    Like the other people said, I hope this channel never loses its quality in the subject of the videos and its production. This channel is a rarity in so many ways that I really hope you continue this. Its really good. Outstanding, I would say.

  • @EvanOfTheDarkness
    @EvanOfTheDarkness 4 года назад +3

    I always wanted to learn more physics, then they teach you at high school. But it is a dry an intimidating read alone, i'm so glad that you take your time to explain it! Keep up the good work!

  • @rayzorrayzor9000
    @rayzorrayzor9000 4 года назад +4

    Wow , I subbed after watching the first five mins of the vid , you are clear, concise and you articulate well, i can’t wait to catch up on your previous vids and learn something.
    Thanks for the upload . R .

  • @thekinghass
    @thekinghass 4 года назад +6

    I love how are you going smoothly into quantum mechanics

  • @abhinavkashyap767
    @abhinavkashyap767 3 года назад +3

    Hey there ! Brilliant video, very helpful. But can you pls explain, between 13:15 & 13:25, when you substitute r into the v² equation, how you get v = e²/n2pi𐒢₀ ? Maybe the pi was supposed to be Plank’s constant h ? Coz after substituting r, I got v = e²/nh2𐒢₀. I’m just confused whether it’s a typo or I’m missing something.

  • @swanclipper
    @swanclipper 4 года назад +1

    Very Very interesting. i think this is one of the first youtube channels to force me to do a little more physics and maths to follow your speedy explanation. i know enough, but i can't share what i know, not like you.
    Enjoy your momentary peaceful interactions. during this pandemic and solitary confinement, expect to gain more views way quicker than usually predicted. you gained a sub from me.... i don't sub. you deserve it. (video length is everything i enjoy more than concise videos which gloss over these connections).
    you know it's good when it makes you feel like you should make a youtube series yourself. Damnit, this guy is brilliant.

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад

      Thanks for the kind words, much appreciated. Glad you enjoyed the video!

  • @rhaegartargaryen9047
    @rhaegartargaryen9047 3 года назад +1

    Dude, this is great. Will you please make a video on Wilson-sommerfield quantisation rule and sommerfield extension of bohr model.

  • @halamish1
    @halamish1 4 года назад +3

    Excellent presentation
    The best I've seen until now

  • @lakshaygupta9061
    @lakshaygupta9061 4 года назад +8

    Splendid work as always! Hoping for a video on Heisenberg's Uncertainty principle soon

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +3

      I will definitely be making a video on Heisenberg's uncertainty principle, watch this space

  • @huseyindenkalan4
    @huseyindenkalan4 4 года назад +1

    superb explanation ! many thanks .

  • @justanotherguy469
    @justanotherguy469 2 года назад

    Dude, I wanna cry with joy. I feel like a child on Christmas Day whenever I watch one of your videos.

  • @dennishoelgaardbal3157
    @dennishoelgaardbal3157 3 года назад +1

    The content is great, but my "Um actually" impulse can not be tamed: The equation for angular momentum at 9:53 has the radius and velocity switched, giving the opposite direction of L. Also, the L in the first equation is a vector, and in the second it is a scalar. Despite this, they are represented with the same symbol.
    Great video though, thanks!

  • @selbststandigerschichtarbe6369
    @selbststandigerschichtarbe6369 4 года назад +1

    You've been having a massive high-quality output this month. Keep up the great work!

  • @robertbetz8461
    @robertbetz8461 4 года назад +2

    Thanks, I've read about Electron Volts for decades, now I understand them!

  • @tomsemo8186
    @tomsemo8186 4 года назад +3

    Excellent video. Well done!

  • @RichardFreeberg
    @RichardFreeberg 4 года назад +3

    Bravo! I wish this were available 50 years ago when I took physical chemistry. I never quite grasped the interplay of the various early theories/models/equations and how Bohr synthesized them. I just subscribed. Count me in!

  • @Ottmar555
    @Ottmar555 4 года назад +41

    Schrödinger's model next?

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +25

      Definitely on the horizon

    • @timbeaton5045
      @timbeaton5045 4 года назад +2

      @Dog Ma Actually I was under the impression, that the Cat thought experiment was to demonstrate that something about the superposition of states was wrong? Can't remember where I came across that.

    • @_modernmage
      @_modernmage 4 года назад +2

      @Dog Ma the thing is that QM doesn't actually deal with cats. Sure, the thought experiment is imperfect, but a perfect example is just the real thing. Superposition is what the example is actually about, and the example makes more sense in that context.

    • @carlosoliveira-rc2xt
      @carlosoliveira-rc2xt 4 года назад

      The cat is dead.

    • @2Worlds_and_InBetween
      @2Worlds_and_InBetween 4 года назад

      @@carlosoliveira-rc2xt not in my worlds

  • @migfed
    @migfed 4 года назад +32

    I can't stop saying myself: this blows my mind and so beautiful indeed.

  • @sussekind9717
    @sussekind9717 3 года назад +2

    6:29 -
    No scientist, worth their salt, would ever react negatively to a claim by another scientist, that some of their work was wrong. As a matter of
    fact, they would embrace it. It would make them want to sit down and discuss at length what the problem is and what evidence they have to put forward to back up their claim.
    In my experience, it brings the scientific community closer together, sharing evidence, and performing even more experiments to come to a more accurate conclusion than before, rather then cause any kind of animosity. Don't get me wrong, there are plenty of competitive scientists out there, wanting desperately to make a mark for themselves.
    In the end however, it is the science that matters.

  • @4n2earth22
    @4n2earth22 4 года назад +2

    One of your best yet!!! Thank you.

  • @DonatoColangelo
    @DonatoColangelo 4 года назад +1

    Just discovered your channel. I am loving it. Just wow! Really good stuff, man! Congratulations!

  • @MrDaanjanssen
    @MrDaanjanssen 4 года назад +2

    You deserve a larger audience than you currently have. Just matter of time if you keep doing what you are

  • @campbellmorrison8540
    @campbellmorrison8540 4 года назад +10

    The best explanation of the Bohr model I've ever seen, thank you

  • @jbflores01
    @jbflores01 4 года назад +1

    Excellent explanation of the Bohr model!

  • @gaussagain
    @gaussagain 4 года назад +3

    Thank you for this (and your other) masterpieces. The contributions and vision of these earliest quantum pioneers cannot be overemphasized (or overappreciated!)

  • @erindreams1790
    @erindreams1790 3 года назад +1

    Very, very helpful information for anyone going through college-level physics or even chemistry and biology in some cases. BRAVO. This is WONDERFUL information and it's so easy to understand. You have no idea how much I appreciate this content! THANK YOUUUU!!!!!

  • @knightwik
    @knightwik 4 года назад +2

    This is amazing, please make more of these in depth explanations on these interesting topics!

  • @thepain2222
    @thepain2222 3 года назад +1

    I have to admit, almost all the math goes completely over my head but I'm still learning. You have a knack for explanation even though I might go cross eyed looking at a complicated equation. It really is a shame that the math seems to scare most people away.

  • @markfischer3626
    @markfischer3626 3 года назад

    I went to an extremely tough school where every course was as hard as they could make it. The unified curriculum covered all major fields of science and engineering. Freshman chemistry day one; this is the derivation of the Bohr model of the hydrogen atom, about 40 steps. Copy it down, memorize it, you will be tested on it on a quiz next week when you will required to reproduce it. And like everything at that school it only got harder and harder. The first few months in chemistry was quantum mechanics as the basis for understanding the behavior of atoms and chemical reactions. If I hadn't majored in electrical engineering I might have majored in chemical engineering. After getting my bachelor's degree I took many more courses in chemistry. If I had it to do over again today I'd become a molecular biologist.

  • @robyngenn872
    @robyngenn872 4 года назад +4

    Great video, a little complicated for me, but great video

  • @Shackled
    @Shackled 4 года назад +1

    This channel is excellent thank you! Cannot wait to see more!

  • @redsan16-78
    @redsan16-78 4 года назад +25

    Man this is an awsome video! I was always baffeled on why we can see what stars and planets are made off so many lightyears away because of the spectral lines. I never knew how the spectral lines worked for each kind of atom, but now I do. Thanks for this amazingly simple explanation!

  • @yurtemre7
    @yurtemre7 4 года назад +2

    What an awesome video man. Sincerely thank you.

  • @sharpnova2
    @sharpnova2 2 года назад

    As someone who teaches physics at all levels, this was organized nicely.
    I'd supplement a few sections, I think, without breaking the rhythm or intended audience. But said addendums would be few and far between.

  • @karangupta4978
    @karangupta4978 4 года назад +1

    Honourable mentions: 1. debroglie waves (helps to understand the relationship with plank constant, 2(pi)r = n(lambda) : lambda is the debroglie wavelength of electron, lambda = h/mv).
    2. Rydberg equation: to find the wavelength of photons emitted by electronic transitions.

  • @parthoroy1864
    @parthoroy1864 3 года назад

    Brilliant for its clarity. So lucidly explained .

  • @afwaller
    @afwaller 4 года назад +2

    Keep them coming! Another incredible video. Great work.

  • @joesimon2018
    @joesimon2018 4 года назад +1

    Bohr's model broke down quickly explaining atoms of higher elements and their electron orbits. This was due to interaction between the many electrons involved in those orbits. These orbits were the p,d,f etc... shells we learned about in school. Unique spectral lines for elements still exist for these elements but it requires far more complex math to predict those energy levels.

  • @beerandmath
    @beerandmath 4 года назад +5

    I believe I lucked out big time when your video on the ultraviolet catastrophe showed up on my homepage. Your presentations are very well -polished and have a great balance of not shying away from the math but also not getting too crazy with it. The history lessons remind me of Feynman's lectures - nobody else has really pulled off the "explain the history, stopping for a few minutes in each era to explain the minimal amount of information you'll need to understand the whole story, and make it captivating" sort of thing as far as I've been able to find. I'm hoping you keep it up!

    • @PhysicsExplainedVideos
      @PhysicsExplainedVideos  4 года назад +1

      Thanks for your detailed feedback and kind words. I absolutely loved reading (and listening to) the Feynman lectures, and they certainly have had a big influence over my approach to teaching. My hope is to produce a whole range of videos that combine the historical narrative with the ideas.

  • @mikkel715
    @mikkel715 Год назад

    Good video! Bohr was not into "Shut up and calculate" Bohr meant "Accept the nature to be so strange"
    At some point there is a transition between the Micro and the Macro world
    Heisenberg even put it to Bohr: "Can nature really be so strange"

  • @tonyennis3008
    @tonyennis3008 4 года назад +1

    This is a remarkable video. Question - if an electron is excited up a few levels, how does it know which one to return to? And what makes it become unexcited?

  • @farzanroshdieh698
    @farzanroshdieh698 2 года назад

    Just mind bunglingly dense accurate presentation. So beautifully put together. Absolutely a public service.

  • @robertgift
    @robertgift 3 года назад

    Well done! Well written! Wonderful seeing the photos. Thank you.

  • @BjornMoren
    @BjornMoren 4 года назад +1

    Brilliant video! I only got a brief intro in school, and this explains much more. Very interesting.