Just how small is an atom? - fun TEDEd video

[Video Link] Bibliog says: "My friend Dan made this kick ass animation for TEDEd, explaining how small an atom actually is!"


  1. Not only did that explain to me just how small an atom is in terms that made perfect sense it also explained how dense the nucleus is in terms that made perfect sense. And it was fun to watch.

    I think my 7th grade science textbook tried to explain the distance between the nucleus and the first electron shell by saying that if the nucleus were the size of a tennis ball the first electron shell would be the distance of a football field from it. If I’m remembering that correctly that textbook slightly underestimated the distance, but then that same textbook, which I was reading in 1984, had a chapter heading titled “Someday Man Will Reach The Moon”.

  2. Good thing he didn’t go into sub atomic particles. Our collective brains would just dribble out our ear like melting brain jell-o.

  3. Thanks,but i’ll stick to WKRP’s Venus Flytrap tough gangs analogy with the Pro-tons and the Elec-trons.This is way too dense for me ( yup,pun intended.)

  4. So there are as many blueberries in the earth as there are cars in a box? And the whole thing is made of grapefruit?

    On reflection, I believe I may have missed the point.

  5. Nitpick from a former undergraduate inorganic chemistry instructor: electrons do not work that way.  The charge density of (for example) a helium atom’s electrons is principally *at* the nucleus, not at the van der Waals radius or whatever the video is defining the “edge” of the atom as.

    Electrons are weird and don’t make sense but they definitively aren’t little particles that whizz around in a fixed orbit about the nucleus, as the video implies.

    1. Yeah, that really bugged me. It’s great this guy is so enthusiastic about teaching, but considering he’s trying to only trying to communicate 4 facts, it’s a little troubling that one of those facts is just plain incorrect. Not even “sort of right” or “dumbed down for laypeople” – it’s just not true. 

      This is what has always bugged me about the TED phenomenon – in trying to make all this pointy-headed-big-think stuff cool, they inevitably privilege style over substance. This guy put orders of magnitude more work into the design of his cute little animation than researching his basic facts.

    2. It make more sens to talk about the RMS size of the electron probability density function. If you just talk about the average position of the electron, of course they will be near the center. The average position of people on earth is somewhere near the earth’s core, but that isn’t a very useful quantity. 

      1. The probability density for the first electron shell is peaked at r=0. It looks nothing like the distribution of people on earth. It would be correct to say that there are no people between the center of the planet and the surface. It’s 100% incorrect to say that there is empty space “between” the electron and nucleus.

        1. Sure, the probability density is peaked at the origin for the lowest energy state. Unless you care about the fine structure of the atom, this isn’t going to matter. 

          Why object to saying there is empty space between the electron and the nucleus? Why not object to the idea of empty space? Make the kiddies learn about vacuum fluctuations and meson seas surrounding the nucleons. I am sure they would love that.

  6. Not helpful at all… We don’t have a visceral knowledge of how large Earth is and the video consistently showed the atom with the size of a pill. The visual noise of literal animations only distracts.

    The numbers used are so large that they are meaningless. I have not seen 6.2 billion of anything so I cannot imagine this amount of cars. Sorry, wish I could say something positive, but would not recommend this.

    I like this size comparison better, as it starts with things I have reference for.


    1. Agreed. I have no real concept of how big the Earth is, so it doesn’t help. Also, blueberries are expensive. I suspect this was made by somebody for who  enjoys global travel and luxury foods.

      Your link was much better – thanks.

      And this is my favorite site showing the inside of a single atom:
      Now THAT is mind blowing: the electron is 1 pixel. Try to print the web page: it’s ELEVEN MILES wide.  And it only shows half the width of the smallest atom there is.

    2. I thought the posted vid was pretty lame too.

      Not so this brilliant scale slider thingy – which is about as good as it gets.

  7. yep, too many different fruits, and why all the untrue assumptions (grapefruits made of nitrogen atoms, everyone owning a car etc). maybe i know too much because i was once a chemist, but I certainly wouldn’t play this to my 5 year old to help her understand atoms. 

    for me the euraka moment (granted not at age 5) in terms of my own understanding of scales within the atom was Rutherford’s famous line about his gold foil experiment.

    It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you. On consideration, I realized that this scattering backward must be the result of a single collision, and when I made calculations I saw that it was impossible to get anything of that order of magnitude unless you took a system in which the greater part of the mass of the atom was concentrated in a minute nucleus. It was then that I had the idea of an atom with a minute massive center, carrying a charge.[2]
    —Ernest Rutherford

  8. I’m still confused… maybe I’m a moron, but I have a human-centric approach to everything. So here’s my question: How big would I have to be to hold an atom between my fingers, the way the professor keeps pinching his fingers in the video? 

    Answers anyone? 

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