Class Warfare Blog

April 7, 2014

What Cosmos Got Wrong Last Night

Filed under: Science — Steve Ruis @ 9:46 pm
Tags: , , , , ,

I have been loving the new Cosmos series which has excellent writing, mellifluous voiceovers by a wonderful host, Neil deGrass Tyson, spectacular special effects and visuals, and which has made very few errors, too, at least until last night. In an attempt to explain how atoms absorb and release photons of light they created an animation of atoms. First their depictions were a bit sci-fiish and bizarre but they settled upon a single hydrogen atom with a fuzzy, jittery large spot representing the nucleus of the atom and a smaller, jittery blob of light representing the electron. There is the problem of scale, which I have written about before. It is impossible to show these particles at their actual scales and at their actual distances (even blown up as they were in the animation. The human eye is not capable of that feat, so I give them a pass on the two particles being overly large and overly close together. It is, after all, T.V.

 “This would have been a quite acceptable description if it were, say, 1922.” 

But then they goofed. They then showed the electron in orbit around the nucleus, one of , they said, many possible orbits. And that the electron, when it absorbed or released light energy, in the form of a photon, would leave one orbit and end up in a different orbit. They showed the glowing orbit (looking like a vapor trail the electron was leaving behind) disappearing and a new orbit appearing elsewhere. This is the so-called “quantum leap.”

This would have been a quite acceptable description if it were, say, 1922.

Since then, though, we have learned a great deal, specifically that there are no orbits. We do not know what atomic electrons are actually doing but we know what they are not doing and that is orbiting the nucleus. They are not in circular orbits. They are not in elliptical orbits. They are not in loop-the-loop orbits. There are no orbits! The locality of an atomic electron can be described but only as a probability map, e.g. it has a high probability of being here, and a low probability of being there, etc. These maps are called “orbitals” to signify that they replaced the orbits of earlier thinking. These orbitals are “unbounded,” that is they have no outer boundaries. A consequence of “unboundedness” is that all possible orbitals of an atom overlap. When an electron in an atom absorbs or spits out a photon of light energy, it does not change position in no time. It simply changes its probability map and since they all overlap (albeit in many cases only a tiny bit) each electron doing this is in its old orbital and its new one at that exact moment. What the electron does from that time forward is to exist as described by its new map rather than its old one.

A “quantum leap” (damned poets) is an instantaneous leap in energy, not in position. In human beings it is like an instantaneous change in mood; like if you were having a bad day but then got the news that your child finally was having another baby after trying for years: bingo, happy days are here again! This mood change does not require a change in position.

And neither does a quantum leap.

There is plenty of quantum wierdnesses to amaze the audience; they do not need to dredge up one hundred year old misconceptions to highlight them. For example, the fact that only a set of fixed energy changes are possible for any element’s atoms. If a photon races through an atom and does not correspond, exactly, to the energy difference between two of that atom’s orbitals, it just keeps going. Nobody knows (yet) why or even how those energies are fixed into the values the are or how the electron can tell whether or not to take on that photon. There is nothing like this behavior in the macroscopic world in which we live.

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16 Comments »

  1. In defense of Cosmos, it’s a real bitch to make a visualization of electron clouds that also manages to clearly communicate quantum energy levels. You could then just as easily complain that no mention would be given to p, d, or f-orbitals, because their inclusion would complicate the presentation even more. Since the topic was light emission and absorption, and not bonds, I can easily forgive them going with the model that best displays quantum levels.

    Still, I’d have preferred to have seen some dumbbell shaped p-orbitals on the fatter atoms, even with the fake wavy line electrons.

    Comment by Ignostic Atheist — April 7, 2014 @ 10:40 pm | Reply

    • Actually they could have dodged the whole thing by just showing an amorphous electron cloud (pulsating for visual interest) then a photon zaps in and the cloud gets larger but looks the same. The problem came from trying to explain a mistaken notion that the electrons jump *through space*from one orbit to another instantaneously. That conundrum was based upon the mistaken notion of orbits, both of which they reinforced and both are nonexistant. I have no problem with them leaving out the gory details of orbital definitions, etc.

      On Mon, Apr 7, 2014 at 10:40 PM, Class Warfare Blog wrote:

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      Comment by Steve Ruis — April 8, 2014 @ 8:39 am | Reply

      • the cloud gets larger but looks the same.

        And there is the problem. A sphere that gets larger looks the same as a sphere that you got closer to. They went with the most visually stimulating model they could. Perhaps when we get to an episode which details the joy and necessity of carbon bonds for life, we’ll see something more in depth.

        And that is why I’d have liked to have seen some p-orbitals in the background, to let people know that there’s more to this than they’re being told.

        Comment by Ignostic Atheist — April 8, 2014 @ 10:06 am | Reply

  2. If we’re talking about probability distribution, wouldn’t it be fair to represent an orbital as a mean of the distribution – or, possibly, as a, say, 95% confidence interval?

    Comment by List of X — April 7, 2014 @ 11:49 pm | Reply

    • Sure, but do you want to drag casually interested viewers through that? They could have dodged the whole thing by just showing an amorphous electron “cloud” (pulsating for visual interest) then a photon zaps in and the cloud gets larger but looks the same. They erred in trying to explain “quantum leaps” as leaps through space instead of energy.

      On Mon, Apr 7, 2014 at 11:49 PM, Class Warfare Blog wrote:

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      Comment by Steve Ruis — April 8, 2014 @ 8:41 am | Reply

  3. Interesting. Matt Rave did a great post recently on the ineffectiveness (and silliness) of trying to use words to explain QM.

    I think Brain Cox (in one of his programs) did a marvellous job in describing the problem of atomic scale.

    Comment by john zande — April 8, 2014 @ 7:14 am | Reply

    • If you think QM is hard to explain in words, try images and animations! It is a real bitch! I went toe to toe with a textbook publisher over a diagram in a college chemistry text. They showed a nucleus as a collection of differently colored little balls (purple and yellow I think) with a wispy electron cloud having a distinct outer surface. There is no such thing as color at that level. The nucleus is not a collection of protons and neutrons, it is a single particle made by fusing those particles together, just like if you melted a bunch of metals into a mixture. And the electrons do not form shapes with hard surfaces, their “locales” just slowly fade out. It is hard enough that our eyes put distinct outer surfaces on things like real clouds (which do not have them) but we shouldn’t be paying graphic designers to portray things as they are not. The book publisher’s response? In the second edition they reduced the size of the misleading graphic from full page to quarter page! Argh!

      If you take a sheet of paper and put the smallest dot you could see in the center of it and then using less ink or pencil lead you draw in a whispy cloud centered on that dot that is denser toward the middle and fades toward the edges, you would have made a reasonable representation of what an atom looks like, and still have overdone the sizes and concentrations of matter involved (the nucleus should be more concentrated, the electron cloud less). And the scale problem the diameter of the cloud is 100,000 times larger than the nucleus, so if your cloud stretches the full width of the page, say 8 in or 20 cm, the nucleus should only be 0.00008 in/0.0002 cm wide which is not really perceivable while keeping the full picture in view. To see the nucleus, you have to stick your head in the cloud as it were. (And really the paper should be black and the ink white,etc. but….) Such is the problem in representing atoms pictorially.

      There a few safe things they could have done (see my comments on the past few comments so I don’t end up repepating myself ad nauseum).

      On Tue, Apr 8, 2014 at 7:14 AM, Class Warfare Blog wrote:

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      Comment by Steve Ruis — April 8, 2014 @ 8:58 am | Reply

      • But a cloud isn’t as exciting! 🙂 But I get your point. We do need a new atomic representation.

        Hey, seriously, you should pen a brief article on it and submit it around the place, see if it can’t gain some traction.

        Comment by john zande — April 8, 2014 @ 9:07 am | Reply

        • That was my old job! I have a new job–archery coach–and archers need better instruction than they are getting, so that’s where I am most focussed now. I was just emailing the US Collegiate Archery association about some of their posted materials being less than they could be.

          On Tue, Apr 8, 2014 at 9:07 AM, Class Warfare Blog wrote:

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          Comment by Steve Ruis — April 8, 2014 @ 9:12 am | Reply

          • OK, I have a PR thing you can get behind. The US loves having enemies, right? You guys love the whole USA! USA! USA! thing. Here’s the plan: organise the Chinese archery fed to send over a small team to go on tour. Promote it like a boxing match…

            Comment by john zande — April 8, 2014 @ 9:17 am | Reply

            • We’d wax them! Especially in Compound (not the Olympic version). But the idea has merit. Still you have to overcome the problem of watching archery competed is right up there with watching paint dry.

              On Tue, Apr 8, 2014 at 9:17 AM, Class Warfare Blog wrote:

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              Comment by Steve Ruis — April 8, 2014 @ 9:22 am | Reply

              • Not if you promote it right!

                Comment by john zande — April 8, 2014 @ 9:41 am | Reply

                • Great acting by Dolph Lundgren. The only direct that works is “look up and looked stunned,” natural actor that boy is.

                  On Tue, Apr 8, 2014 at 9:41 AM, Class Warfare Blog wrote:

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                  Comment by Steve Ruis — April 8, 2014 @ 12:23 pm | Reply

                  • For that, he must break you.

                    Comment by john zande — April 8, 2014 @ 2:15 pm | Reply

                    • I’ve been broke most of my life, remember? I was a teacher.

                      On Tue, Apr 8, 2014 at 2:15 PM, Class Warfare Blog wrote:

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                      Comment by Steve Ruis — April 8, 2014 @ 2:20 pm

  4. The show’s representation irked me (probably to an irrational degree) — thanks for writing this!

    Comment by Benjamin Haas — April 11, 2014 @ 11:09 am | Reply


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