Five Science 'Facts' Taught At School That Are Just Plain Wrong

Image: iStock

Let's start with a quiz: How many senses do you have? Which of the following are magnetic: a tomato, you, paperclips? What are the primary colours of pigments and paints? What region of the tongue is responsible for sensing bitter tastes? What are the states of matter?

If you answered five; paperclips; red, yellow and blue; the back of the tongue; and gas, liquid and solid, then you would have got full marks in any school exam. But you would have been wrong.

The sixth sense and more

Taste, touch, sight, hearing and smell don't even begin to cover the ways we sense the world. We sense movement via accelerometers, which are located in the vestibular system within our ears. The movement of fluid through tiny canals deep in our ears allow use to sense movement and give use our sense of balance. Make yourself dizzy and it's this sense that you are confusing.

When we hold our breath we sense our blood becoming acidic as carbon dioxide dissolves in it forming carbonic acid. Not to mention senses for temperature, pain and time plus a myriad of others that allow us to respond to the need what is going on within us and the environment around. Picture: Wikimedia Commons

Magnetic repulsion

It is not just paperclips that are magnetic. Both tomatoes and humans interact with magnetic fields, too.

Paperclip and other objects that contain iron, cobalt and nickel are ferromagnets, which means that they can be attracted to magnetic fields. While the water in you and the tomato — or more accurately the nuclei in the hydrogen in the water in you and the tomato — is repelled by magnetic fields. This interaction is called diamagnetism.

But the forces involved are incredibly weak. So normally you don't notice them. That is unless you have been in a magnetic resonance imaging (MRI) machine. In there, a massive magnet manipulates nuclei of various atoms inside you in such a way that results in detailed images of your inner workings.

Though you don't need to go to a hospital to see diamagnetic interactions. Just use a couple of cherry tomatoes, a strong magnet, a wooden kebab stick and a pin:

And the types of magnetism don't stop there, but that's for another time.

You're painting with the wrong colour

You were taught that primary colours are those that can't be made by mixing other coloured pigments together, and that all other colours can by produced by blending these primary colours. Red and blue fail on both counts. You can make red by mixing yellow with magenta. While a blend of magenta with cyan yields blue. Meanwhile a massive range of hues are inaccessible if you start with just red, blue and yellow.

Colour theorists had this all worked out by the end of the 19th century but for some reason it hasn't made it to school curriculums. The proof is in your colour printer cartridges. They come in cyan, yellow and magenta, which are the true primary colours. Picture: Wikimedia Commons

A bitter taste in your mouth

Areas 1,2,3 and 4 — there's no difference. Picture: Wikimedia Commons

Remember those tongue maps that crop up in biology text books? They clearly show how the taste buds for bitter sit at the back of the tongue, with sweet, sour and sweet having their own discrete regions.

These tongue maps first appeared in 1942 after Edwin Boring of Harvard University misinterpreted a German study from 1901. Despite Boring's mistake the maps soon started to appear in schools texts. Then in 1974 the topic was revisited and the whole idea was roundly discredited. Nevertheless over 40 years later tongue taste maps still persist in biology text books.

Look at the state of your screen

We all learned solids keep a constant shape because the molecules in them are ordered. These can melt to liquids which keep a constant volume and can be poured. Liquids evaporate to form gases that expand to take up the volume available to them. There we have the three states of matter, end of story.

Expect of course there is more. Liquid crystals have molecules that are ordered like a solid but are fluid like a liquid. These properties are vital for your cells, shampoo and of course liquid crystal (LCD) flat screen devices.

But why stop at four states. There is plasma, the state of matter for most things in the sun, or Bose-Einstein condensates, superfluids and dozens more.

Time to rewrite textbooks?

There are many more than the five "facts" that need to be fixed in school textbooks. I am not suggesting that we should start teaching 6-year-olds about matter that only appears in Nobel Prize-winning physics labs or filling the curriculum with detail on dozens of senses. But maybe we should stop telling kids fibs.

Perhaps a biology lesson should start with: "We have many senses, here are the five we are going to learn about." Or a sentence dropped in here and there that mentions the existence of more than three states of matter. As for the tongue map, just rip that page out of the book.The Conversation

Mark Lorch is Senior Lecturer in Biological Chemistry at University of Hull. He does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published on The Conversation.


Comments

    You could add the list of now debunked 'evidence' for evolution: the horse series, peppered moths (that was faked up for publicity), embyonic recapitulation...and the failure, of course, to cover Haldane's dilemma.

      The Quantum Erasure Experiment shows us that the Past is adjusted to support the Present observation.
      Put that in your pipe and smoke it.

      Evolution debunked? You mean denied by loony morons like yourself because it disproves your beliefs?

      Not sure why I'm bothering to go over this, as in my experience young-earth-creationists are at least as irrational as climate change denialists(*), but here goes.

      1. Horse series: Nope. For a good discussion see http://www.talkorigins.org/faqs/horses/horse_evol.html; basically evolution is not linear in nature - it branches out, had false starts and stops. The fossil record for horses reflects this. (Unfortunately, the sort of old-school textbooks that portrayed linear horse evolution do not.)
      2. Peppered moths. Some pictures were faked up for photos, but that's because moths tend to fly away when people get close. A recently published study showed moth resting sites consistent with the hypothesis. [Matzke, Nick (8 February 2012). "Selective bird predation on the peppered moth: the last experiment of Michael Majerus"]
      3. Embryonic recapitulation: You are correct that this is largely discredited, but it's also not actually required for evolution to work.
      4. Haldane's dilemma: To quote a paper written in 1974, "The special genotypic and populational conditions required for rapid evolutionary change in genetically complex characters are not unusual in higher organisms."

      As for counter-arguments:
      - MRSA is one obvious example of evolution in action.
      - If you're arguing for young-Earth creationism, then since all people are descended from Noah and his sons (and for that matter Adam and Eve), all men must have the same Y chromosome and the entire population must have one (or two) of three X chromosomes. Clearly not the case.
      - Fossil starlight - did God want to fool us that much?
      Too many other examples to count. If evolution has been debunked, then creationism has been debunked, shot, drawn and quartered then diced into small pieces and fed to sharks.

      IMO the best argument against creationism is the simplest: if young-Earth creationism is true, why is there so much evidence that the world is old? Heck, we even have evidence of human activity going back 50k years or so; the oldest cave painting is about 40k years old. If young-earth-creationism is true, then God is a liar.

      You might as well argue that the world came into existence ten minutes ago.

      (*) If anyone wants to argue this, please look at global temperature records over the last five years or so FIRST.

        Let's forget young-Earth creationism, what about creationism in general?

        I personally believe in both, I believe that evolution definitely exists to an extent, however, I also believe that it all began with God.

          I'm perfectly OK with creationism in general. Occam's razor would suggest that God as a first cause is not NECESSARY, but Occam's razor is not a law of nature.

          Personally I count myself as agnostic; more precisely, I sort of wish there was a real God in the mould of that portrayed in the New Testament, but it's been years since I believed that to be the case.

          In the meantime, I try to act ethically, not because I'm anticipating some sort of Judgement after I die, but because I would rather leave the world a better place for my having been part of it. (The assumption of some Christians that atheism = amorality really irks me.)

    There are many more than 5 facts that are ignored at school. Evolution anyone?
    This list avoids some of the bigger elephants in the room, like Intelligent Design.

      I was never taught intelligent design in school...

        Because it is a figment of religion's imagination.

        Intelligent Design is easy to teach. Take a deck of 52 cards, shuffle them, then lay them out. Intelligent Design says that, because the PARTICULAR pattern you made has a probability of one in 52 factorial (52 x 51 x ... x 2 x 1) you MUST have cheated.

      Evolution is a fact, Intelligent design is not.

      Next.

    The thing about the primary colours - isn't that the difference between additive and subtractive colour schemes? RBG is additive (for black backgrounds like a computer screen) and CYM is subtractive (for white backgrounds like paper) ?

      Close, RGB works when adding light (like a screen), CMY works with pigments which cut out certain frequencies of light.
      The big problem though is that schools teach RBY which isn't correct in either context.

      Actually there are no 3 colours that can produce "all other colours".

      The "3" comes from the three different types of cone cells in our eyes, these are sensitve in the red, green and blue parts of the spectrum respectively, and "seeing" a colour requires that one or more of these receptors is stimulated. The red and green cones evolved from a single precursor quite recently (non-primates have only 2 types of cone) and their discrimination overlaps, so yellow (in between them) is the hardest colour to pick.

      The range of mixtures of any three actually visible colours gives a triangular field of possible colours, which will always leave some colours that we can discriminate outside the edges of the triangle. Thus the whole "three primary colours" thing is a myth, not just the RYB that we are taught at school (which is as good as CYM). However, since the full field of colours that we can see is sort of triangular, we can get a close approximation (see https://en.wikipedia.org/wiki/CIE_1931_color_space for a full description).

      The last section of this wikipedia article gives the official standard 3-primary representation of the human colour field, but the catch is that none of the three "primaries" on which it is based can actually be discriminated by the human eye.

      Last edited 14/09/16 5:35 pm

    Not to mention senses for temperature, pain and time

    Wouldn't pain be covered by the sense of touch?

      How about headaches or referred internal pain? Touch as well?
      Proprioception (knowing where your body's at without looking) is another sense.

        Yeah I'd say internal pain too. Touch isn't just restricted to stuff making contact with your skin.

        Last edited 29/10/14 1:24 pm

          And yet that is pretty much its definition.

          Just to have evidence - http://www.thefreedictionary.com/sense+of+touch

          Noun 1. sense of touch - the faculty by which external objects or forces are perceived through contact with the body (especially the hands)sense of touch - the faculty by which external objects or forces are perceived through contact with the body (especially the hands); "only sight and touch enable us to locate objects in the space around us"

      I learnt about the "9" senses a long time ago, but there are up to 21 subs or more... One of my favourite Wikipedia pages for a long time has been http://en.wikipedia.org/wiki/Sense great topic of discussion :P
      Synesthesia is a fascinating disease too relating to senses & how your brain receives them

    Of course, many lies taught to children are deliberate and useful simplifications.

    Newton's Laws of Motion are useful, even though they've been superseded by Einsteinian ideas.

    Talking about electron shells in chemistry is useful, even though quantum superposition would be closer to the truth as we currently understand it.

    Teaching Intelligent Design has its merits. Hey, kids need a good laugh now and then as a break from all the actual facts they're learning!

      Please tell me that was a reference to the Science of Discworld in the first sentence =)

      Even in advanced physics courses, you learn Newton before you learn Einstein, and for good reason.

      Not only is Newton really useful, he's also a great way to learn how to derive laws from symmetries (via Lagrangians and Hamiltonians).

      Also, if you drop out because you couldn't understand Newton, you were NEVER going to get Einstein :)

      It really is better to teach someone to drive straight before letting them loose on a skid-pan :)

      I still don't understand what is so wrong with the intelligent design. It is as probable as the evolution.

        No its not.

        On one hand there is plenty of evidence supporting Evolution.

        On the other hand there is no evidence what so ever supporting Intelligent design.

        We want to teach kids facts. Not tell kids fairly tales and claim they are fact.

          I see what you mean. To me reality is nothing but a fairy tale looked through our fantasies supported by wild theories(like maths and science) concocted by our consciousness . In order for evolution to make sense, reality should make sense first. Otherwise, it is not that far for me to think that the reality is in fact made by myself or someone superior to me.

            You wouldnt happen to be a heavy user of drugs? Or an escaped patient from a lunactic asylum?

    why is Shakespeare important?
    his plays kept English teachers in a job for 350 years

    Last edited 29/10/14 1:34 pm

      Because when the teacher asks "what is the author trying to say", there is no wrong answer.

    Interesting list. Particularly since, as a science teacher, I don't teach a lot of this stuff. We talk about various senses, but I don't say it's a comprehensive list. I tell them that we're learning about simplified models, because they work and they're useful.

    I know I'm not alone in this approach.

      Good to hear it, and /salute a fine profession.

      Most of my education in NZ was at least one step above the examples provided too.

      Frankly, I'm gobsmacked that the author wants to assign CMY a special status in education. I submit that art class needs to know how to mix paints, and that science class needs prism experiments, and that CMYK deserves no more than a brief mention as a useful but arbitrary example of a color space.

      In fact in my school, the fact that the tastebuds map theory appeared in our textbooks was used as an outstanding teaching tool! In '84 when I was in form 4, the bio class learned about the taste map, and devised an experiment (it was taught deadpan, they were specifically NOT told it had been debunked). The bio class came to the common room with toothpicks and essences, and we had great fun trying (and failing) to work out a tongue map, which taught a valuable lesson; that in science, experiment trumps authority every time.

      I remember failing a science exam back at school and the teacher said "It doesn't matter if you're right, it's not about what's right, it's about answering what's in the curriculum"

    I don't recall the "three states of matter" being taught as an exclusive list - plasma was explicitly mentioned as another state, just not one we'd be covering. And that was a fair while ago.

    Similarly for the magnetic properties of people and a tomato. They were mentioned, but not studied in any detail.

    It sounds like the author is confusing "facts" with "truths", in that the facts listed aren't wrong, just that they represent incomplete sets of facts within their domains, which impacts on the "truthiness" of what is being taught - but then agaon, school is the first step in that journey, not the destination. In which case, if such a state of affairs causes such distress, I'd recommend avoiding looking too closely at what is taught in economics classes.

      I took accepting to that part of his list as well.
      There are 3 primary states of matter. Not that they tell you that's all there is. Does the author think 12 year Olds should be learning about transneutonin substances or other substance forms like metallic hydrogen? Before trying to grasp the basics and most important subjects.

      Last edited 20/08/16 6:28 pm

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