Five science 'facts' we learnt at school that are plain wrong

October 28, 2014 by Mark Lorch, The Conversation
Five science ‘facts’ we learnt at school that are plain wrong
The sixth sense is real, but it doesn’t let you see dead people. Credit: Thomas.haslwanter, CC BY

Let's start with a quiz…

  1. How many senses do you have?
  2. Which of the following are magnetic: a tomato, you, paperclips?
  3. What are the primary colours of pigments and paints?
  4. What region of the tongue is responsible for sensing bitter tastes?
  5. 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 its 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.

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 nickle 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 (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.

A bitter taste in your mouth

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.

Five science ‘facts’ we learnt at school that are plain wrong
The true primary colours. Credit: MARKELLOS, CC BY
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.

Five science ‘facts’ we learnt at school that are plain wrong
Areas 1,2,3 and 4 – there’s are no difference MesserWoland, CC BY
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.

Explore further: 'Magnetic tongue' ready to help produce tastier processed foods

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julianpenrod
1 / 5 (5) Oct 28, 2014
Among other things, primary colors are taught in school, generally, not as colors that can't be composed of other colors, but as colors that, in combination, can give rise to other colors. And, at least for grammar school purposes, that is the case. And it gives the idea of compositions of colors using well known names rather than "cyan" and "magenta".
So much, though, for "science". It's constantly drummed at us that "science" is reliable. And textbooks are supposedly the end result of "science". Even journal articles are taken as open to error or correction, buy textbooks are supposed to be distilled truth! Those who are "science" devotees are mouthing materials from texts and many, apparently, are completely untrue! Add doggerel like, "Claims offered without proof can be dismissed without proof" and the rabid mentality of an arrested development misfit and you see the basis for much of devotees' actions.
RobertKarlStonjek
1 / 5 (2) Oct 28, 2014
The simpler formulation is to consider environmental sensors and somatosensory perception.

We sense our environment via Audition, Vision, Olfaction, Taste and various sensory modalities via the skin. Two that are routinely missed are static electricity via the hair (we even have muscles in the hair which make hair move considerably in the presence of a static electric field) and air pressure via the carotid sinus.

Somatosensory perception is what sense about our bodies including proprioception, balance and motion (which, in the modern setting, tells us about the motion of objects that we are travelling with. But this sense did not evolve for that purpose), and the state of several internal organs.

Making this simple division, between environmental and somatosensory perception, greatly simplifies the issue and is backwardly compatible with traditional teaching methods.
Returners
1 / 5 (2) Oct 29, 2014
They come in cyan, yellow and magenta, which are the true primary colours.


I don't believe this, because the EM spectrum is continuous, well, in general. Individual elements have spectral lines, but in principle the spectrum itself is continuous, and the wavelength of light is what determines it's color.

Pointilism is a form of painting which uses the primary colors and tricks the eye into mixing the paints. In reality, it is on the macroscopic scale doing the same thing traditional paint mixing did on the palette.

This shows how what the eye "sees" is actually additive, just like the art class teaches. It doesn't matter that yellow, cyan, and magenta are subtractive. The eye still sees in additive representations.

Yellow and Blue do in fact make "green," but green is also an actual color with a unique wavelength, as there are green lasers.

Also, I have a color blind uncle. Red-Green is the blindness, showing eyes actually see red and green as primary
Returners
1 / 5 (2) Oct 29, 2014
If red was a secondary color and Yellow a primary color, you'd expect he wouldn't be able to see yellow, the common primary on your chart, or that he would be able to see neither Cyan or Magenta, the other two prmaries.

However, this is not the case. He simply can't see Red and Green.

You can also prove this in a chemistry lab by burning different elements. Virtually every major color imaginable is obtainable by burning some element. Since thsi energy is coming from a unique signature of the binding energies of the valence electrons, the "color" produced is a quantum value, and is a "primary" color.

Thus every visible color, and every invisible EM wave for that matter, is in fact a "primary" color.

So you are both wrong.
antialias_physorg
5 / 5 (1) Oct 29, 2014
Time to rewrite textbooks?

It's probably time to stop teaching kids labels and make it out as if that were science - but rather lead them to understanding of the principles involved.
Then we can attach labels (and make sure that kids understand that labels are for convenience of communication only - they do not contain any science).
Uncle Ira
2.6 / 5 (5) Oct 30, 2014
If red was a secondary color and Yellow a primary color, you'd expect he wouldn't be able to see yellow, the common primary on your chart,

You can also prove this in a chemistry lab by burning different elements. Virtually every major color imaginable is obtainable by burning some element. Since thsi energy is coming from a unique signature of the binding energies of the valence electrons, the "color" produced is a quantum value, and is a "primary" color.

Thus every visible color, and every invisible EM wave for that matter, is in fact a "primary" color.

So you are both wrong.


Well Skippy, I hate to ruin your day so early in the morning, but it is you that is wrong. You should try that google-Skippy thing before you explain the stuffs you get wrong,

You got three kinds of cones in your eyes, your brain makes all the colors from mixing just the three. Boy for a genius you sure are stupid.
gkam
3.7 / 5 (3) Oct 30, 2014
This guy has confused additive color with subtractive color. Look them up.

Why is Uncle Ira so offensive?

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