Misconceptions in Science
From Bill Beaty's excellent
Amateur Science website comes this ongoing list of:
"Science Myths" in K-6 Textbooks and Popular culture
"Science Myths" in K-6 Textbooks and Popular culture
The complex and abstract nature of Science makes the subject difficult to understand. But complexity is not the only barrier to our understanding Science. The subject is made much more difficult by the presence of numerous misleading "Science Myths" which circulate in the popular culture, which are handed down from parents to children, and which have become so common and widespread that they appear widely in science textbooks and are taught as facts in grade school.
Here are two examples:
Sound travels better through solids? No.
Many elementary textbooks say that sound travels better through solids and liquids than through air, but they are incorrect. In fact, air, solids, and liquids are nearly transparent to sound waves. Some authors use an experiment to convince us differently: place a solid ruler so it touches both a ticking watch and your ear, and the sound becomes louder. Doesn't this prove that wood is better than air at conducting sound? Not really, because sound has an interesting property not usually mentioned in the books: waves of sound traveling inside a solid will bounce off the air outside the solid. The experiment with the ruler merely proves that a wooden rod can act as a sort of "tube," and it will guide sounds to your head which would otherwise spread in all directions in the air. A hollow pipe can also be used to guide the ticking sounds to your head, thus illustrating that air is a good conductor after all. Sound in a solid has difficulty getting past a crack in the solid, just as sound in the air has difficulty getting past a wall. Solids, liquids, and air are nearly equal as sound conductors.
And (highly excerpted as this is a complex subject and Bill takes the time to explain it very well):
BEN FRANKLIN SHOULD HAVE SAID ELECTRONS ARE POSITIVE?
Wrong.
Many authors bemoan the fact that Ben Franklin labeled "resinous electricity" as negative, and "vitreous electricity" as positive. By choosing the polarities this way, Franklin forces us to say that electrons carry a charge of negative electricity. Because of Franklin's decision, we must name the electric currents in metals as flows of NEGATIVE charge rather than positive charge.
Did Franklin make a mistake? Should he have defined the electron to be positive? ABSOLUTELY NOT. In fact it's a blessing, since these flows of negative charge aren't inherently confusing. Franklin's choice of polarity fortunately helps reveal the true source of confusion: common and widespread misconceptions about electrons and "electricity."
And this little list of facts:
What are the misconceptions? Here is a list:
- All electric currents are flows of electrons. Wrong.
- "Electricity" is made of electrons, not protons. Nope.
- Electrons are a kind of energy particle. Wrong.
- "Electricity" carries zero mass because electrons have little mass. No.
- Positive charge is really just a loss of electrons. Wrong.
- Positive charge cannot flow. Totally wrong.
- To create "static" charge, we move the electrons. Not always.
These seven statements are misconceptions. We have Ben Franklin to thank for rubbing our noses in this fact. If he'd chosen the polarities so that the electrons came out positive, we'd be much more comfortable. We might never even notice our errors.
A lot of this stuff is "common knowledge" and gets passed along. For a kid who is going to go into the
liberal arts waiting tables, this isn't such a big deal but for one who will follow along into a technology career, this is laying a very bad foundation for future understanding of the way things work.
Bill's website is very deep and worth exploring...
Posted by DaveH at October 12, 2008 6:59 PM