Teaching – Page 12 – Science teacher

April 13, 2019January 8, 2022

Staying ahead of the curve

#SatChat question today–too often we ask ourselves questions without challenging the premises.

“Staying ahead of the curve” is adspeak used by an industry that needs you to keep turning over tools. The ed-tech industry runs on perceived obsolescence.

There is no need to get ahead of the curve (whatever that means) if one has the tools to do what is needed doing here and now.

Every tool has a learning curve. Every tool has limitations. Every tool used by humans is crafted by human imagination.

In anatomy, a few pieces of colored chalk are better than markers when using subtle shades to show specific structures. I no longer use chalk because I no longer have a chalk board–our administrators removed them years ago, perhaps to save themselves the embarrassment of falling behind the curve.

Anatomy art found in Honfleur, summer 2018.

I miss using chalk. This is not some romantic notion getting maudlin over days when I had more energy (and more hair). I can get by with more expensive Expo markers using a more expensive white board. (I could get by with a stick and a patch of beach.)

The tools most teachers use are tools thrust upon us by folks who have left the classroom, for whatever reasons.

I clam with a fairly new (about 10 years old) rake with a wooden handle that replaced one about 50 years older. The style hasn’t changed much, but to be fair, neither have clams. There are bigger rakes, there are rakes with baskets, there are rakes with Fiberglas handles, and for all I know there may be rakes with built-in GPS systems.

I could pluck clams from the mud by hand, I suppose, and some days I do just that. There is joy in clamming by hand, even if it lacks the efficiency of a commercial clam dredge.

I traded that curve years ago for the arc of the sun settling on the edge of the bay and the feeling of the arched back of a quahog in my hand.

If you’re ahead of the curve, drop a comment and let me know what I am missing.

March 14, 2019January 8, 2022

On fruit batteries

https://www.stevespanglerscience.com/lab/experiments/fruit-power-battery/

” But, you can actually use chemical energy stored in a lemon and two metals to make a current and light up a small LED. It’s true and we’ll show you exactly how it’s done.”

Steve Spangler Science

Et tu, Steve?

There are many ways to get to the free energy available in a fruit.

The simplest is to eat it. You have a few billions years worth of living behind you, and animals are pretty good at using the energy found in the chemical bonds of foodstuff to recombine phosphate and adenosine diphoshate, giving your cells an abundant supply of their basic energy currency, ATP.

You could dry it out until it’s kindling then light it on fire.

You could mix it with yeast and let it ferment. The yeast will reward you with a wine that will warm you up. If that’s not enough you could distill the wine, concentrating the ethanol enough to make a flammable liquid that can be used for heating your home or powering your car.

Lots of free energy here held in fruits from last fall’s garden

You cannot, however, get free energy from a fruit to power a battery. This is bad science. The fruit simply acts as a bridge for the electrons of one metal to travel to the other, different metal.

There’s a reason you do not find most metals in a pure state in nature. If you want iron, you dig up iron ore, then smelt it. That, of course, requires free energy. When you connect copper and zinc together with some sort of liquid bridge. (Acids work, so does salt water–the salty vinegar dripping from your chips would work great.)

Fruits have tremendous stores of free energy, and animals, fungi, and bacteria take advantage of this–you want to eat the fruit before it rots, but rotting is just another organism beating you to the rich deliciousness of fruit.

If you want its energy, eat it, don’t waste it jamming metals into it. If you want to show that fruit can serve as connection bridge in a battery, because it’s cool and gets kids interested in science, go for it!

Just don’t tell them that the fruit is powering the battery.

March 6, 2019January 8, 2022

Vibrations

Waves on the inner harbor of Honfleur (taken by Leslie)

I have been mostly deaf all of my life, so I pay more attention to sound waves than may be healthy.

For the same reason, I pay way too much attention to light waves as I stare at people’s lips as they talk.

I talk with the universal accent of the congenitally deaf, and a big piece of my learning how to talk was touching the throat of my mother as she taught me the various sounds people make when speaking English.

I learned most of them, but I’m still struggling with “r”. Grrrr….

Waves allow us to know what’s going on with the things not actually touching us. (Well, sound waves are mechanical, so I guess one could argue that the air particles need to touch our ear drum, but the particles are not the wave.)

We do not observe waves directly–we see what our brains allow us to see, forms and sounds that keep our breathing bodies from quickly becoming carcasses.

Still, as I catch a glimpse of a patch of snow glinting in the optimistic light of a March sun, my eye converting waves of light that only I have seen, I realize how little any of us can know, and how much of the universe casually exists outside our senses, our imagination.

So I write about it, to no one in particular, for no particular reason.