It would be fair to say my wife was not really happy when I brought home a plastic bag with some bugs in it, but now things have gotten out of hand.
When I did my training on how to teach the 7th grade science curriculum one of the things we did was to make a sample habitat for milkweed bugs. Nothing like a hands-on activity to help you learn how to do something.
My milkweed bug habitat is about two weeks ahead of the ones we have in the classroom. Let me tell you, my bugs have been quite busy and my plastic bag is full of milkweed bugs of all sizes.
I probably have a hundred nymphs in various stages of development in my habitat.
On Sunday, I walked into my office and lo and behold - a tiny milkweed bug was standing on my keyboard. He (or she) had escaped.
How’d he (or she) get out?
I carefully looked over the habitat and could find no openings beside the tiny airholes at the top - and he (or she) was too big to fit through one of those.
I took my tiny escapee - I named him (or her) Andy (or Andi) after a character in a famous movie - and plopped him (or her) back into the habitat.
But, that’s it for my milkweed bug experiment at home. I’ll be bringing it into school before the Andy (or Andi) tells all the other milkweed bugs how to get out of the joint.
Mechanical pencils are used to provide lines of constant width without sharpening in technical drawing. They were first developed in the 18th century. A professional-grade mechanical pencil is a beautiful and elegant writing instrument.
The mechanical pencils kids bring into my room are of the disposable variety. They are so cheap and flimsy, I’m amazed they work at all, and they don’t seem to work for very long.
My dislike of mechanical pencils knows no bounds. I do not understand the attraction kids have with them.
From my perspective, all I see are problems. It seems like whenever I see a kid taking notes with their trusty mechanical pencil, they are breaking the lead, running out of lead, looking for lead, spilling the lead on the desk, watching the lead roll onto the floor, asking their friends if they can borrow some lead or asking me if I have extra lead.
For the record; No, I do not have lead for your mechanical pencil.
I have pencils - real, number 2, wooden pencils from the Ticonderoga Pencil Company. You may borrow a real pencil, but I do not have lead for you and never will.
Here’s a little inside teaching insight for you: If you leave a pencil behind in my room, I will sharpen it and add it to my loaner bin near the door.
If you leave a mechanical pencil behind….I will throw it away.
“There have been school-wide loudspeaker announcements banning bottle flipping from our school,” posted one of my teacher friends on Facebook recently.
She was writing about the fad that is sweeping the nation. Forget high-tech, smartphone-addicting Pokemon Go, low-tech water bottle flipping is the new rage.
Apparently, it all started with Michael Senatore, a high school senior in Charlotte, North Carolina, who flipped a water bottle during a talent show. The video has gone viral and now, seemingly, every middle-schooler wants to do it.
If you’re going to spend your time trying to land this stunt, you ought to understand the physics involved. Yes, I said physics.
Here are some of the terms you’re going to need to know:
Angular momentum
Mass
Fluid dynamics
Air resistance
Inertia
Gravity
Angular momentum is a lot like linear momentum, with which we’re all familiar. Picture this: Tom Brady throws a fast, tight spiral just over your head. As you reach up and grasp the ball, its momentum pulls your hands and arms in the direction the ball was traveling until it slows enough for you pull it in for a catch. That’s linear momentum.
Angular momentum is the same thing but in a circle. When you flip the bottle you impart spin - that’s angular momentum.
The spin causes the water to slosh around inside the bottle - this is where fluid dynamics comes into play. The bottle tries to transfer its angular momentum to the water but the water has a lot more mass then the plastic bottle and, because of inertia, the liquid doesn’t want to spin. Instead, because it's a fluid, it sloshes around, slowing the rotation.
The trick is to get the angular momentum to zero when the bottle is vertical so gravity can do its thing and the bottle lands upright on a flat surface.
There’s a complex balance between angular momentum, fluid dynamics, air resistance, inertia and gravity.
There’s no reason you have to stop with a single rotation either. If you impart enough angular momentum, you should be able to do 720 degrees of rotation before landing your bottle. Of course, that makes the whole trick much more difficult.
Wouldn’t it make a great science project to build a machine that can flip a bottle perfectly every time? Hmmmmm, maybe we can tackle that challenge in the STEM Club…
