Fighting against a well armed military, the rebels in Syria have had to do a lot of improvisation. A basic knowledge of physics and chemistry has proven somewhat useful.
The Atlantic has a collection of photos of DIY (do it yourself) weapons, that includes catapults and sling-shots.
Sebastiano Tomada Piccolomini has a fascinating photo-essay in the New Republic showing the one item that members of one group of rebels considered as their most crucial weapon. These range from a radio, to a packet of cigarettes, to improvised grenades.
Finally, one of my students discovered that a cell phone and power-source from a computer can be made to look an awful lot like and improvised explosive device.
We are living in the future, but sometimes I wonder if it’s where we want to be.
Darker colored objects absorb more light than lighter colored objects. Darker objects reflect less light; they have a lower albedo. So a deep brown leaf embedded in the ice will absorb more heat than the clear ice around it, warming up the leaf and melting the ice in contact with it. The result, is melting ice with shape and pattern of the leaf. It’s rather neat.
The rapid, snow-melt driven, flow in the creek has receded a little, but it managed to clear out most of the dead leaves that have carpeted the stream bed since the fall. Now that the rocky bottom is exposed, hopefully, we’ll be able to see some more of the benthic fauna that’s been invisible for the last few months.
NASA’s Heliophysics (physics of the sun) website has an excellent collection of videos that would link quite nicely with physics discussions of the physics of light (electromagnetism) and the Earth’s magnetic field (as well as the action of charged particles in a magnetic field.
They also have awesome solar videos, like this one of coronal rain.
Natural phenomena like this are great for students to analyze because they require the integration of multiple concepts to explain.
Our school was recycling some old computers, so my students convinced me that it would be worthwhile o dissect a few of them to see if there was anything worth saving. It was quite remarkable to see just how interested they were in examining the insides of the machines — a few desktop computers and a monitor — but I guess I shouldn’t have been surprised. After all, it’s getting harder and harder to open up their iPods and other electronics, and even more difficult to repair and repurpose them, so I can see why students would jump at the chance of looking inside a device. Also, they tend to like to break things.
To get them to think a little more about what they were seeing, I got a couple students to draw a scale diagram of one of the motherboards, and write up a report on what they’d done.
Some of the other students spent their time trying to make all the motors, LED’s, and lasers work by hooking them up to 9-Volt batteries. Then they found the fans… and someone had the brilliant idea that they could use it to make a hovercraft. Using a gallon sized ziplock bag and some red duct tape, a prototype was constructed.
The fan would inflate the bag which would then let air out the bottom through small holes. I convinced them to try to quantify the effectiveness of their fans before they put the holes in by hooking the bag up to one of our Vernier pressure sensors that plug into their calculators. Unfortunately, the sensor was not quite sensitive enough.
This was not how I had planned spending those days during the interim, but the pull of following the students’ interests was just too strong.
We took a school trip to the ski slopes in Hidden Valley. It was the interim, and it was a day dedicated to taking a break. However, it would have been a great place to talk about gradients, changes in slopes, and first and second differentials. The physics of mass, acceleration, and friction would have been interesting topics as well.
This year has been cooler than last year, but they’ve still struggled a bit to keep snow on the slopes. They make the snow on colder nights, and hope it lasts during the warmer spells. The thermodynamics of ice formation would fit in nicely into physics and discussion of weather, while the impact of a warming climate on the economy is a topic we’ve broached in environmental science already.