## Tuesday, January 31, 2017

### Ampere's law introduction

Check out an introductory video on something called Ampere's law, which has to do with the production of B-fields from 'long,' straight wires, long solenoids, and toroids. Ampere's law will be similar to Gauss's law for E-fields in the past.

## Friday, January 27, 2017

### For Today

Happy Friday, everyone.  :-)

Periods 1-2, 5-6, and 8-9:

Check out magnetic forces on charged particles. A moving charged particle produces its own magnetism, which means magnets will make a force on that moving charged particle. This is where cross products start.

The magnetic force is F = qv x B.  Remember how to do the math for cross products (the 3x3 determinant thing), and that for A x B = C, the magnitude of C is C = ABsin(theta).

Check out two videos, one on the magnetic force on particles, and the second on an application called a mass spectrometer (along with a so-called velocity selector). Take good notes since you will need them for the practice set, which is the book problems and the first AP problem in the new packet you are receiving.

Period 3

We will be going into magnetism, so check out videos on this. First, watch and take good notes on an introduction to magnetism. A second video is on magnetic force. We will begin a lab with magnets on Monday, where you will get to begin (literally) feeling these forces, sometimes attractive and other times repulsive.

For practice and to begin thinking about magnetic fields, try the sheet you will receive. Use the side with diagrams to try and answer the questions.

## Saturday, January 21, 2017

### Scientists can watch an 'optical boom' with photons moving through material

For the first time, scientists can use high-speed videos (we are talking over one trillion frames per second...crazy short time intervals!) of a pulsed laser beam moving through a gaseous material to see the optical equivalent of a sonic boom. A sonic boom happens when a sound producing object like a plane moves faster through air than sound waves - we get a cone shaped structure of sound. The video in the link has a clear image of the cone-shaped pattern of light as the laser pulse moves at different speeds in a material compared to a gas layer that is also in the system. This is really cool!

## Sunday, January 15, 2017

### Here's Problem Solving/Engineering 21st Century Style - Agricultural MRI from Above

What a very cool application of high resolution photography, drones/airplanes/satellites, and computing - a UIUC professor has started a company that may be revolutionary for farmers to be able to identify issues in large farm fields (hundreds or thousands of acres). The company takes large numbers of photos of the farm fields, and then uses software it developed to identify even small areas within the field where there is an issue with disease, weather damage, lack of moisture, weed growth, and so on. In the past this has not been possible, and certain types of issues could spread to large sections of a crop before it was known - crop yields can only be improved using this technology and diagnostic technique. I personally love seeing creative, multidisciplinary solutions that can help make the world just a bit better!