Friday, April 30, 2010

The Grind

The Japanese call it the reason to get up in the morning. It can't be about just getting a pay check, or life becomes increasingly grinding and ugly. I like teaching my students about how cool the universe is. I am starting a new course on compressible aerodynamics based on the NASA web pages. I am using a wind tunnel from Pitsco along with their data acquisition software.

Wednesday, April 14, 2010

A great day teaching.

Taught my students about the velocity selector in AP Physics, where the electric force is balance out by the magnetic force. It is a thing of beauty. Get two parallel metal plate and put a big battery across it, you have instant E-field. Put a magnetic field perpendicular to it. If charged particle goes to fast, magnetic field curves it's path. If it is too slow, electric field curves it the opposite direction. If the speed is just right, v=E/B, it goes through undeflected.
We then talked about the path of the particle once it left this region and went into a magnetic field. It has a constant velocity. As a result, R=mv/qB (R=radius, m=mass, q=charge, B = magnetic field), the only variable being the mass. Different masses mean different radii. You could use this device to find out what isotope by percent were in a sample. Or it could be used to separate U235 from U238.
The Goodyear plant in Chilocothe, OH used this method to enrich uranium. It seems that everyone want's to use centrafuges today.
In robotics I got my students to program their robots to make a perfect square, until they ran into an obstacle. The used infrared leds to modulate a signal. If the modulated reflected signal were picked up, an obstacle was detected. The program would go into an avoidance subroutine, after which it would go back to making a square.

Free Textbooks

Teaching may be a lauded goal for society, but like infrastructure, our society doesn't give many of it's resoureces to it. As a result texts are hard to come by. Especially iratating is the text book racket that follows the texas school board mafia. The government has textbooks it hand out for free. I love them because it assumes the readers know nothing and "floats all boats" as it were. One of my new favorites is the Department of Energy offerings. www.hss.energy.gov/nuclearsafety/ns/techstds/standard/standard.html
They offer physics, electrical science, thermodynamics, mathematics, chemistry, material science, mechanics, the list is endless. I am using the nuclear reactor technology text for my nuclear engineering course.
Another interesting free text source is the Navy online technical manual directory at www.hnsa.org/doc/

Life is good an the good things in life are free. Not only that, they are usually on pdf files.

Tuesday, April 13, 2010

Joys of being a mad scientist.

Had a great time today. Cleaned out the physics store room. Garvin, my colleague wanted to get the stuff he used for his research out. It included a high power laser, two 50,000 V capacitors used to pulse the laser, power supply for the laser, and a $30,000.00 storage oscilloscope. I asked if I could have them and said yes. Bwa Ha Ha Ha!(mad scientist laugh)
I taught my students about macroscopic cross section and the neutron attenuation formula. It's a simple exponential decay, a formula that seems to be used over and over again. We derived Reactor power given a U235 fuel, reactor volume and neutron flux. I'm going to give them homework on the stuff and start the six factor formula for neutron number for each neutron generation.
In AP Physics we had a lab were they learned to properly use a volt and ammeter. Only had two people blow the meter fuse by hooking it up parallel to the resistor as opposed to be in series with it.
Life is good.

Monday, April 12, 2010

Teaching Nuclear Physics

I had a good day in Nuclear Physics today. I taught about the mass absorption coefficient and radiation shielding. I learned that it not only varies from material to material, but also the energy of the gamma rays involved. The constant we were comparing it with was for the gamma decay of a Barium isotope. We were using cobalt 60 which has two gammas at vastly different and higher energies. The half thickness needed for the Barium isotope was 6cm. The half thickness for cobalt 60 was nearly 12 cm. It is cool when experiments teach the teacher something new. I am working on the Nuclear Physics Lecture for tomorrow. I am using a free textbook. Google DOE-HDBK-1019/1-93 to get a look at it. It is for teaching nuclear technicians, and fits well within the high school level. It covers some obscure AP physics topics.
We will be starting work on the big Barbie Jeeps in Thursday's Robotics Lab. I will initiate my guys into the mysteries of dc brushless motors , gear boxes and motor performance curves. There is a lot of engineering stuff that normal high school students don't normally get to look at. I love it when the drive of students to make something leads them to go beyond the normal high school envelope.

Sunday, April 11, 2010

Sometimes, the truth does not set you free.

I remember growing up, my favorite game as a child was "war". We would spend hours on end shooting each other with toy guns. My favorite tv show was "Combat", a world war two themed show. When I was a teen, we had the news on at the supper table. We would discuss the news at each supper. We saw the Vietnam War and over the course of decades we concluded that it was bad for us as a country and we should get out. Now mom and dad where as Republican as the day was long. Exposure to reality had Dad turning on his headlights on war moratorium day. Now we have embedded journalists and don't see the war or it's effects. Then comes wiki leaks. We watched copter jocks massacre journalists and act like they were ringing up points in a video game.
Now we have combat video of an up close and personal massacre in an Afghan village. Truth hurts. At least I hope it does enough to wake people up.

Thankfulness.

I love my life, my wife and children. I love the Gulf coast and the attitude of people here to relax and enjoy life. I love my family and the God they have taught me to love. I love creating things, even though I am a klutz and have at best what could be called improvised results. My old Physics teacher in high school said, "He has it up hear (pointing to the head) but here( waving his hands) Un uh. You call him over if you want to break something." Lately I have taken joy in creating food for my family, which none of them like, or will eat. I make my own wine, which my son likes as do I. Couldn't share with my nephews, since shipping it apparently violates a constitutional amendment.
I actually make robots, not just read books about it. I have one that my students and I took to MIT as an Inventeam. I am finally getting involved in First Robotics, now that I am convinced it is worthwhile.