Physics Teaching and Robotics Blog
May 18, 2011 at 9:53 pm
I want to thank the many BUA alums who nominated me for this award. I am really excited and honored. I read the essay and I am very touched! So many thanks to Maddie, Sara, Craig, Colin, Betsy, Thomas, Roshini, Sam, and Alex! It was a fun evening. As I wrap things up at BUA and prepare for my sabbatical, this was a great moment to be surrounded by some of my favorite students from the past several years!
Woody, Roshini, Maddie, Parker, Sam, Craig, Gary
April 5, 2011 at 8:58 pm
Today was fun. We started out with a discussion of beat frequencies. The class video will be posted soon.
You can play around with beat frequencies at the following Beat Frequency Physlet. Although Beat frequencies are most relevant to music, we will return to beats when we get to optics and modern physics! Last week was exciting because I got my piano tuned and Alejandro got to see someone who gets paid to listen to beat frequencies!
The effects of Doppler Shifts are cool. Again, David Latham talked about this at ASM. Except instead of the Doppler Shift in acoustic waves, he uses the Doppler Shift of light (blue shift/red shift) to measure the wobble in stars around the center of mass of a stat-planet system. You can read about David Latham's project at the AFOE homepage. If you want to play with a Doppler Shift physlet. What is cool about this physlet is you can adjust the speed to greater than the wave speed to create shock waves!
As I mentioned in class, I was watching NOVA last week with Alejandro. The episode of NOVA was on Japan and the Earthquake. There was so much relevant to out current class discussion. The triangulation of Earthquakes using S and P waves. The refraction or change in water wave speed which causes Tsunamis. But relevant to today's discussion of shock waves was that they showed footage of the Cherenkov radiation being emitted from a nuclear reactor. The Cherenkov radiation is essentially an optical shock wave, when electrons are moving faster than the speed of light in water. A reactor has an strange blue glow. I got to see this was I was a young physics teacher and spent two weeks in a summer program at the Nuclear Reactor at Penn State.
April 1, 2011 at 10:54 pm
Wow, what an exciting week it has been. We have been studying waves and sound in physics class. The in class recordings are finally working.
Class of Standing Waves in Pipes
My proposal for the NASA Reduced Gravity Flight was accepted. So come the last week of June, I along with several of my fellow teachers will be flying on a zero-gravity NASA airplane ride! We will be performing an experiment to analyze the motion of a simple pendulum in a reduced gravity and hyper gravity (2g) environment.
Thursday morning David Latham from Harvard talked to the BU Academy students about the recent discoveries of exoplanets. One method for detecting exoplanets is Doppler Shifts which we will study next week. We are on the verge of discovering Earth size planets. This reminded me of my childhood dreams of becoming an astronaut. And this NASA airplane ride is almost as good as it gets to becoming a Teacher in Space!
So this week in physics class we studied waves in strings, water, and springs! The issue of water waves and the tsunami in Japan has had relevance to our current classroom discussion. In the deep ocean, the tsunami is not very tall and moves very fast. In our discussion of refraction, and the change of speed of a wave in different media, we realized that the water wave speed depends on the depth of the water. So as the waves approach shore, they slow down, which results in the catastrophe we have seen on TV. We could view the change in water wave speed in our ripple tank!
Watch the Class on Sound
I borrowed a lot of cool toys from the BU Physics Department. I never played with a vacuum bell jar before, and it was really cool to evacuate the air and hear the sound level diminish. Check out the video file. In space, no one can hear you scream! (Again, my mind is on NASA).
I also borrowed a cool wave machine to make standing waves. At the end of the week we examined waves in strings, interference, constructive and d-d-d-destructive interference. I am not sure why, but the students were making up stories about the dark side of physics (Destructive Interference) and claiming that only Supercrest could save them. I just want to clarify a few things. There is no such thing as Supercrest. I have been hearing silly rumors of Supercrest for nearly 20 years. Noone has ever taken a photo of Supercrest. There is no evidence that he exists. He is like the tooth fairy and Santa Claus.
March 27, 2011 at 8:39 am
Here is a recent article in the BBC news. It goes along with our summer reader "Physics For Future Presidents."
They main point of the article is that the radiation fears are overshadowing the real crisis which is the deaths due to the tsunami itself.
BBC News Article A New Way to Look at Radiation
There is an interesting comparison to Chernobyl and Three Mile Island.
The Author is Wade Allison, the Author of Radiation and Reason.
March 18, 2011 at 7:23 pm
March 16, 2011 at 8:35 am
Our ASM Speaker from a few weeks ago had an article in BU Today on the Nuclear Disaster.
If you remember, in our talk, he discussed the economics of oil, the costs of different forms of energy, and the deep subsidies given to the nuclear industry.
BU Today and Professor Cleveland
Professor Cleveland sounds a familiar theme at the end of his article:
What impact will the Japanese disaster have on the future of nuclear energy?
Nuclear power in the United States was dead in the water a decade ago. We haven’t ordered a new plant since the 1970s. But climate change came along and breathed new life into nuclear power. One of the existing technologies that could significantly decrease carbon dioxide emissions is nuclear power.
We’ve been told by the nuclear industry that the next generation of reactors will be more cost-effective and safer. They’re probably right. But the question is, are they safe enough? We cannot idly stand by and rely on the promises of the nuclear industry. The other big issue is cost. The Obama administration is only one in a line since Eisenhower to provide subsidies. Can the nuclear industry survive on its own in a free market? Nuclear power over the last quarter-century has received more subsidies than oil and gas. The nuclear industry cannot get insurance in the private market. What does that tell you about the technology? The federal government indemnifies them. The taxpayers in essence are insuring the industry.
The cost issue and safety issue need to be examined under a very bright light.
March 15, 2011 at 7:31 am
Hi, here is a link from the Journal of College Science Teaching on a nuclear power accident from 1999.
http://www.nsta.org/publications/download.aspx?s=mail&d=031411&id=Z349URi8cV5jzeFc8j9Jen7lWtpc5exjvgzzl3wOvVQ=
March 15, 2011 at 7:25 am
Recently, NSTA press had a nice article with some links to several web pages to learn about Earthquakes.
This NASA Jet Propulasion Lab Site is middle school level, but has some nice basics of Earthquake mechanics. http://scign.jpl.nasa.gov/learn/plate4.htm
You can look at actual data on the USGS (US Geological Survey) website at http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0001xgp.php
To learn more about Earthquakes, the IRIS Incorporated Research Institute for Seismology Website http://www.iris.edu/hq/retm
There is a nice animation of the Tsunami at the NOAA site http://nctr.pmel.noaa.gov/honshu20110311/
Many thanks to NSTA for organizing these sites!
http://www.nsta.org/publications/news/story.aspx?id=58295
March 10, 2011 at 1:17 pm
On Wednesday, the Ravenclaw Physics Class visited Professor Gevelber's Advanced Materials Process Control Laboratory.
http://www.bu.edu/pcl/
There we saw a plasma spray which is used to test ceramic coatings for the hot temperatures experiences inside jet engines.
http://www.bu.edu/me/people/faculty/gn/gevelber/
We also visited the Fraunhofer Center for Manufacturing Innovation where we saw an e-beam deposition for optical coatings.
http://www.fhcmi.org/
March 10, 2011 at 12:56 pm
Wow! Cathryn brought in a sterling engine. Does it work? It has been sitting on a shelf for 4 years. We just added oil.
Cathryn's Sterling Engine
Here is a link to to the course taught by Cathryn's Dad, Professor Hart!
http://ocw.mit.edu/courses/mechanical-engineering/2-141-modeling-and-simulation-of-dynamic-systems-fall-2006/projects/byl_2141_final.pdf
Thanks for bringing that in! 25 points for Hufflepuff!
