Saturday, March 27, 2010

Noon Day Project - My measurement - part 2

Here's how I measured the sun angle for the Noon Day project.
  • I set up a meter stick perpendicular to the ground with the help of a metal bookend.
  • I checked the Internet for the approximate time of local noon (when the sun is highest in the sky). Sunrise was at 7:00am and sunset at 7:06pm. I found the midpoint between those times which was 1:03pm.
  • I set up my station at about 12:45 and then watched and recorded the lengths of the shadow every 5 minutes using a piece of chalk as the time approached local noon. (The length was getting shorter and the shadow was moving west to east.)
  • After I put down my mark I also took a photo of the shadow and stick from as close to ground as I could.
  • I continued till 1:15 when I noticed that the shadow was now getting slighter longer and more easterly in direction.
  • I used the photo where the shadow appeared to be at its shortest which was 1:03 EDT and copied an pasted it in Geometer's Sketchpad.
  • The Sketchpad tools allowed me to make the sketch with the details that you see in the picture including the sun angle which is formed by the sun's ray and the meter stick. (The image size of the meter stick was 6.7 cm.)
  • Next I'm going to post this summary on the CIESE Noon project page. (My School Name is: CLIME)
This is part 2. See previous post for part 1.

Tuesday, March 16, 2010

Windy News

The Big Tree Take Down

The wind brought it down to its present position. How would you bring it to the ground without further damage?

Here's what the experts did.
I do wonder why the chain saw guy stopped cutting it and was told to saw it elsewhere. I was too busy filming and didn’t think to ask.

I was looking for math in their solution to the problem. But what I learned is that if you have the right tools and the know how to use them properly the job becomes a “no brainer.”

There obviously is a lot of science here. Any suggestions as to how the science might inform the math?

Friday, March 12, 2010

Noon Day project begins this week - March 8, 2010

The Goal of the Noon Day Project is to have students measure the circumference of the earth using a method that was first used by Eratosthenes over 2000 years ago. Students at various sites around the world will measure shadows cast by a meter stick and compare their results. From this data students will be able to calculate the circumference of the earth.

Watch as Carl Sagan describes some of the background surrounding Eratosthenes' experiment in this 6 1/2 minute video.

Follow me on Twitter (Hashtag #noonday) As I recreate the experiment that Eratosthenes did. I hope to my measurements on March 17 weather permitting.
There is some good background material on the measurement at the Noon Day project site hosted by the CIESE (Center for Innovation in Engineering & Science Education) - Stevens Institute of Technology in Hoboken, NJ.

Monday, March 1, 2010

Get real "Do Nows" to kick start your math class

"Do Now" classroom openers are all the rage these days (i.e. Everday Math). Why not reach out of the box and do one that's timely for the day you do them? Today is the day (3/1/10) after the Olympics closed and by the latest count the USA, Germany and Canada were the biggest winners.

What if we wanted to give a gold medal to the country that "won" the Olympics how would you decide? One way might be to assign 3 points for each gold medal won, 2 for the silver and 1 for the bronze. (This is similar to how they determine standings in the National Hockey League.) Who would be the winner? Would Canada's 14 gold medals compensate for their lower total of medals than the USA? (See a Google Spreadsheet with the results.) Feel free to edit it! Help me turn this "do now" into an activity worth exploring.