Tuesday, August 30, 2011

LED Photometers

Many years ago, I read an interesting article (http://www.opticsinfobase.org/abstract.cfm?URI=ao-31-33-6965) at the Physics Department at K-State. In it, Forest Mims discussed using LEDs as frequency specific light detectors. I've played with LEDs off and on for several years before finally following Forest's recommendations and making a descent LED photometer.

While they're not quite ready yet, Nearsys will soon offer LED photometer kits for near space use. The kit comes with a PCB for two LEDs and a temperature sensor. The temperature sensor is required because the light sensitivity of LEDs is strongly dependent on their temperature. It should be an easy process to calibrate the photometer with a styrofoam box and dry ice.

This design of two LEDs and a temperature sensor permits you to compare the relative brightness of sunlight in two different portions of the spectrum. The LEDs I'm in the process of testing now are 940 nm IR and 850 nm IR. I've selected these two because according to Forest's notes, the ratio between the two can be used to measure the amount of water vapor in the air. The amount of water vapor should change dramatically during a near space flight and is an example of the remote sensing that can be performed with BalloonSats. Next up will be to find other LED combinations that will provide interesting information.

You can read more about LEDs and Forest's discovery at http://www.sas.org/tcs/weeklyIssues_2009/2009-01-02/feature1/index.html and http://www.sunandsky.org/Sun_and_Sky_Data.html.

The complete photometer kit. It comes with the photometer head (with its three sensors), transconductance amp, and easy plug for connecting to a NearSys flight computer. I want to thank Mr. Forest Mims for helping me design this photometer and encouraging me to experiment with it in near space.

Monday, August 15, 2011

Changes in the American Economy

Our economy and its interaction with the rest of the world is rapidly changing. In response to concerns expressed by several of the national academies and my interest in near space, I am preparing a research project that incorporates science, technology, engineering, and mathematics, or STEM.

The United States no longer produces the majority of its wealth by manufacturing products for local markets. Instead, services, information, and innovation are our largest sources of revenue. Even when the US does create new products, much of the manufacturing eventually moves overseas. And increasingly, more research is moving overseas as Chinese and Indian students receive good educations

In order to work in occupations involving information and innovation, future employees, that is, our students, must be adequately trained in STEM. For several reasons, this is not the case. One reason students don’t receive a strong STEM education is that there are many teachers not adequately prepared to teach an integration of science, technology, engineering, and mathematics. Even when teachers are well prepared to teach STEM, they lack the real world activities that incorporate STEM. The activities they select must be stimulating in order to prevent students from tuning out.

Rising Above the Gathering Storm: A Report
In 2005, the national academies of science and engineering, the institute of medicine and the national research council were tasked to determine issues and solutions to US prosperity in the 21st century. The commission determined there are two overarching goals to meet if we want to maintain our national prosperity

First is to create more high tech jobs.
Second, to develop additional energy sources that are clean and reliable.

To create more high tech jobs and create additional supplies of clean and dependable energy of the 21st century, The commission developed recommendations in four broad areas. To meet those recommendations, there are 20 specific actions the US needs to take. The four recommendations involve the following areas.

1. K through 12 education
2. Research
3. Higher education
4. Economic policy

I will focus on the K through 12 education recommendations and its actions

The commission concludes it will take 10,000 additional, highly qualified math and science teachers every year to create STEM literacy in the majority of the US student population within the next ten years. It takes time to train college students to become teachers. However, right now, we need 250,000 teachers able to teach challenging subjects. One way to reach this goal is to teach these teachers (in summer classes) how to teach Advanced Placement and International Baccalaureate subjects back in their schools. The United States could consider creating national STEM programs and standards. These standards would need to be taught to currently active teachers (again through summer classes). Finally, the US must invest in the classroom to create more students prepared to take STEM majors in college. The truth is that our future scientists and engineers begin in 6th grade

I want to address one way we may be able to help students prepare now

Before students can become STEM smart, they need to study STEM subjects. And they need to study them diligently. So what makes students want to study difficult subjects?

Myers and Fouts in their study “A cluster analysis of high school science classroom environments and attitude toward science” state that positive attitudes to subjects are associated with higher levels of student involvement in those classes. In other words, students must have a positive attitude toward STEM subjects in order to want to spend the time necessary to acquire a high level of STEM knowledge.

Osborne in, “Attitudes towards science: a review of the literature and its implications” states that one reason students don’t like science is that they see their science class as a history of great ideas. There aren’t enough in-class applications of how science is being done today. To them, the science class is boring. Osborne also states that three of the many factors influencing students’ attitudes towards science include the following.

1. Their enjoyment of science
2. Their past achievement in science
3. And the nature of the classroom environment

In a school district were meeting state standards is the most critical part of the school year, good extracurricular activities become a more important vehicle to positively influence student attitudes towards STEM. That’s because the regular classroom doesn’t have the time for exploration or open-ended investigation. By good after school activities, I mean those that model real world science in action, that are enjoyable, and have high levels of successful completion.

Some good STEM activities in use today include FIRST robotics, BEST Robotics, and Project Lead the Way.

So in a nutshell, the nature of the American economy is changing and has been changing fast for the last 50 or so years. If our students want high paying, stimulating careers, they need to be prepared for STEM occupations. Schools in many cases could use some help finding meaningful and interesting STEM activities. This is one reason resort to robotics. However, it seems to me that the science and mathematics aspect of robotics is lacking. Based on my experience, I have propose there is a better vehicle than robotics for STEM education.

Friday, August 12, 2011

Welcome to my Dissertation

To date, I have found several articles on near space and BalloonSats in an educational setting. Some describe how a near space program was set up, how one is operated, and some of the experiments college level students are performing. However, I have found no dissertations or studies showing the effect of a BalloonSat project on student interests in science. My plan is to address this issue.

My research plan involves creating a BalloonSat challenge similar to the successful FIRST robotics challenge. Student teams will have a limited time to design, construct, and test a BalloonSat design. There is no actual competition between teams; however, students will need to send their BalloonSat back to me before their deadline. I will launch the BalloonSats for all the teams and expect them to reach 90,000 feet. After recovery, the BalloonSats will be returned to their respective schools so that each team can download and analyze the data. Students will have two weeks to process their data and post the results in a web-based report.

Student interest in science will be measured twice, once before the project begins and then one last time after the reports are completed. I also plan to select a convenience sample of students to interview. The results of the surveys, the team reports, and interviews will be the data of my study.

I have designed the BalloonSat kit and selected the science interest inventory. Over the next couple of weeks, I discuss my plans in greater detail and continue asking for volunteers. In the hopes that I can get more classrooms to volunteer, the BalloonSat kits will be free and will the flight. After the study is complete, classrooms will be allowed to keep their BalloonSat. As long as they can find a balloon group, it can be reprogrammed and launched again and again.

Please consider being a part of this study. As I said earlier, no study like this has been done in the past.

Participating classes could get images and data like this.