In a recent thread, I posted a plot of the voltage across a photodiode that was pointing out of the window next to me in my office. The plot showed a negative slope that was likely due to the rotation of the earth -- i.e., it was about 3 hours from sunset and this is the normal variation in light which our eyes don't typically detect.
To check this, I decided to take the data for a 24 hour period. The experimental setup is a cheap Radio Shack photodiode whose axis is tilted about 45 degrees above the horizontal so that the diode is pointing towards the sky. The true bearing of the diode's axis is about 45 degrees true north because of the known orientation of my house. The location is the northwest US at a latitude of around 40 degrees north. A voltage reading of the diode is taken about every second and logged to a file.
I thought it would be interesting to ask folks to predict what these plotted data will look like at the end of a day or two of taking data (the plot will be identical to the plot given in the above thread except that the time period will be longer). The person whose prediction is closest will get 10 absolutely worthless Daddles points and an autographed pictures of Daddles, our duck who is imprinted on humans (and even occasionally comes into our house wearing a diaper). If there is enough interest, I'll also post a story about Daddles and why she can recognize a man with a shovel at 50 m away and come running...
To check this, I decided to take the data for a 24 hour period. The experimental setup is a cheap Radio Shack photodiode whose axis is tilted about 45 degrees above the horizontal so that the diode is pointing towards the sky. The true bearing of the diode's axis is about 45 degrees true north because of the known orientation of my house. The location is the northwest US at a latitude of around 40 degrees north. A voltage reading of the diode is taken about every second and logged to a file.
I thought it would be interesting to ask folks to predict what these plotted data will look like at the end of a day or two of taking data (the plot will be identical to the plot given in the above thread except that the time period will be longer). The person whose prediction is closest will get 10 absolutely worthless Daddles points and an autographed pictures of Daddles, our duck who is imprinted on humans (and even occasionally comes into our house wearing a diaper). If there is enough interest, I'll also post a story about Daddles and why she can recognize a man with a shovel at 50 m away and come running...