29 September, 2003

Monday

It is a beautiful day, warm (0 F,-30 F wind-chill) with bright sun. Perfect for getting the shadow picture I had tried for last week at the equinox. I attach a picture of my first try, I made a mistake because the shadow was on a hill, it is difficult finding flat snow, we are not allowed on the sea ice, and I do not have a level. The wind blew the tape measure everywhere. So, my result on the hill was that the shadow was a bit short, you can correct for it as the hill was about 30 degrees. On my second try I went down to the helicopter pad, it is pretty flat, except you are not allowed on the pad, so I tried a bit to the side using a blue crate. That seemed to work better. I already know what to expect, at solar noon on the equinox, the shadow angle will equal your latitude, and I am at -77 degrees south. It is a good way to find your latitude in case you are lost on the equinox. I attach a picture sent in by students at Chapman Hill elementary. They measured an angle of 54 degrees. You can calculate the circumference of the Earth from these numbers.

On Sunday we had the science lecture, this time Prof. Deshler gave the talk on ozone. Listening to an expert in the field is always a great learning experience. We have a balloon launch in a few hours and another tomorrow night.

Tomorrow brings the first flight of MainBody. In the next two weeks McMurdo will grow to three times it size. Everyone is looking forward to some fresh food.

A beautiful monday morning, the Royal Society Range

My first shadow experiment was on a hill. I used the ice core drill with some help from the penguin. The penguin is at 1 meter high, the shadow is 2.8 meters. But I would not use that shadow length, it was on a hill, I made a calculation for a 30 degree hill and if it was not there the shadow would be 4.1 meters. Can you figure out the radius of the earth?

They are getting the helicopters ready for flights and the ground is flat there.

Another shadow experiment, this time the box is 13.5 inches tall and the shadow is 64 inches long. It was an hour past solar noon.

Chapman Hill Elementray students sent me this picture of the experiment they did.

An interesting physics picture. I took this picture of the street lamp through a triple paned window (the building is very insulated), you can see multiple reflections pointing toward Mt. Discovery.