Feb. 04, 2011

Science Dad and the Groundhog

by Vince Harriman

Click to enlarge images

Trying to find a shadow on the sundial

Well, Punxsutawney Phil sure got it right this year. If the groundhog pops out of his hole and the day is overcast so that he can't see his shadow, we will have an early spring. Well, he popped out and it was overcast -- so overcast that two days later we still don't have much sun.

Beckett and I had planned an experiment to coincide with February 2, the midway point between the winter solstice and the vernal equinox, which is also the day that statistically daylight and nighttime are equal. We were going to build a sundial and see if it could be used to tell time accurately on this special day. Then Phil popped out to a very overcast day, so the experiment we had planned was hampered by a lack of sun.

We built a sundial anyway, with snow on the ground, snow forecast, and no sunshine in sight. At least we had an early spring coming, if you believe in groundhog meteorology.

Sundial at University of Maryland.
Photo courtesy B. Gervais

As a last resort, I asked Beckett if he would mind getting up early one morning to see if we could find a bit of sun before school, but even that didn't work. You can see Beckett in the photo, using the compass app on my phone to line up the sundial and find a shadow. It was very faint and very brief, but we could almost tell that it was just before 8:00 a.m!

Beckett and I talked about the first science experiment we did for TalkingScience on Daylight Savings Time -- about how the earth revolves around the Sun in such a regular way that it can be used to figure out time. I also mentioned briefly that our twenty four hour day and division of hours and minutes is something that humans made up. Our sun and our planet determine what we think of as a day, but on a different planets there are days of different lengths.

Editor's note: Science Dad ultimately had a brief moment of sunshine and sent us this photo taken at 10:34

Beckett wanted to know how you can tell time with a sundial if there is no sun -- the answer to that was fairly obvious and definitive.

We also had a conversation about actually doing science and science experiments. We created an instrument to measure time that relied on sunlight -- and even though it was calibrated and arranged to function at our latitude in the right season, we didn't have any sun! Scientists often have problems like this to solve -- data sets that are impossible to track or record, or data that is coming slowly from millions of miles away and could come back corrupt or incomplete.

It was, for us, an important lesson in science. While the data we need might be out there, getting it could be hard. When planning our experiment, we never dreamed that the sun -- our colossal neighbor that is almost always present and visible -- would be out of sight for almost a week. But that is how it went. We will try again this weekend, although rain is forecast...

We are still collecting videos for our Coriolis Effect experiment...if any readers live outside the continental United States and would like to flush a toilet in the name of science (or if you know someone who might be willing), please leave a comment below and I will contact you about our needs. We have some great video from all over the world and are always happy to add more.

Science Dad, AKA Vince Harriman, is a freelance writer living in Annapolis. His two sons, Beckett-6 and Rowan-2 1/2 ask him ‘why’ approximately 6,547 times a day.

About Vince Harriman

Science Dad, AKA Vince Harriman, is a freelance writer living in Annapolis. His two sons, Beckett-6 and Rowan-2 1/2 ask him 'why' approximately 6,542 times a day.

The views expressed are those of the author and are not necessarily those of Science Friday.

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