Summer Solstice

Wolfeboro Camp School’s Boat Dock (minus the boats since orientation hasn’t started yet) at 8:40 pm on June 18th.

We never fly anywhere as a family of four.  It’s just too darn expensive on a teacher’s salary not to mention inconvenient.  So, we have become expert road trippers to get where we need to go whether it’s to visit the grandparents in NY over March break or the cousins in TX at Thanksgiving.  It is nothing, therefore, for my kids to get in the car for a day or two to wind up in a new place ready for new experiences.  In some ways, I think they’ll better appreciate just how big this country is instead of those who fly from one coast to the other without checking out the middle.  But I digress.

Summer is so wonderful for so many reasons but what makes it all possible in the first place is the abundant daylight, especially around the Solstice.  When we drive from Mississippi to New Hampshire every June, I feel the days lengthening not only because we are nearing the First Day of Summer, but because we are physically changing latitude over the course of the 48-hour journey.

I always get extra excited around a solstice or an equinox, not just for the change of season, but because I know what’s happening mathematically on the graph of the daylight sinusoid.  Right now, all of us in the Northern Hemisphere are nearing the peak of the graph, or in calculus parlance “the maximum”.  This maximum is on a differentiable function, so the peak is smooth.  Thus, the “long days” last for several consecutive days.  I knew the solstice would be around June 20th, so I went to the internet to find out exactly when it would be.  WELL, in Wolfeboro, NH it will be at 12:24 am on June 21st but in Oxford, MS, it will be at 11:24 pm on June 20th.  At first I thought this was due to the latitude difference but DUH it’s a time zone thing.

Anyway, Wolfeboro, NH has about 1 hour more daylight than Oxford, Mississippi at this time of year.  What that means in terms of calculus is that the slope of the tangent line is zero on June 21st (Eastern time) for both towns, but the maximum value is higher in Wolfeboro.  The amplitude of Wolfeboro’s sinusoid is larger because Wolfeboro is closer to the North Pole than Oxford is.  But, the additional daylight in Wolfeboro FEELS like so much more than an hour.  As I was rooting around the internet, looking for information about the upcoming solstice, I found the Farmer’s Almanac site and noticed something interesting.

I have never seen the categories “dawn breaks” or “dark descends” before.  I am not exactly sure how these are measured, but I am sure I (or you) could figure it out pretty quickly with fifteen minutes of research.  If you calculate the elapsed time between the two, Oxford has approximately 6 hours of total darkness…

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… whereas Wolfeboro only has 3.5!!!

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Just another reason why Wolfeboro is such a magical place!  And now I really must type up the Sunrise/Sunset activity I used when I taught trig before we graphed sine and cosine functions.  When I finish typing it up I will post it for free at my TpT store.  UPDATE:  It is available!  Click here!

Happy Summer Solstice!

You might also like these seasonal blog posts:

Vernal Equinox

Autumnal Equinox

Winter Solstice


One thought on “Summer Solstice

  1. Pingback: Happy Fall, Y’all | Math, Teaching, and Teaching Math

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