Class: Celestial Studies (Professor Glimmerwick)
Pairs with: Lesson 29, "Sundials: Catching Shadows."
Trip type: Outdoor, Garden & Park.
Where it works: Any public sundial: in a park, a botanical garden, a churchyard, a museum garden, or set into a public building's wall. They hide in plain sight in most towns, usually with nobody reading them. Free, in daylight, and fairest near midday; the visit itself takes less than an hour once you find your dial.
Why we're going: Lesson 29 teaches how a sundial works: the shadow, the angle, the reason the reading drifts from clock time. This trip takes that lesson to a dial somebody built to be used, outdoors, possibly centuries ago, and makes you its reader. A shadow clock only exists while somebody is watching the shadow. For the length of this trip, that is you.
The mission: Find a sundial and make it work. A sundial is the oldest clock most of us will ever use, and it asks only one thing of you: sunshine and attention. Read the time from its shadow, then check it against a clock and judge how honest it was. You will come home holding both times, the difference between them, and your explanation of the gap.
What to record:
A photograph or sketch of the dial, including its motto if it carries one (many do, and they are usually about time passing).
The time the sundial showed, the time a clock showed at the same moment, and the difference between them.
Which way the dial faces, and what part of it casts the shadow.
Any dates, names, or maker's marks carved on it.
Whether anything now shades the dial that did not when it was made — a grown tree, a new building.
How it runs:
Level One — At Home: Make the garden version: a straight stick set upright in open ground at home, with stones marking where the tip of its shadow falls each hour. By the end of one sunny day you have a working shadow clock of your own; check it against the clock the same way.
Level Two — In Person: Go to a real dial, ideally at midday when the shadow is shortest and the reading is fairest. Read it before you look at any clock, write your reading down, and only then compare.
Picture ideas for the gallery:
The dial with its shadow showing, taken at the moment you read it.
The motto carved on the dial, close enough to read.
Your stick-and-stones garden dial at home, if you built the Level One version.
The dial in its setting: the garden, wall, or churchyard around it.
Etiquette & safety: Never look directly at the sun, not for this trip and not for any other. Do not climb on the dial or move any part of it, and ask permission before using one on private ground.
Field Report: How close was the sundial's time to the clock's, and what explains the gap? File your report in the comments: where you went, what you found, and one thing that surprised you. Photographs go to the Field Trip Gallery through the form on the Field Trip Office page, with the town and country where they were taken.
