Hila, Binary Sundial

Hila Sundial

"The first grand discovery was time, the landscape of experience." - Daniel Boorstin

If you choose to construct a sundial of  your own you may have to
design a sundial for your location using the sundial hour line calculator. 

Link to sundial hour line angle calculator and ideas for paper sundials.

Video support for constructing and using a sundial.

The science curriculum of many states and provinces includes astronomy.
Studying sundials is an excellent way to learn about the motion of our planet.

Hila Binary Sundial

Instructions for mounting and using your sundial.

(Support for sundial constructed at Hila Science Camp)

The sundial you constructed at Hila is designed to work at latitudes close to 45 degrees, i.e. Ottawa.
To set up your sundial, find a place with as much exposure to the sun as possible.    Mount the sundial on top of  a post , use a level to make sure the face of the sundial is level. Fasten the dial in place (with one screw) with the gnomon facing north (The gnomon is the angled piece that casts the shadow).
If you can find Polaris, the north star, point the gnomon of your sundial at Polaris.

Sundial with compass

A compass can be used to determine north.

Sundial 8 AM

 Rotate the sundial until it agrees with the time shown on your watch.  Fasten the sundial in place with a second screw.  This watch shows eight in the morning, the sundial is set with the edge of the shadow along the 8:00 AM line.  Your sundial works best when set to standard time, not daylight saving time. If your sundial is set to standard time you will have to add one hour to the time during summer months.

Your  sundial  uses  binary numbers,  follow this link for an explanation of  binary numbers.
Binary  Numbers.

sundial numbers

Decimal numbers
The sundial above is indicating 11:00 AM.

In the example below the sundial is showing 8:00 AM.

8:00 AM

8:30 AM

9:45  AM

sundial noon

12:00 noon

4:00  PM

sundial 6pm

6:00  PM

Using the sun to determine time is a complicated process.
Here are some links with more information about sundials.

Sundials from NASA
(Includes an excellent graphic showing how angles change for different latitudes.)

Sundial Calculator
(design a sundial for different latitudes)

Binary Numbers

This project is suitable for  high school or senior elementary classes, supporting both the astronomy part of a science curriculum and aspects of  the math curriculum - binary numbers  and geometry.

The hila binary sundial uses binary numbers instead of the usual Roman numerals.
Computers use binary math, here is how it works.

Regular decimal numbers use 10 symbols, the common numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.
Binary math uses only two symbols, 0 and 1.

We use coloured beads on our sundial. "0" is represented by white and "1" is represented by a colour.

We are using "4 bit" binary numbers, represented by 4 beads.  Each bead location has a "value".
The bead on the extreme right has the value 1, the next bead's value is 2, then 4 and 8 at the left end.

To determine the decimal value of a binary number add up the values of the coloured beads (remember white is "0").
For instance 5 = 4 + 1.
Here is a table that shows some of the decimal values for a 4 bit number.

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