babylonian civilization - 4lecours class...

Arko bagchiBabylonian Civilization

Sundial

A sundial is a device that tells the time of day by the position of the sun 3500 BC.

How is it made? Parts of A Sundial

•Gnomon: The shadow caster, in a horizontial dial the angle phi is equal to the Latitude of the location.

•Hour Line(s): The numbered lines that the shadow falls along.•Nodus: A "marker" along the gnomon to get an exact point on the

shadow.•Furniture: Lines and "functions" other than the Hour lines, usually date

lines (this is what the nodus is for).

Sundials- Working

Sunlight & Sundial

6am

8am

9am

12am2pm 10am

3pm

4pm

7pm

Looking North, the Sun appears to rise in the East...

...and travel across the sky until it sets in the West.

The position of the Sun effects the position and length of the shadows created.

Thanks to this natural phenomenon a sundial is able to tell time, as discovered by the Babylonians!!

Concrete

Metal

Stone

Wood

How telling Time Changed With

Time!

candle clock

lamp clock

sand hour glass

greek water clock

austrian wall clock

box chronograph

modern desk clock

time piece

modern wrist watch

sundial

Classified by the plane in which the dial lies, as follows:

Horizontal dials

Types of Sundials

Vertical dials

Equatorial dials Polar dials

Analemmatic Sundial: sundials consisting of hour points (rather than hour lines)

Reflected ceiling dials portable dials

Even today sundials act as artifacts and are of interest to many and even mathematicians use them for various

experiments and calculations.

Thank you !