Home

Site Map

Search

physics,astronomy,education,software,applet,java,shareware,science,mathematics,computerscience,sun,moon,earth,chaos,fractal,sundial,java,applet,programming,quiz
GeoAstro
Applets

Astronomy
physics,education,software,applet,java,shareware,science,astronomy,mathematics,computerscience,sun,moon,earth,chaos,fractal,sundial,java,applet,programming,quiz
Chaos Game
physics,education,software,applet,java,shareware,science,astronomy,mathematics,computerscience,sun,moon,earth,chaos,fractal,sundial,java,applet,programming,quiz
Java
physics,education,software,applet,java,shareware,science,astronomy,mathematics,computerscience,sun,moon,earth,chaos,fractal,sundial,java,applet,programming,quiz
Miscel-

laneous

Gnomon Applet


timezone

local
                      time

Check your time zone offset and the local time.

latitude longitude

Click the applet first!
Enter latitude in decimal degrees, northern positive, southern negative,

enter longitude in decimal degrees, eastern positive, western negative,

and press "Apply input".

gnomon Enter gnomon height,
and press "Apply input".
keys keys

You may use the keys "m", "d", "h", "n" to increase the month, date, hour, minute, or Shift key and "m", "d", "h", "n" to decrease month, date, hour, minute !

east west
Check a box to set the direction of the shadow to East (azimuth 90°) or West (azimuth 270°).
grid size
Select from the "Details" menu to set the grid size.

Hold down Command key and click into the grid plane to change the gnomon position.


More of my sundials



This type of sundial has a vertical rod (gnomon, height H) casting the shadow on a horizontal plane. The shadow of the gnomon's top (point P) is used to read the time (and the date).

 

gnomon

Mearuring the length of the shadow near the prime vertical (azimuth angle 90° or 270°) the geographic latitude can be computed.
prime
                      vertical

h2 = arctan(H/x2), h1 = arctan(H/x1),
dh = h2 - h1 = arctan(H/x2) - arctan(H/x1)

Details: Prime Vertical Applet

  

 
Web Links

Analemma - The solar tracking software Project

The Analemma (Bob Urschel)
Ausführliche astronomische und mathematische Darstellung

Wanderung der Mittagsposition im Verlauf eines Jahres (David Przewozny)

The Analemma Project (Steve Irvine)

The Analemma

Sundials on the Internet

Deutsche Gesellschaft für Chronometrie e.V.

Sundial Links (Daniel Roth)

Shadows (François Blateyron)
A great sundial program for Windows (download, freeware)

Sundials on the Internet - Sundial Design Software

Die Lebende Sonnenuhr (AstroMedia*Verlag)

North American Sundial Society

Fachgruppe Uhren (Förderkreis Industrie- und Technikgeschichte)

Sonnenuhren - Unterrichtshilfen für Schüler und Lehrer

Virtual Sundial

 

Please visit my GeoAstro Applet Collection

 

Last Modified: 2023, Oct 05

© 2011-2023 Juergen Giesen