Explanation of Sundial Time Correction - Vilnius, Lithuania
N 54° 41.140 E 025° 17.333
35U E 389693 N 6061157
This plaque explains how to obtain the correct time from a sundial on the wall of the Palace of the Grand Dukes of Lithuania by using an equation of time graph with correction for longitude.
Waymark Code: WMPGQ6
Location: Lithuania
Date Posted: 08/29/2015
Views: 10
The sign for the sundial includes information in Lithuanian and English. The English text reads:
"Palace Sundial
This sundial displays true solar time -- that which was used in the Palace in former times. The shadow of the arrow indicates the time of day and the shadow of the sphere shows the month and the current Zodiac sign corresponding to the relative position of the sun.
The daily difference between our watch time and solar time is not constant and varies up to about =/- 15 minutes. This is due to the Earth's elliptical orbit around the Sun and the tilt of the orbit's axis. Also, watches are now set to display the time at the middle of the second time zone instead of at their actual location. In Vilnius, this results in an additional constant difference of almost 19 minutes.
The total difference for each day of the year is shown in the Equation of Time graph; when added to the sundial's time, it will agree with out watch time. During daylight savings time, an additional hour is to be added.
EQUATION OF TIME GRAPH WITH CORRECTION FOR LONGITUDE"
Beneath this is the graph.
NOTE: This was approved because of the extensive explanation of how the chart works. Other sundial with the minimal chart will not be accepted. Outspoken1
Scientific Principle(s) being demonstrated:
It explains how to calculate a time correction for longitude for the sundial.
Briefly explain if the experiment was effective for you. Could it have been better?:
I now understand how to correct the time from the sundial to match real time.
When is the apparatus/experiment available to the public:
The sign and sundial can be accessed 24/7 daily, but you need to sun to actually be able to perform the correction.
|
Visit Instructions:
To help give a different perspective and to improve the Waymark for future visitors please tell us about your visit and upload a favorite photograph(s) you took of the Waymark. What was your “Wow” moment?