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## Lunchtime in Greenwich

A cache by George Chronos Message this owner
Hidden : 06/10/2004
Difficulty:
Terrain:

Size:  (not chosen)

#### Watch

How Geocaching Works

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### Geocache Description:

A fun mystery - virtual cache in Traverse City

When it is lunchtime in Greenwich, England, it is time for breakfast in Traverse City. It turns out this can help you find a geocache. To find this geocache you will need to calculate its longitude based on the time difference between these locations (see below).

Calculating longitude was a significant problem for mariners. Only when consistently accurate clocks were invented was it possible to calculate longitude accurately. A little explanation might help with understanding this: The earth rotates about its axis every 24 hours. Therefore, in one hour the earth rotates 360 degrees/24 = 15 degrees of longitude. A clock set to Greenwich Mean Time (at the Prime Meridian) can then be used to calulate longitude. For example, if the sun is at its zenith at your location (ie, it is noon) and the time in Greenwich is 3 pm, then your longitude is 3 hrs. x 15 degrees/hr. = W 045 degrees. If you would like to learn more about the historical problem of calculating longitude click here.

To find this cache ignore the standard time zones. When it is noon in Greenwich, it is 6hrs, 17mins, 32.143 seconds a.m. at this geocache (time for breakfast!). To find this cache it is not necessary to calculate latitude. It is (in standard format): N 44o 45.694.

Time at geocache: 6hrs, 17mins, 32.143 secs
Latitude of geocache: N 44o 45.694

The time, 6:17:32.143, represents local solar time. Until the late 19th century keeping track of time could be bewildering as each locale might have its own time based on the solar cycle. The coming of the railroads required standardization which has led to "standard time zones" as we know them today.

This is also a virtual geocache. There was no practical way of leaving a physical cache at this location. The cache features a large object on which is inscribed a variety of information, part of which concerns time. To get credit for this cache, you must email Whitard with the time period inscribed on this object and the name of the object's manufacturer. The coordinates on the top of this webpage are not for the cache itself. Instead, they are for a location in fairly close proximity.

Have fun with this math and navigation challenge!

gur rnegu ebgngrf 15 qrterrf va bar ubhe; bar ubhe = fvkgl zvaf.; bar ubhe = 3600 frpf.

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)