sun compass

sun compass

[′sən ‚käm·pəs]
(navigation)
A device which utilizes the shadow of a shadow pin, or gnomon, and a suitable dial to facilitate use of the sun for determination of direction.
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References in periodicals archive ?
Monarchs use a time-compensated sun compass in their antenna to help them make their 2,000 mile migratory journey to overwintering sites.
Monarchs use a time-compensated sun compass in their antennae to help them find their way along the 2,000-mile migratory trek.
Scientists think the butterflies know where to go by using the earth's magnetic pull and a kind of sun compass in their antennae.
"Alderney-like crystals could really have been used as an accurate optical sun compass as an aid to ancient navigation, when the Sun was hidden by clouds or below the horizon," the team wrote.
Earlier work by Reppert's group found that monarchs rely on a time-compensated sun compass to direct their navigation south.
The only criticism of this book is probably a minor error of editing, although an alarming one, during the discussion of animals using a sun compass as a navigation tool, which confidently states that "the sun is an ideal visual reference: every day it rises in the west and sets in the east...." No other errors were noted, and readers should not be deterred.
To extend your understanding of our world and its orientation, you might like to take a look at www.timeanddate.com and also to search out Robin Knox-Johnson's web page at www.robinknox-johnson.co.uk/da/20090 on the Viking Sun Compass - both provide more fascinating information and ideas on this subject.
The Garden Planner's Sun Compass is pounds 19.50 (plus pounds 1 p&p) from deboisdesign (www.suncompass.info, 020 3210 1041).
Some 50 years ago, biologists discovered that both honeybees and starlings use the sun in navigating, so monarch biologists speculated that butterflies, too, might find some kind of sun compass in their subjects.
The new study at the University of Massachusetts Medical School confirmed what had been suspected, that the creatures use an internal ``circadian'' clock as part of their sun compass.
Animals are said to possess a "sun compass" when they use the sun to orient themselves and take into consideration its apparent daily movement.