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Collection:
NASA Astronomy Picture of the Day Collection Collection NASA Astronomy Picture of the Day Collection Collection
Title:
Circum-axial Leaf Trails Title Circum-axial Leaf Trails Title
Explanation:
Are photographs of star trails [ http://www.astropix…TRIPOD2.HTM ] really evidence of the Earth's rotation [ http://www.astro.ui…] about its axis? Yes they are, and science journalist Trudy E. Bell discovered that there is a simple way to demonstrate this, if you have the stomach for it. First, find a playground equipped with a standard Merry-Go-Round [ http://scitation.ai…PHTEAH-ft/vol_45/iss _2/85_1.html ] (MGR) located under or near a large, leafy tree. Seat yourself near the middle of the MGR platform. Ask a local playground expert (KID) to get you spinning very, very fast. As the scenery flashes by at a dizzying rate, point your camera skyward and take a picture with a slow shutter speed setting. The result will be similar to this excellent image of concentric, arcing leaf trails centered at a point corresponding to the MGR's axis of rotation - a convincing imitation of circumpolar star trails [ http://antwrp.gsfc.…] recorded in hours-long exposures [ http://antwrp.gsfc.…] of planet Earth's night sky. Then, just stand up and walk away ... if you still can [ http://youtube.com/…]. Explanation Are photographs of star trails [ http://www.astropix…TRIPOD2.HTM ] really evidence of the Earth's rotation [ http://www.astro.ui…] about its axis? Yes they are, and science journalist Trudy E. Bell discovered that there is a simple way to demonstrate this, if you have the stomach for it. First, find a playground equipped with a standard Merry-Go-Round [ http://scitation.ai…PHTEAH-ft/vol_45/iss _2/85_1.html ] (MGR) located under or near a large, leafy tree. Seat yourself near the middle of the MGR platform. Ask a local playground expert (KID) to get you spinning very, very fast. As the scenery flashes by at a dizzying rate, point your camera skyward and take a picture with a slow shutter speed setting. The result will be similar to this excellent image of concentric, arcing leaf trails centered at a point corresponding to the MGR's axis of rotation - a convincing imitation of circumpolar star trails [ http://antwrp.gsfc.…] recorded in hours-long exposures [ http://antwrp.gsfc.…] of planet Earth's night sky. Then, just stand up and walk away ... if you still can [ http://youtube.com/…]. Explanation
Credit and Copyright:
Trudy E. Bell [ mailto:t.e.bell at ieee.org ] Credit_and_Copyright Trudy E. Bell [ mailto:t.e.bell at ieee.org ] Credit and Copyright
facet_where:
Goddard Space Flight Center (GSFC) facet_where Goddard Space Flight Center (GSFC) facet_where
facet_where:
Washington, D.C. facet_where Washington, D.C. facet_where
facet_what:
Earth facet_what Earth facet_what
facet_what:
FAST facet_what FAST facet_what
facet_what:
YES facet_what YES facet_what
original url:
http://antwrp.gsfc.… original_url http://antwrp.gsfc.… original url
UID:
SPD-APOD-ap070519 UID SPD-APOD-ap070519 UID

Circum-axial Leaf Trails

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Circum-axial Leaf Trails