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Featured Videos
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Not Right For WatchKnowLearn
Ages: 3 - 8
6717 Views:
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Learn the names of the 3-d shapes and see real world examples of each. Cubes, triangular prisms, cones and cylinders. Slide show accompanied by music. Names of shapes appear on the screen.
July 9, 2009 at 12:00 PM
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Not Right For WatchKnowLearn
Ages: 10 - 18
989 Views:
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Hear Neil Armstrong utter the famous sentence: "One small step for man; one giant leap for mankind." Through television, motion picture and still photography, this film provides an "eye-witness" perspective of the Apollo 11 mission that put a human o...n the moon in July 1969. (28:24)
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September 8, 2012 at 11:44 AM
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Not Right For WatchKnowLearn
Ages: 8 - 18
1535 Views:
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Powers of Ten is an adventure in magnitudes. Starting at a picnic by the lakeside in Chicago, this famous film transports viewers to the outer edges of the universe. Every ten seconds we view the starting point from ten times farther out until our o...wn galaxy is visible only a s a speck of light among many others. Returning to Earth with breathtaking speed, we move inward- into the hand of the sleeping picnicker- with ten times more magnification every ten seconds. The journey ends inside a proton of a carbon atom within a DNA molecule in a white blood cell. (9:01)
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December 26, 2011 at 12:33 AM
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Not Right For WatchKnowLearn
Ages: 11 - 18
2368 Views:
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Watch the development of an unborn baby from the moment of conception to birth and beyond. No Narration. The images are set to music and mark the development of the baby by weeks (6 weeks, 8 weeks, 11 weeks etc.) Run time 04:31.
April 7, 2009 at 06:27 AM
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Not Right For WatchKnowLearn
Ages: 10 - 18
1513 Views:
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Excellent video on finding and assembling a Dinosaur skeleton including steps taken to crate bones that are missing.
Summary
The rocks where fossils are found can be soft and crumbly or very hard.
Often both the rocks and the fossilized bones c...ontain minerals that
help protect the bones from weathering. Exposed bone, however, is
sometimes very fragile. To prevent the bones from breaking,
paleontologists, the scientists who study dinosaurs, use certain
procedures to protect a fossil during its excavation and shipment to the
laboratory. Once a specimen has been carefully exposed and examined for
minerals, it is prepared for removal. First, the fossil is brushed
with a type of glue or plastic and then covered with strips of wet paper
and burlap dipped in Plaster of Paris for protection and support. The
most critical part of this preparation is when the fossil has to be
carefully turned over and the underside is also covered and protected.
After the plaster sets, the fossil is numbered and examined to determine
what structural part of the animal has been recovered. Back in the
laboratory, each bone is cleaned and strengthened. Knowledge of today's
animals' skeletons can help the scientists investigate the dinosaur's
remains. By comparing features of bones, a paleontologist may be able
to identify the fossil and its function. Bones along the back, from the
skull or in the jaw are very distinctive and often used to identify the
fossil's remains. Most or all of the skeleton can then be pieced
together if enough bones have been found. Paleontologists may have to
estimate the size and shape of missing bones to complete a full
skeleton. Once all the pieces are identified, a model of the animal is
built to assist the scientist in rebuilding the entire skeleton. Then a
large metal framework is welded together to support the fossilized
bones. The bones are then free mounted to the framework. If a simpler
mount is desired, scientists will fasten the fossils to a slab and use a
bas-relief mounting. Bas-relief mountings display the fossil as it was
buried. Either method preserves the dinosaur's structure for further
observation and research.
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April 16, 2012 at 09:44 AM
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