“Anthropic principle,”

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“Dark Energy,”

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“Brane”

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and for more use the DOOR…

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[MORE]

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These definitions are from Beyond Our Galaxy: Exploring the Vastness of Space (National Geographic Society, 2014¹).

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The GLOSSARY at the end of the book is what we’re looking at here.

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This yellow-edged, NG-appearing text builds upon previous recent NG articles that define our newest knowledge of science–in this case astronomy. It is geared for intelligent lay readers. That’s very helpful, but sometimes incomplete. We’ll look at some items from the glossary. Where you see writing in color, that’s our note, hoping to clarify, and in some cases reflecting our interests and concerns.

 

Anthropic principle - the idea that the universe contains the necessary conditions to support the development of life, as proven by our existence on Earth. (For some, this science definition is a starting point for “there must be a God” arguments because so much “fine tuning” of matter and energy factors must be “just so.” Even with billions of other possible starting”places” it would be hard to begin with hydrogen and other simple elements, lots of “energy,” and a bunch of happy accidents to produce life that complex enough to produce and send out these words.)

Dark energy - a property of space that propels the acceleration of the expanding  universe. (Within the past 20 years or so has come a conclusion of many doing basic cosmological research that of all the matter-energy in the universe, 68.3 percent of everything is “dark energy,” which is fairly homogenous throughout space. The need for this seems to be required for current cosmological theory, but astronomers have a hard time nailing down a good description, or explanation, of this.)

Brane - short for membrane, an extended object in string theory that can have any number of dimensions. (Look for “brane” in discussions of “string theory” and “multidimensionality” [dimensions that go beyond the standard 4 dimensions: 3 of space and 1 for time]. Complex stuff!)

Astronomical unit (AU) – (simply) the average distance from Earth to the sun–149,597,870 kilometers (92,955,807 mi.)–employed as a standard unit of astronomical measurement. (Think of this as a convenient “long yardstick” [or meterstick] for talking about distances intermediately long in space. Further, just round these off to “150 million km” and “93 million mi.” to give the memory in your brain [the brain with an "i" in it] a break. “AU” is really a cool and simple unit.

Doppler shift - (Not as hard as it may sound) the observed change in the wavelength of light or sound caused by relative motion between an observer and the object. (Think of a waiting of a train to come and pass by at a railroad crossing. The approaching train whistle sounds higher than normal as it approaches because of its “pushing” the sound waves forward, and as the train passes by, the whistle sounds lower because the sound waves are more “stretched-out” as they come to your ears. The similar thing happens with light as the increase in the wavelength of radiation, including visible light, sent out by a receding celestial body is influenced by the Doppler effect, gravitation, or cosmological expansion. Actually color changes (not sound, of course) at the red of the spectrum.)

Redshift - I just defined it above! We can actually determine distances in space this way.

There are more terms, but that’s enough for now…

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¹ While this is designed and produced by the National Geographic Society, it is printed and distributed by Time Home Entertainment, Inc. While summarizing much, this is a beautiful and informative, up-to-date item for your “paper” bookshelf.