Difference between revisions 932721 and 939961 on enwikiversity

{{yawn}}
Astronomy is performed by location and is subject to local conditions. The shapes and sizes of observatories have changed over time, as have their altitude. The motivations for putting an observatory manned or unmanned at different altitudes has led to a great variety in '''lofting technology'''.
{{secondary}}
{{tertiary}}
{{research}}
{{article}}
{{lecture}}
{{astronomy}}
(contracted; show full)

The delta of the [[w:Mississippi river|Mississippi river]] is further from the center of the Earth than the river’s origin in the state of Minnesota. As the river flows uphill, how is this possible?

==Sea level==


From the Wikipedia article [[w:Sea level|sea level]], “'''Mean sea level''' (MSL) is a measure of the average height of the ocean's surface (such as the halfway point between the mean high tide and the mean low tide); used as a standard in reckoning land elevation.<ref name=Proudman>{{ cite web
|url=http://www.straightdope.com/columns/read/148/what-is-sea-level#1
|title=''What is "Mean Sea Level"?''
|publisher=Proudman Oceanographic Laboratory }}</ref> MSL also plays an extremely important role in [[w:aviation|aviation]], where standard sea level pressure is used as the measurement datum of altitude at [[w:flight level|flight level]]s.”<ref name=SeaLevel>{{ cite journal
|title=Sea level
|journal=Wikipedia
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=September 1,
|year=2012
|url=http://en.wikipedia.org/wiki/Sea_level
|pdf=
|accessdate=2012-09-09 }}</ref>

==Atmosphere==

'''Def.''' "a layer of [[w:Gas|gases]] that may surround a material body of sufficient [[w:Mass|mass]],<ref name=Ontario>{{ cite web
|url=
|title=Ontario Science Centre website }}</ref> and that is held in place by the [[w:gravity|gravity]] of the body", per the Wikipedia article [[w:Atmosphere|atmosphere]], is called an '''atmosphere'''.

(contracted; show full)[[Category:History of science]]
[[Category:Original research]]
[[Category:Physics and Astronomy]]
[[Category:Research]]
[[Category:Research projects]]
[[Category:Resources last modified in August 2012]]

<!-- interlanguage links -->