Jan 18, 2002
http://www.escribe.com/science/keelynet/m11921.html
Hi Folks!
There have long been contentions that life formed in an atmosphere of about 35% oxygen.
The composition of the atmosphere is remarkably constant at all flight altitudes. Air contains about 21% oxygen, 78% nitrogen and traces of argon, carbon dioxide and other rare gases. Closer to the ground some impurities are also found. The amount of water vapor varies significantly as we notice from cloud formation.
The air temperature decreases by about 2 deg.C per
300 meters (3.5 deg.F per 1,000 ft). The
tropopause is reached at 11-12 km (36,000-40,000
ft) where the temperature remains constant at -56 deg.C (-70 deg.F).
Ozone is detected in significant amounts between 12-40 km (40,000-130,000 ft). It protects the life on the ground from excessive ultraviolet radiation of the Sun. Ozone can be an irritant inside the aircraft although in found concentrations it has no detrimental health effect. Ozone filters on new aircraft remove the gas effectively.
The mean pressure at sea level is 1013 millibars
(mb) equal to 760 mm of mercury (mmHg) or 14.7 lb/sq.in. The pressure decreases
to one half at 5 = km (18,000 ft) and to one-fourth at 10 km (33,000 ft).
The proportion of gases in the upper atmosphere remains the same as at
sea level, so
the air still contains 21% oxygen but the partial
pressure of the gas has decreased to one-fourth which diminishes oxygen
uptake of the body.
The resistance of a moving object in the air decreases
as air pressure diminishes; therefore the jet aircraft flies more efficiently
at high altitude. Lower resistance means less energy (fuel) is needed to
move the aircraft through the air thus making the flight more economical.
http://unisci.com/stories/20021/0115025.htm
The Earth may have had an oxygen-rich atmosphere as long ago as three billion years and possibly even earlier, three leading geologists have claimed.
Their theory challenges long-held ideas about when the Earth's atmosphere became enriched with oxygen, and pushes the likely date for formation of an atmosphere resembling today's far back into the early history of the planet.
It may also revolutionize the worldwide search for gold and other minerals, and raises new questions about when and how life could have arisen.
Evidence for the presence of oxygen in the primitive
atmosphere was put forward by the Chief of CSIRO Exploration and Mining
Professor Neil Phillips, Australian-based South African geologist Jonathan
Law and US gold mining consultant Dr Russell Myers in a publication by
the Society
for Economic Geology.
"These findings may have enormous economic implications in that we may simply have been looking in the wrong places for massive gold deposits like South Africa's Witwatersrand," says Professor Phillips.
"Or we may actually have found them -- and not recognised them for what they are, because we did not understand the processes involved in their formation."
The scientists base their case on the presence of iron-rich nodules in the deep strata of the Witwatersrand -- nodules they believe are pisoliths, small balls containing ferric iron produced by exposure to an oxygen-rich air.
Pisoliths still form nowadays and provide important clues in the search for minerals, including gold. Those found in the Rand come from levels 3-4 kilometers down, which are securely dated at 2.7 to 2.8 billion years old.
The researchers' theory has been lent additional weight by evidence from the Western Australian Pilbara region for the presence of sulfates in rocks up to 3.5 billion years old.
These, too, could not have formed without an oxygen-rich atmosphere.
Pisoliths have been a vital tool in the discovery of $5 billion worth of new gold deposits in WA in recent years, using techniques developed by CSIRO's Dr. Ray Smith, Dr. Charles Butt and Dr. Ravi Anand.
The small iron-rich balls form from iron in groundwater and "scavenge" traces of other minerals in the local environment. They provide clues, like fingerprints, which point to deposits lying hidden beneath meters of inscrutable surface rubble.
By analyzing pisoliths over a wide area for gold content, geologists can construct a pattern of steadily enriching traces, with the hidden deposit lying like a bullseye at the heart of it, usually a bit uphill.
Some geologists believe living organisms may play
a part in the formation of pisoliths, raising tantalizing questions about
the nature and role of life in shaping the Earth's early surface and
mineralization.
The presence of pisoliths in the deep strata of
the Rand suggests that the conditions for mineral formation 3 billion years
or so ago were different to what many geologists have believed for the
past
half-century, the team say. These ideas have
already been integrated into a new exploration model for the formation
of the Rand deposits by the same researchers.
The Rand is unique on Earth -- a vast body of rock very rich in gold. The mightiest gold deposit ever found. Nothing like it has been discovered elsewhere.
Professor Phillips says that this may be because we didn't know what to look for, because we made wrong assumptions about the conditions in which it formed.
In other words, fresh Rands may still await discovery.
Some geologists
speculate one of them, at least, lies in central
Western Australia.
http://www.keelynet.com/biology/baugh.htm
Hi Jennifer!
I too have always been fascinated by the 'water canopy' theory but never thought of the pre-flood air as being more dense.... here are some links about it, unfortunately not verifiable as fact from either the science or creationist viewpoints;
http://www.godandscience.org/youngearth/canopy.html
http://www.creationscience.com/onlinebook/FAQ32.html
http://www.nasamike.com/main/book/4hiii.htm
http://www.sentex.net/~tcc/fcanopy.html
and there are more which you can easily look up.
from an Art to a Science - order out of Chaos
discussion list - http://www.escribe.com/science/keelynet