Wednesday, November 29, 2006
Moonage Spacedream: the fear of water vapor
See those pretty little streaks of clouds in that pic? Those are called contrails. Whispery little fragile streaks of ice left behind by jets and rockets that blow away in a very short period of time. There is some debate as to how they affect the Earth's climate since they reflect sunlight. But, that point is somewhat debatable. What is not debatable is how easy it is to scare people over just about anything. To wit per GOPandtheCity:...
Jet trails just water vapor, not sprayed chemicals, experts say - Nashville, Tennessee - Wednesday, 11/29/06 - Tennessean.com
Blue skies have been turning white this month as airplane traffic crisscrosses the sky.
The trails that jets leave behind grow, creating thin, cirrus-style clouds that aviation officials say result from water vapor from engine exhausts and in the air turning to ice crystals.
At least two Nashvillians aren't convinced. They subscribe to a concept that chemicals are being sprayed from planes.
"Why are there times that you don't see them at all?" said Scott Webb. "That's regardless of weather."
Lynn Lowrance, spokeswoman for the Metro Nashville Airport Authority, said it is, in fact, a matter of the weather.
The jet trails — called contrails — can disappear quickly, she said.
When the air is moist and it's colder, the trails can spread in a chain reaction as water vapor turns into ice particles. Feathery clouds result.
"They don't pose any health risk," Lowrance said.
Scott and Guy Avery, a local running coach, disagree, pointing to articles and talk on the Internet alleging that the government is spraying chemicals from planes, perhaps for experimentation.
"Chemtrails," as they're called on Web sites, have been a topic for several years, with unmarked military planes often accused of releasing them.
Representatives of Fort Campbell, which only has helicopters, the Tennessee Air National Guard, which has 10 marked propeller planes here, and a U.S. Air Force spokesman in Washington, D.C., said this week they do no such releases.
A NASA researcher said contrails are a cause for concern, but it's not related to chemicals.
A study has shown that the thin, cirrus clouds that plane exhausts can trigger are trapping heat next to the earth, said Pat Minnis, a NASA senior research scientist in Hampton, Va., and a Vanderbilt University graduate.
As air traffic increases, cirrus cloud coverage over the U.S. is rising by 1 percent a decade, Minnis said.
"A single plane can produce a rather large cloud," he said.
After 9/11, when all but a few planes were grounded, scientists had a chance to see that one lone military plane's contrail extended over Ohio and Pennsylvania, he said.
The icy cloud eventually covered about 6,170 square miles.
While NASA papers indicate that the impact on temperature of plane-produced clouds is significant, not everyone agrees, Minnis said.
"Whether or not it's a global climate problem, we'll see," he said.
More research is going on to try to determine that.
Tuesday, November 28, 2006
Renal Systems from Penal Systems
Scientists look skyward for climate-change clues- The Economic Times
Sunday, November 26, 2006
Stealth plane already being mothballed by Air Force - MarketWatch
Stealth plane already being mothballed by Air Force - MarketWatch: "LOS ANGELES (MarketWatch) -- Less than two decades after the world first got a look at the F-117 stealth fighter, the first aircraft built specifically to elude radar is scheduled for retirement by the Air Force -- and some wonder whether the plane's mothballing is a bit premature.
The reasons for shelving the plane that played a key role in the first Iraqi war are to make room for such aircraft as the F-22 Raptor, which has been under fire for being too expensive. But the Air Force has reasoned that the F-22 can do what the F-117 does, and more. Air Force officials did not return phone calls.
Pentagon analysts point out, though, that the F-117's lifespan will wind up being much shorter than most other Air Force aircraft. It's due to come out of service in 2008.
'It's probably the fastest retirement since the 1960s,' said Bill Sweetman, technology and aerospace editor for Jane's Information Group. 'I think the Air Force is trying to cast off older planes.'
The decision is puzzling to some, as not all the Air Force's older aircraft are headed for the scrap heap. Other fighter planes that were conceived prior to the F-117 -- including the F-15 Eagle, F-16 Fighting Falcon and the F/A-18 Hornet -- still are flying and are expected to endure well in"http://www.marketwatch.com/News/Story/Image.aspx?Guid=55e62f1530134a2fab85452b89303c95&Track=201
The reasons for shelving the plane that played a key role in the first Iraqi war are to make room for such aircraft as the F-22 Raptor, which has been under fire for being too expensive. But the Air Force has reasoned that the F-22 can do what the F-117 does, and more. Air Force officials did not return phone calls.
Pentagon analysts point out, though, that the F-117's lifespan will wind up being much shorter than most other Air Force aircraft. It's due to come out of service in 2008.
'It's probably the fastest retirement since the 1960s,' said Bill Sweetman, technology and aerospace editor for Jane's Information Group. 'I think the Air Force is trying to cast off older planes.'
The decision is puzzling to some, as not all the Air Force's older aircraft are headed for the scrap heap. Other fighter planes that were conceived prior to the F-117 -- including the F-15 Eagle, F-16 Fighting Falcon and the F/A-18 Hornet -- still are flying and are expected to endure well in"http://www.marketwatch.com/News/Story/Image.aspx?Guid=55e62f1530134a2fab85452b89303c95&Track=201
Saturday, November 25, 2006
Re-Open RFK assassination
YouTube - Model Jumbo Jet
Tuesday, November 14, 2006
ShoutWire - Two Canada Professors Win Right to Toke up at Work
Sunday, November 12, 2006
Massive recall of acetaminophen underway - News
Saturday, November 11, 2006
Greenland and Antarctica Ice Caps Linked By Ocean Current
Wednesday, November 01, 2006
YouTube - contrail air pollution
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