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Science
Feb 20, 2006 0:57:47 GMT -5
Post by JOE on Feb 20, 2006 0:57:47 GMT -5
Sounds awesome!
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Science
Feb 21, 2006 11:08:15 GMT -5
Post by degicank on Feb 21, 2006 11:08:15 GMT -5
Robert Speers 2/21/05
"Explaining Ice" by Kenneth Chang
Inspired by the Olympics, reporter Kenneth Chang asks a great question: Why is ice slippery? Chang notes that ice is a solid and most solids don't facilitate sliding on thin metal blades. Chang says the tradition explanation for ice’s low viscosity is incorrect. He remarks that forms of ice are predicted to exist in the hot interior of the Earth, and on the cold surface of Pluto. The article next goes into great detail explaining Faraday’s hypothesis that the out layer of a piece of ice is actually liquid because there are no H2O molecules present to hold them in place. This liquid outer layer is too small to observe visually, but in 1996 scientists at Berkeley experimented with the theory of a liquid outer layer by shooting electrons at ice and examining the pattern of the electrons bouncing back. The data suggest that the outer layer is liquid, even at extremely low temperatures. It seemed that an explanation for the slippery nature of ice was in sight until 2002 when observations with a scanning tunneling microscope showed that friction of the ice was very high. The liquid layer was to thin to have an effect so there is still no useful theory to explain why we slide on ice. Chang goes on to describe the usual hexagonical configuration of ice at normal atmospheric pressure. The ice is held together by H-bonds. Other forms of ice have been formed under great pressures with different crystalline shapes that can exist under far hotter conditions. This is the idea explored in the book Cat’s Cradle by Kurt Vonnegut.
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Science
Feb 21, 2006 11:29:39 GMT -5
Post by DrCank on Feb 21, 2006 11:29:39 GMT -5
I don’t remember Vonnegut going into to frictional coefficients of Ice, he explored the density Issues. In his book, if I remember correctly, he talks about Ice-9. A form of Ice that is denser in the solid phase than liquid water. In this theory as ice freezes it would sink, remember if the Ice in the polar caps where to sink the bottom, the deep oceans would be filled with ice due the relative colder temperatures of the deep oceans. This would cause an enormous amount of water to be held up in under water reserves and lead to a decrease in global ocean levels (remember solid H2O is more dense in this experiment ie. Same amount of mass in less volume).
Since it is widely believed that life started in the oceans it is a good thing Ice is less dense in solid form. Not to mention the fact that the hydrological cycle is one of the major forces that not only shapes our planet, but enables life to exist here. There is only one other compound that is less dense in its solid form than its liquid form. I’ll have to check on this but I believe it is Methane, which is Venus’s version of water (don’t quote me on this just yet I will have to check up on some resources before I stand behind that quote).
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Science
Feb 21, 2006 17:39:43 GMT -5
Post by bencdubois on Feb 21, 2006 17:39:43 GMT -5
Slippery ice. I was a professional ski racer my mid to late teens. I even beat Bode Miller a bunch of times! The science of ice was very important to us, the more one understood how to reduce the friction of the ski base on ice the faster they would go. We wound up using florocarbons on the bases of our skis. Sometimes we could produce a near frictionless surface on the ice! That would leave us to accelerate down the hill in much the same was as a free falling object.
In ski racing they inject the snow with water and allow it to freeze. It creates an ice rink type surface and minimizes wear as each competitor turns and glides across the surface.
My understanding of why objects slip across ice is the friction no matter how slight of the object melts the very surface of the ice and hydroplaning occurs causing the object to slide. You can see when a skiier goes by at a very fast speed thier tracks leave a crisp glaze from the melting. So you aren't sliding on ice you slide on water and actually a skiier at speeds above 65 mph are floating slightly above that water on the air. In a downhill race when you get up to about 70-85 your skis start to "swim". "Swimming" is when the small cushion of air allows the skis to move around underneath you without changing your direction. You are taught to relax your ankles and let the air move the skis around to avoid the slight friction that could be created trying to hold the ski static against the flow of air.
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Feb 21, 2006 19:24:25 GMT -5
Post by Bill on Feb 21, 2006 19:24:25 GMT -5
hey Ben,
have u done any skiing around here?
I've been wanting to go. I think it may be too late.
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Feb 22, 2006 1:49:35 GMT -5
Post by 1bencdubois on Feb 22, 2006 1:49:35 GMT -5
Bill- Tahoe has amazing skiing. Squaw Valley in particular. Squaw spawned the greatest extreme skier of all time Scott Schmitt. Squaw Valley has some great terrain up top for the extreme heads. I used to drop cliffs back in the day up to about 7 meters. Anything above that was unavailable to me at the time. We used to have the sports medicine folks drain our knees afterwards with large needles and inject cortisone to ice the cake. Why do I have degeneration inside my left knee? No brainer.
My doc gives me another season out until the slipped disc finishes resolving. By the way great improvement after the whole grandpa thing.
A friend of mine owns a sweet cabin right on the slope at Squaw. He recently moved to the east coast and I don't know if he got rid of it. Maybe next season we'll check it out. I board as well as parallel.
Skiing is pretty stong out in Tahoe until late spring. I would head up if I were you. They got 5 feet of fresh stuff last week.
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Feb 22, 2006 23:17:54 GMT -5
Post by Joe on Feb 22, 2006 23:17:54 GMT -5
Hello freinds, I was trying to install The Econocank on this terminal but it only had 30 gigs free on a 200 gig hard drive. I looked into cleaning up temp files and expired demos taking up a lot of room. Not enough memory even to copy dvds. TWR says eastern expansion solid.
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Feb 23, 2006 13:08:43 GMT -5
Post by Bill on Feb 23, 2006 13:08:43 GMT -5
What you'll need to do is either copy a portion over or find someone with a DVD burner and copy the whole thing to another DVD.
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Feb 23, 2006 18:59:47 GMT -5
Post by Chris Cank on Feb 23, 2006 18:59:47 GMT -5
No need to worry. Joe just didn't see the additional 200+gigs I have on my secondary and third hardrives. Haven't had a chance to do any serious file moving, but things should be right as rain now.
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Feb 24, 2006 12:32:59 GMT -5
Post by DrCank on Feb 24, 2006 12:32:59 GMT -5
yeah bill calm down
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Feb 28, 2006 10:39:02 GMT -5
Post by DrCank on Feb 28, 2006 10:39:02 GMT -5
Here's an interesting theory I came across today: Europe's "Little Ice Age" may have been triggered by the 14th Century Black Death plague, according to a new study. Pollen and leaf data support the idea that millions of trees sprang up on abandoned farmland, soaking up carbon dioxide from the atmosphere. Check out the full Article: news.bbc.co.uk/2/hi/science/nature/4755328.stm
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Feb 28, 2006 13:27:33 GMT -5
Post by Joe on Feb 28, 2006 13:27:33 GMT -5
Very interesting theory about "little ice age". Robert Speers 2/28/06 Chemistry in the News: Alluring Swordtail Scent Is Lost in Pollution By Henry Fountain This article begins by describing the importance of communication in relationships. Unfortunately it seems the communication between sheepshead swordtails, a type of fish, is being interfered with by agricultural runoff. Heidi S. Fisher, from Boston University, has collected data that shows humic acid interfering with the identification of pairing mates among the Sheepshead swordtails. These fish are native to the Rio Calnali in northeastern Mexico. The males release chemicals that are detected by females in search of a mate. Untreated sewage and agricultural runoff has resulted in a level of humic acid high enough to confuse the female sheepshead swordtails into mating with highland swordtails. Fisher’s research tested these species in clean water and recorded the females mating patterns. Females not exposed to humic acid choose mates of their own species. Females in the sample with humic acid would mate with the highland swordtails to produce hybrid offspring. There is one section of the Rio Calnali that is inhabited exclusively by the hybrid fish. Even if the river was cleaned up today, the hybrid offspring may still take over. It seems even a temporary or reversible change in the chemical composition of a habitat can have a permanent effect on life. www.nytimes.com/2006/02/28/science/28obox.html?_r=1&oref=slogin
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Mar 1, 2006 10:09:19 GMT -5
Post by DrCank on Mar 1, 2006 10:09:19 GMT -5
Malaysia creates team to track 'Bigfoot' KUALA LUMPUR, Malaysia (AP) — A southern Malaysian state will appoint a team of scientists and experts to hunt for a "Bigfoot" beast after the reported sighting of three giant human-like creatures, officials said Thursday. -USA Today
This is the biggest things to happen to bigfoot study since Ohio State decided to call off its DNA research of suspected 'Bigfoot' hairs colleceted in China in the mid-90's. From what I understand Malasia has vowed to imprison any foreigner suspected of searching for the creature. They want this discovery to made by malasian researchers. prints of the suspected hominiod have even been found on residentual streets in the village of Mawai.
According to local historians, Mawai's original name was Mawas, and Mawas is the name locals give to a legendary creature known the world over as Bigfoot. - BBC News
And to all you skeptics don't forget it was only last year that we discovered the remains of HomoFloriensus (may not be spelled right) an ancestrial cousin of modern human found in the Fijian Islands. At only about four feet tall this species has been given the nickname "the hobbit", but screw that I will, atleast try to, use the correct Latin nomenclature.
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Mar 1, 2006 13:29:22 GMT -5
Post by Bill on Mar 1, 2006 13:29:22 GMT -5
Rubbish
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Post by JOE on Mar 3, 2006 2:28:56 GMT -5
Science can only disprove, it can not prove...
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