Doctor Yourself

Saturday, January 22, 2011

Eschimosii din Rai

Tre' sa vedeti asta !  http://www.youtube.com/watch?v=ZGjwe-BCfms&feature=player_embedded

In Rai, arunca apa clocotita in aer, si cade pe pamant ....cubulete de gheata . Asta la -30 C in Yelloknife. La fel se intampla si in Edmonton, prin Alberta ( ne povestea o canadianca nascuta in Rai, mutata din Edmonton in Toronto, de groaza frigului ).

Aici gasiti articolul intreg pe Yahoo http://ca.news.yahoo.com/blogs/dailybrew/video-boiling-water-turning-snow-goes-viral-20110120-181619-194.html

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And you thought it was cold in the rest of Canada.
A YouTube video showing a woman in Yellowknife, Northwest Territories throwing boiling water into the air in -30C weather has racked up more than 1.5 million views since it was posted at the beginning of the month - one view is all it takes to see why.
While the woman in the video describes the phenomena as evaporation, commenters have rushed to correct her.
Evaporation is the process by which the surface of a liquid turns to a gas, but what we see in the video is mostly high-speed freezing. The reason boiling water is used, besides being dramatic, is because cold water simply doesn't behave the same way when thrown.
Time to reach back to high school science. According to Chemistry Ph.D, Joe Larsen, boiling water's high energy makes it less viscous, or thinner, than colder water. This means that when boiling water is thrown into the air it forms into minuscule droplets. These droplets present a much greater surface area than a large blob of cold water would. The greater surface area allows for rapid evaporation on the surface of the droplets and then an almost instantaneous change of state into a solid — or as most of us Canucks call it, snow.
Hot water freezing faster than cold water has fascinated scientists for thousands of years. Read more on the Mpemba effect if the phrase "fluid dynamics" doesn't make you want to run for the hills.

2 comments:

  1. M-a luat frigul cand am vazut-o pe fata, care facea experienta, cu capul descoperit... e calita, nu gluma!

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Pentru ca au fost crestinopati ramasi fara argumente in ceea ce sustineau si care au scris pe blog datele mele personale drept razbunare, comentariile vor fi moderate, ca sa prevenim si alte marlanii dinpartea " prietenilor" . Comentariile vor fi moderate. Forever.