Scientists have discovered that it is air that causes a splash when a droplet hits a flat surface - would water splash on the moon?Click the title to find out. (*.gif image kindly linked from this site)
Friday, April 1, 2005
If a drop of liquid falls on a flat surface and there is no air around it, does it make a splash?
Scientists have discovered that it is air that causes a splash when a droplet hits a flat surface - would water splash on the moon?Click the title to find out. (*.gif image kindly linked from this site)
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I need some help here, what is a splash? I would understand this to be the water that rises from the impact of the droplet as it hits some kind of a surface. Why does it do that anyway...3rd Law per chance? If I drive through a puddle it creates a splash which would have soemthing to do with the force applied by the car wheels and some kind of eureka displacement....ok now you can explain!!
ReplyDeleteOk, here’s what I found out...
ReplyDeleteThe physics behind the formation of the splash are complicated (always the case with the simplest processes!), but this article goes some way in explaining it and has some nice photos (sadly the .avi of the splash is a dead link). The article from the new scientist does go on to explain further but sadly I don’t have subscription. However, the article is explained further on this site from the University of Chicago (again some nice photos). There are some high speed clips of ‘splashes’ on this site (including a face punch and other weird stuff – see fluid mechanics for the drop videos). The following:
“pressure is a measure of the time rate of momentum transfered to a body by the molecules (or atoms!) of the "stuff" that surrounds the body, by collisions with the surface. In a vacuum there are essentially no surrounding molecules and therefore no pressure on the surface. The lack of surface pressure allows the structure of the liquid to expand, or relax,....”
came from this site and could perhaps be the reason why at very low pressures the liquids do not ‘splash’.
Other sites related to this are:
http://courses.ncssm.edu/hsi/splashes/animations.htm gif’s and videos of splashes
http://www.nature.com/nsu_new/000615/000615-10.html reducing splashes using polymers
http://www.findarticles.com/p/articles/mi_m1200/is_n2_v134/ai_6494460 forming drops using computers
....on reading though your question I don’t think I answered it – oh well, that’s teachers for you...
ps liked the baby photos and comments on your times two blog
it'ill be strange to see water not splash
ReplyDeleteit would be REALLY starnge to see water with no oxygen!
ReplyDeletedont you thing it is odd that the water would exisit with no oxygen? Then wouldnt it be just be hydrogen? I could be wrong but i'm just asking!
ReplyDelete