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Author Topic: question about macroscopic vs microscopic  (Read 2796 times)

Offline skipperZ

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question about macroscopic vs microscopic
« on: 20/06/2006 20:17:15 »
Sorry if someone has asked this question before - I didn't really look through the threads past the first page.  I also didn't spend as much time as I usually do with wiki/google before posting this, so sorry again.  

My question is basically about the (average) distance between molecules when two macroscopic objects physically interact?  For an example, how far apart is your hand from your mouse when you put your hand down on it?  Or the bottom of your shoe from the floor when you stand on it?  

I understand there is a high degree of variability to it, but what is it on the order of?  Is it several orders of magnitude greater than the distance between the molecules of your shoe or the mouse, or is it closer to the same distance?  Or is there just too much variability in it to make any generalizations?


Offline Roy P

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Re: question about macroscopic vs microscopic
« Reply #1 on: 20/06/2006 21:39:09 »
Not too sure of the answer to your question, skipper, but I heard an interesting fact yesterday about the volume of atoms:

The world's population would fit into the size of a sugar cube if you squeezed out all the empty space!


Roy P

Offline Soul Surfer

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Re: question about macroscopic vs microscopic
« Reply #2 on: 20/06/2006 23:54:47 »
This is mainly about surface roughness and rigitity.  Even higly polished surfaces can be quite rough on the atomic scale so only the peaks of any surface come into contact with each other at the atomic level. Its a good thing too. If you make exeptionally smooth flat surfaces  
the Van der Walls attractions between the molecules tend to make them stick together quite well.  Some small animals use this to help them walk on vertical or even overhanging surfaces by having very fine bristles on their feet that can contact most surfaces at the atomic level because they conform to the finest roughness on the surface and make maximum use of these tiny forces

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Re: question about macroscopic vs microscopic
« Reply #2 on: 20/06/2006 23:54:47 »


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