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Old 05-20-2019, 03:00 PM   #2 (permalink)
Shaneajanderson
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Quote:
Originally Posted by Vman455 View Post
Breaking this off so as not to muck up another person's thread. In that thread, I wrote:



And another poster responded:



But...

"Some apparently 'solid' substances such as asphalt and lead...actually deform slowly and exhibit definite fluid behavior over long periods." (White, Frank M. Fluid Mechanics, 8th ed. New York: McGraw Hill, 2017. 4)

(Ellipses where I removed the actual answer).

Solids (mostly) maintaining their shapes. Glass, over extremely long time periods, flows. But glass is a solid. Thus, the ability to flow and conform to the shape of a container is not the distinction. So, what makes lead, asphalt, or glass solids vs. fluids...?

I'll post the answer in this thread tonight if no one guesses it before then.
This is why I put the (mostly).

As far as the difference, in fluids the individual molecules move freely, but in a solid they are constrained by those around them. The 'flowing' in lead, asphalt, glass, and other such solids is do to shifting crystal structure, but the individual molecules hold their positions relative to each other, outside of this 'sliding' if you wish to call it that.

Hope that makes sense, I'm good with understanding, bad with wording.
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