Re: [math-fun] High school physics problem
Hmmm... Evolutionary pressures would seem to have optimized *seed shapes* in such a way to *burrow to an optimum level in the ground*. If someone were to do a high school science project, it would be interesting to do some shaking & "artificial weathering" experiments to see how various seed shapes perform in different soils. So the problem isn't so much that Brazil nuts are competing with almonds or peanuts, but that they are competing with bits of dirt & rocks for an optimum space in soil where they can germinate. At 03:53 AM 12/12/2018, Bill Gosper wrote:
[Eavesdroppers: Other respondents offered
https://en.wikipedia.org/wiki/Granular_convection and "the Brazil nut effect".]
On 2018-12-10 09:16, Henry Baker wrote:
Has this problem been studied before?
In the New Jersey gravel pits.
Shore dwellers' lots are plain white sand.
Your cheapest driveway is a truckload of low grade gravel, with granularity ranging from pebbles all the way down to clay. You sink in if you try to drive (or even walk) on it.
But after a few weeks of weather, and then initially light usage, all the big pebbles are on top.
Ârwg
With a slightly different perspective, as the mixture shakes, the smallest bits fill in holes the bigger bits don't fit in --- hence the big bits raise to the top. In turn, that phenomenon is connected to simulated annealing. https://en.wikipedia.org/wiki/Simulated_annealing On 12/13/18 20:52 , Henry Baker wrote:
Hmmm...
Evolutionary pressures would seem to have optimized *seed shapes* in such a way to *burrow to an optimum level in the ground*.
If someone were to do a high school science project, it would be interesting to do some shaking & "artificial weathering" experiments to see how various seed shapes perform in different soils.
So the problem isn't so much that Brazil nuts are competing with almonds or peanuts, but that they are competing with bits of dirt & rocks for an optimum space in soil where they can germinate.
At 03:53 AM 12/12/2018, Bill Gosper wrote:
[Eavesdroppers: Other respondents offered
https://en.wikipedia.org/wiki/Granular_convection and "the Brazil nut effect".]
On 2018-12-10 09:16, Henry Baker wrote:
Has this problem been studied before?
In the New Jersey gravel pits.
Shore dwellers' lots are plain white sand.
Your cheapest driveway is a truckload of low grade gravel, with granularity ranging from pebbles all the way down to clay. You sink in if you try to drive (or even walk) on it.
But after a few weeks of weather, and then initially light usage, all the big pebbles are on top.
-rwg
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun .
But if there is no friction the little bits can't wedge under the big bits. Instead they can flow out from under the big bits. That's what happens when the little bits are lubricated by water molecules or similar. Brent On 12/14/2018 3:07 PM, Andres Valloud wrote:
With a slightly different perspective, as the mixture shakes, the smallest bits fill in holes the bigger bits don't fit in --- hence the big bits raise to the top. In turn, that phenomenon is connected to simulated annealing.
https://en.wikipedia.org/wiki/Simulated_annealing
On 12/13/18 20:52 , Henry Baker wrote:
Hmmm...
Evolutionary pressures would seem to have optimized *seed shapes* in such a way to *burrow to an optimum level in the ground*.
If someone were to do a high school science project, it would be interesting to do some shaking & "artificial weathering" experiments to see how various seed shapes perform in different soils.
So the problem isn't so much that Brazil nuts are competing with almonds or peanuts, but that they are competing with bits of dirt & rocks for an optimum space in soil where they can germinate.
At 03:53 AM 12/12/2018, Bill Gosper wrote:
[Eavesdroppers: Other respondents offered
https://en.wikipedia.org/wiki/Granular_convection and "the Brazil nut effect".]
On 2018-12-10 09:16, Henry Baker wrote:
Has this problem been studied before? In the New Jersey gravel pits.
Shore dwellers' lots are plain white sand.
Your cheapest driveway is a truckload of low grade gravel, with granularity ranging from pebbles all the way down to clay. You sink in if you try to drive (or even walk) on it.
But after a few weeks of weather, and then initially light usage, all the big pebbles are on top.
-rwg
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun .
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (3)
-
Andres Valloud -
Brent Meeker -
Henry Baker