My Math Forum

My Math Forum (http://mymathforum.com/math-forums.php)
-   Physics (http://mymathforum.com/physics/)
-   -   pancakes (http://mymathforum.com/physics/345021-pancakes.html)

Joppy September 29th, 2018 04:49 AM

pancakes
 
This morning I made some pancakes out of that pre-mix stuff that you add water to and shake. I forgot to shake the mix before adding water so the final product wasn't entirely homogeneous (to my disappointment).

Anyway, after heating them on a dead flat non-stick fry pan, I observed that some of the pancakes had very distinct but imperfect honey-comb shaped patterns on one side. What on earth would cause such a thing? The only time I've seen anything even remotely similar is when vibrations are applied to a rectangular membrane with sand on top.

I suppose the unmixed parts of the pancakes would have 'sunk' to the bottom of the pancake faster, heated up and formed ridges, but how this shape I don't know...

skipjack September 29th, 2018 05:57 AM

Was the pan initially very hot? If so, were the affected pancakes cooked on the hottest parts of the pan?

SDK September 29th, 2018 07:52 AM

This is cool. I know that hexagon patterns often emerge in steady state solutions for some nonlinear PDEs. For example, I know it happens in Rayleigh-Benard convection and the Swift-Hohenberg equations.

However, I don't have a single clue what those patterns mean or why they appear. I'd be interested if anyone has a good explanation or link.

Denis September 29th, 2018 08:09 AM

Quote:

Originally Posted by SDK (Post 600010)
This is cool.

Noooooo it's not; Joppy told us:
"Anyway, after heating them on a dead flat non-stick fry pan..."

Joppy September 29th, 2018 02:11 PM

Quote:

Originally Posted by skipjack (Post 600004)
Was the pan initially very hot? If so, were the affected pancakes cooked on the hottest parts of the pan?

I wouldn't say very hot. Just enough to melt butter. And yes, the affected sides were those which went in first, being placed at the center of the pan (the hottest part I assume).

Quote:

Originally Posted by SDK (Post 600010)
This is cool. I know that hexagon patterns often emerge in steady state solutions for some nonlinear PDEs. For example, I know it happens in Rayleigh-Benard convection and the Swift-Hohenberg equations.

However, I don't have a single clue what those patterns mean or why they appear. I'd be interested if anyone has a good explanation or link.

Are you saying they might be convection cells? I can't find any examples of these in viscous liquids though, which I think would resemble the pancake situation better.

v8archie September 29th, 2018 02:37 PM

Quote:

Originally Posted by Joppy (Post 600036)
Just enough to melt butter. And yes, the affected sides were those which went in first, being placed at the center of the pan

Sounds like the oil bubbling. I get it on better mixed pancakes, but only the first after refreshing the oil.

SDK September 29th, 2018 03:29 PM

Quote:

Originally Posted by Joppy (Post 600036)
I wouldn't say very hot. Just enough to melt butter. And yes, the affected sides were those which went in first, being placed at the center of the pan (the hottest part I assume).


Are you saying they might be convection cells? I can't find any examples of these in viscous liquids though, which I think would resemble the pancake situation better.

No I'm not talking about the convection cells themselves. The hexagon patterns form inside and "tile" a single convective cell in the models I mentioned.

Joppy September 29th, 2018 03:50 PM

Quote:

Originally Posted by v8archie (Post 600037)
Sounds like the oil bubbling. I get it on better mixed pancakes, but only the first after refreshing the oil.

Yes that probably adds to it. Though it can happen without re-buttering/oiling.

Quote:

Originally Posted by SDK (Post 600038)
No I'm not talking about the convection cells themselves. The hexagon patterns form inside and "tile" a single convective cell in the models I mentioned.

This is quite similar to what I see. There is a somewhat related discussion about the shape of cracked desert topsoil here.

I can't find examples of polygonal shapes forming inside the cells. It seems the cells are either unstructured 'blobs' or they form polygonal shapes.

What a complicated breakfast!

Denis September 29th, 2018 06:05 PM

Did you get an indigestion?

Joppy September 29th, 2018 06:17 PM

Quote:

Originally Posted by Denis (Post 600041)
Did you get an indigestion?

An indigestion? I don't get it.

But yes I felt like I was chewing on a rubber tire.


All times are GMT -8. The time now is 11:20 AM.

Copyright © 2019 My Math Forum. All rights reserved.