Six yolks in a bowl: Why not optimal circle packing?
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Making soufflé tonight, I wondered if the six yolks took on the
optimal circle packing configuration.
They do not. It is only with seven congruent circles that the optimal
packing places one in the center.
Q.
Why don't the yolks in a bowl follow the optimal packing of congruent
circles in a circle?
Six yolks in a bowl.
Image from Wikipedia.
Optimal packings for $5,6,7$ circles.
discrete-geometry classical-mechanics circle-packing
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show 4 more comments
$begingroup$
Making soufflé tonight, I wondered if the six yolks took on the
optimal circle packing configuration.
They do not. It is only with seven congruent circles that the optimal
packing places one in the center.
Q.
Why don't the yolks in a bowl follow the optimal packing of congruent
circles in a circle?
Six yolks in a bowl.
Image from Wikipedia.
Optimal packings for $5,6,7$ circles.
discrete-geometry classical-mechanics circle-packing
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3
$begingroup$
They do. Five circles touching a center circle is an optimal configuration too. Optimal configurations aren't, in general, unique.
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– Wojowu
2 hours ago
3
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Is not it clearly visible on your photograph that they are NOT circles?
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– Alexandre Eremenko
2 hours ago
1
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I think the yolk in the middle is getting smushed, so the ones on the outside have larger radius effectively. There is an optimal packing with 6 circles where the 1 inside is smaller than 5 congruent circles outside.
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– Douglas Sirk
2 hours ago
3
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I would think since gravity is pulling them down, a configuration with the lowest energy would include an egg at the center for most quantities. The optimal circle packing problem doesn't address the 3rd dimension.
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– Greg Schmit
2 hours ago
1
$begingroup$
Consider a flat-bottomed stainless steel potential well of diameter slightly less than $3$ times the diameter of the yolks. Experimental evidence (namely, i.stack.imgur.com/QE8iT.jpg and i.stack.imgur.com/mmT4b.jpg ) suggests that both configurations are stable. At supercritical diameters (not pictured), the eggs seem to prefer configurations that minimize the total surface area and therefore avoid the configuration with $6$-fold symmetry. Thermal annealing proved uninsightful.
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– MTyson
1 hour ago
|
show 4 more comments
$begingroup$
Making soufflé tonight, I wondered if the six yolks took on the
optimal circle packing configuration.
They do not. It is only with seven congruent circles that the optimal
packing places one in the center.
Q.
Why don't the yolks in a bowl follow the optimal packing of congruent
circles in a circle?
Six yolks in a bowl.
Image from Wikipedia.
Optimal packings for $5,6,7$ circles.
discrete-geometry classical-mechanics circle-packing
$endgroup$
Making soufflé tonight, I wondered if the six yolks took on the
optimal circle packing configuration.
They do not. It is only with seven congruent circles that the optimal
packing places one in the center.
Q.
Why don't the yolks in a bowl follow the optimal packing of congruent
circles in a circle?
Six yolks in a bowl.
Image from Wikipedia.
Optimal packings for $5,6,7$ circles.
discrete-geometry classical-mechanics circle-packing
discrete-geometry classical-mechanics circle-packing
edited 2 hours ago
Joseph O'Rourke
asked 3 hours ago
Joseph O'RourkeJoseph O'Rourke
84.7k16225692
84.7k16225692
3
$begingroup$
They do. Five circles touching a center circle is an optimal configuration too. Optimal configurations aren't, in general, unique.
$endgroup$
– Wojowu
2 hours ago
3
$begingroup$
Is not it clearly visible on your photograph that they are NOT circles?
$endgroup$
– Alexandre Eremenko
2 hours ago
1
$begingroup$
I think the yolk in the middle is getting smushed, so the ones on the outside have larger radius effectively. There is an optimal packing with 6 circles where the 1 inside is smaller than 5 congruent circles outside.
$endgroup$
– Douglas Sirk
2 hours ago
3
$begingroup$
I would think since gravity is pulling them down, a configuration with the lowest energy would include an egg at the center for most quantities. The optimal circle packing problem doesn't address the 3rd dimension.
$endgroup$
– Greg Schmit
2 hours ago
1
$begingroup$
Consider a flat-bottomed stainless steel potential well of diameter slightly less than $3$ times the diameter of the yolks. Experimental evidence (namely, i.stack.imgur.com/QE8iT.jpg and i.stack.imgur.com/mmT4b.jpg ) suggests that both configurations are stable. At supercritical diameters (not pictured), the eggs seem to prefer configurations that minimize the total surface area and therefore avoid the configuration with $6$-fold symmetry. Thermal annealing proved uninsightful.
$endgroup$
– MTyson
1 hour ago
|
show 4 more comments
3
$begingroup$
They do. Five circles touching a center circle is an optimal configuration too. Optimal configurations aren't, in general, unique.
$endgroup$
– Wojowu
2 hours ago
3
$begingroup$
Is not it clearly visible on your photograph that they are NOT circles?
$endgroup$
– Alexandre Eremenko
2 hours ago
1
$begingroup$
I think the yolk in the middle is getting smushed, so the ones on the outside have larger radius effectively. There is an optimal packing with 6 circles where the 1 inside is smaller than 5 congruent circles outside.
$endgroup$
– Douglas Sirk
2 hours ago
3
$begingroup$
I would think since gravity is pulling them down, a configuration with the lowest energy would include an egg at the center for most quantities. The optimal circle packing problem doesn't address the 3rd dimension.
$endgroup$
– Greg Schmit
2 hours ago
1
$begingroup$
Consider a flat-bottomed stainless steel potential well of diameter slightly less than $3$ times the diameter of the yolks. Experimental evidence (namely, i.stack.imgur.com/QE8iT.jpg and i.stack.imgur.com/mmT4b.jpg ) suggests that both configurations are stable. At supercritical diameters (not pictured), the eggs seem to prefer configurations that minimize the total surface area and therefore avoid the configuration with $6$-fold symmetry. Thermal annealing proved uninsightful.
$endgroup$
– MTyson
1 hour ago
3
3
$begingroup$
They do. Five circles touching a center circle is an optimal configuration too. Optimal configurations aren't, in general, unique.
$endgroup$
– Wojowu
2 hours ago
$begingroup$
They do. Five circles touching a center circle is an optimal configuration too. Optimal configurations aren't, in general, unique.
$endgroup$
– Wojowu
2 hours ago
3
3
$begingroup$
Is not it clearly visible on your photograph that they are NOT circles?
$endgroup$
– Alexandre Eremenko
2 hours ago
$begingroup$
Is not it clearly visible on your photograph that they are NOT circles?
$endgroup$
– Alexandre Eremenko
2 hours ago
1
1
$begingroup$
I think the yolk in the middle is getting smushed, so the ones on the outside have larger radius effectively. There is an optimal packing with 6 circles where the 1 inside is smaller than 5 congruent circles outside.
$endgroup$
– Douglas Sirk
2 hours ago
$begingroup$
I think the yolk in the middle is getting smushed, so the ones on the outside have larger radius effectively. There is an optimal packing with 6 circles where the 1 inside is smaller than 5 congruent circles outside.
$endgroup$
– Douglas Sirk
2 hours ago
3
3
$begingroup$
I would think since gravity is pulling them down, a configuration with the lowest energy would include an egg at the center for most quantities. The optimal circle packing problem doesn't address the 3rd dimension.
$endgroup$
– Greg Schmit
2 hours ago
$begingroup$
I would think since gravity is pulling them down, a configuration with the lowest energy would include an egg at the center for most quantities. The optimal circle packing problem doesn't address the 3rd dimension.
$endgroup$
– Greg Schmit
2 hours ago
1
1
$begingroup$
Consider a flat-bottomed stainless steel potential well of diameter slightly less than $3$ times the diameter of the yolks. Experimental evidence (namely, i.stack.imgur.com/QE8iT.jpg and i.stack.imgur.com/mmT4b.jpg ) suggests that both configurations are stable. At supercritical diameters (not pictured), the eggs seem to prefer configurations that minimize the total surface area and therefore avoid the configuration with $6$-fold symmetry. Thermal annealing proved uninsightful.
$endgroup$
– MTyson
1 hour ago
$begingroup$
Consider a flat-bottomed stainless steel potential well of diameter slightly less than $3$ times the diameter of the yolks. Experimental evidence (namely, i.stack.imgur.com/QE8iT.jpg and i.stack.imgur.com/mmT4b.jpg ) suggests that both configurations are stable. At supercritical diameters (not pictured), the eggs seem to prefer configurations that minimize the total surface area and therefore avoid the configuration with $6$-fold symmetry. Thermal annealing proved uninsightful.
$endgroup$
– MTyson
1 hour ago
|
show 4 more comments
2 Answers
2
active
oldest
votes
$begingroup$
The system doesn't try to minimise the radius of the enclosing circle, but its potential energy. We can idealise this as non-overlapping disks in a convex rotationally symmetric potential $V$ with $V(0) = 0$. The configuration that was physically realised then has potential energy $5 V(d)$ (with $d$ the diameter of the yolks) while the configuration from Wikipedia would have potential energy $6 V(d)$.
$endgroup$
add a comment |
$begingroup$
Those packing rules only apply for rigid circles. Anyone who's ever cracked an egg knows that yolks are not rigid. As a result of that, you can clearly see that the sides of yolks are flattened as they touch another yolk.
So those packing rules simply don't apply.
$endgroup$
add a comment |
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2 Answers
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$begingroup$
The system doesn't try to minimise the radius of the enclosing circle, but its potential energy. We can idealise this as non-overlapping disks in a convex rotationally symmetric potential $V$ with $V(0) = 0$. The configuration that was physically realised then has potential energy $5 V(d)$ (with $d$ the diameter of the yolks) while the configuration from Wikipedia would have potential energy $6 V(d)$.
$endgroup$
add a comment |
$begingroup$
The system doesn't try to minimise the radius of the enclosing circle, but its potential energy. We can idealise this as non-overlapping disks in a convex rotationally symmetric potential $V$ with $V(0) = 0$. The configuration that was physically realised then has potential energy $5 V(d)$ (with $d$ the diameter of the yolks) while the configuration from Wikipedia would have potential energy $6 V(d)$.
$endgroup$
add a comment |
$begingroup$
The system doesn't try to minimise the radius of the enclosing circle, but its potential energy. We can idealise this as non-overlapping disks in a convex rotationally symmetric potential $V$ with $V(0) = 0$. The configuration that was physically realised then has potential energy $5 V(d)$ (with $d$ the diameter of the yolks) while the configuration from Wikipedia would have potential energy $6 V(d)$.
$endgroup$
The system doesn't try to minimise the radius of the enclosing circle, but its potential energy. We can idealise this as non-overlapping disks in a convex rotationally symmetric potential $V$ with $V(0) = 0$. The configuration that was physically realised then has potential energy $5 V(d)$ (with $d$ the diameter of the yolks) while the configuration from Wikipedia would have potential energy $6 V(d)$.
answered 3 hours ago
Martin HairerMartin Hairer
3,9611628
3,9611628
add a comment |
add a comment |
$begingroup$
Those packing rules only apply for rigid circles. Anyone who's ever cracked an egg knows that yolks are not rigid. As a result of that, you can clearly see that the sides of yolks are flattened as they touch another yolk.
So those packing rules simply don't apply.
$endgroup$
add a comment |
$begingroup$
Those packing rules only apply for rigid circles. Anyone who's ever cracked an egg knows that yolks are not rigid. As a result of that, you can clearly see that the sides of yolks are flattened as they touch another yolk.
So those packing rules simply don't apply.
$endgroup$
add a comment |
$begingroup$
Those packing rules only apply for rigid circles. Anyone who's ever cracked an egg knows that yolks are not rigid. As a result of that, you can clearly see that the sides of yolks are flattened as they touch another yolk.
So those packing rules simply don't apply.
$endgroup$
Those packing rules only apply for rigid circles. Anyone who's ever cracked an egg knows that yolks are not rigid. As a result of that, you can clearly see that the sides of yolks are flattened as they touch another yolk.
So those packing rules simply don't apply.
answered 1 hour ago
GrahamGraham
1091
1091
add a comment |
add a comment |
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3
$begingroup$
They do. Five circles touching a center circle is an optimal configuration too. Optimal configurations aren't, in general, unique.
$endgroup$
– Wojowu
2 hours ago
3
$begingroup$
Is not it clearly visible on your photograph that they are NOT circles?
$endgroup$
– Alexandre Eremenko
2 hours ago
1
$begingroup$
I think the yolk in the middle is getting smushed, so the ones on the outside have larger radius effectively. There is an optimal packing with 6 circles where the 1 inside is smaller than 5 congruent circles outside.
$endgroup$
– Douglas Sirk
2 hours ago
3
$begingroup$
I would think since gravity is pulling them down, a configuration with the lowest energy would include an egg at the center for most quantities. The optimal circle packing problem doesn't address the 3rd dimension.
$endgroup$
– Greg Schmit
2 hours ago
1
$begingroup$
Consider a flat-bottomed stainless steel potential well of diameter slightly less than $3$ times the diameter of the yolks. Experimental evidence (namely, i.stack.imgur.com/QE8iT.jpg and i.stack.imgur.com/mmT4b.jpg ) suggests that both configurations are stable. At supercritical diameters (not pictured), the eggs seem to prefer configurations that minimize the total surface area and therefore avoid the configuration with $6$-fold symmetry. Thermal annealing proved uninsightful.
$endgroup$
– MTyson
1 hour ago