Friday is here, and the weekly "A Taste of Physics" corner is back — episode 14.
This week: dendritic agate, crystal formation, and the connection to fractals and snowflakes.
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The crystal in the video is called "dendritic agate."
Although the fossil-like pattern inside it resembles a plant or animal, it is actually manganese and iron oxide that have hardened and crystallized.
The crystal's distinctive shape in the video stems from the fact that it is built as a fractal.
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A fractal is a geometric structure in which every part resembles the overall shape. A classic example is a drawing of a tree where each branch is itself a miniature tree, and each sub-branch is an even smaller tree, and so on.
Snowflakes are a natural example of fractals.
The precise shapes of certain snowflakes are fractal — a close look at the arms of a snowflake reveals that each arm is actually a scaled-down version of the original shape.
When manganese and iron oxide harden and crystallize, the crystallization process repeats itself over and over, giving rise to the plant-like fractal form.
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And finally: where does the name "dendritic agate" come from?
Agate is a mineral that typically forms inside rocks; there are many different varieties of agate.
Although dendritic agate is not a true agate, it is a similar phenomenon.
Dendrites are the branching extensions of biological nerve cells.
They serve as receptors through which a nerve cell receives input from its environment.
Because the shape of the crystal resembles the dendrites of nerve cells, it was named after them.
Have a wonderful weekend, everyone 😃 🌷
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