Biologist Mark Norman found octopuses (octopi?) off the coast of Indonesia that use split open coconut shells as hiding places. This is the first known tool use by an invertebrate animal:
An octopus would dig up the two halves of a coconut shell, then use them as protective shielding when stopping in exposed areas or when resting in sediment.
This, on its own, astonished the team. Then they noticed that the octopuses, after using the coconut shells, would arrange them neatly below the centers of their bodies and "walk" around with the shells—awkwardly.
It's uncertain whether these were African or European coconuts. Video at the link.
Link | Photo: Roger Steene
Comments (28)
In the Mandelbulb paragraph, there's a "#D" where I think you meant "3D", but that's a minor quibble. Great article!
Sorry, that's not correct, unless the isosceles triangle also just happens to be a RIGHT triangle (the hypotenuse is the side opposite of the right angle). An isosceles triangle is simply a triangle with two sides of the same length (an equilateral triangle is also an isosceles triangle, incidentally).
Btw, "isosceles" just means that at least two sides of the triangle are the same length--the third could be longer, or shorter, or even the same size.
So, you could have a very wide angle between the two same-length sides (as in your spidron) or
the angle could be very narrow (think of the top part of a capital A)
or they could all be the same length--every equilateral is also isosceles.
(But *not* every isosceles triangle is equilateral--just as every square is a rectangle ie, has 4 right angles, but not every rectangle is a square.)
best regards, Daniel Erdély
Daniel Erdely is in fact the originator of spidrons and some other related forms Here's his main site: http://spidron.szinhaz.org/