Useless, yet intriguing arithmetical fact… Multiplying this large number by 2, the rightmost digit 2 seems to pop to the front.
Such numbers are called “parasitic numbers“, read more: https://en.wikipedia.org/wiki/Parasitic_number
Inspiring and Creative Resources & Tutorials for Science-Curious People
Useless, yet intriguing arithmetical fact… Multiplying this large number by 2, the rightmost digit 2 seems to pop to the front.
Such numbers are called “parasitic numbers“, read more: https://en.wikipedia.org/wiki/Parasitic_number
This is one of my earliest color optical illusions. There is no yellow or green in the diamond shapes, just vertical black lines! (If you don’t believe it, use a eyedropper tool to check it.)
The simplest right triangle with rational sides (the longest side has a denominator of 45 digits!) and area 157, was found by Don Zagier in 1993.
Here is another geometrical Op Art of my creation: “Deep Blue” (2001). The yellowish scintillating rays you see in this picture are a construct of your brain. This work is available as prints from Saatchi Art gallery.
If a cyclic quadrilateral ( = with vertices lying on a common circle) has diagonals which are perpendicular, then the perpendicular to a side from the point of intersection of the diagonals will bisect the opposite side (AF = FD).
Here is an intriguing Roman crystal 20-sided die (icosahedron), used in fortune-telling, ca. 1st century AD.
Continue reading “Amazing Roman Rock-crystal Icosahedron Die”
Is it possible to 3D print an impossible cube ? Here is a way to do it… After all, it’s all about perspective!
Source: Wolfram Community
Numbers 1 to 32 are placed along the circumference of a circle without repeating any number and still the sum of any two adjacent numbers in this circle is a perfect square!
As you maybe know, I am an expert in optical illusions… So, I would like to show you one of my oldest illusions I created in the 90s. In the picture you may see ghost-like dark radial beams. This illusion is a variant of the Herman’s scintillating grid illusion. I designed this illusion just by turning 45 degrees the Herman grid and then by applying a polar transformation.
Continue reading “A Neat Geometrical Illusion: The Scintillating Starburst”
The sum of the first n cubes is the square of the nth triangular number:
13 + 23 + 33 + 43 + 53 + . . . + n3 = (1 + 2 + 3 + 4 + 5 + . . . + n)2.