The River Village Ecologist

atomstargazer:

Happy Pi Day!
What is Pi?

Pi (π) is the ratio of a circle’s circumference to its diameter. Pi is a constant number, meaning that for all circles of any size, Pi will be the same.

The diameter of a circle is the distance from edge to edge, measuring straight through the center. The circumference of a circle is the distance around.

History of Pi

By measuring circular objects, it has always turned out that a circle is a little more than 3 times its width around. In the Old Testament of the Bible (1 Kings 7:23), a circular pool is referred to as being 30 cubits around, and 10 cubits across. The mathematician Archimedes used polygons with many sides to approximate circles and determined that Pi was approximately 22/7. The symbol (Greek letter “π”) was first used in 1706 by William Jones. A ‘p’ was chosen for ‘perimeter’ of circles, and the use of π became popular after it was adopted by the Swiss mathematician Leonhard Euler in 1737. In recent years, Pi has been calculated to over one trillion digits passed its decimal. Only 39 digits past the decimal are needed to accurately calculate the spherical volume of our entire universe, but because of Pi’s infinite & patternless nature, it’s a fun challenge to memorize, and to computationally calculate more and more digits.

Geometry

The number pi is extremely useful when solving geometry problems involving circles. Here are some examples

The area of a circle.

A = πr²

Where ‘r’ is the radius (distance from the center to the edge of the circle). Also, this formula is the origin of the joke “Pies aren’t square, they’re round!”

(via ikenbot)

sciencesoup:

Northern Lights over an Erupting Volcano

In April 2010, the Icelandic volcano Eyjafjallajökull spewed great ash clouds into the sky and caused enormous disruptions to air travel in Europe. The eruptions are best remembered for this inconvenience, but photographer James Appleton managed to capture the event in a different way. In the weeks before the disturbances, a vulcanologist friend of his alerted him to the unfolding volcanic drama, and Appleton travelled straight to the Icelandic mountain before it was closed off. Risking his life to battle extreme cold, high winds, and seismic activity, Appleton captured a rare but gorgeous scene: the glowing lava from an Eyjafjallajökull fissure with the Northern Lights—Aurora Borealis—overhead. These are two very different light sources, so “the photograph needed parts of the scene selectively blocked for sections of the exposure to balance the contrast,” Appleton recalls. “A Mars bar wrapper came in handy for this!”

(via abcstarstuff)

Wow, the wide-mouth frog really exists. And is now threatened by habitat loss :o(

iseegodinbirds:

earth-song:

The escuerzo, Budgett’s Frog or wide-mouth frog (Lepidobatrachus laevis) is a species of frog in the Leptodactylidae family. It is found in Argentina, Bolivia, and Paraguay. Its natural habitats are dry savanna, subtropical or tropical dry shrubland, intermittent freshwater marshes, pastureland, and ponds. It is threatened by habitat loss. by wiki

How is this tiny friend so adorable?!

(via ohmysagan)

treadmill-to-oblivion:

Earthquake Rose.

“When a magnitude 6.8 earthquake shook Olympia, Wash., in 2001, shop owner Jason Ward discovered that a sand-tracing pendulum had recorded the vibrations in the image above. 

Seismologists say that the “flower” at the center reflects the higher-frequency waves that arrived first; the outer, larger-amplitude oscillations record the lower-frequency waves that arrived later.”

(via astrotastic)