What is PHI?

Answer 1

The Golden Ratio (symbolized by the Greek letter Phi)....like its more well known cousin Pi, it is an irrational number. It is one of those numbers that so maddened the Pythagoreans back in the day, because you cannot arrive at it by dividing any one number by another. It is a number that reccurs in nature. There is debate as to whether the ancient Egyptians used it in their building of the pyramids.

For an easy to read and interesting book on the subject, try The Golden Ratio by Mario Livio (ISBN 0767908163).

Answer 2

The golden mean is the felicitous (synonym: apt) middle between two extremes, one of excess and the other of deficiency.

To the Greek mentality, it was an attribute of beauty. Both ancients and moderns realized that "there is a close association in mathematics between beauty and truth".

Pythagoreans

According to legend, the Greek philosopher Pythagoras discovered the concept of harmony when he began his studies of proportion while listening to the different sounds made when blacksmiths' hammers hit their anvils. The weights of the hammers and of the anvils all gave off different sounds. From here he moved to the study of stringed instruments and the different notes they produced. He started with a single string and produced a monochord in the ratio of 1:1 called the Unison. By varying the strings, he produced other chords: a ratio of 2:1 produced notes an octave apart. (Modern music theory calls a 5:4 ratio a "major third" and an 8:5 ratio a "major sixth".) In further studies of nature, he observed certain patterns and numbers recurring. Pythagoras believed that beauty was associated with ratios of small integers.

With this discovery, the Pythagoreans saw the essence of the cosmos as numbers, so numbers took on special meaning and significance. Astonished by this discovery and awed by it, the Pythagoreans endeavored to keep it secret: they vowed that anyone who revealed the secret would be put to death.

The symbol of the Pythagorean brotherhood was the pentagram, the proportions of which embody the golden ratio.

Answer 3

Phi is the 21st letter of the Greek alphabet.

The lower-case letter φ is used as a symbol for the golden ratio 1.618... in mathematics, art, and architecture and about a dozen other things.

The upper-case letter Φ is used as a symbol for the magnetic flux in physics and about half a dozen other things.

Answer 4

The divine proportion
1.618.... its irrational so u cant find it exactly
but it is the solution to the following equation: -x^2+x+1=0
it shows up in several places in nature and in art.

Answer 5

It's like a PHD (POST HOLE DIGGER) : PHI (POST HOLE INSPECTOR)