Friday The 13th, Math and Music.

           Friday the 13^th is perhaps the single most superstition inducing date. Weather you are from China or Italy where 13 is considered a lucky number, or from America where pop-culture has developed Friday the 13^th into a paranoia and horror ridden day. Indeed, Friday the 13^th ranks up there with Halloween and Valentines Day (invisible fairies shooting you with magic arrows… no thanks!) as one of the spookiest days you and I will live through.

            In the spirit of horror and tingly sensations running down your spine, it is important to appreciate, or at lease inspect one of the most bone-chilling ballads of our time: John Carpenter’s Halloween Theme. 

            John Carpenter is one of the early experimenters of synthesizers and digital interfaces in music, and this horrifying song features both analogue and digital elements. Surprisingly enough, the reason both elements are so readily accessible to composers like John Carpenter is because of math!

            Let’s go way back in time, before computers and before the widespread use of mathematical techniques to calculate approximations of irrational numbers: the year is 1600. At about this time, music theorists are on the verge of normalizing the octave into a neatly partitioned scale; and in ten years Simon Stevin will draft a report postulating the 12^th root of two to be the frequency ratio between two semitones. It will be another 20 years after Stevin’s postulate until the French mathematician Marin Mersenne will calculate the 12^th root of two (even before logarithms were used for such calculations!), giving the octave a rigorous tuning standard. This development gave professional composers access to an easy system in which they could change keys freely (the Halloween Theme is in the spookiest key of them all: D), as well as allowing music to spread rapidly since tuning an instrument could now be done in a systematic way. All thanks to math!

The octave split into a nice geometric partition.

            Fast-forward to the 1970’s, electronic music is on the rise, but still very decentralized, it will be 1983 when Dave Smith and Chet Wood pioneer a musical instrument digital interface (MIDI) that will allow synthesizers to ‘talk’ to each other (MIDI uses an 8bit format, which increased the resolution of pitch and other sound synthesis parameters {like volume, panning, frequency oscillation} to 128, but I am getting ahead of myself here). Sadly, the year is 1978, and John Carpenter is composing the Halloween theme without the use of MIDI, relying on circuitry (and a fair amount of under-the-surface math) alone to produce chilling electronic sounds.

            Because of innovations in math, music broke free of the stigma that only professionals could create pieces; so next time you hear a song on the radio, thank mathematics for those sweet vibrations.

Friday the 13th

Did you know today is Friday the 13th? 

Spanning across many cultures and religions, the number 13 tends to have unlucky connotations. Furthermore, it may be a gateway to the weekend for some, but Friday also has historical and religious connections with 'evil' or 'unluckiness'. This being said, it is not surprising that the two culminate in what has been deemed the most unlucky day, Friday the 13th. This suspicion has been furthered by horror movies and pop culture. The legend and superstition began, and psychologists have tried to pinpoint why. Many say that because of the predisposed feelings towards Friday the 13th , people become more aware of unlucky or negative events. Whatever your feelings or superstitions, we have gathered 13 facts about the number 13. Hopefully with a few fun facts in your pocket, your Friday the 13th will be as lucky as any other day!


13 facts about the number 13!

1. Thirteen is often referred to as a baker's dozen.

2. (13)²= 169 and (31)²=961

3. 13 is the  6^th  prime number

4. Triskaidekaphobia is the fear of the number 13. People who suffered from triskaidekaphobia include Winston Churchill (who refused to sit in row 13 of an aircraft or theatre), Napoleon, and Christopher Columbus.

5. 13 is the 7^th   Fibonacci number. 

Tridecagon

6. (1/13)=0.076923076923076923076923...

                 (rational periodic infinite decimal)

7. A thirteen-sided polygon is called a tridecagon. The interior angle measure in a regular tridecagon is 152.3077 degrees.

8. 13 can also be called a Long Dozen. 

9. 13 is the smallest emirp, a prime number whose digit reversal forms a different prime number (31 is prime). Other emirp pairs include 17 & 71, 79 & 97, and 1193 & 3911.

10. Many office buildings and hotels do not have a Floor 13. This is also true for some city streets. 

11. Traditional 13th wedding anniversary gifts have a theme of Lace.

12 . 13 holds a special significance for the United States. 

      There were 13 original colonies. There are 13 stripes on the American flag.


      The US $1.00 has:
      13 levels of the pyramid
      13 stars
      13 arrows
      13 stripes
      13 leaves
      13 olives

      The Great Seal of the United States has:
      13 stars
      13 arrows
      13 berries
      13 stripes
      13 leaves

13. If Friday the 13th is something you dread, in China and Italy, 13 is considered a lucky number! The same is true of Colgate University, in New York.