✋ TREE 774: Three joints, four digits

I’m going to show you something wonderful about your hand. We have to travel through some numbers to get there. Stick with me.

I work with 1920 and 1080 a lot. They are the dimensions of HD videos (double those numbers for 4K) and presentation slides. A square Instagram post is 1080 × 1080.

They seem a bit random. We’re used to the decimal system (things divided by 10) and like nice round numbers, so why didn’t the people who invented HD use nice numbers like 2000 and 1000? I don’t know, but I’m glad they didn’t. 1920 and 1080 are excellent numbers.

1920 can be evenly divided by 2, 3, 4, 5, 6, 8, 10, 12, 15, 20…

1080 can be evenly divided by 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20…

Tidy subdivisions make a graphic designer’s life pleasant.

At the heart of the goodness of 1920 and 1080 is 60. 60 is the smallest number that can be evenly divided by 2, 3, 4, 5 and 6. The Babylonians liked 60 so much they based their counting system it. That’s why we have 60 minutes in and hour and 60 seconds in a minute. It’s why the measure of a circle is 360° (60 × 6) and each of those degrees is made of 60 minutes.

The Babylonians didn’t pull 60 out of thin air. Their counting system was developed from an older Sumerian system based on the number 12. (12 × 5 = 60.) 12 is another great number. You and divide it by 2, 3, 4 and 6. Systems based on 12 are why we have 24 hours in a day and 12 signs of the zodiac. In a handy coincidence, the Moon gives us 12 months in a year.

But why 12? Surely ancient humans would base their counting systems on the human body. We use 10 as a base because we have 10 fingers. Did the Sumerians all have six fingers? No. look at your hand with your palm toward you. Count the joints of your four fingers using your thumb as a pointer.

!!!

Photo: Luis Quintero

12, 60, 1920, 1080 – these numbers are your friends.

Here’s Led Zeppelin with a song in 12/8.

Grow slowly
Jeff