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--- blog:articles:raspberry:mechanical_clock:discuss [2024/07/23 15:08] – Phil Ide
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-====== Mechanical Clock ======
-I was looking around at some of the projects people have done with their Raspberry Pi computers, and I must admit I'm pretty impressed with a lot of them. Then I came across one I've seen before: a binary clock. A binary clock usually has a set of LEDs that indicate a number in binary, so for example, 25 seconds would be displayed as 11001.
-This is all well and good, and a bit (a lot) nerdy, but there are very few people in this world that can read hours, minutes and seconds off such a clock without working out what each of those digits represents. Another base would be better than base 2.
-===== Choosing a Base =====
-People assume - because we were wrongly taught at school - that humans use base 10 (decimal) because we have ten fingers. This is so wrong it is outrageous. Think of all the weird things in our numerical lexicon:
-  * Dozen (base 12)
-  * Guinea (base 21)
-  * Hand (base 5)
-  * Shilling (base 20)
-Those are actual bases we used before the decimal system was eventually imposed by law in France after the revolution (which of course also included weights and measures). Yes, we've always used decimals too, but historically we've used a number of bases for counting, depending upon what was convenient for the things we were counting. Base 2 was never one of them.
-The upshot of this is we are actually fairly proficient at counting in more than just decimal systems - even if you grew up in a modern decimal culture. Base 5 systems are known as Quinary, and counting in fives is very natural for us. Think of this: with a decimal system you can only count to ten using your fingers (without re-using any). With a quinary system you can count five on one hand and multiples of five on the other, allowing you to count up to thirty.
-In fact, senary systems (base 6) are even more efficient, counting multiples of six on one hand and the remainder on the other allows you to count up to thirty-five. Most people struggle with decoding senary values into decimal, but can handle quinary values with ease.