The hidden evil in UPC barcodes

Bar codes are very easy to decode if you understand binary - just take the black bars as ones and the white bars as zeroes, and you can see what the number should be. Not that the number isn't already printed below the bar code, but bear with me here.

Now, if you'll notice, there are three sections on the bar code that are unnumbered. The part at the beginning of the main code, the part at the end, and the part in the middle. Decode it, see what numbers you come up with.

Did you see it? Not all bar codes are like this, but some are... if you'll notice, most bar codes have a double bar in those spaces. That is a 6. And most UPCs have three of those double bars, unmarked, in all three spots...

That's right, kiddies, most bar codes have 6 for the front number, 6 for the middle number, and 6 for the ending number! Folks, this is no coincidence! It's 666! The UPC is the Mark of the Beast. That's right. The evil has been loosed on the world, in the form of little innocuous bars. Let this be a lesson to you, folks. If you look hard enough, you can see Satan and his works everywhere.

In most barcodes used today each digit is encoded as 7 bits. The coding used isn't the regular binary representation of the digit being encoded. The left and right halves of the code use entirely different coding schemes, too, which allows the scanning machine to determine whether the product being scanned is upside down or not. The codes used are as follows (go and find a tin of beans or something if you don't believe me):

DIGIT   LEFT SIDE   RIGHT SIDE
  0      0001101     1110010
  1      0011001     1100110
  2      0010011     1101100
  3      0111101     1000010
  4      0100011     1011100
  5      0110001     1001110
  6      0101111     1010000
  7      0111011     1000100
  8      0110111     1001000
  9      0001011     1110100

The code on the left and right is "101" (or 5, if you like) and the code in the centre is "01010" (or 10).

It is hard to see how people read it as 666. To say "most bar codes have a double bar in those spaces. That is a 6" is misleading. The binary representation of 6 is "110" which would be a single fat bar followed by a space. What we actually see in the centre of a barcode is two twin bars with spaces before, after and between them, or "01010".