What's the greatest invention of all time?

I read this from Raymond, which prompted this post.

To qualify for greatness, an invention would have to affect the most people and benefit humankind in a big way

When pondering this question, I’ve heard things like:

  • Wheel
  • Transistor
  • Computer
  • Printing Press
  • Vaccines
  • In4ternal combustion engine
  • Cars
  • Planes
  • Sandwich
  • Language
  • Internet
  • Tablet PC

Two things that are rarely mentioned come to mind: phonetics and the decimal representation of numbers.

By phonetics I mean that there is a simple relationship between the written and oral representations of a word or concept. Phonetics allows humans to communicate simply through the span of generations. People can learn from the accumulated knowledge of predecessors.

By decimal representation I mean the 1’s, 10’s, 100’s decimal number system that we use today (including understanding and using zero). Imagine mathematics and science without decimal numbers, or even with Roman numerals. Of course, I’d prefer base 8 rather than base 10, so things like ½, ¼, 1/8, etc. would be simpler. Imagine drill bits: which is bigger: 5/64th or 3/32nd ?

Then again, wouldn’t it be nice to have 10 days in a week, 10 months in a year, 10 hours in a day, 10 seconds in a minute? And the US would be using the metric system.

I don’t know to whom to attribute these two “inventions”, but I think they are of such immense importance to humans that they should not be forgotten