Expert Comments on Our Fascination with 123456789

July 09, 2009

Yesterday I posted a blog about how the time and date was 123456789.  While I writing the blog, I also emailed a math expert at Harvard, Oliver Knill, and asked him why humans are so fascinated by numerical sequences such as this. Here is his reply:

This type of numerology is not so much done by professional mathematicians, more by amateurs, but that does not diminish its surprise.

Mathematicians look at it rather as a curiosity. But there an be some interesting combinatorial problems as you mention like how many times do such situations occur in dates. One also bent the rule a bit in this case: the date 12:34:56.7.8.9 certainly occurred in 1909 and will again in 2109. To make the date surprising, we have taken the centuries out when counting the years.

But you are right that such dates with the consecutive numbers 1,2,3,...9 in the same manner appears only every 100 years. So, mathematicians are not so interested in the combinatorics.

The movie "The Number 23" sheds some light on how "surprising" numbers can be.

An other example is the movie "Pi," where one see how crazy this can become.

Humans like patterns and see surprising patterns. A nice story is told by Hardy about the Mathematician Ramanujan. When Hardy mentioned that he came with a taxi with the boring number 1729, Ramanujan pointed out that it is the smallest number which can be written in two different
ways as the sum of two cubes: 1^3+12^3 = 10^3 + 9^3. Such numbers are
today called "taxi cab numbers". See section 8 in this seminar.