## Friday, September 25, 2009

### Fun Fact Friday - That aught a do it!

Imagine if you will, a time in human history where there was no zero. That's right, somehow because of that, you couldn't have ten of anything. You could have five twice, and nine plus one, but nine plus one didn't equal anything. BECAUSE THERE WAS NO ZERO. No aught, no nil, no zilch, zip or nada. Of course, there was a period that there were no negative numbers, too, which is nice because you can't overdraw your checking account. (But since you can't have more than \$9 in the account at any time, does it matter?)
About 5,000 years ago, the Sumerians started inserting a placeholder into large numbers to signify the existence of this important nothing. (Like writing '5000', for example.) This placeholder looked a little more like an italic equals sign than an elipse. According to Robert Kaplan, author of The Nothing That Is: A Natural History of Zero, the symbol changed over time as positional notation (for which zero was crucial), made its way to the Babylonian empire and from there to India, via the Greeks (in whose own culture zero made a late and only occasional appearance; the Romans had no trace of it at all). Arab merchants brought the zero they found in India to the West.

The zero gives us power. We accomplish so much just by its existence. To quote Charles Seife in his book Zero: The Biography of a Dangerous Idea, "Dividing by zero...allows you to prove, mathematically, anything in the universe. You can prove that 1+1=42, and from there you can prove that J. Edgar Hoover is a space alien, that William Shakespeare came from Uzbekistan, or even that the sky is polka-dotted. (See appendix A for a proof that Winston Churchill was a carrot.)"

I don't know about you, but it makes me want to read Appendix A.

Of course, as these things always go, I set out to learn more about one thing, and end up learning about something else entirely.

In this case, I got to learn about the Erdős-Bacon number.

Yes, that Bacon.

A person's Erdős–Bacon number is a concept which reflects the small world phenomenon in academia and entertainment. It is the sum of one's Erdős number—which measures the "collaborative distance" in authoring mathematical papers between that person and Hungarian mathematician Paul Erdős...(yes, that Paul Erdős)—and one's Bacon number—which represents the number of links, through roles in films, by which the individual is separated from American actor Kevin Bacon. The lower the number, the closer a person is to Erdős and Bacon.

For example, Carl Sagan has an Erdős-Bacon number of six. So does Danica McKellar.

Stephen Hawking has an Erdős-Bacon number of seven.

While Natalie Portman's number is six.Oh, and did I mention Danica McKellar's number is a six, too?

I may have.

By extrapolation, this means that two-thirds of all Erdős-Bacon number "six" holders are the hawtness.

Hey, with zero, anything is possible.

the iNDefatigable mjenks said...

Yeah, the Romans had this strange system where they would put a line over or beside their symbols to indicate that the number the symbol represented was multiplied by 50,000 or 100,000 or something like that. Which, to me, made little sense. I guess the idea of metrics didn't work out for them, despite having a number system revolving around base ten (as opposed to Babylon, whose numbers were base 30, I think, so that 2, 3, and 5 were all easily divisible into their base).

It would make a lot more sense, I would think, if a line over something meant that it was multiplied by 10,000, a line on the left meant multiply by 100,000 and so on. But, the Romans didn't ask me because, well, they were dead by the time I rolled around.

Strangely enough, despite the Greeks having it late in their system, zero was not introduced to Europe until the Moors invaded Spain.

Anonymous said...

Mmmmm Danica.........