You almost certainly don't exist.
More accurately, you probably don't exist. Or: the chances of you existing as you are are infentesimlly small.“What are you talking about, you weirdo?” I hear you say, but I intend to demonstrate mathematically that You Almost Certainly Don't Exist.
Before i even start, let me give MAD PROPS to Eric who shares at least half the credit for this. I could never have figured this out.
Ever since I heard of the Many Worlds model that solves some problems that face quantum physicists, I've been a fan of science fiction books and shows that explore the concept. There's a little promotion of a book by a physicist named Deutsch (in which you can find an error to which I enjoy drawing attention) that has a very brief explanation. In shows like Quantum Leap, Sliders, and Jet Li's The One, people leap to parallel universes and find copies of themselves and people they know from their own universe. This has always seemed ludicrous to me. Yeah, I know, the idea of jumping from universe to universe is also ludicrous, and even the concept of Many Worlds defies common sense, but suspending all those disbeliefs still left me with the conviction that the idea of parallel universes happening to produce identical (or even less likely - similar) people ludicrous. Another explanation of the theory may make the idea less ludicrous; that the Many Worlds are very close physically, and interact constantly, and the "yous" are duplicated across them all, or at least the ones closest by. Sounds a bit like branes.
Eric, my brother-in-law who shares credit for this article, is really smart and took a bunch of math classes in college. I SHOULD have taken math in school, but I tested out, and took tons of drawing classes instead, because that's pretty much all I did anyway to relieve boredom (and to show off). So when Eric was visiting here last weekend, I entreated him to help me figure the probability of any specific person existing. We've worked on statistical problems before (like, with Pass the Pigs but it looks like somebody already figured out those probabilities and posted a java version of the game) so i figured he'd be up to it, so we sat down with a couple sheets of paper and a calculator and a pen.
At first, I wanted to figure it out for the entire world population back till the time of Christ, but the numbers were going to be really, really large, and we didn't have access to any kind of population data, meaning no encyclopedias or computers were within reach of the kitchen table.
So, let's start:
Our problem:
What is the probability of a particular conception event within the population of the United States since the foundation of the country.
We made our assumptions - not intended to be accurate:
- We'll look at the population of the USA starting at year 2000 – est. 270,000,000. Ignore immigration and emigration.
- The population decreases as we look farther back, down to 1,000,000 people back in 1775. We made some simple guesses, as documented here.
- There's one generation per 25 years, for a simple ten generations between (and including) 1775 and 2000.
- One egg is released per month during a woman's childbearing years, which lasts 35 years, for a total of 420 available eggs.
- Three million sperm are manufactured per day during a man's childbearing years, which lasts 60 years, for a total of 65,700,000,000 available sperm. 6.75x108. Scientific notation will become useful now.
- Everybody has a chance to producing offspring.
First, we had to find the probability of two people within the population coming together, which we calculated by dividing the population in half (no same-gender relationships, even though the USA is the gayest country) and squaring the result. This variable we'll call U for union.
Then, we had to find the probability of a specific egg-sperm combination. We multiplied the number of eggs by the number of sperm (fig2.), for a result of 2.7594x1013. This variable (although it doesn't vary) we'll call C for conception (that's as opposed to c, which is the speed of light.)
Next, we had to figure the value of U for each generation (the probability of two people coming together).
Then, we figured the total value of U for all ten generations, which we did by multiplying all the single-generation probabilities. We got 4.243x10142.
Finally, the probability of any one, specific person being conceived and born within the population of the United States since the countries founding is C times U, or 4.243x10142 x 2.7594x1013. This final number is 7.0024x10155.
This is an astoundingly large number. There are about 1078 many atoms in the universe, which meant that if you took each atom in the universe, turned each of them into a universe, you'd get 10156 TOTAL ATOMS!!! That's pretty "close" to the odds against you existing. You know... as you are.
You have a one in 80 million chance of winning the 20 state Powerball Lottery. That's 8.0x107. You are almost one and a half googol times more likely to win with one ticket than you were of being born, and you've already done that, so GO PLAY!!! (please don't).
If I existed, I’d be impressed by your thorough presentation!!! Thanks for the Props^2^, but I don’t deserve that much credit… I had to take Calculus twice, you know. :) And again…. as always, you linking prowess is something to be admired and aspired to (something to which one aspires?)!
-- Eric (Email) - 09 March '04 - 15:51Woops ee daisy. I would not have had any babies at that rate – how DID this happen? And my grandchildren would be – well, where WOULD they be?
-- mumu (Email) - 10 March '04 - 17:04