Today I'm gonna tell you what a nuclear physicist and the search for aliens can teach
us about finding love! Ok, so scientists don't know exactly how love works or what it does
to our brains, but that's a topic for another show. But what we DO know, is that at some
point, almost everyone on Earth goes out looking for love. But with 7 billion other humans
out there, so why can love be so hard to find?! Sometimes you feel like saying "Where is
everybody?"
That's exactly what Enrico Fermi asked, except that HE was talking about alien life.
Fermi thought that: in a galaxy of billions of stars and planets, if even a tiny fraction
have life, billions of years should be plenty of time for an alien to pop over and say "Hey!
Welcome to the neighborhood" It's called Fermi's Paradox.
An astronomer named Frank Drake took Fermi's question and answered it with an EQUATION,
because THAT'S what astronomers do. If you plug in some data about the galaxy you can
estimate how many civilizations there might be out there. Let's play around with his
"Drake Equation" and see what we get.
"N star" is the number of stars in the Milky Way, a low estimate being 100 billion.
"f sub p" is the fraction of stars with planets, which NASA's Kepler mission now
says is 100%, or a planet for every single star! "n sub e" is the fraction of planets
that could support life as we know it. One recent guess put that at 2.5 billion possibly
habitable planets, so let's plug in 4%. "f sub little L" is the fraction of those
planets that actually develop life, calculated recently at 13%. That leaves "f sub i"
the fraction that develops intelligence, "f sub c" the fraction that develop technology
and "f sub big L" the fraction of a time a civilization exists before they destroy
themselves, Those last three are hard to calculate, but let's use Carl Sagan's numbers to
be safe, because we can trust Carl.
Plug it into your calculator and you get 52,000 possible communicating civilizations. Yes,
that's absolutely a guess, but it's a scientific guess, so it's ok. I think it
means we've got no reason to feel lonely if we just stay optimistic, right? So . . . what
about finding another life form here, on Earth? Is there a way to calculate your odds of meeting
a special someone? Or maybe many special someones?
Let's say you're a 25 year-old woman named Ann who lives in New York City. "N sub p"
is her target population, or 8,244,910 people for New York City. "F sub g" is the fraction
of Ann's target gender, which is about 50% no matter her preference . . . unless it's
both, then she'd plug in 100%. About 44% of Americans are single at any time, so plug
that in for "F sub s" since Ann's not looking to break up any couples. "F sub
e" is the fraction Ann might encounter, which would be small if she only goes out
to meet people at bars or parties. But about 37% of singles use online dating, so that
maximizes her chances. Based on the "Age/2 + 7 rule" and the "creepy old guy rule",
Ann's looking for someone between 20 and 34, which is 24.7% of New Yorkers ("F sub
y"). Ann wants someone who speaks English, 96% for "F sub Ll". "F sub a" is the
fraction of people Ann finds attractive, a very subjective number that an online poll
of my friends says is about 13% for the average person who happens to be friends with me.
Then there's "F sub a2" the number of people that think Ann is attractive, so 13%
again. Ann also wants someone who shares her love of science, so at the very least it has
to be at least one of the 32.4% of New Yorkers with a college degree, "F sub i".
Crunch the love numbers and there's 871 special someones out there for Ann, like maybe
THIS guy with the dark hair and turtleneck
Of course like any equation there's a factor we call "X". Are they funny? Do they share
your political beliefs? Do they prefer Star Trek or Star Wars? Maybe your last relationship
didn't go well and you've got a "crazy ex" factor. When you do the math, the more
rules you make for how you define love, the fewer special people there are out there for
you to find
So, if we keep an open mind when we look for life and love, there's a lot to feel hopeful
about. Sometimes, the galaxy can feel like a big, lonely place, but like that guy with
the turtleneck reminds us: "For small creatures such as we, the vastness is bearable only
through love."
So how many people are out there that YOU could love?