One of the things I consistently observe when I talk to a group of school kids is that they have no concept of just how BIG space is.  Our experience with cars and airplanes has given us the notion the Moon is just around the corner, the planets are a hop, skip and a jump away and (thanks to Star Wars and Star Trek) other stars are reachable in days at the most.

There are lots of analogies that help people grasp cosmic distances.  I have a scale model solar system in the Planetarium and there are other concepts like the relative sized model of the planets, the Sun and other stars that’s making the e-mail circuit right now, but trying to wrap your mind around long distances is traditionally very hard.

Then, one fine day several years ago, one of those stray cosmic thoughts plowed into my brain when I was trying to help children understand how the Sun could look the same size as the Moon, but be SO much bigger.  I said, “The distance between the Earth and the Moon is roughly 250,000 miles or one quarter of one million miles.  The distance between the Earth and the Sun is 93 million miles.  Now, you take your quarter to the candy store and you take your $93.00 to the candy store and you see which one buys you the most candy.”

Money.  It’s the one concept that we can grasp in huge numbers because we can equate any amount of money to the things it will buy.  A dollar doesn’t buy much; a million dollars buys a lot.
So, if it’s a quarter to the Moon and $93.00 to the Sun, how far is it to Jupiter?  As I tell the kids, I can’t answer that question because the Earth and Jupiter are constantly moving.  If Jupiter and the Earth are on opposite sides of the Sun as they are right now, the distance is certainly different than if we’re both on the same side of the Sun.  

For solar system distances, it’s easier if we measure from the Sun.  Earth is $93.00 from the Sun and Jupiter is $500,00 from our parent star.  Saturn is $1000.00 from the Sun and Neptune, the farthest planet, is $3000.00 away.  So we’ve gone from 25 cents to the Moon to $3000.00 to Neptune.  From a stick of gum to a big screen TV or a used car.  I don’t know about you, but it certainly helps me grasp that Neptune is a serious distance away!

So . . . let’s take a rocket ride to the closest star.  In space operas, they travel between the stars in days or weeks.  Just how far is it to Alpha Centauri, the closest star, in terms of what we can really understand?  Well, it’s a quarter to the Moon, it’s $93.00 to the Sun, $3,000.00 to Neptune and  . . . .  25 MILLION DOLLARS to Alpha Centauri.  Wow!  We’ve gone from a used car to oil baron in one short trip (long trip?).  Sirius, the brightest star in Earth’s skies is 50 million dollars away, Rigel, the brightest star in Orion the Hunter is 5 BILLION dollars away and if you want to go to the center of our galaxy, you’re getting up there into national debt figures!

The money concept also works with time.  If we say that $1.00 equals not one million miles but one million years; then it’s been $65.00 since the dinosaurs died.  That’s certainly an approachable figure.  Using that analogy, the Earth is about $4,500.00 old.  So, we’ve gone from a nice dinner for two to another used car.  

Scientists find the first evidence for life at around $3,800.00.  The first life, and indeed the only life on Earth for a very long time was a very primitive bacteria/plant that scientists call blue-green algae or cyanobacteria.  Chamorus call it tahkee ootson, which roughly translates as ‘that disgusting slimy stuff that grows on the sidewalk when it rains and turns black and crispy when it dries’. 
Life on Earth was tahkee ootson for several thousand dollars.

Then about $600.00 ago (a basic desktop computer or a sofa), for reasons scientists do NOT understand, life exploded into all its many and varied forms over a very small amount of money.  By $400.00, the first animals had made their way onto land.  By $300.00 the reptiles were beginning their long rise and $200.00 ago (a fancy dinner out for 4 people) scientists find the first fossil cockroaches.  And as we said before, that big rock took out the dinosaurs $65.00 ago.

Humans have a very exaggerated concept of our importance in the overall scheme of things.  We picture ourselves as the acme of evolution and in our humble opinion; we’ve been the lords of the Earth forever.  So how much of the Earth’s money is invested in Homo sapiens?

Well, primitive monkeys appear $50.00 ago and $20.00 in the past, our hominid ancestors split from the chimpanzee line.  Those hominids began to walk upright when Australopithecus, widely acknowledged as our direct ancestor shows up about $4.00 ago.  Homo erectus enters the fossil record at around $1.60 and tames fire at around $1.00.  Neanderthals show up about 20 cents ago.

The first fossil evidence for modern day people, Homo sapiens appears about a nickel ago.  Two cents ago, ice covered most of North America and Europe.  All of recorded human history; the wars, the pyramids, the gladiators, the Renaissance, the Moon missions is contained in the last penny of time.

I tell the students that we’re not destroying the Earth with our pollution; we’re just making it more difficult for us to live here.  When we pollute ourselves out of existence, we’ll take a lot of species with us, but the cockroaches love what we’re doing to the Earth.  They’ve been around for over $200.00 and humans have been around for a nickel.  And to give you that final anchor with the cosmos, scientists estimate the age of the universe at $13,700.00.
It’s a big universe that’s been around for a very long time.  Feeling humble yet?