On the Cosmos


Cosmos is Greek for the world of the Heavens, the starry world.  That is: everything out there.  Everything that we can see or grasp or imagine.  All the big things (that, ironically, appear so infinitely tiny).

Most humans don't think cosmically.  Most humans' view of “the world” is their local "world," frequently not more than a 20-mile radius world.  Many affluent First-World citizens have a different perspective of "everything," perhaps the world itself, the planet Earth, or at least vacation spots in far-away places.  But for the most part, most First-Worlders do not ever think about the Earth proper; it is too vast to imagine except in very limited discussions.  For the most part, our “world” is our neighborhood, and we rarely think outside THAT box.

So, just for once, we are going to imagine everything, the Cosmos.

First, let's think about size.  In order to get a picture of the size of the Cosmos, we should create an accurate scale model of it.

Let's have a tiny, sweet green pea (roughly 1/8th of an inch in diameter) represent the Earth.  This is a 4,000,000,000:1 (four-billion to one) scaling.  We ought to be able to model some big stuff with this scaling factor, right?  At this scale, the Sun would be the size of a basketball (one foot in diameter).  At this same scale, the pea would circle the basketball, as the Earth circles the Sun, at a distance of some 107 feet.  At this scale, Mars would be a smaller pea or a peppercorn and it would circle the basketball at a distance of 164 feet.  At this scale, Jupiter and Saturn would be ping-pong ball size and they would circle the basketball at a distance of some 555 and 1020 feet.  At this scale, Uranus and Neptune would circle the basketball at a distance of 2050 feet and 3100 feet.

But all of this is meaningless unless you can visualize it.  For example, how large in the sky does the Sun appear from each planet?  Imagine if you were to place a basketball (the model Sun) 107 feet away from you (with you sitting on the Earth pea, of course); it would appear to be EXACTLY the same size as the Sun appears to you in reality.  If you put the basketball 1020 feet away from you, one-fifth of a mile, it would appear EXACTLY the same size as the Sun would appear to you if you viewed the Sun from Saturn.  If you put the basketball Sun 3100 feet away, twelve city blocks, it would appear EXACTLY the same size as the Sun would appear to you if you viewed it from Neptune.  Now, if you can really visualize this, you will realize that a basketball is nearly completely invisible to the naked eye from four blocks away (Saturn) and it is totally invisible from 12 blocks away (Neptune).  If it were not for the Sun's bright light, it would be invisible to the outer planets of the Solar System (like any other star) and to the outer stretches beyond that which it yet holds in its invisible gravitational grip.

After the Solar System, we make a mental jump to the nearest star, Proxima Centauri, some 4 Light-Years away from the Sun (or the Earth).  At our scale, the Sun the size of a basketball, this neighbor star, roughly the size of our Sun, the basketball, would be nearly 5000 miles away!  Imagine: if you lived in New York, and were giving a home to the basketball Sun in your apartment, the nearest other light-emitting basketball, our nearest neighbor star, would be in Paris!  And the scale model we are creating, if it were to include our Milky Way Galaxy, this scale model would be longer than the distance from the Earth to the Sun!!  Let's scale down for a moment, let's imagine the sun the size of a grain of sand.  At THIS scale, the nearest neighbor star over would be two miles away, two miles between grains of sand; pretty empty, huh?

Another visualization.  Let's imagine the entire Cosmos, the "Observable" Universe, as a sphere.  Let's imagine its width (its diameter) fitting within a football stadium, some 150 yards wide.   At that scale, our Galaxy, the Milky Way, would be a slice of salami, but a small slice of a really skinny salami.  The salami would be 1/50th of an inch around and the slice would be 1/500th of an inch thick.  Big enough to get stuck between your teeth!  It would be invisible unless you could smell it!  The whole galaxy is a nearly invisible piece of matter inside a football stadium representing the Universe.  Now let’s fill the football stadium with the tiny Milky Way.  Our sun, an average sized star, would be 1/1,000,000th of an inch in diameter, invisible no matter how close you got to it!  Now imagine the Solar System filling up that overworked stadium.  Yup, everything is still invisible, except that the sun shines!  So, in a football stadium Universe, galaxies are way smaller than fireflies.  In a football stadium galaxy, stars are tinier than dust specks.  We can only see stars and galactic collections of stars because they emit light, not because they are big enough to be visible.

In other words, the Universe is filled with countless really tiny clumpings of matter called galaxies, which in turn are filled with even tinier clumpings of matter called stars and planets.  But for the most part, the Universe is dark and empty, and the galaxies are even darker and emptier.  But most everywhere you look, if it were not for light hitting your eyes, it's emptiness all around.  Vast reaches of emptiness.  Even where it is not empty, it’s vast emptiness all around!

We’ve looked at how insignificant big things like galaxies, stars and planets are.  What about small things: atoms, atomic nuclei, protons and electrons?  Well, stars count for more than 99% of a star system’s total mass; atomic nuclei account for at least 99.9% of the atom’s total mass.  If a hydrogen atom’s single proton nucleus were scaled up to the size of the Sun, its single circling electron would be further away from it than Pluto is from the Sun.  In other words, atoms are emptier than empty solar systems!  So empty is an atom that if you filled up its entire volume – defined by the sphere marked out by its single electron shell – with protons squeezed together, one cm3 of protonic Hydrogen would weigh {are you ready for this, are you sitting down?} more than 200 million tons!  Or 3.3 billion tons per cubic inch.  (OK, so you don't believe me.  Do the Math!*)  Is that hard to deal with?  Another way to look at this is: take all the humans who have ever lived, strip them of all their electrons, squeeze all their protons and neutrons together; they will all fit in a cube whose side is somewhere between a centimeter and an inch.  Like a gumball.  Is that ridiculous or what!

And what about knocking Time down to size?

The Big Bang, the event that sets Time in motion, is supposed to have happened roughly 13 billion years ago.  If we scale this to a football field, 13 billion years to 100 yards (300 feet), we discover more of the same smallness we just encountered in the spatial realm.  Dinosaurs went extinct some 65,000,000 years ago, having been King of the Hill for some 200,000,000 years.  Their reign began two yards from the End Zone and their reign ended 1 1/2 feet from the End Zone.  The genus Homo may have begun some 3,000,000 years ago, less than an inch from the End Zone, Homo Sapiens 500,000 years ago, one-sixth of an inch away, Neanderthal Man disappeared 50,000 years ago, 1/100th of an inch from the End-Zone, and Historical / Agricultural Man appeared some 10,000 years ago, 1/500th of an inch, the width of a human hair, from the End Zone.

To scale Time to Time, if we collapse the 13 billion years to one year, Dinosaurs begin their reign on December 24th, they ended their reign two days before the New Year, the genus Homo appeared at 8:40PM on December 31st, Homo Sapiens appeared at 11:40PM, Neanderthal Man disappeared at 2 minutes before midnight, Historical Man appeared at 24 seconds before midnight, and Christopher Columbus "discovered" America 1 second before midnight.  And you, dear reader, were born at 11:59:59 and nine-tenths, less than 1/10th of a second before midnight (if you're 50), out of the whole year since the Big Explosion.

Ought we Humans living today to be impressed with ourselves when we contemplate our place, and our time, in the Cosmos?

Yeah, maybe we'd better, our arrogance is all we have; that and our collective ability to understand that this “pale blue dot” is our home and the Universe is our home’s home.  And that our home is vastly more than OURS.  But we need to see our place - one species among millions, billions of species - living on a tiny speck of a tiny rock teeming with life in an incomprehensibly vast ocean of emptiness, dotted with occasional non-emptiness, and stop being so certain this was all made for US.


We are all in the gutter, but some of us are looking at the stars.
Oscar Wilde (1854 - 1900), Lady Windermere's Fan

*    Here's the Math.






9.11 * 10-31 kg




1.673 * 10-27 kg






1.0 * 10-44 m3

Atom (hydrogen assumed)


1.5 * 10-10 m

1.0 * 10-30 m3 (derived)


# of nuclei in the volume of an atom = 1014

mass of such an atom = 1.673 * 10-27 kg * 1014 = 1.673 * 10-13 kg

 mass of 1 cm3 of this stuff = 1.673 * 10-13 kg / 1.0 * 10-24 cm3

= 1.673 * 1011 kg / cm3 = 3.68 * 1011 lbs / cm3

= 1.84 * 108 tons / cm3

= 200 million tons of mass in 1 cm3