How Small We Are

I’ve been up to quite a bit lately — thus the silence for over a month ’round these parts — and there’s thus quite a lot that I might chat about here: academic news, fiction work, teaching successes, sudden family vacations, and so forth. And perhaps I will bring that up in time.

Just not now. Right this moment, I want to talk a bit about some interesting science news I came across this evening.

The news, no doubt easily missed in the latest buzz of the world (as I write this, the lead items are whether Sarah Palin will run for prez and how LeBron James will do in his return to Cleveland), is that scientists think there may be three times as many stars out there than we previously supposed. There’s a lot of guesswork involved in something as complex as counting all the stars in the universe when we cannot — nor will we ever be able to — see them all, but this new estimate is that there are 300 sextillion bulbs out there:

300,000,000,000,000,000,000,000.

That’s a big number, obviously, and it got me to thinking about our place in the Big Picture. Sure, we like to think that we’re a pretty important bunch of semi-civilized primates — that who is going to design Kate Middleton’s bridal dress is a Big Deal and Really Matters — but then you see a number like that and your mind goes all sideways and you might feel, well, kind of small.

But just how small should you feel? I’ve got answers, my friend.

Since I don’t know your height, let’s look at how small Ryan Clady should feel.

Now, Ryan Clady is obviously a very large man as we human beings go, and that’s a very good thing: He plays left tackle for my beloved Denver Broncos. He’s 6’6″ tall and weighs 325 pounds. He can bench press a whole bunch of me a whole bunch of times.

That said, he’s still pretty darn small when you think about it. Ryan is about 2 meters tall. So let’s start some scaling, using the standard measurement of the Ryan.

The distance from my house here in Charleston, SC to Ryan’s house somewhere in Denver, CO is probably about 1,700 miles. That’s about 1,367,943 Ryans laid end-to-end. Poor little guy.

Of course, the distance from here to Denver is itself pretty small-scale when you think about it. The circumference of the earth, for instance, is 20,038,000 Ryans at the equator, which starts to make Ryan (and clearly the rest of us), look rather insignificant. It may also put an end to my attempt to establish the Ryan as a scale for things in the Big Picture.

Fair enough. Let’s move to something bigger. Something like, I don’t know, our beautiful planet.

The diameter of the Earth is 6,377,831 Ryans. So let’s use that as our scale. The distance from the Earth to the Moon varies over time, but the current average is about 30 Earths set end-to-end. Easy to imagine, right? Easier than 191,334,930 Ryans, right?

The distance from the Earth to the Moon is a pretty good haul, for sure, but it’s nothing like the distance from the Earth to the Sun: an average of 11,728 Earths. Scientists use this distance as a standard of measurement, called the Astronomical Unit (AU). If you’re following along at home, an AU equals 74,796,953,380 Ryans — which might be enough to give the Broncos a good running game these days. Bada-bing!

The Sun itself is as wide as 110 Earths set one beside the other. And in the scale of things in the universe, our star is actually a fairly small fish in the sea: the largest known star is VY Canis Majoris, which is the width of about 2,000 Suns set one beside the other. To give you a good sense of this difference, I’ve found a happy little movie illustrating star scales, showing how dinky that big ol’ yellow star we have really is. In watching this, try to keep in mind that new estimate that there are 300 sextillion stars out there in the universe:

Freaked out yet? Don’t worry … it gets worse. Much, much worse.

Because, you see, it isn’t the Big Things out there that’ll really make you feel small. It’s the Nothing.

Determining the edge of our Solar System is a bit of a conundrum, especially since recent NASA missions have changed some of our perceptions of the heliosphere, but 100 AUs from the sun is a good round number that’s near enough to the range of reality. To put that into perspective, the little “bubble” of our Solar System (it isn’t really a sphere, but bear with me) is the width of 21,324 Suns set side by side. And most of it — think of the scales we’ve already seen — is a whole lot of blank space.

And that’s just our Solar System. The closest known star to our own is Proxima Centauri, which is 4.2 light-years away from us. That’s … hold on, I’ve got to really plug away at the calculator for this one … a distance of 1,328 Solar Systems the size of ours, set end to end. It takes light from that star 4.2 years to reach our Sun.

And that’s the closest thing to us.

When you look up at the night sky, every star that you see is a part of our galaxy, the Milky Way. It holds roughly 300 billion stars, and it takes 100,000 years for light from a star to travel from one end of it to the other. In more familiar terms, this galaxy is the width of 31,619,048 of our Solar Systems, or 674,244,571,400 Suns, set side by side. And most of it, again, is literally space.

Yet as mind-boggling big as the Milky Way is, it is seemingly just an average galaxy among the hundreds of billions in the observable universe. And they themselves are separated by unfathomable distances.

The nearest spiral galaxy like our own is Andromeda, which is one of the few objects outside our galaxy visible with the naked eye at night. Light from one of its hundreds of billions of stars takes 2,540,000 years to reach us. There are a few things scattered out in the space between here and there, but not many: and that great void betwixt us is the width of some 25 mighty Milky Ways.

If all this hasn’t underscored enough how very small we all are, I suggest you watch the following short video that presents the extraordinary findings of the Hubble Deep Field and Ultra Deep Field images:

I have a high-res shot of the Hubble Ultra Deep Field on my computer here, and I open it from time to time just to stare in wondrous awe at the majestic scale and beauty of our universe. It’s humbling, of course, and I do indeed live my life in constant awareness of how itty-bitty I am. It is the Truth, and I am one who thinks it wise to grapple with Truth, not What We Want Things To Be.

Some of this came up in a conversation I had with a student the other day, who happened to notice the spectroscope in my office and asked me about it. He thought it a strange thing in the office of a medievalist; clearly he doesn’t know me very well. One thing led to another and I went through a lot of this — absent a lot of the numbers here, which I can’t calculate off the top of my head. After I’d finished he was quiet for a bit. Then he asked if we should just despair in the face of our insignificance.

I don’t, I told him. Because there are other Truths out there, too. My dog wags her tail every time I get home, my heart still thrills to see my children, and The Simpsons are still damn funny after all these years: