An Awesome Illustration of Empty Space

This is a long one, but worth the read. If you've been reading the blog for a while you already know about my fascination with scale, both macro and microscopic. In the second category, I found a website that does a great job at illustrating just how much empty space there is in a single atom. I'll give you the website and then my perspective.

http://www.phrenopolis.com/perspective/atom/

The page doesn't seem to work correctly in every browser. I tried it in Firefox unsuccessfully, but had good results with Safari. I'm sure Internet Explorer with work fine, too. The short explanation of what you'll see is a scale model of the constituent elements of a hydrogen atom, the simplest of all elements, and the space between them. The smallest bit in an atom is the electron which, in this demonstration is rendered as one on-screen pixel. It's at the far right side of the page. The nucleus, which in the case of hydrogen is only a proton and no neutron, is 1,000 times larger than the electron circling it. It's understandably rendered in this illustration as a circle 1,000 pixels across.

Here's the incredible bit. At the scale we're working with in this model, the distance between the electron orbiting the proton in the center of the atom and the proton itself is 50,000,000 pixels. At a screen resolution of 72 pixels per inch (a resolution all computer monitors share), this distance, illustrated on the website is eleven miles long.

Eleven miles. Try and take that in. The electron is a single pixel. The proton just about fills the screen, and the space between them is eleven miles of nothing. When you come to the page you'll see the proton. Then click and hold on the bottom scroll bar to start moving the page off to the right. You'll be moving in the direction of the electron, on the far right side of the page, but it will take you a long time to get there. You'll see the scroll bar moving, but just barely. If you had the patience and held the scroll bar you'd pan the full eleven miles to the electron on the right. It takes a lot of patience.

That's eleven miles of empty space. And remember, this page is illustrating the distance between the center of the atom and its outer edge, the electron. In other words, the radius. The full diameter of the atom in this demonstration is 22 miles. 22 miles of almost pure empty space.

What does that translate to in volume, looking at the atom as a full sphere? Framed at a scale we can envision, the one we've been using, in a hydrogen atom, a basic building block of matter, there is 4,188,790,206 pixels of actual mass (the proton and the electron) and...wait for it...523,598,775,598,333,300,000,000 pixels of nothing. 523 septilion pixels of empty space. Void. Complete and total nothingness.

Percentage wise, that puts actual stuff in the atom, the proton and electron at .0000000000000008 the total volume. Only eight ten quadrillionths of the total mass of the atom. Imagine you had a neighborhood with 10 quadrillion (10,000,000,000,000,000) houses in it (that's a separate house for every single person on the face of the earth more than 1,000,000 times over). In this example most of these houses stand vacant.In fact only eight actually have people living in them. The rest is nothing but empty space. There's virtually no actual stuff in an atom. Really. The math doesn't lie.

What does that mean on a macro scale? What does that mean for everything we touch? What does that mean for us? We're comprised of atoms, 99 percent of which are hydrogen, oxygen and carbon, all relatively simple atoms. The average human contains roughly 7*10²⁷ atoms. That's a lot of atoms, but those atoms contain almost nothing in them. In fact, the number of atoms contained in our bodies doesn't really matter. Since we're made of atoms, and atoms are almost entirely empty space, regardless of the number of atoms we contain, we are still forced to accept the conclusion that we too are almost entirely empty space. In the same percentages as the atoms themselves.

For something that seems so solid, so real, it's hard to accept that we sort of barely exist. But it's true. Our bodies are only roughly .0000000000000008 percent stuff. The rest is empty space. Our solidity is owed completely to the strong nuclear force that holds the nucleus of our atoms together and the electric charge that binds the electrons inside. We're not solid because we're made of stuff. We're solid because of the energy that binds together what infinitely little stuff we actually are. So, in a very real sense we are simply empty space and energy with an infinitesimal spit of "stuff" thrown in.

See that? No matter which direction you go, to the tiniest of things, or to the universe at large you find mostly empty space and energy. I find that awe-inspiring.

More on the Speed of Light

This is a favorite subject of mine, so I thought I'd delve a little deeper than I did yesterday. This may be old hat to some of you, but others might find it interesting.

The question I presented yesterday was essentially, "How can extreme distance cause the past to appear as the present?" To get a better fix on the solution, imagine we're all at a baseball game, box seats. A batter comes up to the plate, we'll call him Swingy McBallsmacker. He lines up, receives the pitch and cracks a home run out into the stands.

At that moment, if we're paying attention we'll notice that the sound of the crack of the bat comes a second after we see Swingy hit the ball. We've probably all experienced that, and we likely all know the explanation. Sound travels much slower than light, so while the light bouncing off of Swingy as he hits his home run reaches our eyes nearly instantaneously, the sound takes a perceivably longer amount of time to get to our ears. And the further away our box seats are from the action the longer the delay we'll perceive between the sight of the bat striking the ball and the resulting crack. In a sense, we're hearing the past, sensing with our ears an event that has already occurred.

Sound travels at 768 mph, or roughly one mile every five seconds. So if our box moved out to ten miles from Swingy and his triumphant home run, assuming our ears were sensitive enough we'd hear the crack 50 seconds after we saw Swingy swing. We'd be listening almost a minute into the past. But, assuming the glass windows of our box allowed us to telescopically see the batter from any distance away, even ten miles away we'd see Swingy's home run in realtime. Light travels at 186,000 miles a second. At that speed, even at 1,000 miles away the light coming from the action at the plate would reach our eyes nearly instantly.

But the point here is that light, like sound, travels at a finite speed. Like sound, if we got sufficiently far away so that we outstripped the distance light can travel in a given time period, we would sense the light from events, and thus see those events delayed from their actual happening. Imagine our box tore free from its moorings, lifted off into space and traveled a million miles from earth. Because of our telescopic box windows we can still see the stadium and Swingy's home run. However, we'll see it happen almost six seconds after the event occurs. Traveling at 186,000 miles a second the light takes about that long to reach us a million miles away. And the further away we are when Swingy knocks it out of the park the longer our perception of the event will be delayed.

Now imagine that our box is somewhere out in deep space, let's say one light year from earth. A light year is the distance light can travel in a year, or 6.87 trillion miles. Let's say we don't know anything about what's going on back on earth. We point our telescopic windows in the direction of the stadium just in time to see Swingy win it for the team. To our eyes the event just happened. But in actuality the light that allows us to see the event has been traveling toward us for a year. By the time we see Swingy smack the ball out into the bleachers he has long since gone home, finished the season, and started the next. In a very real sense we've just peered one year into the past.

Finally, scrap the box. We're now alien astronomers living on a planet 1o0,000 light years from earth. In the course of our normal investigations we train our telescope on a point of space that happens to be the surface of earth, inside a sports arena, where a strange looking creature with "Swingy" emblazoned on his shirt swings an elongated cylindrical object at a sphere another creature has hurtled at him. We make notes about this latest observation. We've been following the exploits of this distant alien culture for some time. However, our insights are tempered by the fact that what we're seeing took place 100,000 years ago. It has taken that long for the light leaving the surface of the earth to reach us. We have no idea what's actually going on for earth cultures in the present. That light is just leaving the planet. In fact, given the time span its likely that humanity no longer exists. 100,000 years is a long time, and while the human cities we're studying now seem strong and vibrant, a lot has happened in the intervening time. Cultures and peoples don't last forever, and it's very possible that the culture we're studying has died off or changed radically.

The point is, we're studying the past. We are seeing, in the present what happened to humanity, if it still exists, 100,000 years in its past. Swingy McBallsmacker is long dead, as is the game of baseball. If humanity still exists 100,000 years after Swingy's exploits it's likely unrecognizable. But we, alien astronomers living 100,000 light years from earth will never know. Or rather we'll have to wait 100,000 years to find out.

That's how extreme distance allows, and in fact forces us to see the past in the present. And it's further evidence of just how cool reality is.

Fun with Space Time

Let's say that you, at age 20 go out on a cloudless night with an immensely powerful telescope, aim it at another, far distant planet 50 light years away. Light, leaving that planet will take 50 years to reach you. At the exact same time, on that far distant planet a member of another sentient species sits out on a cloudless night pointing a telescope back at you. Both of you, looking directly at the spots where each of you are sitting will see nothing. Empty space. Because the light each of you are seeing left that point on the other planet 50 years before each of you got there.

So you see nothing, but, on a lark each of you waves at the nothing you both perceive.

Fast forward 50 years. You're both 70 now, and for fun you both return to the same spot you took your telescopes to fifty years prior. Nostalgically you look back to the same point in space where you once waved to an imaginary alien, an empty spot of soil. Amazingly you now both behold a creature sitting at the spot that 50 years ago was empty. They seem to be young creatures, both peering back at you through a telescope. Excited that your sight-seeing didn't return empty-handed this time you both wave excitedly. And, in seeming recognition of your gesture, the creature on either other end of the telescope waves back.

Of course that wave happened 50 years ago, and was in response to seeing nothing. But, in a sense, there is real contact in the present. At least in the minds of each of our observers. And that's likely the closest we'll come to traveling in time. But it's enough. The farther away we peer into the cosmos, the farther back in time we're seeing. It's very possible that one day we may find another sentient civilization in some far flung part of the universe. But we may be seeing things that happened hundreds or thousands (or hundreds of thousands) of years earlier. By the time we find them, they may already be gone. But we can still watch their past. Observe them as our two stargazers observed each other fifty years in each other's pasts. We can observe but we can't participate.

Time travel is a spectator sport only.