Thursday, August 13, 2009

The Kingdom of Heaven is Like Gravity


Though Jesus refused to come right out and say what the kingdom of heaven is, he did speak constantly about what it is like and to what it can be compared. He spoke in mysteries. You may be wondering why. Here’s one pretty cool reason.

Defining something for you doesn’t mean you experience it. Jesus was more interested in your experiencing it than in your pocketing a portable definition. To me, trying to define the kingdom of heaven is like trying to define gravity. It almost defies definition. Let me show you.

Gravity doesn’t work in a direct line between two objects like most people think. Take the earth and the moon, for example. Gravity doesn’t exist as a straight-line attraction between the earth and moon like when you whirl a ball on a string over your head. It works more like a golf ball rolling around a bowling ball on a trampoline.

Picture it. The weight of the bowling ball resting on a trampoline bends its surface. Now what happens when you take a golf ball and try to roll it past the bowling ball? The curve of the trampoline’s surface created by the weight of the bowling ball will interrupt the straight path of the golf ball. If you roll it with too much force, it will fly past the bowling ball and off the trampoline. But if you roll it just right, it might “orbit” the bowling ball a time or two before falling into it.

Now imagine the earth is like the bowling ball. And the earth is so massive that it actually bends space like the bowling ball bends the trampoline’s surface. And imaging the moon is the golf ball. What if there were no friction between the golf ball and the trampoline surface? Could you roll it with exactly the force needed to make it “orbit” the bowling ball indefinitely? That’s a picture of gravity. The bent trampoline’s surface can be compared to gravity.

Of course there is not just one plane of space. Imagine an infinite number of trampoline surfaces going in every direction around our earth, all of them bent by its immense mass. The reason that the moon doesn’t fall into or fly away from the earth is because it’s going just the right speed to have a stable orbit. (Almost stable! The moon moves an inch-and-a-half away from the earth every year.) The moon neither slingshots into space nor “falls” into the earth, just like a perfectly rolled golf ball on a frictionless trampoline surface. Round and round she goes.

Likewise, the earth neither slingshots into space nor “falls” into the sun. The sun’s enormous fields of gravity (curved spacetime) are holding the earth in a nearly stable orbit around our sun.

Likewise, our sun neither slingshots into space nor “falls” into the black hole at the center of our Milky Way Galaxy. The black hole’s enormous fields of gravity (curved spacetime) are holding the sun in a nearly stable orbit around our local black hole.

An orbit then is nothing more than a controlled fall. The moon is falling around the earth. The earth is falling around the sun. The sun is falling around a black hole. All of these can be “seen” more accurately when we imagine a golf ball falling around a bowling ball resting on a trampoline. Can you see it? The trampoline is gravity!

Imagine you’re skydiving. We call that falling. As I just suggested, gravity does not operate as a straight line force. It is fields of bent spacetime. So when you skydive, you aren’t really falling in a straight line because of an invisible magnetic-like force pulling you straight “down” to earth. You’re actually sliding down curved spacetime. You’re the golf ball wanting to “roll” directly into the bowling ball.

Can anyone actually see gravity? No. Can you observe its effects? Constantly! It is there whether you can see it or define it exactly. You experience its power whether you see or understand its substance. You interact with it and you trust it in everything you do.

If I didn’t trust gravity, I would never walk without holding onto something that would anchor me to earth. I certainly wouldn’t risk jumping! But since I trust gravity, I not only can let go of whatever I’m clinging to and walk, but I can run and jump without worry of sailing off toward Alpha Centauri.

Notice that I just did what Jesus did. I didn’t tell you what the kingdom of heaven is exactly. I spoke instead about gravity. I made gravity a parabolic analogy. The kingdom of heaven is like gravity in that it is something invisible, it is nearly indefinable, yet it is powerful, it is all around you, it has a hold on you, and it facilitates everything you do.

Rather than seeing gravity directly, you experience its effects. You feel it every day of your life. It is only when someone brings it to your attention, when someone tells you how to really “see” what’s happening and how to ask the fundamental question do you become conscious of the mysterious presence and properties of bent spacetime---gravity.

Newton is credited with asking a cataclysmic question about something that the world takes for granted. Newton simply asked, “Why do things fall?” Newton never figured it out. It was 200 years later that physicist Albert Einstein figured it out. He introduced us to his “general theory of relativity.” It explains why things fall. This theory today is more than a theory. It’s been proven again and again in countless experiments. Lot’s of time and brain cells have been devoted to Newton’s question. And today the question has been answered to the satisfaction of most, though the mystery of what it is at a smaller-than-microscopic level (gravitons?) remains.


When I hit a grounder to the shortstop and try to run out the throw to first base, however, I’m not asking any questions. I’m just playing baseball! Yet I would not have been able to hit the ball and run out the throw if gravity were not acting on me, on the pitcher, on the ball, and on the shortstop I hit it to. Gravity, a mysterious invisible force throughout the universe, made every bit of the fun possible, though I may not have been thinking about Newton and Einstein as I hustled for first base.