Imagine for a moment a very large, flat meadow of grass with a crowd of people standing in it. You are somewhere in the crowd. Through just simple observation, it would not be hard to guess where you are in the crowd. If all the people are on one side of you and no one on the other, you would be on the very edge of the crowd. If there were more people on one side than the other, you would be toward the edge. If there were about the same number of people everywhere you looked, you would be closer to the center. It's not hard, right?
As we look around in the universe, we observe about the same number of stars no matter which direction we look. Just as in my crowd analogy, it would be very reasonable to conclude from this observation that we are somewhere near the center of the universe. Of course, the universe is very, very large and since we cannot see the edge of it in any direction, it makes it hard to be sure that we're in the center. It would be like being in the ocean with no land in sight; you would really have no idea if you're in the middle of the ocean or just outside sight of the shore. To really know we're in the center, we'd have to have more information.
In the mid-19th century, Dutch physicist, Christian Doppler noticed that sound waves changed frequency relative to the observer when the source was in motion. He dubbed this phenomenon, “the Doppler Effect” and believed it would apply to all waves including light and radiometric waves. In the beginning of the 20th century, we were able to observe this phenomenon in the light from distant stars. The light from the stars was “redshifted” indicating that the light wave was being stretched and that the star was moving away from us. As we began to survey more and more stars, we realized that the stars uniformly seemed to be moving away from us at a constant speed.
The implications of what was being observed was huge. Obviously it meant the universe was expanding but more than that, the general movement of the stars directly away from us further seemed to confirm our position near the center of the universe.
To help visualize this, let's go back to my crowd analogy for a moment. If everyone in the crowd – including you – began running away from the center, you would notice a couple of things. Someone running right next to you at the same speed would barely seem redshifted at all. However, someone who was running in the opposite direction would be moving away from you very rapidly so would appear highly redshifted (see my illustration). If we were anywhere else but the center of an expanding universe, this is how the redshifts of different stars should appear to us.
Now imagine you were in the center of the crowd and everyone was running directly away from you. As they got further away from you, they would also move further away from each other, but each runner's redshift in relation to you would be approximately the same. This is exactly what we observe. So the simplest explanation (and most secular scientists claim to prefer the simplest explanation) is that we occupy the unique position of the center of the universe.
In this enormous universe, the odds of us coincidentally being in the center are mind numbingly small. I'm not sure how to describe how impossible it seems. I read one source that estimates there are 1 septillion stars (1024). So that would mean the odds of our star being in the center would be 1 in 1,000,000,000,000,000,000,000,000. It would seem impossible if we believed were here by mere chance.
If God had intended us to be in the center of the universe, then the remote odds of it happening randomly don't matter. However, scientists, because of their bias toward natural explanations will not allow themselves to consider that we're here by design. Still, accepting that we occupy this special place by mere coincidence is too incredible to believe. So what is the solution?
Scientists have put forth a model of the universe where there really is no center – or rather everywhere is the center. Space is like a flat surface that is being stretched. All points on the surface would be moving away from each other. They also suggest there is no edge to the universe. Instead, space is curved like the surface of the earth and if you started in one direction and headed in a straight line, you would eventually end up where you began. In other words, no matter where you are in the universe, we would observe exactly the same things that we observe on earth.
To help visualize this strange explanation, many people have compared the universe to the surface of a balloon painted with stars. As the balloon expands, all the stars would move away from each other at about the same rate. Also, any point on the balloon would have the same amount of surface surrounding it so no particular point is the center. It's actually a very clever analogy that paints a vivid picture of the theory it attempts to explain. And the theory seems to cleverly explain how we can look like we're in the center of the universe yet not really be in the center.
No matter how clever the analogy, there is still one, huge, nagging problem I see with it – namely, the balloon really has three dimensions. To believe that the universe somehow exists on an immensely curved plane resembling just the 2D surface of a balloon seems a stark contrast to everything else we experience. It seems an unnecessarily complicated solution, especially when we know a much simpler explanation exists.
In my crowd analogy, if I saw the same number of people on every side of me, I would conclude that I was close to the center. I could test that theory by walking to the edge and seeing if I was right. However, if I had no way to walk to the edge, I would simply have to trust my conclusion as being reasonable. What I believe is unreasonable is if I suggested there really is no center to the crowd and if I tried to walk to the edge, I would eventually end up where I started. Such an idea seems insane. Yet scientists would have us believe that is the correct way to view our universe.
Does the universe have an edge or not? Does the universe have a center or not? The problem with either theory is that we can't really test it. There's no way we could fly to edge of the universe to see if it's there. We can't stand back from the universe and see if it resembles the surface of a balloon. We can only picture the universe based upon we can observe from the earth. What I'll do instead is appeal to what seems the most reasonable explanation.