Red Shift and the Ever Expanding Universe Explained

Ok, this isn't directed at anyone who reads this blog, but I've found in my reading online that a LOT of people don't understand what the Big Bang did. I won't presume to be a scientist here. I'm not, but I am a reader and I do read a LOT of science content and, frankly, when I read things like CNN (and other fairly legitimate online sources for information) and everyone seems to make a muddle out of what it is (essentially) the defining characteristic of our existence in the universe, it bugs me.

So, here you go, for anyone who is interested or in posterity who stumbles across it. This is the ever epanding universe explained.

To understand the expansion, you only need to understand one extra "technical" thing, and that's called "Red Shift" and its really just common sense. Imagine that there is a mouse hole on a wall facing you. Every second or so, a mouse runs out of that hole and out the door behind you at the exact same speed, over and over again without any alterations of behavior. With me so far? Now, in theory, if nothing is changing in the scenario (ie, everything is constant,) each of those mice are a fixed distance between one another, yes? Now, imagine (any fear of rodents that you have not withstanding) that you start to slowly move (at a fixed rate) toward the mouse hole while nothing else in the thought experiment changes. What will happen? The mice will still be their fixed distance apart, and they are still emerging from the hole at one per second (or whatever. Right! They'll be passing you more quickly than one per second. The exact math is just a function of how quickly you're moving toward the hole, but the specifics don't matter for the explanation here.

Okay, if we're all clear on the mouse experiment, lets use the same scenario but use a light bulb emitting light waves instead of a mouse hole. Light producing objects (light bulbs, stars, fire) emit light waves at a fixed rate, just like the mice coming out of their hole. So, in this experiment, you walk toward the light bulb (at a normal, fixed rate) and what happens? The light waves will now hit your retina at a faster (fixed) rate than before. But mice and light waves aren't the same. If the distance between mice passing you is decreased, nothing really happens, but if the distance between light waves decreases the color of the light appears to change. If you were moving toward the light at a super high speed, the light being emitted from the bulb would shift toward violet. On the other hand, if you were back pedaling from the light bulb at a fast enough rate, the light from the bulb would appear red.

Are we all still together? We're almost there. . .

Now, imagine that someone pointed their radars toward the sky and found that light coming from the sun was undergoing the same physical effect that we found when we thought about running backwards from our light bulb. You would have to assume that either the radar was moving away from the sun or that the sun was moving away from the radar. Or both.

The truth of the matter is that when scientists point their instruments into space, the find that everything is moving away from us. And that is the legacy of the Big Bang.

The misconception is that the Universe is expanding like a balloon, so that there is a set center of the universe and all points outward from it are getting farther away (like the outside of a balloon from the center) but the truth is that the Universe IS expanding like a balloon, only in a different way. Imagine if you drew five or six black dots on a deflated balloon and then blew it up. The more you inflated the balloon, the further those black dots would stretch from one another, and that is almost EXACTLY like science says our Universe is expanding.