Our Expanding Universe

I get it! I understand! I had to reach my Third Third, but I finally have the answer. So, what’s the question?

It’s about the Big Bang and how our universe is continuing to expand. I get that. (Stay with me; it’s more than a metaphor.) But when I was in New York City, I blogged about this problem I had:

In the Hayden Planetarium show “Dark Universe,” Neil deGrasse Tyson (one of my heroes), said that when things move away from us, their light waves “redshift” [as if we’re seeing tail lights], that from our position in the universe, everything is moving away from us. He distinctly said that from ANY point in the universe, everything is moving away from it. How can that be? Something has to be in front of something. In fact, one of the panels mentioned the galaxy “in the foreground,” so wouldn’t it be chased by the galaxies in the background? This bothers me.

Then the UAA Planetarium featured a special event in which Michael Turner of the University of Chicago delivered a program in the Adler Planetarium and we got to watch it live here. His topic was “From the Big Bang to the Multiverse and Beyond,” and he said the exact same thing I’d heard in New York.

By now I was truly bothered, but with the audacity of my Third Third, I decided to get to the bottom of this. I wrote them both emails and asked for an explanation. I got two replies, and now I get it! Years of planetariums and reading and I just didn’t have my head wrapped around the universe just right.

This is the answer from Dr. Turner, Director of the Kavli Institute for Cosmological Physics:

“The expansion of the Universe is NOT galaxies moving away from an explosion; but rather, an explosion of space with galaxies being carried along. Think of a rubber sheet (space) decorated with my hand drawn galaxies being stretched; that is the big bang universe. Space expanding in all directions and galaxies being carried along.”

And this from Dr. Or Graur of the Hayden Planetarium:

‘The problem here is with the word “moving.” When we talk about the universe expanding, we mean that distances between objects are getting larger. That creates the illusion that everything is moving away from you, and is why you’ll see this effect no matter where you are in the universe. But it doesn’t mean anything is moving, only that the distances are getting bigger.’

Aha! It’s not that we’re moving; things are just enlarging around us. Something in my world – my universe – just got more explicable. Something was illuminated and made sense on a foundational level. My understandable universe expanded!

This is a Helen Keller moment – the awareness that the word “water” is what water is. I’m sure you know what I mean. Maybe the expanding universe is not your thing or maybe you already understood about space and expansion; but you know that giant light bulb moment. The world shifts and makes sense. Aha!

I feel sort of pumped about emailing those guys. This time, I didn’t just give up and resign myself to my little vexing confusion – how many times have I done that! When you’re in your Third Third, “now or never” is an even less flexible ultimatum.

Now I’m deciding what other things I need to clear up.