Full Transcript
What's a basic thing you learned in school that you're ashamed to admit you still don't really understand? I don't understand how the universe can be expanding and every time somebody tries to explain it or simplify it, I get more confused. Their favorite metaphor is always a balloon. They'll say just imagine that the universe is a balloon being inflated by a giant invisible clown. So, we are living on the surface of the balloon. So, everything is getting farther apart. But this is such a bad metaphor because everybody immediately asks the exact same question. In this metaphor, what does the empty room around the balloon represent? In other words, what is the balloon expanding into? And they say, well, nothing. And then you ask, well, what if I try to launch a rocket ship off of the balloon or what if I just built a telescope to look outward from it? What would I see? And they say you're misunderstanding it. Imagine if you were a two-dimensional being living on the surface of a balloon. Like the concept of up doesn't exist. That's us. Only the surface is actually three dimensions. When we're talking about looking away from the balloon, that's a direction that doesn't exist. So you say, okay, but if there was a two-dimensional being living on the balloon, if they kept going this direction long enough, eventually they would come around on the other side. Is that what would happen if we were to reach the edge of our universe? and they will say no and then they will have to admit that it's actually not like an inflated balloon at all. I realize that the failure is on my part. It's a failure to understand other concepts that I was taught. But I will admit as an extremely old man, I still can't answer the question that I had when I was told this in kindergarten, which is what if I had a rocket ship and flew it out to the very edge of the universe and then just tried to keep going, what would stop me? Or if I built one of those gigantic telescopes and positioned it right there at the edge and looked out, what would I see? And I know that the answer to this question is that the question is nonsense. But no matter how much they dumb it down for me, I never get