Your Place In The Universe

Your Place in the Universe:
Understanding Our Big, Messy Existence
Paul M. Sutter
Prometheus Books

Some things I learned from Your Place in the Universe by Paul M. Sutter (a cosmologist from Ohio State University):

1. The universe is not "infinitely" large, but it's so dang big it just might as well be! And it's approximately 13.8 billion years old, although it's hard to know if time worked the same way back when or will work the same way as it does now in the future.

2. We can see, taste, touch, smell, hear, and experience only about 5% of what all makes up the universe. About 30% of the remainder is called "dark matter" and it's what fills the vacuums/voids we see when we look out into the cosmos.

3. About 70% of what we can't directly experience is called "dark energy" and it's what is speeding up the galaxies as they speed away from each other. Yes, there's no speed limit in the universe because of dark energy. Light has a speed limit and it's possibly our speed limit when it comes to interstellar travel, but the universe itself is just getting faster the older it gets.

4. This means that, although we like to think of gravity as being strong enough to pull things like galaxies back into another "Big Bang," the odds of this happening are extremely low to non-existent. But this is still a theory, and who knows? There still isn't a "Grand Unifying Theory" or "GUT" that ties gravity to the electromagnetic, and the weak and strong nuclear forces. And how do we account and explain for dark energy in a GUT? (We don't--or at least we haven't yet.)

5. And for all we can observe of the "observable universe" we can only conjecture that the "universe is flat." Sutter doesn't go into the "holographic universe" idea, but he does explain why we can only say that the observable universe if "flat"--it's just too dang big to see enough of it to determine whether or not it does have a shape of any kind with our limited three (or four, counting time) dimensions.

6. My idea is that we can only experience a "flat universe" because we can't directly experience or conceptualize a more than four dimensional universe with our very limited four dimensional brains. (I have read about how a GUT will work mathematically with up to 17 dimensions, so there you go!)

7. Most of all, I learned that I wish I had taken more astronomy and physics courses in high school and college because it's such a fascinating subject, isn't it?