To put it into a visual perspective. You are away from the city and you look up into the sky.
It is a clear night and the sky is full of stars like this:
Amazing and beautiful. The sky is covered, you can hardly put your finger to the sky without it blocking the view of at least a dozen stars. But what about the blackness in between? What if you could focus a powerful telescope and magnify the darkness, what would you see?
It just so happens that the Hubble telescope performed just such an action trying to illuminate a quintuple quasar. I was more blown away by what was around it than the item itself.
Those are not stars, they are galaxies and it makes you wonder about what's in the black spots in this picture.
Based on what we can see, scientists estimate that there are 10 to the power of 21 stars in our universe. That is 1,000,000,000,000,000,000,000 stars.
That figure is based on calculations of visible stellar bodies. We don't know what lies outside of our view. Now that is only 3 dimensional math, factor in the 4D math and the number grows.
Estimates peg our universe at 12-14 billion years old (12,000,000,000 - 14,000,000,000).
So Terry's argument is that in 12-14 billion years, in 10 to the 21st power number of stars, we here on earth were the only life to form.
Based on what? Math? Odds? Facts?
Nope, just a hunch. Haven't seen any aliens recently so they can't exist.
Think of this argument the next time a theist argues that there must be a God because evolution is so unlikely. You believe the exact same thing as them, you have just replaced God with Earth.