We could measure the year thousands of years ago, long before we could definitely say what caused the year to be this long. Eratosthenes measured the true circumference of the Earth long before we had settled on Earth being round. We can always measure things, even if we don’t know what’s behind that which we measure.
If you look up into the sky on a clear day, you are looking back in time. The moon is as it was a second ago. The image of the sun on our retinas is eight minutes old when we see it in the sky. The nearest star looks like it did over three years ago. Watching the sky is time travel.
We can see billions of years back in time with telescopes powerful enough, and this is where religion runs into problems, because the literalists insist that the Universe is six thousand years old. It simply cannot be, because we can measure the distances in the universe.
We don’t have to know everything about the universe to measure it. Just like we did back on Earth before, we can count that which we see, and we can see how far away the stars and the galaxies are. In a Universe that is only six thousand years old, we wouldn’t be able to see anything but a small part of our own galaxy – much less galaxies beyond it.
Light travels at a set speed. The speed of light is about 300 thousand kilometres per second. Which is why we see the moon as it was a second ago, and the sun as it was eight minutes ago. The Milky way is somewhere around 100 thousand light years across. A light-year is a measure of distance, much like the mile or the kilometre. It is the distance which light travels in a year.
Already there the literalist interpretation of religion falls apart because the Milky Way can not be that large if the universe is only a few thousand years old. We would not be able to see the light from most of it, because it would not have reached us yet. And we certainly wouldn’t see the Milky Way’s sibling, the Andromeda galaxy.
We can measure things, we can see for ourselves, and we can make judgements about the truth of literalist sayings, and because of it, we can see that literalists are lying. Or they are ill-informed. And that is why Europe is now primarily atheist, and that is why the United States is moving that way too.
And it’s not a moment too soon.