There are some terms and concepts we throw around like we really understand them; I know I do. I’m sure you can think of many, but two in particular came to mind recently.
They both have to do with time, one directly and one indirectly. We’ve all probably read about fossils that are found which are millions of years old. We read about the time when dinosaurs went extinct about 65 million years ago. One million years, a few million years, back when the earth was formed five billion years ago. What’s the difference? They all blur in our minds.
We say we know what a million years is like – it’s one year, 365 days, that have occurred one million times. But do we really comprehend just how long one million or 65 million years are? How does one appreciate the amount of time they symbolize? We talk about the time of Jesus Christ and that was only two thousand years ago, a mere one five-hundredth of a million years. If we go back to the start of Homo sapiens (us), then we’re talking about 200,000 years ago or one fifth of a million years ago. That’s how long we’ve been around.
So how does one fully appreciate just how much time one million or 65 million or 5 billion years really are? Our mind starts to blur over once we get back a few decades, let alone a few centuries.
The second one is similar in that it involves time. We often hear about a star that is maybe 5 or 10 light-years away. Only five or ten? It sounds like it is in our own backyard. Does anyone really know just how far that is? To help you, a light-year is the distance an object would travel in one year moving at the speed of light. The speed or light is approximately 186,000 miles per second (that’s a second, not a minute or hour), so a light year is about 6.2 trillion miles. Can we really comprehend that distance?
We get scientists talking about galaxies hundreds and thousands of light years away. Are your eyes starting to glaze over? They even talk about galaxies being hundreds and thousands of light-years across. No taking an afternoon trip to visit the neighbors on the other side of the galaxy there. The real clincher is that our observable universe is over 14 billion light years – now that’s big, that’s far. Luckily, the nearest drug store isn’t that far away.
The point is we are comfortable in talking about the abstract, the numbers, be it years or distances measured in light years, but we really have no comprehension of what those numbers really represent. We just can’t wrap our heads around them, and I suspect neither can the scientists, historians and archeologists. And I suspect there are many things in our lives that we talk about in the abstract but truly have no idea of what they really mean.