When I am preoccupied with our small lives, political upheaval, and a raging pandemic, it always helps me when I get some perspective on the my life, the world, and ultimately what really matters.
Invariably, I get drawn to astronomy, and visualizing the amazing distances involved. We even have this saying that when some number is huge, it’s “astronomical.”
At one time I speculated and visualized the size of our galaxy with respect to the sun. I wanted to know the distance to the nearest star if the sun was the size of a red blood cell. I documented that in this post Tangerines and the Size of the Solar System and Galaxy, which you might read again.
Recently I stumbled upon this video by a young man in Switzerland. He used a more humanly imaginable scale of the sun being 1 millimeter in diameter, or about size size of a grain of sand. After all, I am sure you can’t really visualize the size of a red blood cell of 7 micrometers. But we all know the size of a grain of sand. Here is his video. It takes a few minutes, but you will enjoy it.
You must admit, that after he walked away from his yard and got in his car, you were amazed, but then, as he kept driving, it brought it home more and more.
30 kilometers, or about 19 miles, is a huge distance from one to the next grain of sand. There is nothing else in between. Imagine a space ship having to travel that distance, and you quickly realize how unlikely travel between the stars actually is. Then think about that when somebody tells you about UFOs coming from “outer space.”
At that scale, our galaxy would be about the size of the orbit of the moon around the earth. Imagine a disk as big as the path of the moon around the earth, all filled with grains of sand (stars) being some 30 kilometers apart from each other on the outside, and a bit more dense in the center. This also helps with visualizing two galaxies colliding. Would stars ever collide, when they are grains of sand 30 kilometers apart in each galaxy? Not very likely at all.