LONELY.

Hey, Vsauce Michael here, and I am back in New York City. And today, we're going to talk about loneliness.

But first, I just learned this yesterday. Bear Grylls, the host of Man vs. Wild, has three sons, and I'm not kidding, their names are Jesse, Huckleberry, and Marmaduke. Well, here's another name for you: Michael Collins. Not the Irish Revolutionary leader, but Michael Collins, the NASA astronaut.

This guy was part of the Apollo 11 crew, meaning that he was part of the team that went to, landed on the moon, and became the first people to walk on the moon, except you might know Michael Collins' name as well, because he did not get to walk on the moon. Neil Armstrong and Buzz Aldrin walked around, but Michael Collins had to stay orbiting the moon in the command module to link up with them later.

Well, this is where things get lonely. People realize that Michael Collins, there in the command module, orbiting the moon alone, was in a quite unique position. When he circled around to the far side of the moon, the side that faced away from Earth, he lost all radio contact with Earth and with Armstrong and Aldrin. For about the 48 minutes that Michael Collins was orbiting around the other end of the moon, he was quite literally the most lonely a human being has ever been.

He was the furthest from any other humans than any human has ever been since the very beginning of mankind. If you haven't yet seen Veritasium's video about how far away the moon is from Earth, you should definitely check it out. But the whole point is that we tend to think that the moon is much closer than it really is, because most illustrations we see put the two objects quite close because it's easier.

But to scale, this is how far away the moon is. We actually measure the distance to the moon quite frequently using reflectors that were left on the moon. That's right, they're just sitting there all alone on the surface of the moon waiting for us to shoot lasers at them. By looking at how long it took the light to return to us, we can calculate quite accurately how far away the moon is.

And we've been doing this for a while, and one of the most bizarre things we've learned is that the moon is actually spiraling away from Earth quite slowly. Every year, the moon is about 38 millimeters further away than it was the year before. Thirty-eight millimeters is about one and a half inches. Those reflectors are not the only thing we left on the moon.

We actually left a lot of man-made stuff, a lot of junk there. There is an entire Wikipedia article just listing the big stuff we left behind. But there are man-made objects that are even further away from the Earth than the moon. In fact, there are four things that humans have built that have traveled so far away from Earth, they are no longer within our solar system.

Voyager I is actually the furthest man-made object from Earth ever. And aboard, NASA included a gold plated record that contained information about humanity, just in case anything out there found them. You can read all about everything that NASA put on the disc by following a link in this video's description.

But the item that has always resonated with me is a song they chose. They put lots and lots of audio on the disc, but one song in particular was chosen to represent to whoever or whatever found it, the human emotion of loneliness. The song is by blind Willie Johnson, and it's called Dark Was the Night, Cold Was the Ground. There are no lyrics, just humming.

You can listen to it by following the link in this video's description. And as you listen, think about the weight of that meaning. This song was picked to represent to aliens what loneliness is. Blind Willie Johnson himself wasn't blind his whole life; he was blinded as a child when his stepmother threw lye in his face, and he died of malarial fever after his home burned down and he had nowhere else to live but on wet newspaper.

But now, his song is way out there in interstellar space representing us. Thanks for watching. This point of light is Earth, as seen from 4 billion miles away by Voyager 1 in 1990.