Clearly, I am not concerned. But hearing about this really sort of set my head spinning when I started pondering the scale of the world around us. And by "world" I mean "universe." And by "us" I mean "you and me." And by "around" I mean "doesn't fucking notice at all." Because it's like this. Here's this hydrogen cloud, right? It's out there, floating through space...just chilling. When I heard that phrase..."hydrogen cloud"...I was picturing lying on some grassy hill somewhere, staring up at little fluffy white cotton-looking thing sauntering across a blue, blue sky. Oh, look! A bunny! You know...clouds. Except this cloud is eleven thousand light-years long. Eleven. Thousand. LIGHT-YEARS.
Let me reiterate that. If you were traveling at the speed of light, which is really, REALLY fast, mind you, it would take you eleven thousand years to cross this bad boy. I mean, give or take. Everyone's gotta stop to hit the rest room once in a while. But come on! Plus...this baby (Smith's Cloud, it's called) is moving pretty fast itself. You've been in a car, right? On the highway? Maybe you've gone 75 miles an hour? Okay, picture that. The scenery whipping by, a nice, smooth ride... Okay, now double it. Fast, right? Kind of a rush? Maybe a little scared you can't make that next turn? Still...after an hour, might get a little dull. Now think about that. You've just been doing 150 for the past hour. Think about sitting in that car for an hour...think about the ground you've covered. That's how far Smith's Cloud went in one second. That is bloody fast! And now think about this: if you were going that fast, 150 miles every second, and you wanted to see Smith's Cloud from end to end, it would take you juuust about 13.7 million years. That amount of time pretty much covers the history of all life on planet Earth working backward from now until the first little microbes grew up out of the soup...if it repeated itself three or four times in a row. That's a long time. I'm telling you...this sucker is big. They say it "contains enough hydrogen to make a million stars like the Sun." That's a lot.
How much? Okay...think about the Earth. The Earth is a pretty big thing, right? Sizable, you might say. Now picture an M&M. If that little M&M is the Earth, you'd have to put together about six pounds of M&Ms to get to the mass off the sun. Hear what I'm saying? And if you don't think six pounds of M&Ms is a lot...try to eat it. Seriously. That's a lot. Okay, so, you have some idea about how big the Sun is. Now take that six pounds of M&Ms you thought you could eat. Now imagine, instead, that that big ball of chocolate and candy coating is, instead, a tiny, tiny grain of sand. See it? Getting lost in the folds of your fingerprint there? Okay. Now drop that bad boy into a two-liter bottle of soda. Got that? That's how big Smith's Cloud is. It is a giant bottle of soda to our own Sun's grain of sand, and it is flying toward our galaxy at 150 miles per second. Whoosh!
But not to worry, that shit won't be here for another 40 million years. Now...that's a long time. It's hard to think about how long that is, but we'll try and take steps here. Think back to, oh, 10 years ago. 10 years ago: we were about to learn the name "Monica Lewinsky"; 9/11 has yet to occur. 100 years ago: the British Empire was the shit; both World Wars have yet to occur. 1,000 years ago: Europe's High Middle Ages; the Crusades have yet to occur. 10,000 years ago: humans are just about learning agriculture; cities have yet to occur. 100,000 years ago: an anatomy is emerging in the primate world that we will come to think of as that used by modern man; speech has yet to occur. 1,000,000 years ago: the Earth is experiencing an ice age and is probably about 30% covered in ice; the extinction of the glyptodon (a car-sized, armadillo-like, armored mammal) has yet to occur. 40,000,000 years ago: the shape of land on the Earth is not as you know it today; the South American continent has yet to occur. I mean...think about that. In that amount of time, the globe would look different. That's a long time. Who knows what could possibly be the state of us in 40 million years. And that's the state of us...just some little squeaking moving parts running around a tiny piece of rock spinning around a grain of sand unheeded by the soda-bottle of hydrogen taking it's leisurely 150-miles-per-second time to smash into our galaxy in 40 million years. Just think...if Smith's Cloud had started its trip 40 million years sooner, it could smack into us right now and wipe out our little tiny-fragment-of-a-grain-of-sand-sized-M&M planet with not even the tiniest of whispers to be heard and no one would know we were ever here. No South American continent, no glyptodon, no people, no cities, no you. Who knows how many times this has happened already. And sometimes you wonder if things matter?!