2012 A.D.: So, we've been around billions of years? Please......!! Where is all of the dust?
Sometimes when I was young, on a little farm my father owned, I would go into a barn we had for milking and goof around. It was pretty dark in there, so sometimes I'd open the door, but you didn't really have to. The lights came through some cracks and gaps and a few small windows. One of the things I can remember pretty clearly is how some of the boards that made up the shell of the barn had the knots missing. So there was an oval shaped hole where the knot had been. Sunshine could stream through these like a two inch laser beam, and did! Very interesting to an exploring youngster! It would make an elongated oval on the cement floor of the barn, and sometimes I would imagine that there was something special...like a super power ....in the beam of light. Stuff like that happened on cartoons. I would stick my hand in the way, and become embued with the super power. Usually it was the ability to jumb really high, or run really fast, or to be amazingly strong. All the powers that a four or five year old boy could ask for.
Dust particles would float around lazily in the beam of light. Some were like tiny short hairs, others almost like a dot. I sometimes managed to catch one on a spit wetted finger tip and look at it, but not often. They tended to dance away from your skin just as you got close to them. But if you could hold yourself still enough (not an easy thing!!) sometimes they would just land on your finger and stay there.
The ledges inside the barn had such dust on them, laying in a fine layer. I am sure that this barn was not more than 30 years old, but on the ledges in the more undisturbed corners there was probably 1/16 of an inch, because only the really Obsessive Compulsive farmers dust their barns.
Actually, I have never heard of anyone dusting their barn. I will bet, in this big world, that some farmer does....somewhere....but not many. Such an oddity is going to get kicked around some at the local cafe, anyway. You can be sure of it. Farmers (by no means a bunch of gossipy girls) never the less score big at the local cafe if they have a pretty juicy piece of news. And, your hard working farm wife sort of relied upon you to keep her in the loop concerning the latest hot gossip....at least back in the day, before cell phones, it was sort of that way. So, an attention worthy story, such as finding out that one of your neighbors dusts their barn, would certainly have been news that you'd like to break to the other wives. Long story short...if you were a barn duster, and it became known, it would have gotten around. I never heard of one.
So, in thirty years of sitting there in Idaho, by the Snake River, our barn had gotten a buildup of about 1/16th of an inch of dust. Now that doesn't seem like a lot, but....
I was just thinking that in 480 years, that would have added up to an inch! That doesn't seem like so much, but....we're supposed to be a 6 billion year old planet. I mean, how long would it take a foot of dust to collect? 12 x 480 years, I guess, right? So, every 5760 years (call it 5,000 for easy math, though it will swell the results a little, I admit) you get a foot of barn dust!!
Well, no farmer is going to sweat that one, since both he and the barn will be a long distant memory by then. But, it does make you wonder just how much dust would build up in 6 billion years, doesn't it, given steady state barn dust build up conditions?
Well, let's assume that you actually do get 1 foot every 5,000 years. How long would it take to get a layer of barn dust a mile deep? Well, if you cheat about 5% you can just call a mile 5,000 feet. So, it would take about 25,000,000 years to get one mile of barn dust. 25 million years. It would take ages to get there, but of course, once you did, people would understand if you broke out the vacuum and dusted your barn.....which would be under about a mile of dust somewhere, down there with your cows.
But, as long as 25 million years might seem to be, there are 40 times that many years in a billion years. 40 miles of dust...a 40 mile deep layer of dust assaulting your barn and your cows every billion years. No wonder we are not given a 1 billion year life span. We would spend it dusting!!!! A dauntingly deep layer indeed!
The top of Mount Everest is only about 6 miles above sea level, not even that, actually!! And don't forget: this same layer is landing on the surface of the sea. So, the sea bottom is receiving this same rain of dust...constantly!! How many parts of the sea are 40 miles deep? None of them!! Not a single place in the sea is 40 miles deep, yet if there has been a 40 mile deep layer of dust falling every billion years, and the Earth is 6 billion years old, then we could have a 240 mile deep layer of barn dust to deal with...roughly speaking....on both land and out there in the sea. All life forms, even plants, would have developed some form of deadly bronchitis, I speculate. Pugs and bull dogs would have been extremely impractical breeds, but none would have really flourished.
About 80% of the gases in the atmosphere are within 10 miles of the surgface, even though there is some sort of atmosphere out to about 300 miles....a very thin atmosphere. Even on top of mount Everest (less than 6 miles up) nearly all climbers must use oxygen. So, though a 1 billion year layer of dust would shove the atmosphere ever upward as it deposited, still, if you presently just flew up in the air 40 miles you would die from lack of oxygen.
Dust lays down gently, and there are a lot of air spaces between the particles. I would be willing to assume that in 6 billion years time, instead of 240 miles of fluffy dust, you would only have 1/10th of that. Or, better yet, only 1/20th of that deep a layer. It would have compressed by a factor of 20, I hypothesizing. So, the 240 mile deep layer is only 12 miles deep. But, a 12 mile deep layer of dust!! What an awesome thing to contend with.
There is such a thing as a 'dust trap'. Researchers have built deposition rate gauges that catch the dust so that they can gage the rate of accumulation, and also so they could see what the dust was made of...study its composition. One study by a Kansas college in the 1960's, which was posted on the internet to look at, put a trap in Hayes, Kansas, and another in Manhattan, Kansas. In both places they found the gross deposition rate to be between 52 and 54 pounds per acre per month. Call it 600 pounds of dust per acre per year, though it was a bit more. So, in a million years, you would get 600,000,000 pounds of dust. 300,000 tons of dust at the 2,000 pounds per ton conversion. It would take 600,000 of the 1/2 ton payload rating variety of pickup truck to bring that much dust to your 1 acre parcel of land. If each pickup truck was 12 feet long that would be a line of pickup trucks more than 1,400 miles long, and remember, that is only the dust from 1,000,000 years falling on each acre. There would be 1,000 times as many pickups required to bring you the dust from a billion years of time that should have fallen upon one single acre of land. And the Earth is supposed to be a few billion years old, not just one billion. (For the metrically trained, multiply pounds/acre times 1.12 to get kilograms/hectare)
How odd it is that the moon, lacking an atmosphere (essentially) and having at least 1/6th the gravity of Earth, how odd is it that it would have only a couple of inches of dust on its surface? Unexplainable!! Totally unexplainable!! Shouldn't there at least be a mile or so of dust on the moon if it too is billions of years old? But at any rate, even if there is not a mile or so...a couple of inches is all that we find there? How could this be? Surely we should be able to formulate a potent dust repellent using whichever materials that the moon is composed of.
Much of what is in dust oxidizes, but even so....the remaining fraction should have become a mighty mighty pile.
Where has all of our barn dust gone, scientists? Where has all of it gone during these many billions of years that you assure us have passed? So, I hope that some of you will join me in a campaign that I'm thinking of starting: Now, while there is still time to act...while we can still see the top of the barn, and while we still have milk cows, let's put a picture of a pile of barn dust (a pile many dozens of miles high) on our milk cartons, and let's see if someone somewhere can find out what these scientists have done with our barn dust. They have hidden it, stored it away somewhere out of sight, and it's time they were brought to justice. We need our barn dust back. With it in hand, we can make hundreds of thousands of new pastures, where cows yet unborn can graze near to barns yet unbuilt, and the world can be as those whose expertise is guessing the age of the Earth have told us things ought to be: dusty! Very very dusty.
Justice! We need the dust they have promised us (well, it was implicit in their promise that our planet was billions of years old, anyway.) We need a place to return to, right? For man is made of dust, and to dust we shall return. If we can only find the dust!