"These are the types of experiments that freshmen physics students should do! Go on top of a train at 20 mph and see for yourself Galileo’s postulate and his reasoning. Although I knew it would work, the only “experiment” I had seen for that effect was just computer simulations in class. It makes it all the difference when you actually see it firsthand (Especially on top of a speeding train in West Africa at night!)"
Peace Corps Volunteer Mike Sheppard in The Gamiba: On top of the Train!
Thursday, July 28, 2005
On top of the Train!
Day 7
Sun July 24th
Start: Somewhere in the desert
Mid: Choum [21 11 N 13 03 W]
End: Somewhere in northern Mauritania
This being an almost impossible day of travel, time wise, we got up and left the oasis at 6:30 in the morning. Two hours later we were back in Chinguetti, after riding the camels back and watching our guide and Mahommed walk the ways again. Not knowing whether we could make it to the train in Choum by nightfall or not, we were trying an almost impossible task of getting three different modes of transport in one day, all separated by hours of riding.
At the car park we met another traveler, Ulf, a 22-year old German who after finishing High School just traveled to Australia, then to Africa and was now heading home through Morroco. He had spent five months traveling through Africa with three of them in Ghana. His German was fluent, which made Erika happy since she also knows German, and his English and French were understandable. We had another guide!
We rode on top of the pickup again, on top of all the luggages, for the ride to Atar. At Atar Nate was almost kidnapped by a Wollof woman who was so happy to meet someone who spoke Wollof that she grabbed him and rushed him to her shop, all the while jumping up and down and speaking a thousand words a minute.
A few minutes after arriving into Atar we got real lucky and had transport to Choum, where the iron ore train would meet up with us. For what we thought was less than the ticket cost, we had rented out the back of a pickup to ourselves (with no luggage to sit on top) and he would leave now to Choum. The driver and two passengers were up front while we were all in the back, the four of us.
This was the hottest part of the trip to date.
For three hours we were in the back of the pickup in the hottest part of the day going across the desert; the landscape changing from lunar to martian to Arizona badlands. At some points the ‘road’ didn’t exist and we were going over small rocks and boulders. Once they had to ask for directions. We all had our turbans on, but even the sun was getting to us. My arms were sunburnt with the hair on them bleached white. Others were as well. We drank all our water in the first two hours and didn’t have any more until they stopped for a break and shared theirs which I had been sitting on and didn’t know. They let us fill up all our canteens and bottles.
We were all dehydrated, hot, sun burnt, and tired – all from three hours in the back of the car.
Choum reminded us of the old wild-west ghost towns. Very few buildings and train tracks alongside the town. We had been very lucky so far with transport and now were going to make the train tonight. We had some dinner (dried rice with no flavor, shared by all) and bought supplies to last the night on the train.
At six-thirty the iron ore train arrived and we had five minutes to climb aboard. Enough time to take pictures and get comfortable. The train is supposedly the longest in the world at 2.3 kilometers in length. The four of us shared an entire car to ourselves. You could pay to ride, in the passenger car, but it is usually crowded and you have to fight to get a seat. Or, ride on top for free!
The iron ore was like a big sandbox, just much dirtier. It wasn’t big sections of rock, but fine grains. The Mauritanians a few cars over gave us a huge tarp to use as cover (cover the iron dust, not ourselves - basically to use as a mat), which we gladly appreciated.
I safety-pinned my turban to completely cover my face as the train accelerated to about 20 mph. The wind was blowing the ore into our face, bags, clothes, shoes and in every open area. For dinner, we used Ulf’s small gas burner he had brought and made some tea while eating the driest sandwich to date: stale bread with sardines and onions with no sauces for taste.
The train stopped only briefly at hours 4,6,7,10.5 before arriving at Nouadhibou after 13 hours travel.
Around 10pm the train stopped, at hour four, and kids in the village were selling everything from bread, snacks, camel milk (which we bought), and coke to the “passengers” on top of the ore. Flashlights were used to see the items and the money.
I was quite amazed at the physics of the trains as well. I took a small clumped up section of the iron ore and watched it fall off the train to explode upon impact. In the 1600s there was an argument that the Earth can’t be moving since if you dropped something, and if the Earth was moving, that the item would fly off and not land at your feet. Since that doesn’t happen Earth isn’t moving. Wrong argument. Galileo was the first to see the reason why. If you drop something, that item is still going the same speed of that the Earth was going before it dropped and it seems to be dropping in a straight line.
I tested it on top of the train. With one eye closed I peered over the train and dropped a small pellet. I had it lined up originally with a vertical pole going up the car. Other than air friction it followed that metal pole all the way down before hitting the ground and exploding as we passed the explosion. It had hit the ground going 20 mph horizontally (speed of the train) and 24 mph vertically (gravity). It exploded since it hit the ground going over 30 mph at almost a 45 degree angle. It was quite an explosion too! Watching the dust go in every direction! I ended up getting bigger and bigger clumps just to watch the explosion. The few pennies I had wasted the iron company was nothing compared to the tons of iron that was flying off every second from the 2 kilometer long train going 20mph.
I then took my compass out and walked around the car watching the compass go haywire with all the iron ore around. Fascinating!
These are the types of experiments that freshmen physics students should do! Go on top of a train at 20 mph and see for yourself Galileo’s postulate and his reasoning. Although I knew it would work, the only “experiment” I had seen for that effect was just computer simulations in class. It makes it all the difference when you actually see it firsthand (Especially on top of a speeding train in West Africa at night!)
Einstein, himself, had constructed his Special Relativity theory by doing thought experiments of riding on trains and what happens to different viewpoints.
As we passed another train I counted the cars. 147 give or take a few. I could swear I counted more cars on a trains before in the US as a kid waiting for them to pass. But, according to the Guinness World Records these are the longest trains.
During late in the night I had to go the bathroom. What to do? If you urinate off one side of the train it’ll come right back at you at 20 mph. No thank you. Off the sides and you splatter the people in the next car. Nope. Did the next best thing: went in the corner of the car and kicked some ore on top of it.
We all went to sleep around ten after the longest day of travel we had, stress wise and being exhausted. All of our water that we had filled up, including Ulf’s 5-liter jug was gone – either used to make pasta on the train or drunk. We slept until morning.
