‘If I’d only … my son would still be alive today’ - John Halligan has told 1 million students and counting the story of his son Ryan, a 13-year-old Vermonter who killed himself after facing a tsunami of so...
Thursday, February 18, 2010
Nouhoume: Madu, what is it like in America?
Madu: That is a very difficult question to answer… I don’t quite know where to start…
N: Is there millet in America?
M: Not really. It is so dry here in Mali, so it makes sense for Malians to grow millet. But we have a lot more rain in America, so we can farm a lot of wheat and corn and rice instead.
N: Do you farm peanuts in America?
M: Yes, we have lots of peanuts! Particularly in the American South, there are lots of peanut farmers. In fact, peanuts are such an important staple of the American economy that there was one peanut farmer who went on to become President!
N: Do you have the Moon in America?
M: Um… well, the Moon isn’t in America per se… but we can see the Moon from America, if that’s what I assume you meant.
N: But America is so far away!
M: America is indeed far from Mali – but we can see the Moon in America too, because the Moon is just as far from America as it is from Mali. (grabs a soccer ball for reference) You see, Mali is to the East of America, and the Earth rotates counter-clockwise from the West to the East, so though we are both seeing the same Moon from both countries, in New York we can start to see the Moon about five hours after it can be seen from Mali.
N: What about the stars?
M: We can see most of the same stars in America. But America is further North than Mali, so there are some stars of the Southern sky that you can see here but we can’t in America – and there are some stars in the Northern sky that you can see in America but not in Mali.
Do you see that thing between the stars that’s a different color than all the rest? It looks red.
N: Yes. Why is that star red?
M: It's not a star at all! It's another world revolving around the Sun just like Earth! It is called Mars. After the Moon, it is the closest body to our planet.
N: What about the Sun? The Sun is so much bigger!
M: Yes, the Sun is much much much bigger than Mars, but it is also much farther. If the Sun were as close to Earth as Mars is, then the whole world would be much too hot for us to live!
N: Are there any people there?
M: No, it is much too cold on Mars for any people to live there. And though there is air there, it is not like the air here on Earth - if we were to go to Mars we would not be able to breath... But a few years back America sent some machines to Mars that can drive around and take pictures and study the rocks on the Martian surface. They are still there today.
So Madu, why are all of those stars in a big line there?
M: That, Nouhoume, is what we call "The Milky Way".
You see, there is this force called "gravity" which attracts any two objects in the whole Universe towards each other. Gravity is attracting you to this soccer ball right now, but both you and the soccer ball are so small that you don't move towards each other. But Earth is really, really, really big - and you are so much smaller, and that is why you stay on top of the Earth. Even though the Moon is big too, Earth is a lot bigger, so the Moon is attracted to the Earth. The only thing big enough and close enough to Earth to attract it is the Sun - that is why Earth revolves around the Sun once every 365 days.
Stars work the same way. Gravity pulls stars towards each other if they are big enough and close enough, and when they get really, really close stars will rotate around each other as well! Eventually, millions and millions of stars start revolving around each other and make a big spiral like this (draws a spiral galaxy in the dirt). That is what we call a "galaxy".
Our Sun - our star - is revolving around with other stars in a spiral like this. Our star is on one of the arms of the spiral, which is why we can see so many other stars. When you see all of those stars clumped together in that big, thick line called "The Milky Way", those are just more stars in the same arm of the spiral that ours is on.
Most of the stars that we can see are in our own galaxy, but there are billions and billions of other stars in their own galaxies. We can see some of them, but it is very difficult because they are so far away.
Madu, can you see all of these things in America too?
M: Yes, America and Mali are both on Earth, you see, so like I explained most of the things in the night sky that you can see here we can see in America too - but not all of them.
N: Madu, I have another question.
N: Do you have fire in America?