My little 7 yr old nephew once asked why the planets are round, and not square? How do you explain to this little boy in his language so he can understand Rajini Rao ?
I can try, Tom Lee ! Gravity pulls everything equally towards the center, so the final shape is round. Small bodies like moons can have odd shapes because their gravity is not large enough. Also, because the Earth spins, the equator bulges out in the middle because of centrifugal force. Tell him that the Earth has a bit of a tummy around the middle 😉
This 7 yr old nephew is a little smart kid. He’d probably take the explanation to verify with his teacher. But for a second grader I’m not sure he knows what gravity and centrifugal force is. So the round spinning top can be used to compare and explain? 🙂
Uh oh, the dreaded elementary school teacher! Gravity, he will get because everything falls to the ground. If you draw a big circle with a little stick figure on the two poles he will see that they both stay on the ground because they are being pulled to the center. Spinning top is a good one for centrifugal force. You can also swing a weighted rope around and let it go..it will fly off at a tangent, but I’m guessing his mom will get mad at him (and you) when it breaks something 🙂
madame scientist's not-so-mad musings 
My little 7 yr old nephew once asked why the planets are round, and not square? How do you explain to this little boy in his language so he can understand Rajini Rao ?
I can try, Tom Lee ! Gravity pulls everything equally towards the center, so the final shape is round. Small bodies like moons can have odd shapes because their gravity is not large enough. Also, because the Earth spins, the equator bulges out in the middle because of centrifugal force. Tell him that the Earth has a bit of a tummy around the middle 😉
Rajini Rao your explanation is similar to this Scientific American explanation.
http://www.scientificamerican.com/article.cfm?id=why-are-planets-round
This 7 yr old nephew is a little smart kid. He’d probably take the explanation to verify with his teacher. But for a second grader I’m not sure he knows what gravity and centrifugal force is. So the round spinning top can be used to compare and explain? 🙂
Uh oh, the dreaded elementary school teacher! Gravity, he will get because everything falls to the ground. If you draw a big circle with a little stick figure on the two poles he will see that they both stay on the ground because they are being pulled to the center. Spinning top is a good one for centrifugal force. You can also swing a weighted rope around and let it go..it will fly off at a tangent, but I’m guessing his mom will get mad at him (and you) when it breaks something 🙂
LOL! 🙂
Yeah. So lets go with the tops 🙂
Spectacular! What a photo, and what a mind?
Terrific snap Rajini