Blinded by Science blog #2: Why doesn’t the sun always shine and where does it go?

Hello and welcome to the second entry of my science blog, “Blinded by Science.”  In today’s installment, I will again answer a question posed by my cute, three-year-old godson, G.

G asks, “Why doesn’t the sun always shine and where does it go?”

Another astronomy question means I will have my work cut out for me convincing him to go into biology.  Though he has said he wants to “be a doctor like T” (photographic proof below), so it is a challenge I am willing to accept.  I’m thinking copious amounts of bribery while he grows up and possibly some Diet Coke and Mentos (which doesn’t really have anything to do with biology but would still be cool to do).

See.  He looks pretty good in a lab coat.

When asked why he thought the sun doesn’t always shine, he answered that it goes to sleep at night, like him.  Compared to his thoughts on the moon question he asked last time, this answer is less plausible but so much cuter!

Well G, the sun doesn’t really go anywhere.  The Earth is really big and constantly spinning in space.  So sometimes the part of the Earth that you live on is facing the sun (daytime) and sometimes it is facing away from the sun (nighttime).  The cool thing is even if you can’t see the sun shining, someone else in another part of the world can.

Let’s ask your mom to help with another demonstration.  This time all that’s needed is a flashlight to be the sun.  Go stand in the middle of a dark room and have your mom stand a little behind you with the flashlight pointed at you.  Ask her to turn it on.  You can’t see the flashlight because the back of your head is blocking the light and you don’t have eyes in the back of your head (only mothers have eyes in the back of their head, which is why they always know what you have done . . . always).  While standing in the same spot, slowly turn to your left.*  Soon you will begin to see the flashlight (1).  This is what happens when the sun rises in the morning.

As you continue to turn, you will soon be able to see the whole flashlight as you look right at it (2).  This is what happens around noon when the sun is high in the sky.  Eventually you will start to see less of the flashlight (3).  This is what happens when the sun sets and it is getting close to your bed time.  Finally you get back to where you started and the flashlight is behind you.  This is why it becomes dark during nighttime.  But the flashlight is still shining on the back of your head, just like the sun still shines on the other side of the Earth.

*This is actually the direction the Earth spins.  In other words, if you were an observer in space looking straight down over the North Pole, you would see the Earth spin counter-clockwise.