Astronomy Part 2 - The Sun

The Sun

We have learned so much about the Sun this past week.  There are so many things that we didn't know or just didn't think about.  For instance:

Did you know that the Sun is so bright it is 1,000,000,000,000,000,000,000,000 (that's one septillion) times brighter than a light bulb?

  

Solar flares can reach up a million miles away from the Sun's surface?

Sunspots are actually cooler than the rest of the Sun's surface by 3000*?

Explosions on the Sun (thermonuclear fusion) disproves some scientists belief that the Earth is billions or even millions of years old?

The color of the Sun is actually all the colors of the rainbow?  And without the Sun we would have no color at all?

We did a lot of experiments during our Sun Week.  

#1: "Why you shouldn't stare at the Sun."  

Now, we all know that staring at the Sun is a bad idea, but do you know why it's a bad idea?  Have you ever taken a magnifying glass outside and burned a leaf or anything else?  A magnifying glass has a curved lens.  Your eye has a curved lens.  A magnifying glass takes the light from the Sun and places it in one area.  Your eye lens takes the light from the Sun and places it in one area.  By putting a magnifying glass directly in the Sunlight, it will burn or melt the object you are holding the magnifying glass over.  By looking directly at the Sun, your eye will concentrate the Sun's light and shine it back to your retina, and it will burn it without you even knowing it.  (Your retina doesn't have any nerves.)  In fact, the Sun is so bright, if you were standing on Pluto, you still wouldn't be able to look directly at the Sun.  Now that's bright!

The melting of a cold chocolate bar.

Concentrating the Sun's light (which was very hard to look at btw) on the chocolate.

It did such a good job at melting it, we got a chocolaty treat afterward.

Be brought a leaf into the mix.  The black spot is where we were concentrating the Sun's light.

We got it to get a little flame, but our magnifying glass is plastic and we didn't want to melt it.

If you look close, you'll see the smoke coming off of the leaf.

#2: Rotating, Revolving & Shadows

We learned the difference between rotating and revolving and the effect those two things have on shadows.  Rotating is spinning (as in the Earth), and Revolving is one or more objects going around another object.  We tried an experiment where one child was the "Sun", one child was the "Earth" and another child was the "Moon".  It was dizzying.  =)  Our other experiment was about the Sun's position and the effect it has on shadows.

The Sun (in red) stands still as the Earth rotates and revolves (in blue shorts) and the Moon (the blur) orbits the Earth.

The Sun, Earth and Moon appear to be colliding here. :)

The Sun has not been agreeable with us during these experiments.  We only had it from 2:30-4:00pm.  Then it rained.  But we did record that within an hour and a half, the position and length of the shadow moved significantly.

#3: Color-What color is black?

This one really confused me.  If the Sun puts out all colors (except for black) and it is white light, then what color is black?   Black is all colors.  Phwew.  I think I just blew some brain cells on that one.  White is all colors being reflected back to you.  Black is all colors being absorbed by an object.  So actually black is not a color, because color is what you see when something bounces back into your eye.  So what have we learned here? Black is all color, but not actually a color at all, it is the absence of color being reflected in your eye.  White is all color.  Whoa.  I need a mental break. Haha!

For this experiment, we used a coffee filter, a black washable marker and rubbing alcohol.  The goal: To separate the different colors of black.

As the alcohol climbed up the coffee filter, we began to see the different colors.

The yellow colors were harder to see at this point.

But toward the end, we saw them laced throughout the red.

#4: Solar Prints

What effect does the Sun have on the colors red and blue?  We laid two pieces of card stock paper out in the driveway.  One red, One blue.  We placed an oak block on each.  Now, if it were a perfect experiment, it wouldn't have rained at all the day we did it.  This was not a perfect experiment.  Both papers were laid out in the driveway at 8:30am.  The Sun did shine for a good 4 hours on them before the heavens opened up.  Both papers did bleed from the rain, but I think the experiment worked well enough to see the difference.  Before we did this experiment, we guessed what we thought would happen.  More than one child thought it would start the paper on fire.  (I'm assuming from the magnifying glass experiment.)  And others thought it would turn the paper's color.  Well, it didn't start a fire, but it did change a paper.

Papers out early in the morning - Wood blocks used to block out the Sun's rays.

To our surprise, only the blue paper was really effected.  Now remember, we had rain so it slightly desaturated the colors on both papers, but with that being said, the blue one was a lot more faded than the red one.  And once the papers dried, it was obvious that the blue had a better solar print.

 What lesson can be learned here??  I guess . . . if you don't want your clothes fading as fast in the sun, wear red???  ;)

#5: UV Rays

Do you ever wonder if sunscreen really helps?  We bought some UV beads and made our own UV bracelets.  One we left untouched.  One we used a spray on sunblock.  One we applied an ointment sun block.  And one we left unprotected and stood in the shade of a tree.  So what was the difference really?

These are UV detecting beads.  They change color when UV rays are detected.

From left to right: 1. No sunscreen, full sun; 2. Coppertone Kids 50spf; 3. Coppertone Full Spectrum 50spf spray; 4. No sunscreen, shade

Full Sun: His lit up beautifully.  The bracelet was pretty colored, meaning the beads detected a lot of UV rays.

Coppertone Full Spectrum Spray: The bracelet turned color, but the colors were not as vibrant as full sun.  Still, too much UV detection for how much the spray costs and for how high the spf is.

Coppertone Kids spf50 was a bit dimmer than the other spray, but still, I was surprised so much UV was still getting through.

No sunscreen, shade: Her bracelet lit up too.  Not as bright as the full sun bracelet, but bright enough to know there is little protection in the shade of a tree.

Comparing three bracelets, 1. spray; 2. nothing; 3. lotion

I washed the bracelet with the sunscreen in dish detergent and warm water.  It's hard to tell here, but his bracelet was still not quite as brightly colored.

#6: Making a Solar Eclipse

The last time I remember a solar eclipse was in school, so it had to have been a while ago.  They do happen multiple times every year.  But the real trick is getting it to happen in your neighborhood - Which happens once in a blue moon. (pun intended!)  Well, it's realistically impossible to take your kids miles above the Earth so they can see one happening. So what do you do?  Bring the solar eclipse to your living room!

Trying to place a solar eclipse over the southeastern part of the U.S.

#7: Safely Viewing the Sun

Without buying an insanely expensive pair of solar glasses, there is no safe way to look directly at the Sun. (Even during a solar eclipse!)  But there is a safe way to look non-directly at the Sun.  We made a Solar Viewing Box.  This experiment is called a Pinhole Viewing Box, and it projects the Sun on the inside of it.  It shows us where the sunspots are too.  The bigger the hole, the larger the image, but the fuzzier it will appear.  The smaller the hole, the smaller the image, but it will have better clarity.  Well, let's see what happened.

Well, I don't know...but we kind of thought this was lame.  It was pretty much like looking at sunlight through a hole.  There were no sunspots.  We may have done something wrong, so we'll try it again on another day.

And that my dear readers,
Is the end of our study on the Sun.
Hope you enjoyed!