Wednesday, January 25, 2012

How to Make Your Own Telescope

This post is brought to you by our favorite eleven year old!

I had a very big science assignment to make an optical instrument and write an instruction manual. I chose to make a telescope (it was originally meant to be a Galilean Telescope, but that didn’t work out). Here’s how I made my awesome zebra print telescope!


Materials to find/buy:

  • A concave/convex lens. I got mine at American Science and Surplus.
  • A big double convex lens. I got this by buying a magnifying glass and snapping off the handle. This needs to be much bigger than the concave/convex lens.
  • Two mailing tubes- one should be bigger than the other, but the difference in size shouldn’t be ludicrous. It would work best if the tubes were fairly close in size to their intended lenses. Notice I said fairly- they just need to be very roughly estimated.
  • Foam
  • Cloth. Make sure it doesn’t clash with your telescope’s color.
  • Patterned duct tape. Preferably peace signs, zebra print, pink, or lime green, but if you’re a guy you might want something different. I suppose that you could use paint (but that’s not as cool as duct tape) or not decorate it at all (and THAT’S just plain lame).
  • Foamy stickers. Read Step 6 to determine if they are needed.
Steps:
1. Hold your lenses, big one farther away and little one near your eye. Look through the small lens and move the big lens closer and farther away.  When you see maximum magnification have someone else measure how far away the lenses are. REMEMBER THIS NUMBER!!!
 
2. Now you need to experiment with your tubes. Mark a section on each tube that is the measurement that you figured out before. So if you measured 4 ½ inches, you need 4 ½ inches of each tube. Saw out these sections.


3. If you’re going to duct tape this telescope, you better do it now! Wrap the tubes in duct tape. If you’re going to paint it, wait. If you’re not going to decorate it, CHANGE YOUR MIND NOW!!!
 
4. Trace the outline of your small tube onto a piece of foam. Cut it out with a craft knife. Then, trace the outline of your small lens onto the circle of foam. Then cut it out with a craft knife. Yes, the tracing, NOT the lens! 


5. You need to work fast at this point to prevent the hot glue from hardening before its put together. Your foam should look like a donut right now. Run a line of hot glue around the donut hole, and then quickly and carefully insert the small lens into the donut hole. Straighten it.
 
6. If the difference in size between the big lens and the tube is significant, then repeat step 5. If not, then stick some foamy stickers near the edge of the inside of the tube and glue the lens straight into the tube. The same goes for the small tube/lens.  If you think you need to because the lens and tube are way different sizes, then use the foam donut method. If not, use foamies.

7. Wrap about 2/3 of the end of the small tube in cloth that doesn’t clash with your duct tape. I glued, wrapped, glued, wrapped, etc. Do this until there is enough cloth covering the tube that the tubes slide easily and they are snug.
 
8. Stick the tubes inside each other. The cloth covered end should be the end that’s farther away from your eye.


If you’re painting the telescope, you should do it now. Otherwise, happy telescoping!!!

Sunday, October 16, 2011

Teaching Kids about Sound Waves

For Sunday Science this week, Daddy got out the function generator to teach the kids about sound waves.  David and I could hear sounds up to about 14-15 kHz and the kids could hear sounds up to 17 kHz.  We suspect that Mr. Two Year Old could hear higher frequency sounds, though, as he was covering up his ears when no one else could hear a thing!

Monday, August 15, 2011

Rocket Cake


I made a rocket cake for our six year old's birthday today! The big flash at the bottom of the cake is not a camera malfunction--it's six lighted birthday candles, powering the rocket for lift off!
  • Cake Plans: Family Fun
  • Recipe: Black Midnight Cake (Betty Crocker, 1991).  This is my go-to chocolate cake recipe.  It calls for cocoa (a staple in my pantry) rather than unsweetened chocolate (which I buy only on occasion), so I always have the right ingredients on hand.  This chocolate cake is super easy and better than a box cake any day!
2 1/4 cups flour
1 2/3 sugar
2/3 cup cocoa
3/4 cup shortening
1 1/4 cups water
1 1/4 tsp. baking soda
1 tsp. salt
1/4 tsp. baking powder
1 tsp. vanilla
2 eggs

Beat on high for 3 minutes, bake at 350 for 40-45 minutes.

    Thursday, July 21, 2011

    Photo Puzzle

    I used Mathematica to create an interactive photo puzzle using pictures of our kids! 




    Download the free Wolfram CDF Player to play with this interactive photo puzzle.  You make a move by clicking on a piece next to the empty space.



    Source code from Yu Sung Chang's PicturePuzzle Wolfram Demonstration. Also see Jon McLoone's SliderPuzzle, another cool Wolfram Demonstration.

    Mulching the Garden

    A friend of ours gave David some spoiled hay for mulching the garden.  Now our five year old really believes we live on a farm.  We've got a giant garden, a raspberry patch, some apple trees, six chickens, and a freckle-faced redhead who wears his John Deere shirt whenever it's clean.  I guess all we needed was a few bales of hay to make our "farm" complete!