Sunday, February 27, 2011

Chess for Beginners

   During the recent holidays I was amazed to learn that grandson John, in Kindergarten, had learned from his dad the basic chess moves. John challenged granddad to a game and by golly he knew how to count the Knight move as either 1 vertical, 2 horizontal or 2 vertical, 1 horizontal. He knew the Bishops move along the diagonals, and so on, for all the chess pieces!
   For many years Martin Gardner wrote the Mathematical Games column in the Scientific American magazine. He had a large following among professional and laymen alike. He stripped away the drudgery-coating on school mathematics and revealed the hidden kernel of logic, beauty, and utility. My life-long interest in mathematics was sparked by a problem, I deemed insoluble, in one of his columns.
   In 1969 he suggested a chess variant on a 5 x 5 board in which all chess moves, including pawn double-move, en-passant capture, as and castling can be made. Here’s the board’s setup.
   I’ve often recommended the smaller board to parents and teachers interested in teaching the basics of chess. The smaller board makes for quicker games and let’s kids master the basic moves before moving to the larger 64-square battlefield. Also, the pawn double-move, en passant capture, and castling can be introduced when the transition to the larger board is made.
   If you are a chess player, share your knowledge with your kids and grand kids. Mask off a 5 x 5 section of a regular chess board or mark off a mini-chess board on a sheet of paper. Learning to play chess is one of those skills that anyone can take into adulthood and enjoy through life.
   I've been playing chess on my computer just to practice up for John's future challenges. I don't want grandadscience to be embarrassed.

Saturday, February 19, 2011

The ABCs, D, and E for Elecricity

I recently received this E-mail from our oldest son. He and his family are currently living in Ohio.  Our grandson John is in Kindergarten and his younger brother, Andrew, is still at home with mom. Our son sent me this e-mail which inspired this post.

Dad - The kids have a 'How Things Work' book that they often ask to have read before bed.  One of the sections is on a coal power plant.  I explain the whole process from coal in the furnace to turning on the light in the bedroom.  One of the stages is the turbine/electro-magnet. 
Ann heard me read it to the boys today and mentioned that John was downstairs with a refrigerator magnet wrapped in a telephone recharger wire...spinning it to see if he could make electricity.  Do you have any cool creations on electro-magnets?
JG

    Obviously, John would like to build an electric generator. But before helping him and his dad make a generator, I sent the boys a couple of electromagnets made using a nail, insulated wire, masking tape, a rubber band, and a D-size battery for them to play with. 
It’s easy to wrap an electromagnet. To make one, have the kids or grand kids follow these steps.
•   Wrap the pointed end of the nail with a four-inch strip of masking tape. This covers the sharp end of the nail. Next to the taped end, wrap a second four-inch strip to provide a barrier that will hold the wire in tight coils. Stretch the rubber band around the battery and wrap a strip of masking tape around the battery to keep the band from slipping off and to hold the band snug against the ends of the battery .
•   Beginning at the masking tape, leaving 6-inches of wire at one end, start wrapping the wire in tight coils around the nail. Shove the coils together with your fingers. Wrap coils to the head end of the nail.
•   Wrap masking tape around the first layer to hold the coils in place. 
        
•  Wrap the wire in the opposite direction being careful to keep the coils together. Wrap to the end of the masking tape covering the first layer of coils.
•   Wrap masking tape around the second layer of coils to hold them in place.

   The electromagnet is ready for testing. Make a pile of paper clips or some other metal objects. Slide the bare end of each wire under the rubber band at the positive and negative ends of the battery. Press the ends of the battery with thumb and forefinger, put the head end of the nail in the pile of paper clips, and lift up as many clips as possible.
   When connected to the battery, the electromagnet can get hot. If they feel the electromagnet getting hot, tell the kids to drop the battery immediately and to pull the ends of the wires from the under the rubber band.
   With a working electromagnet, kids can explore which materials are attracted to the electromagnet and which are not. Encourage the kids to classify the materials. Challenge the kids to find a metal that is not attracted to the electromagnet.

   The electromagnet demonstrates to kids that electricity and magnetism are connected concepts.
In 1820, Hans Oersted discovered that a compass needle moved when placed near a wire carrying electricity. Compass needles detect magnetic fields. Oersted's discovery led to the electric motor. Soon after, Michael Faraday discovered that moving a magnet near a wire creates an electrical current in the wire. Faraday's discovery is the key to the electrical generator.

   What was in John’s mind, what was he expecting to observe when he wrapped wire around the refrigerator magnet? None of us know. But we can help our kids by making sure we know what they are curious about and then provide the materials they need to expand their knowledge of the physical world.
   A generator is harder to make than an electric motor. Next, I will send the boys a simple homopolar motor. It has a magnet, a coil of wire, and a battery. When assembled, the coil spins rapidly. The motor should show John how close he was to getting that refrigerator magnet to spin. I will describe how to make the homopolar motor in a later post.


Thursday, February 10, 2011

John and Andrew's First Experiment

   During a recent visit to our oldest son's family in Ohio, we arrived near the end of a snowstorm. The extreme cold weather made staying indoors, even for two boys, where they could play all day in their pajamas, very attractive.
   The two grandsons, John and Andrew, play extremely well together. They also amaze us with their antics.
   I grew up in a two-story house with carpeted stairs and my brother and I spent a lot of time playing on those steps, particularly in the winter. We slid down the banister, sledded down the stairs in a cardboard box, and shoved innumerable toys over the cliff to crash on the landing below. But we never thought of the method John and Andrew use, as seen in the following video, for getting from the upstairs to downstairs of their home.

   John is in Kindergarten and Andrew is a year younger. One of the things John is learning in school is the use of time to regulate events. The clock now tells him when to get up, get dressed, eat breakfast and when to catch the school bus. But time is also used to measure the duration of an even
   It’s common for kids at all grade levels to carry a cell phone. Besides a clock, the cell phone also has a calculator and stop watch. The boy’s dad, an Air Force officer with a degree in mechanical engineering, had the boys repeat the stair slide five times, using the stop watch cell phone function to measure and record the duration of each slide. Here’s the table dad sent.
   Besides learning that numbers can be attached to intervals of time, I wish I could have been there to hear how the boys related the numbers to ‘fastest’ and ‘slowest’! The larger the 'time' number, the slower the slide.
   Almost all the physical science concepts John and Andrew will meet in school are measured using just three units; mass, length, and time (MLT) or combinations of two or more of these units. For example, 60 miles per hour has the units length/time.
   Kids need a lot of hands-on experience measuring mass, length, and time separately before they are asked to understand concepts measured by combinations of two or more of these basic units. Timing the duration of an event with a stop watch, measuring the length of objects around the house, and checking the mass information on cans of food and are good activities for kids five years and older. The earlier kids learn that numbers describe properties of objects and events in the real world, the better. Don’t count on schools to do this.
  Perhaps it's time to put a spring-load tape measure and a simple mass balance in John and Andrew’s  toy box and let them start connecting numbers to the real world and not the abstractions met in textbooks.