Shocking Science

Nancy and I had the opportunity to help with the Girls in Science, Girls in Research program again.  This time the sessions were held at Pikeville College.   The girls tried to duplicate some of the experiments that early researchers conducted.  Then they all had the chance to see what it felt like to be charged up to several hundred thousand volts and then what happened when they were suddenly discharged.  Not all of them were brave enough, but most tried it.

Here they were checking the attraction of opposite charges. 
First charge a balloon by rubbing it on fur or hair.  Then hold it near a stick suspended on a string.  The negative charge on the balloon induces a positive charge on the part of the stick nearest to it which is then attracted to the balloon.  By quickly moving the balloon when the stick approaches it, the stick can be set spinning.
 

Here they are carrying electrons in a pie pan supported by a plastic straw insulator. 
They held the pie pan near a charged balloon.  Then they touched it with their finger to let the electrons that were repelled by the charge on the balloon move away. Taking their finger off of the pie pan then traps the charge on it.  Since there are fewer negative charges on it than before it is positively charged.  They then used an electroscope made from a pop bottle, a paper clip and a strip of aluminized mylar gift wrap to detect the charge.  We also discovered that the charge could light a fluorescent light bulb, very briefly (just a blink).
   

The Van de Graaff uses a similar principal to carry charge from the bottom to the sphere on the top.  Several hundred thousand volts can be developed with one this size if conditions are right.  We saw how discharges could light fluorescent bulbs held by our intrepid experimenters and how the light from discharges in neon and xenon were different colors.  They saw how charges could pass through the air and power a pair of bells.  But the real hit was when they stood on an insulating platform and discovered that each strand of hair repelled every other one when they were charged.  I have never before had this demonstration work this well.
  

We then turned our attention to the science of cryogenics.  You can see some of the experiments here.  We finished the session by making ice cream in 30 seconds then enjoying the product of that experiment.

Go to our Science Fun page
Go to our Travels page
Go to our Personal home page
Go to our Community page

E-mail Nancy and Alan