Archives of Ask A Scientist!
About "Ask A Scientist!"
On September 17th, 1998 the Ithaca Journal ran its first "Ask A Scientist!" article in which Professor Neil Ashcroft , who was then the director of CCMR, answered the question "What is Jupiter made of?" Since then, we have received over 1,000 questions from students and adults from all over the world. Select questions are answered weekly and published in the Ithaca Journal and on our web site. "Ask A Scientist!" reaches more than 21,000 Central New York residents through the Ithaca Journal and countless others around the world throught the "Ask a Scientist!" web site.
Across disciplines and across the state, from Nobel Prize winning scientist David Lee to notable science education advocate Bill Nye, researchers and scientists have been called on to respond to these questions. For more than seven years, kids - and a few adults - have been submitting their queries to find out the answer to life's everyday questions.
When two different objects touch each other or are rubbed together (like a comb and your hair or a brush and your cat's hair or different kinds of clothing in a clothes dryer), electrons can be "stolen" by the "electron-greedy" object from the other object. One object now has too many electrons (the comb or brush) and is negatively charged, while the other has too few electrons and is positively charged (the hair). The "crackles" you often hear when rubbing objects together are sparks made by rubbed-off electrons jumping back onto the object they came from to try to make both objects neutral again. But lots of the rubbed off electrons can't make it back, so the objects stay electrically charged...at least for awhile. This is static electricity.
In the winter, air is dry--there's very little water vapor in it. In the summer, air is more humid--it contains more water vapor. Water is an "electrical conductor"--it makes it easier for electrons to move from one place to another. Water in the air lets extra electrons on charged objects leak off into the air and find their way back to charged objects that have too few electrons. Humid air helps to "discharge" static electricity this way, so we don't notice it as much in the summer. In the winter, dry air makes it harder for electrons to leak off, so static electricity discharges by crackling sparks.
When dryer sheets tumble around with clothes inside a clothes dryer, the heat and tumbling move chemicals from the dryer sheets onto the clothes, coating or "lubricating" the clothes with a thin layer of these chemicals. Now the surfaces of the clothes rubbing together are all equally greedy for electrons since they're all coated with the same chemicals from the dryer sheets. When two different pieces of these clothes touch and rub against each other, neither one is able to steal very many electrons from the other, so the clothes stay uncharged or neutral. But now there is a layer of chemicals on the clothes (and on the inside of the dryer) that can build up from drying to drying if the washing machine doesn't wash them all off. Before using dryer sheets you should always check the labels on your clothing (especially clothing that is supposed to be flame resistant) and the directions on the box of dryer sheets and in your dryer's instruction manual to see if they're okay to use. But if you are able to use them, dryer sheets can make clothes feel soft and smell nice, and they do help prevent static electricity!
- What causes lightbulbs to be so inefficient, and how is efficiency rated?
- How hot is it at the earth's core? Does the heat affect our temperature?
- My instructor told me that the wavelength of laser light is determined by the distance between the mirrors in the laser device. I say he is not correct, it is the nature of the lasing medium itself as the molecules that make it up emit characteristic wavelenghts when excited. Which of us is correct?
- What molecular property causes certain matter to be transparent?
- How does sun block work?
- How do underwater flares and torches work, when water puts out fires?
- Why does popcorn stick to your tongue or anything else that is damp?
- How do you make a man made element?
- How come deserts have sand instead of dirt and soil?
- How do magnets work?