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.
For example, 1 liter of water contains roughly one million, billion, billion molecules, each composed of one oxygen and two hydrogen atoms.
In solids, the molecules composing the material stick strongly to each other and cannot move. In liquids (such as water), on the other hand, the molecules are less strongly attracted to each other and can rearrange. At room temperature, the relatively small water molecules flow past one another to form a liquid.
The molecules that make up cornstarch are very different from the small water molecules. They consist of long chains of repeating units called sugars. Sucrose or table sugar has two such repeating units per molecule, whereas starch has many, many, more. In pure cornstarch, the sugar chains stick strongly and cannot move past one another, thus starch is a solid.
However, if we add water to starch, the water gets between the starch chains, separates them and allows the chains to slide past one another; the mixture behaves as a liquid.
If we apply pressure to the starch mixture, the water is squeezed out from between the chains and they are able to grab one another. Sliding is prevented and the material behaves as a solid. If we release the pressure, the water can enter between the chains to allow sliding once more.
This behavior is not limited to the molecular scale. A similar phenomena occurs when you run on wet sand at the beach. If you run fast and generate pressure quickly the sand feels hard as water is squeezed out and the sand particles cling to each other. If you step slowly to apply the pressure gradually, the sand particles have time to move past one another -- your foot sinks!
- What happens at the edge of a diamond? How does the carbon end?
- If you burn a liter of fuel in an internal combustion engine are the emissions the same weight as the weight of the original liter, if not why?
- How does a fluorescent light bulb work?
- What about the atomic structure of a substance determines its color and/or luster?
- I heard that peppermint candy will help you do better on a test. Is this true? And, is there anything in peppermint candy that will boost my scores?
- Why does my milkshake stay thick even when it warms up? Shouldn't it get thinner as it melts?
- What is Jupiter made of?
- How do scientists determine the viscosity of lava?
- Is being a scientist fun? How is it fun?
- The laws of thermodynamics teach that things in nature go from order to disorder but the theory of evolution teaches that well ordered creatures evolved from disordered ones. How can both be true?