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!
- Why does hot air go up and cold air go down?
- How do you make a magnet?
- How come ice skates slide over ice so easily when hydrogen bonds usually make things stick?
- Are cats and dogs colorblind? Do cats' eyes glow in the dark?
- What is in batteries that causes electricity?
- How do magnets work?
- When hydrogen explodes and combines with oxygen, where does the energy that is released in the explosion come from?
- What causes a heat sensitive material, such as a mood ring, to change color when it's temperate is altered? What is this material made of, and where else might it be used?
- What material is flame made of?
- Can you please tell me what exactly nanobiotechnology is. Also, does it have a future? Or will it greatly effect the future and will nanobiotechnology be one of the leading areas of research?