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.
The water that comes out of the hydrant is the same water that comes into homes, businesses, and schools. This water has a water pressure of about 50-80 psi (pounds per square inch). This pressure is high enough for everyday use, but is not high enough for use by firefighters. So, the pumps on the fire engines increase the pressure. Then, there are smaller hoses that attach to the engines that firefighters use to fight fires.
Fire hydrants in the cooler states have an added level of complexity because the temperature often goes below freezing in the winter. Since water expands when it freezes and turns to ice, the hydrant could crack if there is water in the hydrant when it freezes and expands. Also, if there was a fire during the freezing weather, the hydrants wouldn't work, because there would be a huge chuck of ice clogging the hydrant.
To avoid the problem of freezing water, many hydrants are 'dry barrel hydrants', which means that no water stays in the upper section of the hydrant when the hydrant valve is turned off. The valve that controls the water flow is below ground and there is a long rod that connects the stem nut to the valve. Next to the valve, there is a drain hole to let water drain out of the barrel of the hydrant after firefighters turn the valve off. The pipe that holds the water is buried deep enough so that it never freezes. (A bit of trivia: Because of this mechanism, it's near impossible for a car to run over a fire hydrant and cause it to gush water as they do in the movies, since there usually is no water in the upper part of the barrel.)
- If you take a substance like water and were able to get it to absolute zero, where supposedly the molecules would cease to move, and then you reheated it, would the molecules recover and start to move again?
- If the mantle can rise when weight has been lifted off of it (isostasy), then why are some islands sinking into the ocean?
- What would happen if a tornado started in the southern hemisphere and progressed into the northern hemisphere? Would it change directions?
- How does two-photon microscopy work? How do the resonance patterns create a photon with half the wavelength of the parent photons?
- How are plastics made into useful products?
- Is jello an amorphous solid? If not, what is it?
- Are there any nontoxic ingestible fluorescent materials?
- How is ink made?
- How would gravity function if the earth were a torus?
- Do mountains ever fall?