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.)
- How is mercury a liquid like substance, but it does not make anything wet?
- Is it possible to use electrolysis or another method to separate NaCl into sodium and free floating chlorine gas?
- How do underwater flares and torches work, when water puts out fires?
- How do magnets work?
- Is being a scientist fun? How is it fun?
- What molecular property causes certain matter to be transparent?
- If an object passes in front of a projector/point-source of light that illuminates a screen far away, it will cast a shadow on the screen. Now, if the object moves fast enough, and/or if the screen is far enough, the shadow will move much faster than the object, and at a certain speed of the object, the shadow will move faster than the speed of light. What would a bystander, or a camera, see?
- Why do crystal glasses give off sound when you rub them with a wet finger?
- Where does the chlorine from pools go when the water evaporates? Does this harm the ozone?
- In Einstein's equation, E = mc2, he says that the energy released by an object is equal to the object's mass times the speed of light squared. Why is the speed of light a factor in determining energy release?