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.
In a light bulb, electricity passes through the tungsten filament, causing it to heat up and give off light. The filament becomes so hot that the tungsten metal slowly evaporates, turning to vapor and then solidifying as a thin layer on the inside of the glass bulb. Eventually, the filament weakens and breaks, and the bulb "burns out." A brighter bulb has a hotter filament, which causes faster evaporation of the tungsten. There is a limit to how bright a regular light bulb can be because the filament in a very bright bulb would thin and break too quickly to be practical.
In a halogen bulb, light is produced in the same way, and tungsten metal still evaporates from the hot filament. However, the evaporated tungsten reacts with the halogen in the bulb to form a compound called a tungsten halide. This compound forms at the relatively low temperature near the glass wall and breaks apart at the high temperature of the filament, redepositing tungsten metal on the filament. The halogen serves to transport tungsten back to the filament. A halogen bulb can be brighter and hotter than a regular bulb and can last longer because reaction with the halogen repairs the filament!
- Does gravity get stronger nearer to the ground? If so by how much?
- If a person stands on a circular rotating stand, facing away from the centre with arms outstretched holding a spinning bicycle wheel and tilts the wheel to once side this causes the stand they are standing on to rotate. My questions are: Why is this? Does it make a difference which way the bicycle wheel is spinning? Will the bicycle wheel's momentum be effected by the spin of the stand the person is stood on? For the strongest anti-clockwise pull on the stand should the wheel be angled by raising the right hand and lowering the left(tilting), or pushing forward the right hand and drawing back the left (turning).
- If the electrons are attracted to the protons, why don't they come crashing into the nucleus?
- We learned that plastics are being used as lights. Can any other ordinary products be developed in the same way?
- Why are the boiling points of metals with metallic bonds so varied?
- How do underwater flares and torches work, when water puts out fires?
- When a water surface reflects something (when looking from the top), does it undergo total internal reflection?
- What about the atomic structure of a substance determines its color and/or luster?
- What would happen if I dyed water green with food coloring, then put it in a humidifier? I was going to do it but my mom made me stop at the last second.
- Why does oil float above water?