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.
Now, do cats' eyes glow in the dark? No they don't. Cats and dogs have some cells behind the retina that act like a mirror. These cells are found in a part of the eye called the tapetum. This mirror reflects light back, giving the rods and cones a second chance to pick up the small amount of light available at night. It is this tapetum that makes cats' and dogs' eyes seem to glow in the dark.
Humans don't have a tapetum. You may have noticed that if you use flash to take a photo, humans tend to look like they have red eyes. This is because there is a reflection of the red blood vessels behind our retinas. If you took a flash picture of your dog, you might see yellow or orange eyes instead. This is a reflection of the light of the flash by the dog's tapetum.
- How does a microphone work?
- How do we know how old the earth is?
- What is blood made out of? If you wanted to make blood, what ingredients would you need?
- What exactly is radiation and why is it harmful? What can it do to you? How is it made?
- How many types of rocks are there throughout the world?
- I am currently studying electronics and how they work together to perform work. But I seem to get confused when the term "ground" is used. I understand that it is a "zero" reference point, and that it is a common return path for electrons to earth ground. I get stumped though when I see a schematic that has a ground attached to the negative end of a battery terminal in a dc circuit. Why don't the electrons just flow straight to ground? Then in an AC circuit schematic, I see a ground connection again connected to the negative side of a circuit. Can I assume that the ground is positively polarized which attracts the electrons?
- If radioactive elements are getting converted into half in each of their successive half lives, then are radioactive elements going to disappear from universe after certain amount of time?
- How do minerals and nutrients form? Why do some foods have metals in them?
- 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?
- Recycled metal looks like the same color as non-recycled metal. When soda cans are recycled, what happened to the paint or dye that was on top of the aluminum?