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.
However, further magnification is sometimes not possible since every microscope has a limit to its ability to magnify and resolve details in an image. Light microscopes are limited to a magnification of about 1000X and a resolution of about 300 nanometers. When higher magnification and greater resolution is required researchers turn to electron microscopes which can magnify hundreds of thousands of times and resolve biological structures at the nanometer scale. Viruses and ribosomes, for example, are only visible under an electron microscope. The superior resolving power of an electron microscope will also produce a clearer image than a light microscope at the same magnification.
Finally, one of the most important steps in imaging cells (or any sample) under a microscope is specimen preparation. Researchers take great care to prepare good specimens. If a sample is not prepared well even an expensive, high quality microscope will have trouble producing a good image. Samples must be very thin to enable light or electrons to pass through them and a stain is often used to improve contrast in the image.
Microscopy is a very exciting field and as instruments and techniques continue to improve whole new worlds are opening up for us to see.
- We learned that plastics are being used as lights. Can any other ordinary products be developed in the same way?
- What is nanotechnology used for? Why do scientists study it?
- How are carbon nanotubes formed? Can they be positioned easily? How?
- 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?
- I have heard of ways to get energy through the braking of a car. How does this work?
- Can the human eye be compared to a computer monitor? Does the view we see refresh itself or is it more like live feed? If something was moving too quickly, would it appear jumpy like a low frames/second?
- Is the human eye like a fingerprint? Can it be used for positive identification purposes?
- How does RADAR work?
- Why do graphic equalizers have so many bars? I could understand 2 bars for L and R channels, but I get puzzled every time I look at one. If I took the left or right channel plug out of my receiver, would half of the bars stop moving?
- Why are the small computers of today faster than the big IBM computers of the past?