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.
"Fake" ruby results from mis-identification of another red mineral, commonly garnet or tourmaline, or of colored silica glass. These mis-identifications are relatively easy to detect making use of physical properties. For instance, ruby is much harder than tourmaline, garnet, or especially glass. As well, fake rubies are often less dense than the real thing. It's easy to do these physical tests.
Now comes the hard part: telling natural from synthetic ruby As is the case for diamond, a lot of ruby crystals have been grown (synthesized) in the lab. Growing rubies is by no means easy, but unlike mis-identified ruby, synthetic ruby is no less "real" than natural ruby. It can be extraordinarily difficult to tell the two apart. In the Verneuil synthesis process (used for over a century), rubies are grown by dripping fused alumina onto a plate, where it crystallizes. Characteristically curved growth features--observed with a microscope-- remain in the synthetic single crystal and are tell-tale signs of a synthetic origin. Heat treatment changes the internal features of the crystal making detection of this type of synthetic ruby more difficult. More recently, the appearance and physical properties of ruby crystals grown in a flux can be made to be essentially identical to those of natural ruby. Chemical analysis to detect trace amounts of impurities characteristic of the flux--like lead-- may be the only way to tell natural from synthetic.
Interested is seeing some natural ruby and corundum? Come to the Snee Hall mineral museum on the Cornell campus!
- After mixing 1oz of cornstarch and some water together, why does it get hard when pressure is applied? And then when the pressure is released, the mixture becomes drippy?
- Our textbook tells us the speed of the molecules that make up the air we breathe, but the speed it gives us is faster than the speed of sound. Why don't we hear sonic booms as when an airplane breaks the sound barrier? Are the particles just too small for us to hear the booms?
- Why does the earth have more water than land?
- Can you please tell me what exactly nanobiotechnology is. Also, does it have a future? Or will it greatly effect the future and will nanobiotechnology be one of the leading areas of research?
- Isaac Newton discovered gravity, but why did he call it gravity?
- Is popping popcorn a physical or a chemical change?
- Can you explain the darkening of glass by irradiation? I am working with a high school chemistry teacher who would like to be able to use some old glass samples in discussions of atomic structure. Some of the glass has been turned purple through exposure to Cobalt-60.
- Why are combustion reactions exothermic (why is fire hot)? What makes these reactions produce heat the way they do?
- How are submarines able to go down so deep under the water, and then surface?
- My dad just got some new tennis shoes with that reflective stuff on them. What is the difference between those reflective stickers and the glow in the dark stars over my bed?