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 biggest difference between compressing air and a pure gas is that the inlet needs to come from a source of pure gas, rather than just the room. For oxygen, the next big difference is that the seals and lubricants (rubber and oils) that are used to keep the high pressure gas from leaking past the piston and escaping into the atmosphere could easily burn because oxygen is so reactive. So, special fluoridated materials (related to TeflonŽ) are used instead.
In principle there are many things that could be used as a source of pure oxygen. For example, it would be possible to pass an electric current through water, and collect hydrogen at one electrode and oxygen at the other. But in practice, almost all pure oxygen produced commercially is obtained by liquefying air, then distilling it to separate out liquid nitrogen, oxygen, argon, and neon (and usually throwing away water, carbon dioxide and other contaminants). Small consumers of oxygen then use compressed gas from this liquid after it has been warmed up as a convenient means of storage without having to provide refrigeration. More major users like the steel industry or big chemical plants are likely not to bother with warming it and compressing it. They will buy it in the form of liquid transported by tank trucks that look from the outside much like an oil tanker, but which are really giant 10,000 gallon thermos bottles. Then heat is just supplied at a rate to supply moderate pressure oxygen gas as needed.
- What are electromagnets and what metals are included?
- Does the moon have lithospheric plates? Do other planets have distinct layers such as the inner core, outer core, and mantle, like the earth does?
- Can fire stay lit in space? For example, when a rocket takes off into space, there is fire coming out of the engines, but while in space is there still fire coming out of the engine? If not, how does the rocket get propelled without the force of the engine fire?
- What is fire? Does it have mass?
- How do airplanes fly?
- Can you turn gas into a solid form?
- Why do we get a shock from electricity?
- 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?
- Water doesn't spoil, but why do some water bottles have expiration dates?
- Is jello an amorphous solid? If not, what is it?