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.
You all remember when on a dry winter day you shuffle along your carpeted living room floor and then touch somebody with your extended finger. You may have seen a little spark. That's a lightning bolt on a small scale (the sensation may not be too pleasant - but that's a sacrifice needed in the name of science). Now, in the lightning in the sky, your shuffling on the carpet is replaced by a vigorous wind rushing past rain drops and ice particles (yes - it's cold where the clouds are) and the result is a spontaneous lightning flash. Physicists describe this as positive (+) and negative (-) electric charges which are separated by the wind and reunite with a sudden flash.
What about the thunder? That's even easier to demonstrate: Just clap your hands, or better still, let an adult do it. Their hands are bigger. The demonstration works best if the hands are cupped so they catch some air between them: Bang! In the sky, the lightning flash will heat the air in its path. That will make it expand. You can show that also at home: Put an inflated rubber balloon into the warm oven (careful: not too hot - your mother doesn't like bits of rubber stuck to its walls). When you take the balloon out, you notice that it has grown bigger. When it cools, it shrinks again. The same occurs when the lightning flash is moving through the air. When the air cools off afterwards, it rushes back together and: Boom - the clapping of the hands in the cloud of a thunderstorm!
There are many other questions, for example: Why do the lightning bolt and the thunder sometimes occur simultaneously, and sometimes not, and why does even the fastest moving car seem motionless when illuminated by a lightning bolt? Think about it!
- In 1987, there was a supernova which was detected on earth by a burst of neutrinos and also by a flash of light coming from the exploding star. Einstein's relativity principle mandates that nothing can travel faster than the speed of light, so the light and the neutrinos should have reached earth at the same time. But instead, the neutrinos arrived first, followed 6 hours later by the light. What is the explanation of this? Does it mean that Einstein was wrong?
- Will a candle burn in a space ship where everything is weightless?
- If light has no mass, why is it affected by gravity? I read that light can not escape a black hole because of the gravitational pull and that light from distant stars bends around our sun's gravitational field, making it appear that they are in a different direction from Earth than they actually are. I also read that light is massless, and that gravitational force is a function of mass. These seem inconsistent.
- How come there is no thunder and lightning in the winter time?
- If light travels in a straight line, why is lightning crooked?
- How many active volcanoes are there in the world?
- Why do stars form pictures?
- How did scientists get the idea for light years?
- Why do the moon and the sun seem to change colors?
- Why does each snowflake have a different shape?