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.

Previous Week's Question Published: 20 December, 2000 Next Week's Question
Experiment will reflect mirrors' hand reversal
Question
Why is a mirror left-right reversed, and not up-down backwards?

Question
A mirror always changes a left hand into a right hand and vice versa. Sometimes it can even change up to down.

A flat mirror bounces light back to an object in a straight line. If you hold up your right hand with thumbs up in front of a mirror on the wall, the light comes straight back from the top of your thumb, and the image in the mirror gives you the 'thumbs up'. But, the light from your fingertips also comes straight back making the image in the mirror look like a left hand. Your left hand is the mirror image of your right hand and vice versa.

Try an experiment: Place a hand mirror on the floor and give the thumbs up sign with your right hand just over it. What will you see in the mirror? Will the reflection be a right hand with thumbs up or thumbs down? Will it be a left hand with thumbs up or thumbs down? The results of the experiment will answer your question. You will learn that whether the mirror changes up to down depends on how you position it.

Do you know that many molecules come in left- and right-handed forms? For example, your body makes the sugar glucose in only one handed form, called D-glucose. Your body can't use the mirror image form, called L-glucose, which can be made in the lab. So you see, mirror images are important in nature too.

Related Questions