If you've ever glanced skyward, you've probably noticed the sheer numbers of stars. Some are tiny, barely visible points. Others radiate strong white light.
Why are letters reversed in a mirror? Try this experiment with pen and paper.
You may notice in a mirror that words are backwards in the reflection, but it's actually more than words that are reversed; it's everything!
Photocopying machines are fairly complicated devices, but the basic principal is pretty simple.
Why can't we landlubbers focus underwater without goggles?
This is partly due to pollution, but even in the cleanest air the sky is lighter near the horizon due to the effect of earth's atmosphere on sunlight.
How many times have you heard a jet plane going over but not been able to find it even though you were looking toward where the sound was coming from?
Are you familiar with the study done by Wolfgang Miltner at Friedrich Schiller University in Germany?
Why is the moon sometimes orange or red? Why is the sky blue? These questions are closely related!