The light we use today in our homes and offices comes more than 150 years ago. Throughout the nineteenth century, inventors produced simple electric lights. For example, Joseph Swan produced a simple electric light. But, he struggled to maintain a power source and the filament soon burned out when the vacuum was exhausted. Thomas A. […]
During the day time, we can see things clearly. But we switch on the lights to see them at night. If we close our eyes we cannot see anything even during day time or at night with lights on. Why is that? So, let us find what requirements should be fulfilled to have “vision”. […]
We can see the bright moon in the night sky. Because of this you must have thought that it is a luminous object. But the moon does not emit its own light. We see it as a bright object because the rays of light emitted by the sun fall on the surface of the moon. […]
