“Newton’s inverse-square law has been around for a while,” Daniel Kapner tells PhysOrg.com. “But, by testing this law, we’re looking for new physics.” The new physics Kapner and his colleagues are ...

The Inverse Square Law of Illumination has been with us for so long and is commonly taken for granted that it might seem to be a questionable subject for discussion. I feel revival of interest in this ...

Anyone who’s delved into lighting knows that it’s a complex blend of art, craft and science. Within that pillar of science is the formula, which helps us predict how lights spread over distance—The ...

A lamp illuminates a screen of area \(2.0m^{2}\), which is \(4 m\) away. The irradiance at the screen is \(0.02Wm^{-2}\). a) Calculate the power of the incident beam. b) If the screen is moved to a ...

Gravity is the weakest of the fundamental forces, but it’s the only force that operates over very long distances. Hence, planets orbit stars, stars form galaxies, and galaxies cluster. Gravity also ...