# Light and energy

1. Nov 26, 2005

### benzun_1999

Though all EM waves travels in the same speed each one has a diiferent energy. can any one tell me why. i know it is because of planks equation. but i am looking for some logical explanation.

2. Nov 26, 2005

### ahrkron

Staff Emeritus
Naively, you can think of it as an "internal vibration", the speed of which (its frequency) determines the energy of the radiation.

3. Nov 30, 2005

### benzun_1999

yes by the way what happens to the energy of the light when it passes through a different medium pls explain to me in detail.

4. Nov 30, 2005

### Staff: Mentor

When light passes through a passive medium its frequency (and thus the energy of a photon) remains the same but its wavelength changes.

5. Nov 30, 2005

### vaishakh

Energy of light rays does not change as it change mediums. the speed of differant frequence light rays are differant in differant mediums and thus the wavelength of differant frequency rays take the appropriate value

6. Dec 4, 2005

### benzun_1999

thanks for the help