![]() ![]() This drawing shows how light follows an inverse square law. Finally the last square is the least bright as it is 5 times the distance from the first and the light intensity decreases by a factor of 25.įigure 2. The fourth square is 4 times the distance as the first so light intensity decreases by a factor of 16. The third square is 3 times the distance as the first so the light intensity decreases by a factor of 9. The second light square is twice as far from the light source as the first square, so the light intensity decreases by a factor of 4. The smallest square is closest to the point of light and is the brightest. As light travels a certain distance, the intensity of the light will decrease by a square of the distance. ![]() At three units away, the intensity goes down by a factor of nine, and so on.Ī point of light spreads out in an increasing pattern of squares to represent the inverse-square law. This is illustrated in the Figure 2, where the red dot, the point source of light, has a light intensity we will name L 0 for this example, at one unit (it could represent any unit) away from the light source but as you double the distance to two units away, the intensity goes down by a factor of four. This means that as the distance from a light source doubles, its light intensity decreases by a factor of four, (which is the square of the factor of change). Scientists experimented and predicted that the relationship between intensity and distance would follow an inverse-square law. Light intensity is a measure of how much light falls on a certain area, like one square meter. To find out just how far away a star is, scientists first had to figure out how the light intensity of a point source of light, like a star, changes with distance. A photo, taken by Science Buddies founder Kenneth Hess, of 100 billion stars in the Milky Way at the ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |