Apparent Magnitude
It is a scale where each successive integer is half as bright as the one below it (-3 is twice as bright as -2, etc). For example, Venus is around mag -4, and the human eye can see object up to mag 7
The amount of starlight received on Earth varies depending on factors like the distance from the star, the star's luminosity, and atmospheric conditions. On average, about 1 billionth of the total light emitted by the Sun reaches Earth's surface, providing energy for life and driving Earth's climate system.
No. A light year measures such large distances that it would be highly impractical to measure anything on Earth. The light year is used to measure distance in space beyond the solar system.
A light meter is commonly used to measure the amount of light under a tree. It measures the intensity of light in lux or foot-candles, giving a numerical value that indicates the level of illumination in that area.
light years
Light years is a measure of distance, not of time; it is the distance that light travels in one year.
Parallax
Parallax
B:See related question;
The amount of starlight received on Earth varies depending on factors like the distance from the star, the star's luminosity, and atmospheric conditions. On average, about 1 billionth of the total light emitted by the Sun reaches Earth's surface, providing energy for life and driving Earth's climate system.
David smallman waz ere 2k12!
How: Earth receives the Sun's radiation as sunlight (and a smaller amount of invisible light, such as infrared and ultraviolet radiation). This is a huge amount of power received by Earth.
A "light year" is a measure of distance, derived from "how far light can travel in one Earth year". Thus, if you shine a torch for the amount of time it takes the Earth to orbit the sun exactly once, that light would have travelled the distance of a "light year".
light beams are received from the sun.
No part of the Earth receives the same amount of light every day, but every point on Earth receives the same amount of light in a whole year.
Beam spreading is when the sun's rays (or angles) spread out because the earth is in it's revolution and rotation. However this is the definition of beam spreading relating light and the amount of light received to earth, not relevant to another meaning. So basically beam spreading is when the sun's light spreads on earth.
Parallax
When the amount of light reflected increases, it is referred to as brightness or luminance. This is a measure of how intense the light appears to the human eye.