how does solar energy become heat energy on earth?
2 thoughts on “Solar energy?”
A.V.R.
Blame the second law of thermodynamics for it. The surface temperature of the sun is about 6000K. Bulk of its radiation is already heat; the rest becomes heat when absorbed by various things in the atmosphere and degrades to heat, which is the lowest form of energy.
campbelp2002
Visible light is absorbed by the ground. As each atom absorbs a photon of light, it increases its kinetic energy. Heat is just the sum total of all the kinetic energy of all the atoms in a substance. So the ground warms up. All warm things emit light, but the ground, being much cooler than the Sun, emits infrared light instead of visible light. That would escape back to space if it were not blocked by clouds, water vapor and carbon dioxide in the air. It is the increasing amount of carbon dioxide in the air, from burning coal, oil and natural gas, that is reducing the amount of heat that escapes back to space, resulting in the Earth warming. The effect is extremely small, so the temperature rise is very small, but not zero.
Blame the second law of thermodynamics for it. The surface temperature of the sun is about 6000K. Bulk of its radiation is already heat; the rest becomes heat when absorbed by various things in the atmosphere and degrades to heat, which is the lowest form of energy.
Visible light is absorbed by the ground. As each atom absorbs a photon of light, it increases its kinetic energy. Heat is just the sum total of all the kinetic energy of all the atoms in a substance. So the ground warms up. All warm things emit light, but the ground, being much cooler than the Sun, emits infrared light instead of visible light. That would escape back to space if it were not blocked by clouds, water vapor and carbon dioxide in the air. It is the increasing amount of carbon dioxide in the air, from burning coal, oil and natural gas, that is reducing the amount of heat that escapes back to space, resulting in the Earth warming. The effect is extremely small, so the temperature rise is very small, but not zero.