Explaining Energy Transfer on Earth

In summary, the Earth is in thermal equilibrium and maintains a constant temperature by exchanging heat through radiation. All energy eventually becomes part of the EM spectrum and leaves the Earth. The temperature of the Earth depends on the balance between incoming energy from sunlight and internal heating, and outgoing energy through radiation. Seasons are specific to a hemisphere, but overall the Earth does not experience a net difference in energy from one season to the next.
  • #1
Greenhippo
2
0
just a quick query, i hope you physics folk can explain

If all of the energy that enters Earth comes form EM waves from the sun and once inside the atmosphere the waves change into all different forms of energy (ie heat Ek electrical). Doesnt it make sense to prevent a build up of energy in Earth an equal amount of energy must leave earth, and the only way i know of energy escaping Earth is via more EM waves.

Does this mean that all energy eventually becomes part of the EM spectrum and leaves, or is there a net build up of total energy or is there simply some physics phenomonia I am unaware of
 
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  • #2
Originally posted by Greenhippo
just a quick query, i hope you physics folk can explain

If all of the energy that enters Earth comes form EM waves from the sun and once inside the atmosphere the waves change into all different forms of energy (ie heat Ek electrical). Doesnt it make sense to prevent a build up of energy in Earth an equal amount of energy must leave earth, and the only way i know of energy escaping Earth is via more EM waves.

Does this mean that all energy eventually becomes part of the EM spectrum and leaves, or is there a net build up of total energy or is there simply some physics phenomonia I am unaware of

Pretty much. The Earth is in rough thermal equilibrium. It has two main sources of heat, sunlight, and internal heating. If its temperature is not to continually increase then it must get rid of heat at the same rate that those two sources provide it.

The only way for a body in empty space (approximately true for the earth) to get rid of heat is by radiation. By a law of physics, the frequency of the radiation, and so the energy density or efficiency of radiation for removing heat, depends on the temperature. So the temperature of the Earth will rise until its own radiation (max in the infra-red) takes away heat at the same rate as the two sources supply it. As soon as this condition is reached, and as long as it is maintained, the overall temperature will stay constant.

As I said, that is roughly the situation we are in.
 
  • #3
Essentially, while the sunny side is soaking up energy mainly in the visible spectrum (Is this correct? Perhaps others will correct me if it is not.) The dark side is radiating infra red, according to local surface temperatures. The longer the night, the more heat that is lost. This is why summers are hot and winters are colder. Long days and short nights mean net gain in energy, the temperature increases. In the winter,long nights and short days, a net loss of energy, the temperature decreases.
 
  • #4
I think that the light from the sun is peaked in the UV range somewhere; it is at a pretty high temperature.

The summer winter thing is specific to a hemisphere, but the overall Earth doesn't see any net difference from one season to the next. It is summer in Australia when it is winter in Texas.
 

1. How does energy transfer on Earth?

Energy on Earth is primarily transferred through three main mechanisms: conduction, convection, and radiation. Conduction is the transfer of heat through direct contact between two objects. Convection is the transfer of heat through the movement of fluids, such as air or water. Radiation is the transfer of heat through electromagnetic waves, such as sunlight.

2. What is the role of the sun in energy transfer on Earth?

The sun is the primary source of energy on Earth. It provides heat and light through radiation, which is essential for sustaining life on our planet. The sun's energy is absorbed by Earth's atmosphere, land, and oceans, and then redistributed through the three mechanisms of energy transfer.

3. How does energy transfer affect Earth's climate?

Energy transfer plays a crucial role in regulating Earth's climate. The amount of energy transferred from the sun to Earth and back to space determines the overall temperature of our planet. Any changes in the amount or efficiency of energy transfer can have a significant impact on Earth's climate, leading to phenomena such as global warming and climate change.

4. What are some examples of energy transfer on Earth?

Energy transfer can be observed in various natural phenomena and human activities. For example, when you feel the warmth of the sun on your skin, that is energy transfer through radiation. Cooking food on a stove involves energy transfer through conduction, as the heat is transferred from the stove to the pot and then to the food. Convection is also at work when you see hot air rising from a hot surface, such as a heated road on a summer day.

5. How can we increase the efficiency of energy transfer on Earth?

There are various ways to increase the efficiency of energy transfer on Earth. One approach is to use more efficient technologies, such as energy-efficient light bulbs and appliances, which can reduce the amount of energy lost during transfer. Another way is to reduce the barriers to energy transfer, such as improving insulation in buildings to reduce heat loss. Additionally, switching to renewable energy sources, such as solar and wind power, can also lead to more efficient and sustainable energy transfer on Earth.

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