How much mass does the sun add to the earth each day?

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Discussion Overview

The discussion centers on the question of how much mass the Sun adds to the Earth each day, exploring the implications of energy transfer from the Sun, particularly through insolation and solar phenomena. The conversation touches on theoretical aspects, energy balance, and the effects of solar wind and radiation on Earth's atmosphere.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that the Earth is in thermodynamic balance, with incoming solar energy being countered by outgoing infrared radiation.
  • Another participant discusses the conditions under which mass-energy equivalence (e = mc^2) applies, noting that high-energy photons are required for particle production, which are rare from the Sun.
  • A participant mentions that particles from solar flares reach Earth but their mass contribution is negligible.
  • There is a discussion about the solar wind potentially removing matter from Earth's atmosphere, with differing views on its impact.
  • One participant argues that while individual particle mass does not increase, the mass of the system may still be affected by thermal energy contributions.
  • A later reply corrects a previous claim about the energy required for pair production, suggesting a different energy threshold and discussing the ionization of gases in the atmosphere.
  • Another participant introduces a mathematical perspective on the fraction of solar radiation that Earth receives, emphasizing the small solid angle covered by Earth compared to the Sun.

Areas of Agreement / Disagreement

Participants express differing views on the effects of solar phenomena on Earth's mass and atmosphere, and there is no consensus on the overall impact of solar energy on Earth's mass. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Limitations include assumptions about energy transfer mechanisms, the specific conditions required for mass-energy conversion, and the mathematical approximations used to describe the interaction between solar radiation and Earth.

S = k log w
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How much mass does the sun add to the Earth each day?
 
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Evidently you mean via the energy of insolation and some assumed physics supporting e = mc^2?

Not much, for two reasons.
1) The Earth is in rough thermodynamic balance. The incoming energy from the sun is balanced by the outgoing energy of the Earth's infrared radiation.

2) e = mc^2 doesn't just happen. You have to have a specific event, such as a photon producing an electron and a positron. But in order to do that, the photon has to have enough energy to cover the masses of the two particles, 1022 electron volts. And the only photons with that kind of energy are up in the gamma ray range. Very few solar gamma rays (there are a few), make it down to the surface of the earth.
 
Particles from the recent solar flare would have made it to Earth... but their mass would have been absolutely minute.
 
I thought the solar wind was removing matter from Earth's atmosphere...
 
2) e = mc^2 doesn't just happen.

It would contribute thermal energy, though. While the mass of any individual particle doesn't increase, the mass of the system does, doesn't it?
 
Originally posted by FZ+
I thought the solar wind was removing matter from Earth's atmosphere...
Solar wind or not, our atmosphere does "evaporate," which is why it doesn't have much in the way of lighter elements - like hydrogen.
 
Correction

Originally posted by selfAdjoint
2) You have to have a specific event, such as a photon producing an electron and a positron. But in order to do that, the photon has to have enough energy to cover the masses of the two particles, 1022 electron volts. And the only photons with that kind of energy are up in the gamma ray range. Very few solar gamma rays (there are a few), make it down to the surface of the earth.

Hi selfAdjoint,
I think you mean for "enough energy", 1.02 x 10^6 electron volts.
Also, in the context of this string, isn't the absorption of gamma rays by the stratospheric environmental gases manifest as the ionization of those gases that end up rising into the ionosphere? Any Earthbound high voltage (>1.02 MeV) accelerator is capable of producing copious "pair-production" events. Cheers, Jim
 
According to my geology books, the atmosphere is not "evaporating." That is except for hydrogen. Helium is to big to escape the earth.
 
Another factor to take into account when computing how much mass and radiation the Earth gets from the Sun is the extremely small solid angle we cover.

Sun's wind and radiation escapes in all directions; Earth's radius is roughly 1/100th of the Sun's, and is located at about 100 Sun diameters from it.

Edit:

Using Earth's orbit as unit of length (say, u), Sun's radiation is distributed on a spherical surface with an area 4[pi] u2, while Earth "catches" only an area of [pi]r2, with r ~ (10-4u)/2:

Earth's receiving area = [pi](0.5*10-4u)2
= [pi]0.25*10-8u2

So, our fraction of the total is:

f = (Earth's area)/(Area of the sphere)
~ 0.25*10-8/4 = 6.25*10-10

Now that I think of it, it is impressive the amount of power the Sun is putting out, given the fact that we get warm at all!
 
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