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What is the reason for the emission of electromagnetic waves from the sun and why curve its in about the visible light is maximum?


marked as duplicate by Bill N, Rob Jeffries astrophysics Mar 6 at 19:51

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    $\begingroup$ Unclear: What are you asking about: 1) fluctuations in the total intensity 2) electromagnetic radiation in general 3) shape of the blackbody radiation curve 4) the specific peak intensity wavelength. ?? $\endgroup$ – Bill N Mar 6 at 19:06
  • $\begingroup$ Since the sun is a black body and emits electromagnetic waves, the question is: what is the origin of all electromagnetic waves in the sun, such as ultraviolet , infrared, visible, etc radiations, and why in the wavelength-temperature curves, Is maximized in visible light? $\endgroup$ – abolfazl soulat Mar 6 at 19:22
  • $\begingroup$ You should edit that info into your question. $\endgroup$ – PM 2Ring Mar 6 at 19:28
  • $\begingroup$ It is a plasma , i.e. ions and electrons at the temperature of the sun radiating in the fields of each other $\endgroup$ – anna v Mar 6 at 19:29
  • $\begingroup$ So why does it radiate at different wavelengths? $\endgroup$ – abolfazl soulat Mar 6 at 19:31

If you vibrate a charged object back and forth, it will emit electromagnetic radiation. The atoms and molecules that make up matter vibrate randomly and hence produce radiation. The hotter they are, the more violently they vibrate, and the more energetic (meaning higher frequencies) becomes the radiation they produce. The resulting spectrum of frequencies is called a blackbody spectrum which has a peak in it that we use to define that object's temperature. The surface of the sun emits like a black body and its temperature (~5800K) happens to put the peak of its emission spectrum in the visible range.

  • $\begingroup$ sun and black body en.wikipedia.org/wiki/Sunlight#Composition_and_power $\endgroup$ – anna v Mar 6 at 19:09
  • $\begingroup$ So with this account, in the center of the sun, where the temperature is much higher than its surface, an electromagnetic wave with a wavelength higher than the visible light wavelength should be generated !!!!!!! $\endgroup$ – abolfazl soulat Mar 6 at 19:28
  • $\begingroup$ @abolfazlsoulat ultraviolet has a frequency ( not wavelength, large wavelengths are small energy E=hnu) larger than visible, and xrays and gamma rays also, and yes they exist but it takes aeons for em radiation from the center of the sun to get to the .surface. see en.wikipedia.org/wiki/Solar_core $\endgroup$ – anna v Mar 6 at 19:33
  • $\begingroup$ @abolfazlsoulat Also see, image.gsfc.nasa.gov/poetry/ask/a11354.html $\endgroup$ – Bill N Mar 6 at 19:36
  • $\begingroup$ Yes @abolfazlsoulat, in the center of the sun it's so hot that the radiation is in the form of gamma rays! $\endgroup$ – niels nielsen Mar 6 at 19:49

"why curve its in about the visible light is maximum?" We could turn this question round and ask why radiation near the peak spectral intensity of the Sun is visible. A Darwinist might reply that eyes have evolved to make use of most intense available radiation.


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