The sun produces light, heat, and other things. If the visible spectrum of light from the sun stopped hitting the earth but only the light directly from the sun, so moonlight and if heat can be traveled without light, stopped hitting the earth what would the effects be?

In this case please assume the visible spectrum of light is anything a living thing can detect with eyes, so some infrared and some ultraviolet.

**Edit: **I understand that eventually everything would either adapt, bacteria is whack, or completely die off. If you could include how long you think that would take and what would die off first and the like, that would be nice. Also, Trioxidane suggested that this question was similar to another question. I'd like to clarify the sun isn't gone but most of the light coming from it is.

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    $\begingroup$ Does this answer your question? Earth was suddenly teleported away from the sun. Can we recover? $\endgroup$
    – Trioxidane
    May 8, 2021 at 17:14
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    $\begingroup$ @Trioxidane Useful information but it doesn't quite answer my question. I want to know if the visible light spectrum goes away. The sun is still there most of the light is just gone. $\endgroup$
    – Idan
    May 8, 2021 at 17:18
  • $\begingroup$ Also near-duplicates: Sun's Light Goes Out, Humans surviving on surface without sun. $\endgroup$
    – jdunlop
    May 8, 2021 at 18:12
  • $\begingroup$ Visible spectrum to what? Some fish and frogs can literally see infrared, snakes can essentially "see" it through specialized pit organs, as can vampire bats, and birds can see ultraviolet. If you mean no light that can be perceived by any creature is reaching the planet then I'd have to ask whether this answers your question, since in your question the sun would still be there, but would essentially not be emitting any kind of light other than some very low frequency waves. $\endgroup$ May 8, 2021 at 18:31
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    $\begingroup$ This question does not deserve to be closed. it is not a duplicate. I can think of several possible scenarios that would filter out visible light from the earth, some involving alien intervention, that do not stretch science believability but let all other wavelengths through. The other questions do not allow for that. $\endgroup$ May 8, 2021 at 23:29

2 Answers 2


(More than) two thirds of the power output of the Sun is in the visible spectrum; that's gone.

The rest is mostly in infrared and ultraviolet. Earth's atmosphere is opaque to ultraviolet, so that's gone too.

All that remains is about one sixth of the power which is in infrared... and which is nowhere near enough to keep Earth from freezing solid.

In a few days, temperatures on land will drop way below freezing. Plants and animals will die immediately; humans may linger for a while, but they will die too, soon enough.

The ocean will eventually freeze. Earth will become a ball of ice.

(The infrared radiation of the Sun will prevent temperatures from dropping low enough for the air to freeze, so at least the ice ball will retain an atmosphere.)

  • $\begingroup$ Could you explain what you mean by opaque to ultraviolet? $\endgroup$
    – Idan
    May 8, 2021 at 17:20
  • $\begingroup$ Also, how long do you think everything dying would take? A few hours, days, years? $\endgroup$
    – Idan
    May 8, 2021 at 17:24
  • $\begingroup$ @Idan: Air is opaque to ultraviolet light in the sense that ultraviolet light is absorbed and most of it does not reach the surface. As for how long wound the dying take, I don't know, in a few days it will be very very cold. I guess it depends on the species and the individual, but I don't expect that a lot of land plants and animals will survive for more than a few weeks. $\endgroup$
    – AlexP
    May 8, 2021 at 17:58

You might be interested in this information.

As can be seen from the chart, there is still a considerable amount of energy reaching the Earth - about 55%. The oxygen and water in the atmosphere is still absorbing and converting a lot of energy to heat. It is very doubtful the Earth would ever freeze over, and the greenhouse effect would not be much effected.

Since humans tan based on UV light, we would still be prone to skin cancer and such, and we would still warm up as usual on a sunny day, it just wouldn't be a bright sunny day.

It would be dark, but not completely, as the moon would provide illumination sufficient to see, depending on the moon phase.

Photosynthesis would be altered, but there are life forms in the oceans that are not dependent on photosynthesis. Also, there are cyanobacteria that use infrared for photosynthesis.

Far-red absorbing chlorophylls are constitutively present as chlorophyll (Chl) d in the cyanobacterium Acaryochloris marina, or dynamically expressed by synthesis of Chl f, red-shifted phycobiliproteins and minor amounts of Chl d via far-red light photoacclimation in a range of cyanobacteria, which enables them to use near-infrared-radiation (NIR) for oxygenic photosynthesis.

And cameras in phones and other devices would still be able to take pictures.

Solar energy using solar panels is also not completely out of the question.

One of the ways scientists have looked to increase the performance of solar panels is by supercharging them with special kinds of nanoparticles. By doping these tiny particles with dyes containing metal ions such as lanthanide, it is possible to equip them with the ability to make use of other types of light (such as infrared) and then have it converted into energy.

Oh, and mosquitoes would still find us.

Mosquitoes, vampire bats, bed bugs, and some snake and beetle species, however, can use portions of the infrared spectrum for vision.

  • $\begingroup$ As far as I know, if Earth received only half of the solar energy it does it would absolutely be a ball of ice. I would love to see why you believe that it would not freeze; serious question, I like learning new stuff. $\endgroup$
    – AlexP
    May 8, 2021 at 23:46
  • $\begingroup$ @AlexP The higher UV frequencies are higher energy, plus all of the x-rays and gamma rays above them. Also, as I stated, the water vapor and CO2 and such absorb the energy from the IR wavelengths still arriving at the Earth. It is the IR that heats the Earth, the visible spectrum is reflected back to space, very little is absorbed (that is why we can see things) and contributes far less to heating. It's main claim to fame is photosynthesis. As long as we keep getting the IR, the earth will continue to be heated. We just won't be able to see things from the reflected visible light. $\endgroup$ May 9, 2021 at 2:04
  • $\begingroup$ All of that visible spectrum light that we see, reflecting off mountains, grass, water, trees. plants, is obviously not contributing to heating, because it is obviously not being absorbed. It is the IR spectrum that is absorbed. $\endgroup$ May 9, 2021 at 2:08
  • $\begingroup$ No, most of it is absorbed, eventually. Earth's albedo is 0.3 to 0.4 (depending on the particular definition); 60 to 70% of the incindent light is absorbed. Think of a mountain covered with a conifer forest; we can see it fine, but it reflects only 10 to 15% percent of the incident light. $\endgroup$
    – AlexP
    May 9, 2021 at 2:45
  • $\begingroup$ @AlexP I researched the albedo, but I could not find a good reference to what frequencies were measured by it. It is my understanding that it covers a broad spectrum, including IR. So reflecting 40% of all spectrum could amount to 70% of the visible spectrum, perhaps. But 60% absorption of 40% incident spectrum leaves 24% absorption of the entire spectrum. Still leaves lots of energy to heat things up. www-das.uwyo.edu/~geerts/cwx/notes/chap02/… $\endgroup$ May 9, 2021 at 3:30

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