Questions tagged [sunlight]

For questions involving radiant energy from the Sun.

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6 votes
6 answers
2k views

Illuminating Minerva?

It would be convenient for both astrophysics and for the plot of the story set in this world if there exists a ninth planet in the Solar System far outside Pluto’s orbit (with appropriate mass, Ap, Pe,...
1 vote
1 answer
63 views

Green-appearing sun atmosphere composition

What would the composition of a planetary atmosphere would cause a sun to appear green (i.e. green sunlight) for most of the day? I don't mean a green sky, as similar questions have asked. If there ...
1 vote
0 answers
58 views

The calculation of sky surface brightness based on the apparent magnitude of the light source [closed]

I am wandering aimlessly to find the proper formula, which would calculate the sky surface brightness in any direction based on: apparent magnitude of the light source angular distance from the light ...
32 votes
11 answers
7k views

Can there be plants on the dark side of a tidally locked world?

In my story, there is an Earth-sized planet orbiting a red dwarf, tidally locked to its parent star, with large oceans like Earth, two moons similar to ours and a thick atmosphere to distribute heat ...
2 votes
1 answer
104 views

How to estimate the energy output of artificial suns

Setting I'm designing a world where only a thin belt wrapping the equator of a planet is hospitable. It would look something like this: The backstory, diluted for brevity, is that the central sun was ...
4 votes
2 answers
230 views

How to increase Jupiter’s reflectivity?

The idea of turning Jupiter into a sun to terraform the Galilean moons is a popular one. This concept goes by the alluring name of “stellification,” but has a few important drawbacks when prodded with ...
7 votes
5 answers
438 views

How would a crystal moon interact with light from the sun? Would a crystal moon reflect "too much" light for night time?

I have an earth-like planet in a fantasy setting with two moons, one of them made of crystal. It will be a fantasy crystal, properties TBD (probably by some of the answers to this question). My main ...
5 votes
2 answers
305 views

How deep underwater can red photosynthesis work?

The Setting: I have a binary star system. First star: K5.2V class Orange Dwarf, 60% the mass of Sol, 17% luminosity of Sol, and at 4.5 billion years old. This star is the only one with a planetary ...
2 votes
2 answers
2k views

Would it be possible to build a powerless holographic projector?

For one of my (many) science-fiction projects, I am designing immense rotating space-habitats. These titanic structures, (similar to Bishop rings; see here https://en.wikipedia.org/wiki/Bishop_Ring_(...
8 votes
5 answers
4k views

Would My Planet’s Blue Sun Kill Earth-Life?

I’m creating an Earth-like world where the sun appears blue to people from the planet’s surface. I think I’ve narrowed down the cause of this effect to the presence of 1 micron particles in the ...
4 votes
4 answers
416 views

Why does daytime on my planet resemble twilight/dusk?

The setting is science-fantasy, so there are some unnatural features that dictate the properties of the setting, but I'd rather not rely on it. So basically this planet is very similar to our own, but ...
2 votes
1 answer
192 views

Does My Planet Have to Have a Perpetual Sand Storm to Have a Blue Sun?

I’m creating an Earth-like world where the inhabitants and visitors to the planet see the planet’s sun as blue in color. I think that the best way to achieve this result is via atmospheric light ...
13 votes
9 answers
4k views

Could a moon made of fissile uranium produce enough heat to replace the sun?

This was my answer to this question: Retrofitting geocentrism - what replaces the star? I spent long enough on it and got an interesting enough result that I wanted to share, so that it might be a ...
2 votes
2 answers
423 views

What changes would be expected of Earth plants on a low-light planet?

I've read about plants on worlds orbiting red dwarfs potentially having black leaves due to the higher infrared radiation, but what kind of changes would be expected of plants on a planet like Mars ...
-1 votes
1 answer
125 views

Artificially simulate a northern-latitude environment in India (UV radiation) in order to make its natives fair-skinned

Assuming the Himalayas are successfully lowered to around 1,000-3,000 meters in altitude with artificial means, with some mountains kept at their actual altitude to feed the most important rivers, the ...
1 vote
1 answer
85 views

What would be the climatic and solar conditions of a canyon 1 kilometer below sea level in the West Siberian Plain?

Imagine a 3km wide, 99km long canyon which is 1km below sea level, just next to the city of Surgut but not passing through. This canyon has been dug as part of some superproject which seeks to create ...
1 vote
1 answer
311 views

Colour of the sky on a planet near a red dwarf [duplicate]

The twin planets Rhoda and Mary are two planets orbiting Barnard’s Star, a red dwarf star 6 lightyears from earth. The two orbit 0.05 AU from their sun, and 415,000 km from each other. They are ...
8 votes
3 answers
2k views

Suppose an array of mirrors 50 km above the surface reflect light straight down. How long before the sun rise are they illuminated?

Suppose at a point in the earth’s future, a superstructure has been built at the northern 45 parallel. 50 kilometers above sea level, a large array of mirrors has been built. The mirrors are ...
6 votes
5 answers
612 views

How can we prevent the Earth being scorched and swallowed as the Sun grows and eventually enters its red giant phase?

The Sun is slowly growing more and more luminous. As a result of these processes, multicellular life forms may be extinct in about 800 million years, and eukaryotes in 1.3 billion years, leaving only ...
4 votes
2 answers
377 views

How would the 'sky' look in a Stanford Torus?

I hope this is focused enough: my question boils down to: "How do people living in a Stanford Torus experience the sky?" Context: Operating on the assumption that we're in a fairly typical ...
12 votes
7 answers
818 views

How can a remote planet with little to no sunlight have high wind speeds?

I saw this question here: Can I have wind turbines on my base? and someone else asked about how the planet can have 60-100mph winds without very much sunlight to cause the energy differential, to ...
4 votes
3 answers
366 views

Would merfolk have pale skin?

Quite simply question. In my story I am depicting merfolk as having lighter skin than even Caucasian people, contrasting to my human society which bears resemblance skin tone wise to Hispanics. I've ...
14 votes
3 answers
585 views

How big does a world have to be to not have a sunset?

Normally we watch the sun descend, it's dimmed a bit by the atmosphere before dropping below the horizon. What I'm interested in is how big it would have to be so the atmospheric dimming is sufficient ...
4 votes
5 answers
449 views

Would living on around Alpha Centauri change how our eyes see color?

I am writing a sci fi novel in which one of the primary factions is a lost space colony sent to Proxima Centauri (Alpha Centauri C) roughly 350 years prior on a generation ship. The trip took roughly ...
13 votes
5 answers
1k views

Viability of solar furnace/smelter in pre-industrial society

I am trying to figure out how plausible it would be for people without electricity or steam power technology to use the sun to smelt and forge iron and steel. The people developing this solar furnace ...
4 votes
2 answers
199 views

How would Blue/Yellow colored plants change during different weather seasons

My planet basically revolves around a blue star or a star that gives off more blue wavelengths, and the color of the plants are either blue or yellow or both because they are trying to absorb the most ...
5 votes
1 answer
80 views

What changes to a humans physical form would occur if society lived inside the Earth?

(Mandatory I am new here, hello, nice to meet some fellow world builders, sorry for any mistakes, yikkity yak and all that) In my "world", it has been 500 years since the majority of human ...
4 votes
2 answers
206 views

How large must a solar furnace be in order to sweep a planets surface melting everything in its path?

To melt a planets surface erasing all traces of civilisation, I figured a solar furnace would do the trick. It is more elegant than nuking a planet, not to mention leaves no nuclear fallout. Perfect ...
8 votes
3 answers
519 views

Visibility of a Dyson swarm "creature" from its orbiting planet

An alien species has built Dyson swarms around stars which have orbiting planets with primitive life on them. The section of the star which is facing the planet with life is left uncovered to let the ...
4 votes
4 answers
297 views

Can one half of a planet be desolate, while the other half is lush vegetation?

Is it possible for half a planet to be cold, dark and lifeless while the other is a lush jungle? Can a planet be tidally locked to a sun where the jungle surface is always facing the light, and the ...
9 votes
5 answers
4k views

How do migratory dragons avoid being blinded by sun?

These dragons are as big as double decker with wing span approaching 20m measuring from tip to tip, they migrate in large numbers and fly at an altitude between 10,000m to 20,000m above sea level. ...
3 votes
4 answers
908 views

Where does most of a sun's energy go?

first post ever here. I've read the guidelines, but please do let me know if I'm breaking any rule or doing something wrong. So, I am creating a magic system based on the energy of a star. More ...
7 votes
6 answers
2k views

Can mirrors on the moon allow solar panels to operate at night?

Solar panels cannot operate at night. If we put self-adjusting mirrors on the near side of the moon, they could reflect sunlight back to the dark Earth, allowing solar panels to operate at night. How ...
9 votes
2 answers
4k views

Can fiber optic cables be used to pipe sunlight into an underground bunker for growing plants?

One major problem with living underground is you lose all of that wonderful energy provided by the sun. This energy is useful for many things including growing plants for food. A window is effectively ...
1 vote
1 answer
110 views

Concerning Earth plants on an alien world, how much "sunlight" would "too much" and "too little" be compared to our sunlight?

In a binary system of artificially immortal stars, each one orbited by a ring of mirrors, a whole line of Earthlike planets orbits the binary within its habitable zone, from 400 to 800 AUs. While ...
2 votes
4 answers
2k views

Can humanoids be of dark skin despite living somewhat lower than the equator and vice versa?

So if the places on the equator of my world has light skinned people of the deserts while the places a bit south of the equator can have dark skinned folks of tropical rainforests, is that explainable ...
3 votes
5 answers
1k views

Why does my arcology let light in, when it was originally a sleeper ship

In my story the protagonist lives in an arcology, but this is not just any arcology. Over a 100 years ago, a global war fought between those who sided with a massively distributed and rather 'insane' ...
2 votes
2 answers
421 views

If visible light from the sun stopped hitting the earth but the sun still existed, how would this affect the earth?

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 ...
1 vote
1 answer
4k views

What Would the Sky Look Like If the Sun Were a Different Color (And Still Half a Degree Wide)? [duplicate]

This question has been asked many, many, many times--what would the sky look like if the sun were a different color? But the mistake I keep seeing is that they used actual stars and imagined Earth as ...
5 votes
1 answer
146 views

Creating fog over the ocean and large island using electricity and..?

Short version: This sea dragon can discharge and manipulate electricity. It wants to cover a large area of the ocean's surface in fog, how could it accomplish this? The creature is intelligent and has ...
2 votes
1 answer
201 views

Magic system- photosynthesis/"solar cell" dragons using electricity for warmth?

Background: So, I'm creating a magic system for a race of dragons based on the abilities of the Oriental Hornet and the Elysia chlorotica. both of these animals can directly utilize solar energy. I ...
3 votes
5 answers
429 views

Earth with no sunlight

What phenomenon could stop or reduce the sunlight on Earth? I am thinking about a prolonged solar eclipse. Is it possible for it to last for years? If not, is there a way for the sun to stop shining ...
-3 votes
2 answers
283 views

How Bright Would a "Summer" Night Be on This Extreme Alternate Earth?

Here is the oversimplified map of the solar system of an alternate Earth: It is actually two separate binaries--one consisting of a red giant 100 times as wide, one-third as massive and 1,000 times ...
10 votes
6 answers
7k views

How would a Dyson Swarm transmit energy to the Earth?

The Dyson Swarm is common in sci fi as an energy source, and sometimes also as a powerful weapon. As it is commonly understood, it harnesses the energy of the sun, which stores a vast amount of energy....
0 votes
2 answers
464 views

Humans surviving on surface without Sun

Is it possible for humans to survive on the surface of the Earth, assuming the Sun was, for some reason, not emitting any light/heat/other radiation? Would whether the Sun was actually present affect ...
41 votes
10 answers
8k views

Would life always name the light from their sun "white" [closed]

I've heard it said that white light contains all the colors in it. Our sun produces white light and that the visible spectrum is just the range we evolved to see because our atmosphere is transparent ...
3 votes
2 answers
594 views

Would Venusian Sunlight Be Too Much for Earth Plants?

This is Chris Wayans's map of a terraformed Venus: While there have been questions in this Stack Exchange on how to make Venus more livable for us humans, one question stands glaringly absent, and ...
6 votes
4 answers
1k views

Which Crops Could be Grown in a Subpolar Oceanic (CFC) Climate Zone?

In my fantasy series, the area the main protagonist is from is cool and dreary year-round, but never cold and never hot. For example, it never really gets higher than the 60s farenheit at the peak of ...
19 votes
4 answers
3k views

If only the sun's light went out, how long would it take for all living things to die out?

If by some form of magic, the sun went out, but the earth was still warm a.k.a the Earth did not just freeze and kill us all, who would die first, and how long would it take for all terrestrial living ...
1 vote
2 answers
207 views

Red Sun Plus Blue Sun Equals Magenta Sky?

Okay, my second cousin is working on a story that takes place on a planet named Odroia. It is an Earthlike planet with a supercontinent similar to Pangea, that has scattered rivers and lakes, with its ...