Questions tagged [light]

For questions concerning electromagnetic radiation in the visible spectrum.

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14 votes
6 answers
3k views

Seeing in the Dark - Flashlight Eyes

Darkvision, or seeing in the dark. But how does it work? In my world, I've been envisioning darkvision as eyes that emit a color of light that most humanoids can't see. Are there any problems inherent ...
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6 votes
3 answers
203 views

Could life as we know it exist if there were no speed limit and no special-relativistic effects?

My perception based on reading popular-science articles is this: Nothing can exceed speed of light in vacuum Speed of light is the same for all observers, irrelevant of their own relative speed But ...
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5 votes
5 answers
182 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 ...
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  • 181
0 votes
2 answers
96 views

How bright would these four stars look on the planet you're standing on right now?

Most of the numbers here have been plugged to me by someone you would find on both Reddit and the Speculative Evolution Forum. Imagine yourself standing on a planet in a quaternary solar system. The ...
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2 votes
1 answer
70 views

Future limits detecting the Cosmic Microwave Background (CMB)

I am working on a part of my story where a long-lived civilization is deciphering information in the cosmic microwave background (CMB). I have read that in the future as distant CMB light reaches us, ...
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6 votes
3 answers
144 views

Would the light reflected off of a blue moon and red moon combine into a purple hue on the surface of the local planet at night?

Edited: I suppose the setting doesn't really matter. Scenario: An earth-like planet in size and material and atmospheric composition experiences a phenomenon of purple light being the visible light at ...
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-2 votes
2 answers
106 views

How would fully autonomous holographic killer drone work wirelessly?

Now we have drones capable of dodging missiles and sometimes evade radar detection and carry out assassination without ever exposing our soldiers to danger, given time could we fly holographic version ...
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6 votes
6 answers
538 views

Shimmering Bird

Leaving dragons a little aside, a memory came to my mind when I researched about mythological/folk creatures that fly and remembered a very peculiar one: the Firebird. It's basically a glowing bird ...
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  • 2,674
5 votes
1 answer
121 views

What minerals could carry light inside a hollow mountain for illumination?

I have this hollow mountain that has a closed ecosystem inside it. What's interesting is that vegetation thrives within the bowels of the mountain despite being almost completely closed off from the ...
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  • 8,887
5 votes
1 answer
138 views

Visual gravitational effect of cosmic string network on background light

A scientific paper last year proposed the idea of cosmic string life-forms which could flourish within stars. The basic idea is that cosmic strings,theoretical topological defects from the early ...
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31 votes
14 answers
3k views

Rural broomstick navigation on a moonless night

These days we have so much street lighting that the stars are blocked out, and cities are easily seen from space. That wasn't the case a few centuries ago. Flyers in the middle ages (witches on ...
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  • 13.2k
1 vote
2 answers
114 views

Could radiation like Hawking Radiation be used to illuminate an enclosed habitat

While true Hawking radiation wouldn't be useful for illumination, what if, through some sort of strange spacetime warp, we managed to produce, through the same method as Hawking radiation, visible ...
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0 votes
1 answer
127 views

Could Hawking radiation illuminate an enclosed habitat?

Could visible hawking radiation be used to illuminate an enclosed space in a way that would be useful to a human? The specific space would be habitable for the human, and be close enough to the black ...
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2 votes
1 answer
115 views

More Moons = Brighter Nights?

Now, firstly, I understand that the moon reflects a portion of sunlight onto the night's surface; So if a planet had multiple moons--say two or three, how would the additional celestial mirrors affect ...
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  • 21
5 votes
3 answers
338 views

Enlightening Dark Matter?

As an ironic twist, I wanted a story in which dark matter is actually caused by light. Somehow, the physics of light cause it to create the appearance of the existence of dark matter. But I'm not a ...
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7 votes
9 answers
2k views

Reasons an alien would need protective eyewear

On their homeworld, they can see "normally" but when traveling off world they need to wear protective eyewear (but not full body protection.) I was thinking some kind of light sensitivity, ...
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0 votes
1 answer
75 views

How big would my habitable moon's primary planet appear in the nightsky in these two situations?

How much bigger than earth's moon would my habitable moon's primary appear in the nightsky? And is there a way to calculate how bright it would be in lux when it is illuminated in full? Here is the ...
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8 votes
3 answers
4k views

Would a moon with plantlife still give off (reflect) light?

The title basically says it all, but i will elaborate. Earth's moon light up the night sky by reflecting sunlight. But our moon is barren and made up of grey/white rock thus making it highly ...
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16 votes
8 answers
634 views

What would be the appearance and color of a deep, pure and vast liquid CO₂ ocean as viewed from space (ignoring the atmosphere's influence)?

So far I had no luck trying to find the visible absorption spectrum of CO₂ anywhere, all I get is the far infrared absorption spectrum and stuff like that. If you just search "what color is ...
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  • 372
2 votes
2 answers
401 views

My "Fairy Weave" is a transparent/translucent material with high tensile strength and elasticity. What should it be made out of exactly?

So, I've been thinking of materials that I can use on mundane things to make them more "magical". What I found was that many tools don't appear magical, because the materials they're made ...
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3 votes
1 answer
634 views

What temperature should a beam of light be at to burn through a person in a couple of seconds? [closed]

A magical technician who creates weapons with lenses, LEDs, and mirrors. What temperature should a beam of light be at to burn through a person in a couple of seconds? Cut a bone in a couple of ...
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4 votes
1 answer
164 views

Will owls become extinct without airglow?

Given a planet in most ways very similar to Earth (gravity, daylight, atmosphere etc.) with a full transplanted biosphere (all the familiar plants and animals), where the main difference is that as a ...
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  • 4,418
3 votes
4 answers
145 views

Effect of time distortion on light

In a story I've recently started writing, one thing that can be done with magic is alter the rate at which someone moves through time. It occurred to me first that the colors they would be seeing ...
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4 votes
3 answers
140 views

Finding an ideal UV-transparent refrigerant, or how to miniaturize a Fulminium reactor

In my setting, I have Fulminium crystal reactors. Fulminium decays emitting an electrical current spontaneously, but at a greater rate when stimulated by UV light, and it also emits UV and orange ...
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2 votes
1 answer
128 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 ...
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4 votes
2 answers
226 views

How bright is night on a moon orbiting a gas giant?

I have an Earth-like moon tidally-locked to a gas giant that is Saturn-like but without rings. On the side facing the gas giant, how much brighter would nights appear when the gas giant is fully ...
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9 votes
4 answers
2k views

Making the Moon brighter with talcum powder - how much brighter could it be?

A future nation wants to make the Moon as bright as possible in order to save massive amounts of night-time electricity on Earth at certain phases of the moon. The plan is to coat the Moon's surface ...
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-3 votes
2 answers
251 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 ...
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4 votes
2 answers
278 views

In This Picture, How Far Can One Binary Orbit the Other?

In an alternate Milky Way in an alternate universe, there is a cluster of stars so dense that nights are over 60 times brighter than our full moon. In that cluster is a solar system presented (albeit ...
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5 votes
2 answers
282 views

Plausibility of a cosmic flashbulb

Pendorain, admiral of the illustrious Tenth Fleet, had gathered its fleet near the Xzlicyan Pulsar to nurse its wounds. Battle against the hated Andecklin was not going well. The fleet was using the ...
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3 votes
2 answers
98 views

Could mermaids grow algae with bioluminescence?

Bioluminescence can cause photosynthesis, it has been confirmed. But is it feasible to grow algae, or some other plant, by the light of bioluminescence alone? Is it technically feasible with existing ...
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  • 4,098
2 votes
1 answer
94 views

How would light be affected when viewed though a Boson star?

A Boson star is a theoretical type of exotic star that on observation from a distance would present itself like a blackhole. It would have an accretion disk from the heated up drawn in matter, and as ...
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1 vote
1 answer
232 views

Star that gives heat but no light? [closed]

Is a star that emits heat, enough for life to exist on its planets, however does not emit much light possible? NOTE: I'm not asking if life on a lightless planet is possible.
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  • 27
4 votes
2 answers
255 views

What if the speed of light was based off wavelength?

Im making a sci fi story (first part here) and I needed a cool and interesting way to make ftl communication possible, at first I thought, make the speed of light infinite but thats kinda boring so I ...
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  • 2,193
1 vote
0 answers
105 views

How Bright Would the Sky on This Alternate Earth Be? The Sequel to "The 372-Day Calendar"

Long ago, I asked how far Earth would orbit the sun if one year lasts 372 days instead of 365 and how much it'd affect the overall brightness. What I got was that Earth with a 372-day calendar would ...
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11 votes
3 answers
2k views

What would a Rainbow look like on an earth-like Planet orbiting a Red Sun?

Okay, so in my setting I'm writing, the planet is very earth-like, similar atmosphere, liquid water exists, etc.. But the planet orbits a red giant. I've done a lot of fiddling around with various ...
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2 votes
3 answers
247 views

What wavelength light is most effective?

My character can burn calories and turn it into a beam of light a few centimeters in diameter with nearly 100% efficiency. What wavelength would be best as an antipersonel ability, calorie for calorie?...
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  • 1,340
7 votes
1 answer
200 views

How close can I bring a beam of light to a black hole before the information the beam contains is corrupted?

Given the following conditions: Two space stations of insignificant mass (compared to what can affect the transmission of a beam of light) are separated by a distance of 100,000 light years. With ...
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  • 89.8k
-5 votes
3 answers
172 views

how to make a photon weapon? [closed]

How would one go about making a photon weapon? I've thought about this for a bit, but with my very limited knowledge of light and waves/particles/sciency stuff I have come up with the following: We'...
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8 votes
2 answers
216 views

“Portal to the past” by slowing light speed

Light travels at different speeds through different types of media, which causes phenomena such as refraction and Cherenkov radiation. However, in most cases, the light still travels through the ...
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16 votes
9 answers
4k views

Could a world with a extremely bright night sky exist?

How could an Earth-like tidally locked planet with no Moon have a bright and livable night sky? The bluish night sky should look like this: But it should be 1% as bright as Earth's day sky and ...
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  • 4,120
-4 votes
2 answers
112 views

Flying islands and shadows

Let's say you have a "planet" of floating islands, and you still have a star (In similar size and distance to our Sun) around which this collection of floating islands resolve (Or maybe the ...
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  • 1,048
8 votes
4 answers
1k views

What would mer-folk use as lights and soft surfaces

I'm writing a story where one of the main races is orca (killer whale) mer-folk. Being orcas need to breath oxygen from the surface so do they, this said they live in a halfly submerged cave...but it'...
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7 votes
4 answers
781 views

Using frozen light as a starship shield

Frozen/Solid light Shields I can't find much online; but after listening to an Isaac Arthur episode where he briefly mentions frozen light, I immediately thought about the Hardlight items from the ...
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  • 885
7 votes
1 answer
377 views

How far could you see the Andes from the Pacific on a flat Earth?

Several questions on related subtopics of vision distance on a flat world have been asked before, but this one remains unaddressed. Specifically: The answer from Euclidean geometry would be infinite (...
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  • 4,418
10 votes
7 answers
3k views

Would a sapient being sensitive to polarized light be able to see the angle of polarization in a photograph?

Many animals have the ability to see polarized light (or rather, are sensitive to the direction of polarization), most notably birds and bees but also a wide range of other animals including ...
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  • 13.3k
8 votes
8 answers
1k views

Is radar better than visible light in deep space?

On the earths surface, radar is pretty sweet. It apparently penetrates the atmosphere well and bounces back and can be detected. I think this has to do with the wavelengths absorbed by our ...
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  • 276k
9 votes
4 answers
201 views

how big does my creature's organ need to blind or stun predator of all size?

Ok so my creature will look like this They're not big, about 2 feet tall. They're technically amphibians but have the scaly hide of a reptile. They live near the sea. Their life cycle is similar to ...
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3 votes
1 answer
466 views

Science of Green Lantern and solid light constructs

Many know that the Lantern Corps of DC Comics are capable of constructing objects of any shape or size out of hard light using their power ring fueled by their emotions. However, I'm wondering what ...
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  • 395
6 votes
1 answer
157 views

What can merfolk use to see in the abyss?

A particular species of merfolk inhabit the abyss of the pacific ocean, they belonged to the secret clan which was tasked by the Atlantean emperor to seek immortality elixir. The emperor ordered their ...
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  • 46k