Questions tagged [light]
For questions concerning electromagnetic radiation in the visible spectrum.
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What size should my inside-out planets be so that people on the surface can see the curvature?
The universe is filled with a fluid, and people live on the inside surface of planets. I want planets to be roughly Earth-size or larger (maybe up to 3x), but I want to make sure people on the surface ...
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If the Moon started emitting light, how would it affect human sleep/wake cycles?
I'm working on a sci-fi setting, and things start when the Moon starts emitting a unique type of light.
Things to note
The light being emitted by the Moon doesn't produce heat. Things are getting ...
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Is it reasonable that my human-habitable alternate universe look different?
In the story I am planning, I wanted to have two universes, one just like ours, in which humans evolved, and another that is sufficiently similar to our own that humans may survive, but in which ...
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What would a beacon of light activated on Earth's surface look like from space?
Would it be physically possible to have a beacon on the Earth's surface so powerful its beam would continue outwards past the Earth, further into space, and out into the cosmos? What would that beam ...
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Could you breed livestock with structurally colored wool?
Imagine you have low magic, low tech nomads with a magical equivalent of microscopes, and a rudimentary understanding of genetics and optics (blame magic). They are selectively breeding livestock for ...
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industrial grade UVC light design to cause 1st degree burns on skin after 5 second exposure
First of all the base setting, a non realistic world that has humans, and also beings some could be particularly weak to strong UV: vampires, eyeballs of anything that has eyeballs, beings with skin ...
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Will changing the range of EM that my aliens can see affect how they can relate colors to humans?
We have humans, who can see in the spectrum of 380-740 nm.
Let’s take the aliens, who can see in the spectrum of 500-860 nm. This gives them vision into the infrared. They also cannot see purple as ...
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Bioluminescence due to photosynthesis
I'm wondering about how to make my photosynthesising organisms all glow. Basically, I want to make bioluminescence a consequence of photosynthesis, as if the organelles themselves produce light in the ...
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Artificially lighting a large underground city
I'm trying to think of a somewhat plausible way to create artificial "sunlight" in a very large underground city. To summarise some key points:
The cavern containing this city is ...
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Animals with fur that fluoresces under UV, and a star with high UV levels--how dramatic is the affect, and how badly would it mess up camouflage?
I am considering the possibility of giving the creatures on my planet fur with UV-florescent pigments as an extra defense against the high levels of UV radiation from their star, an F3.5V
This planet ...
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Would a star's spectroscopy be stable enough on approach to use it as a navigational reference from a great distance?
NOTE: The offered "duplicate" question IS NOT WHAT I AM ASKING. Alternative methods of navigation ARE NOT ACCEPTABLE as answers. I am specifically asking whether or not a ship traveling in ...
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Plant life on a planet with extremely bright "moon"? [duplicate]
The planet in question is part of a Binary Planet pair, both of which are tidally locked to each other at a fairly close distance (~129,000 km) from each other, meaning that the "moon" is ...
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Is a blue sun/star visually possible with a orange sky?
I know an orange sky is achievable in at least two ways; large particles in the air (for example: smoke); or a thicker and:or denser atmosphere, so that light is getting bounced around and only longer ...
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How to create a "fog of war" on an interstellar scale?
I want to create a universe where the visible universe is much smaller than that of our own. The idea is to create a sort of "fog of war" around every star system. In our universe, you can ...
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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_(...
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Why would bioluminescence evolve in a Europa-like world?
In my sci-fi universe, I have a planet called Tateos Prime. It is a Pluto or Europa-like world, which orbits too far from its twin red suns to support liquid water at its surface. However, geothermal ...
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What color should my planet's skies be?
Assuming the skies are clear of suspended particles, what color should they be at mid-day if viewed with human eyes?
The planet is larger and twice as massive as Earth, with a nearly identical ...
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Could a sun gun work from the surface?
The concept of a sun gun is of a parabolic reflector, placed it orbit around a planet, which focuses sunlight as a deadly beam on a specific point of the surface.
What I want to know is this: what if, ...
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Amount of fuel needed for a long-running fusion reactor
Let’s say people (humans) arrive on a planet. Oh no, it’s too hot! Okay, we live underground in lava tubes. Oh no, it’s too dark! Okay, so illuminate the tubes with self-repairing fusion-reactors that ...
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How Can We Illuminate a Bishop Ring?
A Bishop ring is a space habitat, in my project about 100 km long and with huge walls 10 km high to keep the atmosphere in.
The ring rotates about once every 20 minutes to simulate 1 G, and is built ...
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A natural light source on Europa
In our solar system, Europa, a moon of Jupiter, has a large and warm ocean under the icy crust. However, due to it having a rocky core and the icy crust, there is no light in the ocean. I want to make ...
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If two spaceships are traveling closely to the speed of light in different directions, how can they communicate?
Supposed we have two spaceships at a speed close to lightspeed relative to each other, what would communication look like, for example with a laser beam, taking special relativity into consideration?
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If a planet orbits fast enough could it make a star appear red/blue-shifted depending on the direction of travel?
Suppose a copy of Earth. This planet can travel at any arbitrary speed, and it's set to travel along the galaxy's spiral arms. It rotates counterclockwise, at the rate of 24 hours a rotation. It keeps ...
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What evolutionary pressures would lead humans to evolve to be able to see ultraviolet light?
In my world, there is a species from the Homo genus named Homo maritimus (which means marine human) (there are still humans, just not Homo sapiens). They are commonly named merfolk. However, they do ...
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Is Xanthophyll good at absorbing Light? or do i need another light wavelenght?
I want my alien planet to have yellow or orange-yellow plants.
Is xanthophyll a good option for plants to absorb light, or do I need to make my sun give off More of a certain wavelength so they can be ...
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The variety of colour in a world under a red dwarf [closed]
I'm designing a world orbiting a red dwarf. Now, I want the life on my planet to have a rich variety of color just like life on earth does. The problem is that I don't know if that's feasible. From ...
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Sensory Extension Overwhelming? [closed]
Amplifying the sensibility and spectrum of your senses, and even adding new senses altogether, in order to perceive the most information from the environment is a common theme in my futuristic setting,...
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Beam Convergence?
I have a character that can release laser beams from both his hands and i just want to know if he can shoot these 2 lasers at a single point and converge causing it to become a singular stronger beam.
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Effective Design for Light-Powered Aircraft Engines? [closed]
How would aircraft engines be designed which use magic orbs able to output insane amounts of light for power?
In this industrial era setting, ordinary engines exist and are the cheapest option for ...
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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