Questions tagged [light]
For questions concerning electromagnetic radiation in the visible spectrum.
100
questions
20
votes
18answers
6k views
Are there any medieval light sources without fire? [closed]
In a world of my story, which is loosely based on medieval times, fire disappeared. Are there any sources of lighting without fire that would be possible in a medieval setting?
It is a fantasy book ...
6
votes
3answers
212 views
Could people harness the bioluminescence of a firefly?
The world I am creating is in a swamp that contains larger than life bugs; this includes fireflies. What I ask is, could the bioluminescence of their glow somehow be harnessed or used as a light ...
32
votes
13answers
7k views
What does the view outside my ship traveling at light speed look like?
World Rules:
Travelers are able to move at the speed of light without disruption of their lives. Time passes "normally" for them. They think, breathe, love, cry, and steer the ship as if they were ...
20
votes
10answers
5k views
Could there be a material that inverts the colours seen through it?
I had a vision of a creature that touched things, and wherever it touched, it left a mark opposite to the original colour.
For example when it walked across the grass the grass had red footprints, ...
7
votes
6answers
301 views
Can there be substantial darkness?
OK, OK, I know, darkness is nothing but absence of light, so there can be no substantial darkness. Darkness, on its own, doesn't exist.
But, can we not get pretty close to this?
Can there be ...
4
votes
6answers
218 views
How would organisms adapt to survive darkness beasts? [expansion to my old question]
[This is an expanded/refined version of my old question:
How would animals adapt to darkness-made beasts? ]
Premise:
'Beasts'/Seraphins are other-worldly intangible beings (you can't touch them, but ...
0
votes
1answer
97 views
Speed of light, Motionlessness, and Time Travel [closed]
i want to ask something
I quote from some web and got this :
'According to Einstein’s Special Relativity Theory, time is affected by speed. It’s already been proven in the lab that subatomic ...
9
votes
2answers
3k views
Is it possible to create light that imparts a greater proportion of its energy as momentum rather than heat?
This is yet another question concerning lasers as employed by sorcerers in a particular fantasy setting, but this one pertains to the momentum that photons possess and whether it's possible to ...
4
votes
2answers
271 views
How to explain day is 10 times as bright but no warmer?
Set at the present day Earth, the daylight on average is ten times as bright as today, approximately 111,000 lux at noon for example and subject to geographic and the air quality etc. I am looking for ...
19
votes
8answers
12k views
Car headlights in a world without electricity
In a world like ours in the 1980s, but which for whatever reason does not use any form of electricity. (Either it does not exist or batteries and generators etc have not been invented.) For purposes ...
5
votes
6answers
321 views
How could a silver sword give off a golden glow in the light?
Now, I am not talking about a golden glow that overtakes the sword itself. I'm not looking for a Lightsaber. I'm talking about a sword that is silver in color giving off a golden reflection (or ...
3
votes
3answers
129 views
How can the interior of temple lit automatically during medieval time?
In the 1400AD, there was a temple built to honor a late king somewhere in the middle east. The temple can house a thousand people and have many facilities from amenities to entertainment plus an ...
9
votes
6answers
271 views
What light would my cloudy planet receive from a red dwarf star?
What light spectrum would hit the surface of a planet orbiting a red dwarf star?
The planet is a humid greenhouse with a cloudy atmosphere and a strong ozone layer. Over 80% of the surface is water. ...
7
votes
5answers
288 views
Describing what the world looks like in UV and IR [closed]
In my world I have introduced two super powers, and both can be accidentally acquired by an otherwise normal human: one is to see infrared and the other is to see ultraviolet. I am aiming to have that ...
19
votes
5answers
4k views
How much light is too much?
A mage has created an amulet of light. It shines light from one side, and the user is capable of controlling the color and intensity of that light.
In an effort to avoid abuse, the mage has limited ...
-4
votes
1answer
75 views
What would be the most viable form of lighting in future bladerunner-esque cities? By viable, I mean widespread and efficient [closed]
Neon has been around for a very long time in cyberpunk narratives. LED seems like the way to go according to some of the responses - any other viable candidates?
6
votes
3answers
318 views
What would it look like in the accretion disk of a feeding supermassive black hole?
I wanted two characters unaffected by the heat and gravity to be close to a super massive black hole within the accretion disk, at times moving in orbit and at times completely still.
Stars and ...
13
votes
4answers
1k views
Full-body bioluminescence
A creature I am imagining is a small mammal about the size of a domestic cat which - through symbiotic bacteria which live in its fur - is covered its whole body over in blue-white bioluminescence, 24-...
12
votes
8answers
3k views
Trap light in a cage [closed]
Is it possible to build a mirror cage in order to catch light in it?
Let's assume the surface of the mirror reflects absolutely 100% of the light.
Which shape of cage is the best to do this?
Is it ...
3
votes
5answers
274 views
How to create a sunny atmosphere without an actual sun?
I have a large underground fantasy world which is only accessible through the Mariana Trench. I'd like to do a day/night cycle and have have a bright, sunny atmosphere part of the time, but I'm not ...
15
votes
5answers
4k views
Using light as a barrier to block people without grilling them
We know that light exerts pressure upon matter.
I'm imagining a hallway where an intense light source on one end shines towards the other end. The goal is to have the beam of light exert so much ...
3
votes
3answers
172 views
Mechanism to slow down the light emitted by an object such that it will result in inaccurate position of the object to the observer?
Let's say that there are two people named S and C. They are not far apart; less than 10 meters. Let's also assume the scenario takes place in late evening or in the night, for simplicity.
Normally ...
13
votes
3answers
2k views
Is it really possible to see across a ringworld? [duplicate]
Almost all illustrations of ringworlds that I've come across tend to show off the shape of the ringworld from the surface.
This doesn't seem realistic to me, because the ringworld's radius would ...
22
votes
13answers
4k views
Always a full Moon for the Emperor - Can this be achieved with solar panels and LEDs?
The Emperor of the World wants there always to be a full moon. His Scientific Advisor (the SA) comes up with a plan.
He plans to cost out the venture, hand it over to the Keeper of the Treasury who ...
4
votes
4answers
271 views
Purple plants on a planet orbiting a green star?
Before I continue, yes, green stars don't really exist visually. Although stars like the Sun are green stars, they appear white (and are known as yellow dwarfs) because it doesn't only emit green ...
8
votes
3answers
511 views
The Complicated Nature of Photokinesis
I am currently working an a magic system that involves Photokinesis. However, I am having difficulty understanding its limits and its capabilities.
Visual example
The best definition for this type ...
12
votes
1answer
193 views
Would Rayleigh scattering (blue skies) be noticeable in an O'Neill cylinder?
In my story there is a full size (Island Three) O'Neill cylinder, 5 miles in diameter and 20 miles long.
It doesn't have windows, but is lit internally down the center of the cylinder with a 20 mile ...
5
votes
3answers
168 views
Determining the energy efficiency of a Light Wand
So, I'm working out some of the types of wands people can purchase in my flintlock fantasy setting, and I'm having an issue with one of them. Before I get to that, let me explain how Magic in my ...
22
votes
6answers
6k views
What does a solid, 1 mile diameter subterranean glass sphere look like?
There is a solid glass sphere that is 1 mile in diameter. It is completely covered in dirt and rock, except for one small room that is built adjacent to the sphere. One of the four walls of this ...
35
votes
6answers
6k views
What light colors/bulbs should be used inside a spaceship?
I've noticed in recent scifi shows/movies such as the Expanse or Star Trek that the lighting inside spaceships have two characteristics:
Punishingly blue lighting
Dark/dimmed miscellaneous lighting ...
-3
votes
1answer
209 views
What if light didn't decay by a square law, but instead by an INVERSE square? [closed]
I want to build a character that can control a light source's brightness in different ways. I want to see if instead of proportional to $1/r^2$, my light and darkness controlling character could make ...
6
votes
2answers
147 views
Vision on Titan/Early Earth and the technicalities of a creature seeing in near infrared
I am trying to develop an alien species that could live on Titan and at first I supposed it would be easy with the species being able to use yellow, red and near-infrared wavelengths of light to see.
...
2
votes
2answers
125 views
Albedo of a planet like Crait
If a planet like Crait existed and was covered by (mostly) white sand, what would its average albedo be? Crait is a planet from Star Wars that has a thin layer of white salt on its surface.
2
votes
1answer
145 views
How bright does this planet look from its neighboring planet?
I have two planets that share an orbit around a pair of stars at a distance of 2.05 Earth-AU from the Barycenter of those two stars. (I can provide more details about the two stars, if needed)
Using ...
18
votes
5answers
4k views
Can visible light be blocked while still allowing for light for plants to survive to pass through?
What I'm thinking for this question is that some kind of filter is put around the sun by aliens that prevents some kinds of solar energy from passing through but allows other types.
Like if it ...
10
votes
4answers
2k views
How do vampires react to passive UV light sources?
Certain fantasy creatures are extremely sensitive to concentrated UV light. eg modern vampires. They either slowly or rapidly burn up in-front of you when exposed to direct sunlight or modern high ...
4
votes
2answers
201 views
Is it possible for a planet with life to orbit around a white hole?
I have created a planet called Betiler. I don't want Betiler to be in a classic space system like a star and some planets. So I put it around a white hole called Phulom. In my world, wormhole doesn't ...
5
votes
3answers
287 views
What would be easy or difficult to do with the power to directly control light?
Without going into too much detail, let's say someone has a superpower which gives them "control" over actual, physical light: Photons, electromagnetic radiation, what have you. This power requires ...
5
votes
1answer
122 views
Can I see my secondary star?
I have a binary star system and have come up with some stats for it.
My primary star is an F-type, with a mass of 1.3 sols and a luminosity of 2.197 sols. My secondary star is a K-type, with a mass ...
25
votes
16answers
6k views
How to make sure humans do not know the meteorological phenomenon rainbow?
You've got to love the rainbow, it's an awesome sight. But I don't want humans to have the pleasure of seeing the rainbow.
What change to the earth, atmosphere and so on, is needed so that humans ...
6
votes
1answer
340 views
Could a light mage microwave your face?
First post, so I’d appreciate suggestions and help on how to make this question better.
Question
Suppose there’s a sorcerer with power over light. He can use these abilities to perform all the ...
26
votes
5answers
5k views
How reflective is blood?
If you were on a raft in say, an ocean of blood, and it was very still, would you be able to see the stars of the night sky reflected in it? Would you be able to see your own reflection? How far down ...
9
votes
2answers
557 views
How would sunlight work in the area of shared atmosphere of a Rocheworld?
(See diagram) Presupposing that a Rocheworld can even exist...
I imagine that sunlight would work more or less the same in the atmosphere of any part of an Earth like planet that was tidally locked ...
-2
votes
1answer
199 views
How would computer monitors work if we could sense the frequency of light?
Human's abilities to perceive light is quite limited. Essentially, we have three type of light sensors that each give a linear signal, and if two different light sources give the same signals they ...
3
votes
2answers
191 views
How to make glowing rain/mist?
So I've been playing Xenoblade Chronicles 2 and one of the effects that is used through the game (and the series really) is that ether (the game's version of mana) can often be seen floating in the ...
5
votes
3answers
542 views
A double-bright Moon and plant growth
It's Earth and the moon with all parameters as they are in real life with one exception, the moon is twice as reflective as usual. Instead of an albedo of 0.12, the moon has an albedo of 0.24. This ...
-5
votes
4answers
228 views
The Planetary Light Curve
I know that light can be affected by gravity. But what if there was a planet where if you shone a light in a direction and it could hit your back. I'm talking about a planet where light is bent around ...
18
votes
9answers
939 views
Compressed air lighting?
So I've got this civilization that doesn't have electricity, but does have municipal power distribution via compressed air lines.
Now, you can do a lot of useful things with compressed air. Even in ...
1
vote
1answer
83 views
What would be more effective for a Shkadov thruster? An entirely white one or a mirror one? [closed]
A Shkadov thruster is a megastructure which reflects all light from a star in a given direction.
What reflects more radiation, a white or a mirrored surface?
6
votes
1answer
102 views
Defining the perceived appearance of a moon from a planetary surface
I have a homebrew setting with a moon that has some specific features orbiting an Earth sized planet, and I'm trying to find out how these features would affect how the moon looks from the surface of ...
