Questions tagged [light]

For questions concerning electromagnetic radiation in the visible spectrum.

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4
votes
1answer
50 views

Visible light from the brain

I'm building a magic system where magic isn't just controlled by human brains, but is actively produced there. As a byproduct, when casting a spell, the brain generates a large quantity of visible ...
21
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13answers
8k views

Metal that glows when near pieces of itself

First question! I'm excited to see if anyone can help me. Any missteps are unintentional, but feel free to tell me so that I may learn. So, I've recently started brainstorming over a possible story, ...
3
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3answers
170 views

Which Stars Would Best Suit For the Habitable Zone of The Nine Norse Earths?

In an alternate universe, the nine realms of Norse mythology--Midgard, Asgard, Vanaheimr, Jotunheimr, Alfheimr, Hel, Nidavellir, Niflheim and Museplheim--are actual, real-life "Earths", in the sense ...
6
votes
3answers
248 views

How impossible would a bioluminescent plant-based lifeform be?

Looking for alternative sources of lighting for my current worldbuilding project so I couldn't help but wonder if a bioluminescent plant-based lifeforms could be realistically feasible. I'm just ...
10
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3answers
1k views

Deflecting lasers/plasma bolts/blaster bolts with lightsabers [closed]

In Star Wars, there's some shots where Jedi deflect lasers with their lightsabers. I know there's a law that says you can't go faster then the speed of light and lasers are light, so what is the ...
20
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11answers
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, ...
3
votes
2answers
184 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.
4
votes
1answer
140 views

Mesas of hard(solid) light

I searched the site and found answers saying hard light can't exist. Apparently in the three years since the last question was asked, scientists started making inroads on making solid light a reality, ...
5
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5answers
869 views

Creating Darkness

Can we create any electrical equipment which works in the opposite way to a bulb, such that is whilst it is switched on all the light in the surrounding area gets absorbed creating darkness?
1
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3answers
197 views

In Search of a Super-Bright, Super-Stable Star

Long ago, I asked a question on how to make possible turning the nine realms of Norse mythology--Midgard, Asgard, Vanaheimr, Jotunheimr, Alfheimr, Hel, Nidavellir, Niflheim and Museplheim--into nine ...
21
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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
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3answers
229 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 ...
33
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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 ...
9
votes
6answers
280 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. ...
20
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3answers
1k views

How large of a telescope would one need in order to read someone's lips on a planet light years away?

If I wanted to image an Earth-like planet at a resolution where one could read the lips of a human speaking on the surface 1, 10, and 1000 light years away, how large would the telescope reflector ...
7
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6answers
314 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 ...
94
votes
9answers
16k views

What could make a star green?

Stars are never green. When a star's spectra "peaks" in the green range, it also releases a significant number of waves of the adjacent colors - so "green" stars appear yellow or white. I want a ...
4
votes
6answers
224 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
102 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 ...
4
votes
2answers
272 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 ...
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 ...
19
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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 ...
4
votes
12answers
2k views

How could there be a horizon on a flat earth?

I'm building a world that happens to be flat. Well, it has hills and mountains, but no curvature. However, I still want to limit the eyesight to a few kilometers even if there are no hills around. I ...
5
votes
6answers
335 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 ...
4
votes
3answers
130 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 ...
6
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3answers
323 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 ...
7
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5answers
295 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
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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 ...
10
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3answers
1k views

What would the eyes of a cave-dwelling race be like?

So here's the deal: In a D&D-fantasy-style world, the continent of Archaon is inhabited by a wide variety of elves, whose physical characteristics vary based on their dwellings. The forest elves ...
-4
votes
1answer
76 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?
3
votes
3answers
173 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 ...
12
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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 ...
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-...
3
votes
5answers
280 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
5k 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 ...
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
281 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 ...
18
votes
9answers
977 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 ...
8
votes
3answers
530 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
196 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 ...
11
votes
4answers
1k views

Blacklight Star

Tangentially related to The evolution of neon kittens Is is possible for a star to radiate in the ultra violet spectrum but not much in the visible light spectrum? If not, is there any mechanism ...
5
votes
3answers
176 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
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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
150 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. ...
18
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5answers
1k views

How can I safely brighten my secondary star?

I have an earth-like planet orbiting one of the stars in a binary system. I have learned that, for G-class stars, if the secondary star is 100AU from the primary one, I can expect the secondary star ...
2
votes
1answer
148 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 ...