Questions tagged [light]

For questions concerning electromagnetic radiation in the visible spectrum.

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Would you read about a universe that has no shadow? [closed]

I'm devising a story that, due to some physical/mythical/"spiritual" reasons, has an entire universe that exhibits NO SHADOW at all. The explanation to this phenomena I'm thinking about is ...
Lucas Silva's user avatar
5 votes
5 answers
348 views

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 ...
Sandtaster's user avatar
6 votes
3 answers
433 views

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 ...
Lynx's user avatar
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10 votes
5 answers
596 views

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 ...
JBH's user avatar
  • 116k
0 votes
1 answer
63 views

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 ...
Foosic17's user avatar
  • 1,110
3 votes
2 answers
125 views

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 ...
Nogus101's user avatar
14 votes
7 answers
3k views

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 ...
The Zip Creator's user avatar
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_(...
user98816's user avatar
  • 8,459
6 votes
4 answers
693 views

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 ...
user98816's user avatar
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7 votes
2 answers
522 views

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 ...
Thoth's user avatar
  • 317
2 votes
4 answers
255 views

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, ...
user98816's user avatar
  • 8,459
3 votes
1 answer
158 views

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 ...
user98816's user avatar
  • 8,459
3 votes
2 answers
297 views

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 ...
user98816's user avatar
  • 8,459
6 votes
4 answers
259 views

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 ...
Faito Dayo's user avatar
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0 votes
2 answers
251 views

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? ...
Mark's user avatar
  • 117
3 votes
2 answers
154 views

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 ...
AmiralPatate's user avatar
  • 8,902
1 vote
4 answers
302 views

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 ...
mammifereviolet4694's user avatar
1 vote
1 answer
126 views

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 ...
Erik Sanchez's user avatar
1 vote
3 answers
139 views

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 ...
ΓΙΑΝΝΗΣ ΜΙΧΑΗΛΙΔΗΣ's user avatar
3 votes
2 answers
206 views

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,...
Paulo Raposo's user avatar
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-1 votes
3 answers
204 views

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. ...
MaelstromV's user avatar
1 vote
2 answers
112 views

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 ...
Vakus Drake's user avatar
  • 2,398
15 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 ...
Firedestroyer's user avatar
6 votes
3 answers
220 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 ...
nametopostquestionaboutleave's user avatar
7 votes
5 answers
410 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 ...
slowmomo's user avatar
  • 191
0 votes
2 answers
113 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 ...
JohnWDailey's user avatar
  • 14.5k
2 votes
1 answer
96 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, ...
Alan Davies's user avatar
6 votes
3 answers
244 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 ...
Rubrikon's user avatar
  • 1,473
-2 votes
2 answers
151 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 ...
user6760's user avatar
  • 46.4k
6 votes
6 answers
586 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 ...
Wizard King's user avatar
  • 2,694
5 votes
1 answer
147 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 ...
LiveInAmbeR's user avatar
  • 10.5k
5 votes
1 answer
166 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 ...
user avatar
34 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 ...
KeizerHarm's user avatar
  • 14.2k
1 vote
2 answers
121 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 ...
Ichthys King's user avatar
  • 15.6k
0 votes
1 answer
134 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 ...
Ichthys King's user avatar
  • 15.6k
2 votes
1 answer
178 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 ...
GN Luis's user avatar
  • 21
5 votes
3 answers
359 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 ...
DWKraus's user avatar
  • 63.2k
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, ...
Micromanic's user avatar
0 votes
1 answer
88 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 ...
JuimyTheHyena's user avatar
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 ...
Blue Devil's user avatar
  • 1,749
17 votes
8 answers
833 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 ...
DeMooniC's user avatar
  • 392
2 votes
2 answers
431 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 ...
Mephistopheles's user avatar
3 votes
1 answer
645 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 ...
g0ldenlights's user avatar
4 votes
1 answer
176 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 ...
rwallace's user avatar
  • 4,888
3 votes
4 answers
160 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 ...
David Monroe's user avatar
4 votes
3 answers
164 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 ...
Monty Wild's user avatar
  • 55.4k
2 votes
1 answer
185 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 ...
Littlepip21's user avatar
4 votes
2 answers
389 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 ...
B. T. Newberg's user avatar
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 ...
chasly - supports Monica's user avatar
-3 votes
2 answers
277 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 ...
JohnWDailey's user avatar
  • 14.5k