Questions tagged [reality-check]

Asks if a given concept is realistic in a given context. Answers should say yes or no, with supporting info. Compare this with the science-based and hard-science tags. This tag should never be the only tag on a question, because this tag frames how a question should be answered, not the topic.

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3
votes
6answers
350 views

How far could the roman empire expand? [closed]

Assuming Rome never fell and the empire was never divided, how far could it have expanded? What would it take for them to have an empire whose size is similar to that of the british or Spanish empires?...
10
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11answers
2k views

How does a religion based around destroying the world attract followers

How would a religion centered around summoning a god of destrucion to destroy the world attract new members? What incentives or arguments would convince a mostly sane population to go along with ...
4
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5answers
2k views

Could the Unarmed Knight be successful in a battle?

So, one of my characters is this mysterious guy, called the Unarmed Knight. Basically, for some reason, he doesn't use any weapon, besides his body, in combat. Some say it's because of pacifism, his ...
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5answers
2k views

How to explain the absence of transmitted diseases between two unconnected cultures

In my story, I have two late renaissance era cultures discovering each other for the first time and I plan for the story to develop into more of how they both understand each other. However, I don't ...
3
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3answers
204 views

How to get time to pass faster on another planet compared to earth?

I'm developing a story where humans colonize a few planets. One planet, lets call it Planet A, has similar gravity to earth, air pressure, and solar radiation. You cannot however, walk on the surface ...
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1answer
97 views

What would be some noticeable differences on tiny human beings? [closed]

Let's say a very advanced alien race makes tiny human beings just for fun. Of course they wouldn't be just shrunken normal humans because they'd just die, the alien race made the necessary changes for ...
4
votes
3answers
282 views

Hydrogen Dragons

Let's talk about dragons for a bit. Giant, flying, deadly predators with teeth and claws and fire and scales. Unfortunately, "giant" and "flying" don't play together nicely in physics' playground. ...
4
votes
3answers
217 views

Making a Plasma Gun that works

I have seen in this site that there has been constant attempts to make a working Plasma Gun, only to be constantly met up with failure, as shown with my post regarding Warhammer's Plasma Cannons. ...
6
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2answers
117 views

How tall could a fictional cactus species realistically grow?

I had an idea for a new world that included cactus forests, with cactuses the size of a giant sequoia. Is this realistic?
1
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1answer
43 views

How would the strong magnetic field of a white dwarf affect humans inhabiting a planet that orbits such a star?

Magnetic white dwarfs (MWD) comprise almost 2 % of all white dwarfs and they are characterized by having a strong magnetic field, whose strength varies between 1 T and 100 kT. Compared to the Earth's ...
0
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1answer
120 views

Feasibility of Warhammer 40k Weapons Part 2: Exterminatus

So the Plasma Cannon proved to be a bust, now to the next weapon, what which is commonly associated with 'Exterminatus', the Atmospheric Incineration Torpedo. This bomb is far more powerful than a ...
6
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4answers
130 views

How to limit naval combat in a world of giant canals

My world is a drier variant of Earth and the civilization there has built a massive canal network that is used for moving water from the pole to the temperate zone as the temperate zone is lacking in ...
2
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2answers
78 views

Could a humanoid alien species evolve to have a natural melanin deficiency but still have colourful skin/skin markings?

Summary at bottom. I have a character from a homemade alien species. The species has silver/white hair and blue/violet eyes. I know these are traits of a melanin deficiency, but I imagined her having ...
0
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2answers
71 views

How much more efficient would human metabolism be if fat were denser?

If the density of fat were raised to about a density of 3g/mm, how would human metabolism be affected? Would it be massively improved, or is there some fatal flaw I'm not taking into account?
1
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2answers
145 views

Feasibility of Warhammer 40k's Plasma Cannon

In the world of Warhammer 40k, come multiple weapons with variable levels of feasibility, most namely the Bolter and the Chainsword, which are the simplest. On the other hand, there are other weapons ...
27
votes
15answers
7k views

Are generation ships inherently implausible?

So I've been thinking about the idea of a series that takes place on a small fleet of generation ships, traveling at around 10% of lightspeed to Proxima Centauri, which should take around a century. ...
3
votes
5answers
168 views

Could a language based on absolute pitch develop music?

For those that are arguing that without vocabularly, it isn't considered a language: From Wikipedia: Language is a system that consists of the development, acquisition, maintenance and use of complex ...
3
votes
1answer
82 views

Can a planet's artificial ring always face the sun?

A habitat/space harbor ring encircles an ice giant crossing both poles (polar orbit) and rotating to create artificial gravity. Can the ring also precess in synchronization with the planet's year, so ...
1
vote
2answers
121 views

Can a liquid mercury pistol flamethrower exist?

The Cold War just got a whole lot hotter. Ordinary 20th century flamethrowers are, let's admit it, huge. Covert operations, especially in urban settings, would not stay covert for long, if our custom-...
2
votes
2answers
183 views

do these mountains look to be in realistic locations?

I'm getting into mapmaking, which I enjoy, but some of the specifics of realism still elude me. I know generally how plate tectonics work, but I was hoping to get some help on a specific example. I ...
5
votes
2answers
82 views

Geckos walking on two legs

I was thinking of a situation, in which there is a mass extinction that wipes out all large land animals, and after this mass extinction some of the descendants of modern geckos evolve to fill the ...
4
votes
3answers
198 views

The cure for all bacteria-caused diseases

Which minimal order of magnitude is required to simulate single cells and microorganisms in cyberspace? In an utopian future, people will be possibly able to rapidly design new cures, be their ...
4
votes
2answers
122 views

Long range laser using wormholes

So, I was recently watching Stargate: Atlantis, and I saw a very interesting concept. In one episode, the villainous Replicators use the stargate network to fire what is essentially a high-powered ...
4
votes
1answer
135 views

Are elliptical rings feasible?

Around a rocky planet or small gas giant, could there be a system of rings that follow an elliptical orbit? I have used a gravity simulator (this one) to test it, but the way it handles its particles ...
5
votes
5answers
125 views

Super insulated box/room to store extreme heat possible?

Is it possible in 21st century Earth for someone to create a small super insulated box to store heat like an "anti-freezer" such as putting lava inside the box and the box not being hot to the touch ...
2
votes
4answers
299 views

Cheapest material per ton on earth?

What is the cheapest material per ton that one could purchase on our Earth in the 21st century? This could also include the cheapest material per ton to harvest so dirt may seem like the obvious ...
1
vote
3answers
151 views

Could a material exist that is glass-like on the outside but spongy on the inside?

In my DND world, I've established that there is a substance that has these properties: It is made from a chalky "dust" that can be mined The dust gets mixed with unspecified chemicals to create a ...
5
votes
2answers
169 views

What effect would it have on the human psyche to be able to observe, but not interact, with other humans for an extended length of time?

I had an idea for a character that was stuck in a ghost-like state for a length of time after an accident. During this time, they would have very limited ability to interact with the rest of the ...
1
vote
4answers
144 views

Can Particle Decoupling Weapons exist?

So, it seems that I will always be asking about the feasibility of semi-scifi weapons to the real world, now, as a trend. I have looked for weapons that operate under "exotic physics", shown here: ...
-1
votes
1answer
69 views

Modification of a standard cannon to project water instead of iron ball?

Cannonballs may be a thing of human warfare past, but it is not difficult to imagine the sense of dread at seeing a 40-pound metal projectile headed toward your ship, unable to tell for a few ...
-1
votes
5answers
153 views

Iron Age: Feasibility of maritime travel without timepiece or star navigation?

Having fled under haste, from a near assassination in Crete, a storm catches up with my naval crew. The sky is overcast, meaning no stars and an accident results in the loss of their compass. Is my ...
2
votes
3answers
114 views

Feasibility of Molecular Disassemblers

When I come across weapons associated with Nanotechnology, the first that often shows up are Molecular Disassemblers, or what others would like to call Grey Goo. Molecular Disassemblers utilise ...
4
votes
4answers
207 views

A setting in which people have discovered all of science

So this is very loosely inspired by a theory I have about Star Wars as a setting, but it is not something they really discuss overtly even in the Extended Universe. One of the interesting things about ...
0
votes
1answer
92 views

If I could sense magnetic north, could I sense magnetic south?

In a world I am helping build there is a certain group of people with the ability to produce electricity from their bodies (and control it, I believe), an additional power I gave them was the ability ...
1
vote
2answers
103 views

How to make fail-safe for full body virtual reality?

My VR machine isn't the plug-it-to-your-brain type, but instead it's more like a "reality sphere" around your body that have some kind of gravity machine to keep you in the center of the sphere and ...
9
votes
4answers
296 views

If we dug a really big hole on Mars, how long would it last?

How long will a 400 km wide 30 km deep pit (trench or crater) with a relatively shallow (for stability) gradient of slope of 20 degrees from the edge to the surface of the planets crust be expected to ...
1
vote
2answers
94 views

Feasibility of Psycho Pass' Dominator

So, in the world of Psycho Pass, the main weapon of enforcement is the Dominator. There is not much information on how the weapon works, other than it utilises electromagnetic waves, and has an ID ...
5
votes
5answers
435 views

The effect of a 20 kilojoule punch on a person that is wearing a plate armor

I have always been in love of hand to hand combat but I realize the concept of efficiency and why that is not an ideal choice for combat so I decided to write a story in which characters who are ...
2
votes
1answer
69 views

Hiding spots in a big city? [closed]

Basically, one of my protagonists is a science experiment on the run who ends up in a modern day big city (like LA or Chicago). She's teamed up with a hustler who's lived on the streets for most of ...
27
votes
18answers
6k views

Why give an android emotions?

As far as my baby world goes, androids are slaves to humans, but a niche group of humans wants androids to have basic rights (sort of like Hermione and the house elves in Harry Potter). Androids ...
2
votes
1answer
171 views

Anatomically Correct Quantum Slime

I recently came across a few examples of a "quantum slime" entity, namely from Starfinder and Slime Rancher, that has the ability to make copies of itself via quantum superposition, and then cause any ...
4
votes
2answers
407 views

Can tiny astronauts reach space?

Imagine a species one foot tall that has a relatively large brain for its size. The species has human like intelligence and in principle the ability to build anything that we could. It lives on a ...
2
votes
3answers
136 views

Anatomically correct Kryptonian, part 1

Part of the Anatomically Correct series of questions. Due to the nature of Superman having so many different powers, I wanted to focus specifically on one aspect of his character: the ability to be ...
0
votes
3answers
128 views

Feasibility of a Hydrogen Ion Weapon

I was searching on reddit for powerful theoretical weapons, until I came across an interesting response: "Confine a bunch of hydrogen ions in a very small space. Then release them. The force they ...
3
votes
7answers
219 views

Plausibility of Star Trek's Voth

In Star Trek Voyager, the Voth are an intelligent, humanoid species of descendants of dinosaurs (hadrosaurs). Paleontologists estimate, that up around 99% of species, that ever lived, died out. ...
1
vote
2answers
110 views

What would happen if a disease broke out in LAX?

To some up my question: If a super contagious disease broke out in the middle of Los Angeles International Airport (LAX), what would be the response by the US government? Long explanation: I had an ...
4
votes
4answers
215 views

Are continent wide forest fires possible?

The setting I have in mind is an Earth-similar planet which has most of its landmass covered in forests. A civil conflict on this planet ingnites forests fires, which then spread. I was wondering if ...
5
votes
2answers
139 views

Feasibility of Larry Niven's Wunderland Treatymaker

So it seems that the Nuclear Handgun, Powergun and Absorbic Bomb have all been busted, but this one might be more interesting, Larry Niven's Wunderland Treatymaker. Description of how the weapon (...
10
votes
1answer
190 views

Would roleplaying as wacky Nazis help my deities maintain their mental health while they're stuck in a bunker?

So, once there was a war between the titans and the gods. In the end, the gods' leader, Anon, found a way to permanently remove the titans from the world, but the victory extracted a terrible price. ...
1
vote
2answers
90 views

How to survive a Jaculas (javelin snake) attack?

So if you were running through a forest and stumbled into a nest of Jaculi? Jaculuses? They are up in the trees around you and they start flinging themselves at you, trying to pierce through your ...