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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.

28
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7answers
5k views

Is my plasma cannon concept viable?

I’ve developed a concept for a plasma cannon, and I need it reality-checked. The cannon would gather ammunition by pumping air into the gun through an external fan. The air would gather inside a ...
17
votes
10answers
4k 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 ...
14
votes
14answers
6k views

A steel cutting sword?

So within my world there exists a faction of monks on a secluded mountain whose scientific and philosophical knowledge outstrips the outside medieval world. And with these monks being famous more for ...
5
votes
5answers
173 views

At what point in European history could a government build a printing press given a basic description?

Say a time traveler ends up back in time and has earned the good graces of one of the nations' kings by sharing some of his future knowledge. Knowing that the printing press was an important ...
0
votes
0answers
24 views

Could Xenarthrans Be Ferried Outside South America?

Right from the beginning, the xenarthrans--armadillos, sloths and anteaters--have been at a disadvantage. For the longest time, their home was an island continent, which made them extremely ...
2
votes
2answers
41 views

Would this “self driving” car work?

The great venture capitalist Elian Minsk has decided to start an "autonomous" car driving service. But who needs complicated AI based systems when he can hire tech support workers in India to drive ...
0
votes
0answers
26 views

Terraforming the Nine Earths, Episode I: Could Cyanobacteria Thrive in Muspellheim?

Long ago, I asked a question on how to make the Nine Realms of Norse mythology--Niflheim, Muspelheim, Asgard, Midgard, Jotunheim, Vanaheim, Alfhiem, Svartalfheim and Helheim--a reality in regards to ...
4
votes
2answers
146 views

A Dozen Cubic Miles of Volcanic Ash--How Big Would the Cloud Be?

On May 18, 1980, Mount Saint Helens made American history with an eruption that took 57 human lives and killed thousands of animals. It has released only a quarter of a cubic mile of ash, but it is ...
7
votes
7answers
202 views

Would intelligence affect the evolution of colorful display patters for attracting mates?

On another planet there is a group of organisms that have colorful display patterns allowing them to attract mates. Eventually a branch of this type of organism evolves the intelligence of early ...
3
votes
2answers
99 views

Seasonal Shade-Plant

There is a forest in my world with a special property: All the trees are optimised to shade as much as possible during summer and give as little shadow as possible during winter, to regulate the ...
3
votes
3answers
127 views

Could six-limbed creatures evolve from griffin or dragon to centaur?

In my setting, centaurs are related to other six-limbed creatures such as dragons and griffins (the "fur" is actually made up of tiny feathers). Assuming they were originally creatures similar to six-...
25
votes
6answers
5k views

Could a 19.25mm revolver actually exist?

I'm working on writing a story wherein there is a revolver inspired by Guillermo del Toro's Hellboy's samaritan. My question is; can such a gun, as described below, work? Or would it be a bone breaker ...
5
votes
5answers
506 views

What is the lower bound for lightspeed?

I am investigating the possibility of modifying the speed of light in my world. Assuming that the speed of light in a vacuum can (and in my world, is) modified, what lower bound exists that would ...
1
vote
4answers
167 views

How would the terrain of a snow-covered mountain deter a mechanized army?

My story is set in a fortress town built below a mountain, and revolves around the struggle between the witch who protects the mountain and the tyrant who seeks to plunder it for resources (think ...
19
votes
7answers
4k views

Is it possible to remotely hack the GPS system and disable GPS service worldwide?

The title pretty much says it all. I'm wondering if it is possible through "digital" means only (aka any physical disruption of satellites is not allowed) to disable the US GPS satellite ...
2
votes
2answers
273 views

What is the upper bound for Lightspeed?

Followup to my lower bound light speed question. I was told on the Sandbox to split the lower and upper bound for light speed in different Questions. Yes they are similar but it is possible that ...
18
votes
3answers
4k views

Does water in vacuum form a solid shell or freeze solid?

I'm working on a sci-fi setting which includes an aquatic space-faring species. When a human space vessel is ruptured and depressurizes, the gas can escape rapidly and we immediately suffer from the ...
3
votes
4answers
238 views

A WMD whose destructive potential stops at the border of a country

In the Belgian comic book "De laatste Hollander" (en.: "The last of the Dutchmen"), an alien accidentally uses a WMD (a beam that lights up the entire country) to completely engulf the entire country ...
5
votes
3answers
287 views

Could life in a planemo be sustained by cosmic background radiation?

I need to create a race that should be utterly older than humanity (and as such, much more powerful). My idea is to have that race originate from a rock planemo - a rogue planet, orbiting the center ...
1
vote
0answers
91 views

What is the limit of Graphene CPUs? [on hold]

In the world I'm building, set roughly 350 years in the future, the humans have colonized the Solar System and other systems beyond using a hyperlane network discovered at the edges of the Solar ...
7
votes
2answers
94 views

Are these atmosphere compositions for habitation in space plausible/do they cause problems I don´t see?

On Earth, our atmosphere contains 78.09% nitrogen, 20.95% oxygen, on average around 1% water vapor at sea level, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Looking through ...
8
votes
2answers
2k views

Would cybernetic implants allow humans to use biofeedback to boost their performance to superhuman levels? If so how far could we take it?

So I was surfing this website which gives rpg stats for various fictional characters in various media, when I came across this character called "The Frenchman" who apparently uses biofeedback to boost ...
98
votes
10answers
16k views

Could a Dwarven Civilization Exist?

Could a Dwarven society as described by Tolkien mythology actually work? Dwarves for the purposes of this question are short, stout, bearded men and women who live primarily underground. They have a ...
3
votes
1answer
177 views

The World is ending, but we have a time-machine [on hold]

Let's say an event is occuring that within a short timeframe makes at least the entire solarsystem uninhabitable. However, in a global effort, scientists and engineers have developed a backwards time ...
1
vote
2answers
151 views

Defense against endless hordes [closed]

Imagine humans of the present day and an enemy who suddenly appeared (seemingly) out of nowhere. The enemy has following capabilities: Their army consist of all kinds of creatures from kind of ...
4
votes
2answers
197 views

How Would Plate Tectonics on an Inverted World Work?

Recently, I came across an inverted world map on the MapPorn Reddit made by MChainsaw. "Inverted" as in, the "continents" are now below sea level and the "ocean floors" are high and dry. (...
77
votes
18answers
17k views

Would a 'World Tree' be feasible in real life?

A livescience.com article claims that trees can reach a theoretical height of 400 to 426 feet (122 to 130m). This is due to the tree being unable to carry water up to the top at that certain point due ...
3
votes
4answers
830 views

Giving Tolkien Architecture a Reality Check: Lothlorien

I need to bring something up before continuing on with another question. This is Giving Tolkien Architecture a Reality Check, which means whether or not the architecture that Tolkien described and ...
5
votes
5answers
1k views

Giving Tolkien Architecture a Reality Check: Dwarvish Kingdoms

Having escaped Isengard and left Rivendell, we are off to destroy the Ring. Our first stop--Khazad-dum, known contemporarily as "Moria". Being a Dwarvish kingdom, the problems I see with Moria are ...
2
votes
3answers
363 views

Can a large hemispherical planet be stable? [duplicate]

I had a vision of a planet twice the size of earth sliced in half like an apple by an invisible force, one half drifting away from the other into eternity. Unlike the planet Earth, it did no longer ...
57
votes
30answers
13k views

My perfect evil overlord plan… or is it?

Me You might call me evil but the facts are I deserve to rule all of the world, everyone & everything in it. What I already have done For years I have worked in the shadows (as much as you can ...
4
votes
2answers
149 views

Would advanced Plantoids be plausible? [closed]

Could it be plausible that if enough time given and favorable conditions are met, the dominant species of an alien planet could be a species of plant and by dominant I mean achieving sentience and ...
0
votes
4answers
159 views

How significantly would the course of rivers change over 10,000 years?

This one is rather straightforward. A character falls into a magically-induced coma for about 10,000 years and then wakes up to find the world around him different in quite a few ways. There's not a ...
4
votes
1answer
79 views

Solar insolation/flux's effect on biome diversity/richness on an alien world

The Questions I'm trying to answer three main questions: Does a three-axis biome chart make sense for my world? How productive/life-rich should a biome be given a specific level of solar flux (...
-1
votes
1answer
141 views

Could a black hole be used to lessen surface gravity on a Super-Earth?

Due to the moon's gravitational pull, objects at Earth's surface directly under the moon are slightly lighter. This tiny lessening of gravity would also take effect if the moon were on the exact ...
12
votes
9answers
2k views

How do I make oxygen for a generation ship?

On a generation ship, the people living on it need oxygen, lots of oxygen. More than they can realistically carry, thus a generation ship must be able to create breathable air from relatively common ...
13
votes
1answer
1k views

How long can language drift before it becomes indecipherable, and how to minimize drift?

A general question here, relevant to many world-building scenarios. Language drifts, to the point that I likely could never understand old English, but I'm not sure how much. I want to know how long ...
5
votes
3answers
763 views

Anatomically Correct Demons

Demons have been a staple of multiple religions for thousands of years, just like angels. While some of the points brought up in the Anatomically Correct Angels post (and other posts on flying ...
12
votes
5answers
3k views

How might a landlocked lake become a complete ecosystem?

Let's assume that there is a lake that has formed from snowmelt and rainfall. The lake has never been in contact with other bodies of water. How might this lake become a complete ecosystem?
29
votes
11answers
4k views

Half of living beings in the universe die: Does society survive? [closed]

Some purple person, somewhere, collected the Eternity Baubles, clicked their heels and suddenly, half of all living beings in the universe just go poof.1 The effect isn't restricted to sentient ...
49
votes
6answers
9k views

Could two planets be tidally locked to each other so close they share their atmosphere?

Could two planets be tidally locked to each other at such a small distance from one another that they share their atmosphere, and material is floating around between the two?
23
votes
8answers
4k views

What could cause an entire planet of humans to become aphasic?

I'm working on a story in which there is some sort of planetary erosion of language. Humans lose the ability to communicate verbally (orally and written). They can remember having language, can even ...
-2
votes
1answer
122 views

How realistic is the travel of the Wandering Earth, would its mass be enough as energy source? [closed]

In the movie Wandering Earth, our planet travels to another sun. That is, it gets attached about 10000 engines fed by rocks. https://en.wikipedia.org/wiki/The_Wandering_Earth Given humanity could ...
4
votes
5answers
133 views

Logical explanation for why Brainbots would not retain their original identities memories

So, my setting is a post apocalyptic one, 197 years after WW3 kicked off and destroyed pretty much everything. The current date is 2259. Before WW3 started, the USA was experimenting heavily with ...
-1
votes
2answers
90 views

Laminar Flow Fountain Shelter?

Say you were stranded on an island with no shelter whatsoever, but for some odd reason you had all the supplies and water necessary to construct a laminar flow water dome as a shelter. Keep in mind -- ...
9
votes
5answers
155 views

Reality check: Is this a plausible way to breed raccoons?

You’re a lone immortal who’s decided to breed raccoons to a human-level intelligence (over the course of hundreds of thousands or millions of years). To do so, you need to both feed a significant ...
2
votes
1answer
162 views

Highest level of 1930's Technology possible [closed]

Backstory I have a character who goes back in time to plant an idea in the minds of government scientists during the 1930's. The idea is to analyze a DNA sample and recreate it for future use in the ...
24
votes
10answers
9k views

How long would it take for people to notice a mass disappearance?

If 5 million people disappeared at the same time globally, assuming an even spread of random disappearances (not focused in any one location) how long would it be before people noticed there had been ...
12
votes
13answers
6k views

Is this state of Earth possible, after humans left for a million years?

It is the year 4056 (or probably later). The rocket with the last residents of Earth just took off, because global warming and pollution couldn't be stopped nor reverted and Earth became uninhabitable....
8
votes
6answers
385 views

How long would it take for a group of humans to travel across a continent by foot?

Think a Lord of the Rings-esque quest to save their kingdom. This quest would also involve detours, but I can just factor those in later. The continent is around the size of Australia, with a lot of ...