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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.

114
votes
18answers
29k views

Could a planet made completely of water exist?

In the Star Trek: Voyager episode "Thirty Days", there was a planet made completely out of water, which is the inspiration for this question. However, that planet was held together by an artificial ...
33
votes
8answers
5k views

Do different star systems experience time differently?

Somewhat in relation to this question - What could restrain post-singularity societies from spreading across the Galaxy? I'm assuming not all star systems move at the same velocity in relation to the ...
16
votes
6answers
2k views

Would a species evolved for very high environmental pressure necessarily die in lower pressures?

I'm aware that deep sea fish don't actually "explode" when brought to the surface but any air sacs in their bodies would expand and cause them possibly fatal damage. However, what other physiological ...
7
votes
4answers
782 views

Could Pluto/Charon support an atmosphere between them?

Somewhat inspired by this question : Could a civilization as advanced as humans exist on a planet/dwarf planet like Pluto? Assume two dwarf planets in tide lock orbit around one-another. Assume ...
12
votes
5answers
447 views

Constant artificial light

Is a scifi setting of constant artificial light everywhere plausible? I'm thinking to the point that the average adult person has not gone out of a city and has no experience of general darkness (...
34
votes
9answers
5k views

How would tattoos fare on reptilian scales?

In a world with humanized (or at least tool using) reptiles, how long would a tattoo be able to last on the scales? Would the tools need to be much different than what we use today? Would it be ...
27
votes
14answers
7k views

Is it plausible that humanity goes extinct due to not making enough children? If not, what would make it more plausible?

With the increase in living standards, the number of children by women is decreasing in highly developed countries. Question: Is it conceivable (with the aggravating factors proposed below) to see ...
50
votes
14answers
6k views

Would charging unicorns survive the impact with a line of infantry?

The unicorns would be used to charge a line of infantry with their horn. They are as big as a horse and the horn is similar to this image: The infantry is a standard medieval army made mostly of ...
20
votes
10answers
3k views

Motivations for interstellar colonizations

Question is ultimately asking why would we do this? A few parameters first... Technological: Our current knowledge of physics is correct and there is no such thing as faster than light travel, nor ...
14
votes
6answers
2k views

How difficult would it be to make high-power energy weapons undetectable?

Take, if you will, a sci-fi setting in which power is cheap and handheld energy weapons (blasters, lasers, plasma rifles, that sorta thing) are common. In this setting is an isolated community ...
9
votes
4answers
722 views

What natural or human-induced disaster could bring to a scenario like in McCarthy's "The Road'?

This post-apocalyptic environment, as narrated in the book, depicts a world where most if not all animal life has been abruptly killed, and similarly most vegetation burned out. After the disaster, ...
24
votes
13answers
2k views

How would a user interact with a direct neural interface?

Assume humanity has developed a cybernetic implant technology which allowed humans to be "advanced". The technology would be surgically implanted and provide a range of functionality (I'm not ...
7
votes
4answers
572 views

Life in planets with little Solar exposure

Could life originate on planets outside the circumstellar habitable zone (CHZ) where there is very little exposure to sun (like Uranus). If so what kind of energy source would they depend on. Could ...
24
votes
14answers
4k views

What are the social implications of discovering a formula for immortality?

Here is a hypothetical, but not entirely plausible, scenario: An organization or company (likely pharmaceutical) discovers the formula to develop a drug that stops aging (the human body's cells are ...
19
votes
12answers
3k views

Are two cities in enmity within visibility range of each other reasonable?

So, I would like to know if it is reasonable that two walled cities exist in extreme proximity of each other. A little background: The story is set in an imaginary world, comparable to the Late ...
43
votes
5answers
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?
12
votes
2answers
616 views

Zero - G fire visuals and Oxygen consumption

Lets say there is a fire on a zero-g space station (no efforts have been made to give gravity to the structure and it's far enough away from any planet/sun that gravity is negligible). It is ...
7
votes
7answers
999 views

Are these gaps in post-apocalyptic tech possible?

So humans ended up all dead in a hundred years, and then after some time humans appeared back on Earth, but know nothing about the previous humans. They found records and blueprints of things like ...
-1
votes
3answers
511 views

What would change and how long would information last if all humans died? (and it's effects) [closed]

You know those angel Apocalypse stories where angels come down and kill all the humans? Well, I'm writing what would happen if the angels had won, and what happens after. So it goes like this: The ...
10
votes
9answers
2k views

What form of anti-gravity is the most feasible?

Many sci-fi words use anti-gravity or artificial gravity to manipulate the weight of their ships making flight much easier. Wikipedia even has an article on it which discusses several attempts to make ...
16
votes
2answers
1k views

Consistency of Giant Spider Webs

Giant spider webs in fiction always seem very thin compared to the scale of the spider itself. (See: Hobbit 2) I would expect giant spider webs to be like cables, but that might not be the case. My ...
7
votes
3answers
1k views

Is this shattered planet scenario possible?

Suppose there's a planet that has similar characteristics of Earth and can provide life, suddenly shatters in many pieces and scattered over the system. A small but very dense object is attached into ...
10
votes
3answers
2k views

What technology is required to detect an underground civilization?

Suppose a world has huge underground caverns, capable of supporting large agricultural societies (something like described in Our Hollow Earth). What technological level, or better yet specific ...
4
votes
2answers
347 views

Polarity of a planet's lightning strikes reversed?

On Earth, the planet itself is negatively charged and the clouds are positively charged, causing lightning to travel from the clouds to the surface. While there are significantly smaller wisps of ...
18
votes
12answers
9k views

Could a space-dwelling creature survive solely off of sunlight?

On Earth, photosynthetic organisms require additional nutrients to survive; in addition to "feeding" off of sunlight, plants respire and absorb water from the ground in order to grow. However, the ...
18
votes
3answers
2k views

How much stuff could we get into Earth orbit for the start-up cost of initiating asteroid mining?

I was reading this question and realized that I didn't actually know enough to give the answer that I wanted. Obviously in the near term, all our raw materials come from the Earth. The only other ...
11
votes
4answers
1k views

Could there be a group of people with highly advanced technology?

Is it possible that a group of "elite" humans have highly advanced technology, but have kept it hidden? For example, is it possible that some people already had powerful computers and automobiles (...
17
votes
20answers
12k views

Could communism become a strong alternative to capitalism in the future? [closed]

From Marx, capitalism and communism are: From each according to his ability, to each according to his needs. From the Encyclopedia Britannica: Communism, the political and economic doctrine that ...
8
votes
5answers
1k views

Effects on the visual systems of humans when temporarily having several stars illuminating the living space

A modern day Earth nation is at war with another. That other nation is extremely advanced but they are also pacifists. Instead of killing peoples their gun rounds and shells have the effect of ...
12
votes
5answers
2k views

Is Superman a peeping Tom? or Would x-ray vision be biologically reasonable?

Real x-ray vision, the ability to (at least) detect X-rays as a 'visible' light (or any other detection system) seems it would be very problematic. First X-Rays are a high energy electromagnetic ...
13
votes
2answers
2k views

How would nanobots consume objects?

I've been thinking about a cyberpunk universe where nanobots are a universal force capable of achieving many things, examples include: Biological and medical modifications of the human body Construct/...
30
votes
5answers
4k views

Dietary Requirements of Giant Spiders

Giant Spiders are a traditional element of fantasy worlds. They prey upon most human's primal fears, and are easy to make as evil as possible. (Note: Not to scale) But are they actually plausible? ...
9
votes
2answers
846 views

Seasons on a planet that's tidally locked with the smaller star in a dual-star system

Consider a dual-star system, with the distances between S (larger star) and J (smaller star) similar to Sun–Jupiter. A planet P rotates around J on a 90-degree ecliptic and is Earth-like otherwise. ...
21
votes
9answers
2k views

Cataclysmic event resulting in a region of glass?

I have in my world a "crystalline desert". The idea is that a major cataclysmic event turned the surrounding area into glass, color irrelevant. Then following the event, major earthquakes and the ...
5
votes
5answers
660 views

Background for hi-tech in low tech

For some time, I have been playing around with the idea of a medieval-like world, but with the twist: Some sci-fi tools exist and are fully operational. But I cannot come up with good and plausible ...
15
votes
6answers
3k views

Planet with dual core

My premise involves a habitable planet with a dual core: it has two masses similar in composition to Earth's core, which revolve around each other over the course of hundreds of thousands of years. ...
37
votes
14answers
8k views

Can I keep our universe, but without the speed limit (of light)?

It seems like nothing can move faster than light and this is quite bothersome for interstellar travel. It takes decades in the best case to get anywhere interesting in our little Milkyway (Many ...
18
votes
12answers
7k views

If a space ship crashes on a planet, is it realistic that things from that space ship could be rescued afterwards?

The situation I'm considering is as follows: A space ship (a transport ship operated by two people) crashes onto a planet on which a swing-by was planned. The crew could escape using an escape ...
2
votes
2answers
882 views

How would tectonics behave on a two continent planet?

I am working on constructing a world which is basically (from the northern pole to the southern pole): smallish frozen over ocean huge land mass encompassing the northern hemisphere tremendous ocean ...
11
votes
5answers
1k views

Could higher land-based life exist on a planet with a pressure of about 1 MPa?

This is somewhat of a follow-up question to my ammonia-based world question. I've found out that the melting point of ammonia is at 25°C at a pressure of about 1 MPa (about 10 times the atmospheric ...
27
votes
8answers
4k views

Building the Death Star with today's tech

I found an interesting Wikipedia article, quoted in an answer here. I'm looking into writing a story where someone has built a Death Star. The purpose of this craft is important to the story (and the ...
8
votes
3answers
1k views

Could a government control its people using frequencies?

Setting: Earth, in the future, near 2060 or 2100 Technology: a bit more advanced than ours Armies and police forces are already using systems for crowd control. Some devices can generate discomfort ...
32
votes
8answers
5k views

Can we 'beam' energy from the moon?

Really can't believe I have to edit this in, but this question has no bearing on our current use and generation of nuclear energy on Earth. There are dangers to nuclear energy generation, or we would ...
10
votes
2answers
3k views

Can anything survive by eating rocks and other ground minerals?

Are there bacteria or other types of lifeforms that feed on rocks and other ground minerals? And if there aren't, is it technically possible? It can eat other things but the majority of its diet ...
4
votes
4answers
410 views

Could life survive on a diet of dust?

Could life survive on a diet of dust or some other substance that is both abundant and that we don't place any value on?
5
votes
6answers
9k views

Can a genetically modified human breathe something other than Earth's oxygen/nitrogen atmosphere?

If a human is kidnapped by an alien vessel and taken to another planet - and, for the sake of argument, let's assume that the alien life-form lives in a completely different environment than Earth's. ...
5
votes
1answer
830 views

How big is a big city?

According to two RPG systems; Dungeon & dragon and Pathfinder; a metropolis is the largest category for medieval city. The population of a metropolis starts at 25 000 people. I remember that they ...
33
votes
9answers
5k views

Could a technological society develop without agriculture?

Before the advent of agriculture, humans fed themselves by hunting and gathering. Hunter-gatherer societies tend to function quite differently from agricultural societies. Arguably, historically, ...
16
votes
2answers
4k views

Is metal-based, or other non-carbon-based, life realistic?

One science fiction short story I read (I don't remember the title or author, sorry!) featured some small creatures (unnamed) that were formed from metal, with the argument that "just like life ...
14
votes
5answers
2k views

Asteroid impact. How big does it have to be to globally affect plate tectonics?

I want to know about the plausibility and required parameters of the following scenario: Take an Earth-like planet, about the same size, composition and gravity. It has no plate tectonics to speak of....