Questions tagged [science-based]

For questions that require answers based on hard science, not magic or pseudo-science, but do not require scientific citations. Contrast with the hard-science and reality-check tags. Do not use this tag as the only tag on a question because it describes how the question should be answered, not the topic.

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4answers
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How to make a realistic 'giant'

Imagine a race of what we would call 'giants', each of them possibly around 8 to 10 feet (2.40-3.00 meters) tall. What differences would they need compared to us regular humans in order to function? I ...
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19answers
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How long could a late WW2-era battleship last under sustained ship of the line cannon fire?

In an alternate world of magic, a battleship similar in design to the Bismarck is stopped in the middle of the ocean. It was built by a society of Earth humans who moved to this world. All other ...
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12answers
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Is It Possible to Make a Computer Virus That Acts as an Anti-virus?

After receiving answers to this question, I now know that viruses cannot be written in machine code in such a way that they can universally infect all kinds of systems. Every machine has a unique set ...
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19answers
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Is it possible to encode a message in such a way that can only be read by someone or something capable of seeing into the very near future?

Say you have some way of seeing somewhere between a microsecond to 0.1 seconds into the future, or at least the most likely future. Is it possible,through something like a flip-book effect or some ...
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14answers
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What conditions would prevent the possibility of human-made satellites orbiting a habitable planet?

I'm looking for something that would prevent humans being able to establish the use of satellites on an alien planet, but also would not prevent humans from living on the planet, or life developing on ...
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15answers
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What methods might an ancient civilization use to desalinate sea water?

Following on from my previous question here concerning the ancient civilization I have called the Androy and their struggle to survive terrible drought conditions on their planet. After years of ...
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12answers
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Can we build a world in 1,000 years?

We have a fleet of sub-light speed generation ships and associated engineering devices/ships. Their original world can no longer support their species, and they must move to survive. The fleet of ...
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14answers
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How can hornets be engineered to kill a human with a single sting?

Asian Giant Hornets are particularly vicious and deliver a dose of neurotoxin to its victims. Generally an average of 59 stings are sufficient to kill a healthy non-allergic man Given a suitable ...
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12answers
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How to get directions in deep space?

A spaceship crew, during their interstellar travel loses control of the spaceship for a few hours due to external factors (exact factor not important). This causes the spaceship to deviate from its ...
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17answers
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How far could civilisation develop within one lifetime - starting from nothing?

This question here asked if it would be possible to reach the moon within a lifetime for a civilisation starting with "nothing". The answer to that question, quite clearly, is: no way. But ...
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13answers
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How to stop a massive canal system from silting up?

Based on the desert world from this question I need to transport around 500 cubic kilometres of water / year across a desert. Using this calculator. this can be achieved if the main feeder canal is ...
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19answers
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How can I keep the computers on my spaceship from temperature related death after a hull breach?

Spaceships are a peculiar thing. We've got them in all forms, sizes & colours. They have vast computers needed to do all the real-time calculations required for astrogation. Assuming our ...
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What's it like to be an uploaded human with limited computing power?

In most science fiction where humans are simulated or uploaded onto computers, the humans are simulated with perfect fidelity. But this seems unlikely-- humans are very expensive to run. In Robin ...
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8answers
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Are diamond berries possible?

Diamonds are carbon. Plants take in CO2 and use the carbon. Chemically, could the right kind of plant have diamonds for berries, or is there some other limiting factor?
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7answers
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Can 3 planets rotate around each other like this?

I was wondering if three planets can rotate around each other so that: Two of the planets are smaller and rotate around each other Both of the smaller planets rotate around another, bigger planet. ...
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5answers
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What would happen if magic was constrained by the second law of thermodynamics

This is a followup question to the question Wondering what would happen if magic was constrained by Conservation of Energy and it's related to this post. This question asks which sources of energy ...
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3answers
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How would a Reflecting-Oven-Jay Evolve?

This answer to my question about light-as-a-weapon came up with an interesting concept: The Reflecting-Oven-Jay This is a small African predatory bird with a perfectly smooth set of wings with ...
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34answers
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Why would a fighter have a weaker shield than a capital ship?

I enjoy designing games, and in one that I'm working on the ships have shields, similar to the shields in Star Trek. They are created via some kind of force field projection mechanism and are ...
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13answers
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Is there a liquid that could protect a human inside it from impact?

I am trying to figure out what kind of liquid, if any, can be used to severely impede or slow human motion without killing or severely damaging their bodies (IE if after being submerged in this liquid ...
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17answers
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Deadly, Heavier than Air Gas

In a given fantasy world, I need a deadly (yet not magical) gas that will naturally pool in low depressions and valleys. The level of magic is not high, so I'd like it to be an actual chemical that ...
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9answers
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What are the effects of slicing the Earth in half with a particle beam?

Scenario: An exact copy of our world is sliced in half by a particle beam. The beam has a diameter of 40 meters and moves at a speed of 0.999c. The beam slices the earth from top to bottom in 600 ...
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20answers
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Possible Long Term Effects of Frequent Teleportation

This is a follow-up to my previous question, based on one of the comments that was made. While the answers to the original make it quite reasonable that there will be no permanent effects manifested ...
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19answers
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What sort of world would help prevent an intelligent species from discovering evolution?

I’m working on a first contact story set in the near future where an advanced alien species arrives at Earth and reveals itself to humanity, but is utterly baffled by the diversity of life that it ...
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23answers
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Economic reasons to put people on Mars?

I am working a hard science fiction story and I cannot come up with a really good reason to put people on Mars. I need people on Mars for the story to work, but there is no reason for them to be there....
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13answers
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Can a river be put under enough pressure to jet straight up for a mile?

I've been mulling over an idea for my preferred RPG setting, and I wanted to check if anyone knows the following: Is it possible for a river to flow underground for miles, and then suddenly be put ...
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11answers
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How does an ordinary person announce major discoveries?

While this is a hypothetical question, I am actually looking for a 'real-world' answer. This is my first time here, so please let me know if I should ask it somewhere else. So, let's say I am an ...
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12answers
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Super Spies Reality Check

It's a common trope that during the Cold War (and afterwards) America, the UK, the USSR, and sometimes nations beyond these developed super spies, capable of acts of espionage, sabotage, and direct ...
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7answers
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How far can a time traveller go into the past before his electrical equipment becomes unchargeable?

My time traveller has a maybe 20-minutes-into-the-future smartphone and laptop. They can store large amounts of data, on the Petabytes level or higher. The time traveller can effectively store the ...
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10answers
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How can I destroy a gas giant planet?

We have already discussed how difficult it would be to blow up a planet like Earth, basically deciding that you can't do that with any reasonable amounts of energy. But what if I don't need to blow up ...
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10answers
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No newborns on Earth. How much time to find a cure?

Pretty much what it says on the tin: It's the beginning of 2016. Due to a fast-spreading virus, humans have lost the ability to reproduce themselves. The virus makes current artifical fertilization ...
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5answers
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Is diamond armor better than traditional armor?

A medieval alchemist (from Europe) has figured out how to crystallize any object and turn it into diamond. Would diamond armor (e.g. chain mail and plate armor) and weapons be superior to their ...
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3answers
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How many plants does it take to breathe?

I'm working on a space story in which an astronaut is travelling to Neptune to validate our CurrentEarth™ corporation's findings regarding our Solar System. The setting is a moving ship similar to the ...
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9answers
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How long does it take to build a medieval city wall?

There is a medieval city that, for multiple reasons, doesn't have any kind of structural defense, but they decided to build a wall now as there is risk of a war in the bordering kingdom, which can ...
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5answers
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Can a planet realistically have multiple suns?

Several science fiction books I have read (including, IINM, Nightfall by Asimov) have featured planets with several suns. Some worlds where this happened wrought interesting effects on the inhabitants ...
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9answers
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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 ...
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17answers
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An object that is gold in one specific area but becomes worthless if you leave that area?

Let us pretend there is some "sacred city" created by gods, where gold is so common that it is the standard form of currency and everyone has lots of it. But once you try to leave the city with this ...
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16answers
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Best species to breed to intelligence

I’ve included more background below, but the TL;DR is that you’re a lone immortal who’s decided to breed some species of animal to a human-level intelligence (over the course of hundreds of thousands ...
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12answers
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Weaponry made from extreme light-weight steel: swords and daggers

Imagine there was a material that was mostly identical to steel in almost every way, but instead of a density of $7.85–7.87 g/cm^3$ it would be a tenth of that. That is about 4 times lighter than ...
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9answers
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Are external lights on spaceships even necessary?

Many fictional spaceships of all kinds are known to have external lights. Do they even need them? Outer space is lit by the billions of stars and galaxies, so why are there external lights on ...
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19answers
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Which fast STL drive could not be weaponized or results in perpetual motion?

I'm looking for a slower-than-light (STL) drive for fast inter-system travel. It should make trips from one planet of a system to another (e.g. Earth, Mars, Jupiter) with sublight speed possible in a ...
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6answers
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Would a suit that acts as extra-cardiovascular system allow you to run indefinitely?

Generally, when you run a long distance or do something particularly strenuous, you start breathing heavily because of a decrease of oxygen in your blood. Your gasping and weezing is in an effort to ...
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7answers
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What makes a dragon's scale so tough?

Many fantasy stories involve some variation of a dragon, and while there's a lot of variation in whether or not they fly, if they can breathe fire, how magical they are, etc., the strength of dragon ...
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8answers
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What would be the effects on the human body if the oxygen level increased by a lot?

How would the human body be affected if oxygen levels increased by a lot? Our air is 78% nitrogen and 21% oxygen. If it increased to 30% oxygen, what would the effects be and how long would it take ...
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7answers
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Delivering the Eternal Sausage

In a future world, well-to-do people have access to piped food that travels straight to their kitchens. Let us focus on one such food; the eternal sausage. My first idea was to simply force sausage ...
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6answers
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What's the smallest reasonable natural planet or moon with Earth-like surface gravity?

We all know that equation for surface gravity is $$ g = \frac{4\pi}{3} G \rho r $$ So if we want Earth-like surface gravity of $ g = 9.81 $, then the equation for radius is $$ r = \frac{3 g}{4\pi G ...
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16answers
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Is it possible for nature to create bubble wrap?

Bubble wrap is a synthetic packing material featuring small bubbles that are designed to provide cushion to the protected object and pop in place of damaging the object under excessive stress. They ...
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12answers
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Is it possible for a substance to be thermally inert?

Heat is energy. Temperature is an indication of the level of heat in a substance. But the normal way to measure temperature is to observe how the substance interacts with its surroundings - most ...
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15answers
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Precision Destruction by a Cosmic Being (Or how to destroy StackExchange from space)

We have a lot of weird questions come up in chat and fun comments about how we destroy worlds over a lunch break. Here is one that though I might share. You are a power that can affect cosmic bodies ...
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12answers
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How would one design an undetectable nuke to hit the Moon with?

Colonists have set up a viable, long term lunar colony on the near-side of the moon in the mid-21st century. They are quickly reaching total self-sufficiency and the earth governments who sponsored ...
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8answers
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Could the Romans have colonised the New World?

The question of whether the Romans could have crossed the Atlantic in a storm has already been answered and the answer seems to be: yes but unlikely. Could the Romans have crossed the Atlantic in a ...

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