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.

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23answers
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What scientifically would make it possible that certain large bodies of water be impassable?

What scientifically would make it possible that certain large bodies of water be impassable while others that seem very similar are able to be navigated? This is not what I am attempting to do, but ...
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14answers
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Can I produce a true 3D orbit?

I've been doing a little research (including reading Howard Curtis' Orbital Mechanics for Engineering Students) because I want to build a solar system with a planet that has a true three-dimensional ...
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How long could the sun be turned off without overly damaging planet Earth + humanity?

Background story: Current Earth, in the close future. Astronomers have found first signs of extraterrestrial life: huge sheet-like objects (with surfaces easily as large as the surface of the Earth) ...
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10answers
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Will unattended nuclear power plants actually cause damage to their surroundings?

Scenario: Deadly virus wiped out 80 - 90% world population and it did it pretty quickly (in 2 months) Although it is plausible that among these 10 - 20% of survivors will be people who actually know ...
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4answers
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What would a planet spinning fast enough to allow geostationary orbit near the surface look like?

From an answer to a previous question of mine: A planet spinning fast enough to allow geostationary orbit near the surface would result in odd side effects. Any object at rest on the equator would ...
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3answers
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Is there a maximum size an ocean bound creature could grow to?

Assuming the ocean is deep enough and not overcrowded is there any upper limits to the size a "sea monster" can grow? On land creatures are limited by gravity, they have to be able to generate the ...
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5answers
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Anatomically correct sharknado shark

Raining animals is a rare meteorological phenomenon in which flightless animals fall from the sky. Such occurrences have been reported in many countries throughout history. One hypothesis is that ...
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18answers
12k views

Is it possible for a species to have more than two sexes?

Every species I'm aware of on earth has two sexes (with the possible exception of species which change their sexes to allow self fertilization). Is it possible for a species to evolve which could ...
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8answers
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Stopping time, by speeding it up inside a bubble

Imagine I have a device that can stop time for the person who holds it (similar to Bernard's Watch). This device works in a very specific way - it creates a bubble around the user (just large enough ...
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28answers
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Poison which constantly needs to be treated by antidote to not get killed

Inspired by Frank Herbert's Dune: Action Joe is kept prisoner in Doctor Evil's prison. Doctor Evil knows that Joe's escape is inevitable. So he decides to introduce poison to Joe's body. Joe gets his ...
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19answers
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(How) can I provide reliable water sources in a world of flying islands?

I have humans who live in a world filled with floating islands. These islands span all heights in the planet: from the core to the upper atmosphere. The problem I have is that most of these islands ...
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18answers
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What would be the possible benefits of pointed ears?

The title fairly well sums up the question. We all know elves have pointed ears. Whether they be LotR style with slight tapers, or full blown foot long impracticalities, all elves have pointed ears. ...
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13answers
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How large would a world have to be for a sailing ship to never make it past the horizon?

I have a sailing ship. It leaves port. As it goes away, it grows smaller and smaller. In our world, it eventually is hidden by the curvature of the Earth, such that the top mast stays visible longer. ...
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9answers
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Are there any real world examples of where a desert and a swamp meet each other?

I am building a world with many deserts and swamps. So a simple question: Are there any real world examples of where a desert and a swamp meet each other? Deserts and swamps are vastly different ...
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14answers
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Ridiculously Fast Supercomputer

Let's say that somehow, Earth suddenly acquired a computer with ridiculous speed. This computer can run a program described in a language of your choice, which can be described by a readme file that ...
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12answers
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How would you know your floating island was losing altitude?

The question: What realistic environmental signs would telegraph to the occupants of a floating landmass that their home was slowly losing altitude? The planet: I'm working on a story that takes ...
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13answers
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Pressure inside an infinite ocean?

Handwaving the origin of one such place, imagine a universe where every part of space is filled fully and evenly with liquid water (at, say 1 degree Celsius). What would be the experience of a solid ...
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11answers
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How could we time travel backwards without killing everyone with germs from the future?

Consider a world in which time travel has been made viable possibility. Initially, many are ecstatic at the new technology and the knowledge it will unlock. However, biologists and other scientists ...
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5answers
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What is the amputationility of a monomolecular wire weapon?

Monomolecular wire weapons are a somewhat common element in science-fiction. Including in this this fantastic image I found while looking into this: Is the only infeasible thing in this image that ...
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25answers
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With what liquid should I fill my dead, intraversable seas?

My planet has interesting geography; there are large islands, each with a unique civilisation of people. But separating them are impassible barriers; they consist of a double range of tall, steep ...
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16answers
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Is this alternate history plausible? (Hard Sci-Fi, Realistic History)

Is this alternate history I came up with plausible? What holes does it have? Are some events very unlikely to happen, even impossible? Should I change some dates of some events? Most of my knowledge ...
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18answers
7k views

Parachute equivalent when there is no ground

In this world wandwavium machines fly around with glee. But, between one flying island and another, there is no ground. Beneath your flying machine the air only gets denser, and denser, until ...
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12answers
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When will the last unambiguous evidence of mankind disappear?

Humanity just disappears tomorrow, let's say it is like the Thanos-snap but it kills everyone. How long until the last unambiguous evidence of our existence disappears? What was this last relic? The ...
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23answers
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What would be best way to re-melt Mars' mantle and core to revive its magnetosphere

Missing magnetosphere on Mars keeps popping up. Most likely caused by Mars core being cold, mantle not bubbly enough. Mars mantle is dormant, core does not move. What would be good way to get it ...
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20answers
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Is there a reason to believe that programming languages are going to converge?

On Earth today, even though most people speak some English, there is seemingly no reason to believe that future generation's main language will be the same in decades/centuries to come (i.e., we'll ...
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3answers
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How early was the Earth liveable for today's humans?

Say you were to drop a (bunch of) human(s) at some past era of our Earth. I'm assuming they might encounter a few problems such as the composition of the air not being breathable, the water being too ...
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8answers
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How do creatures with a hive mind communicate?

Suppose we have a civilisation which is made up of many creatures sharing a single hive mind. Each creature can see, hear and remember what each other member of the species (or possibly hive) has seen ...
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2answers
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How would winds behave on a tidally locked planet?

If an earth-sized planet were tidally locked to a star, and was in the life zone of its star with an earth-like atmosphere, what would its wind patterns be like? The planet would have one hot ...
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11answers
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Time Warp: Modern chemist as court alchemist

Premise The premise is an adept modern chemist is transported back in time and is to serve as the court alchemist to a wealthy prince in the late 16th century. Assumptions: "Transmuting" gold is ...
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26answers
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Advantages of “Spider Mechs” over Tanks?

I've seen the discussion on how bipedal mechs are inferior to treaded and wheeled vehicles in almost every way. However, all of these questions appear to be related to bipedal mechs. I'm wondering if ...
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11answers
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Would a wound from a monomolecular blade instantly heal?

Or, phrased another way, how thick would the blade behind the cutting edge need to be in order to cause significant and lasting damage to a human body? My question can be considered an expansion of ...
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8answers
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Could humanity survive the sun going dark?

The sun inexplicably ceases to give light. It's still there and continues to have a gravitational pull keeping us in orbit. The solar system continues to operate as normal, but the sun has gone dark ...
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29answers
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What is my malfunctioning AI harvesting from humans?

The scenario described below is for a role-playing game. The setting is Earth-like but with a healthy dose of sci-fi. Even though the setting is sci-fi I would prefer answers be largely based in real ...
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12answers
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Could two planets follow the same orbit and never “see” each other?

Imagine two identical planets planet A and planet B, orbiting the same star. Is it possible that these two planets follow the exact same "route" as they orbit their sun, but are just distant enough ...
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11answers
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How long will it take to discover they live on a moon and not on a planet?

In my alternate reality, Earth is not a planet. It is a moon and orbits a gas giant (however it has all of Earth's characteristics, it is also full of humans and life as we know it). This is the only ...
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17answers
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Surviving an Overwhelming Siege

The evil enemy has us surrounded. They outnumber our forces, they have us outgunned. These helldogs have a trillion dollars/year for their war budget, and they can afford the fanciest toys, numerous ...
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16answers
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A pill to make you think faster: Side effects?

OK, so scientists have found a great new substance: That substance makes you think ten times as fast! The advantages are obvious. However, as every medicine, this pill will have side effects. There ...
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7answers
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How powerful of a computer do I need to simulate and emulate a human brain?

The title is pretty self-explanatory. How powerful does a computer have to be before it has the hardware capability to simulate and emulate a human mind in real-time? I'm leaving the question of the ...
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28answers
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What distinction could there be between space torpedoes and space missiles?

In the game "Stelaris" torpedoes and missiles are different categories of weapon. Presumably they wanted to include numerous kinds of weapons for the player to chose from. These weapons are all ...
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15answers
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Would a horse be sufficient buffer to prevent injury when falling from a great height?

I'm writing a sci-fi story with some fantasy elements, and I'm trying to keep even the most outrageous moments grounded in the laws of our universe. This is one of those moments. The Situation A man ...
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9answers
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Is an organism with both animal-like traits and plant-like traits scientifically possible?

Can an organism have traits that resemble both an animal and a plant? Such as bone, chlorophyll, muscles, and cell walls. Not necessarily a hybrid, but something that can be classified in between the ...
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8answers
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How dangerous is a 500-year-old nuclear warhead?

Inspired by this question: For several excellent reasons, a 500-year-old nuclear warhead is not going to produce an actual nuclear explosion. But that doesn't mean it's not dangerous anymore. ...
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5answers
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How do seasons work in a binary system (planet orbits one star, not both)?

I have a planet orbiting one star in a binary system. When the planet is exactly between the two stars it will experience a double day; when the primary sun sets the secondary one rises, no overlap. ...
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9answers
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Wondering what would happen if magic was constrained by Conservation of Energy

Would throwing a fireball leave a trail of frost in its wake? Would transmuting too much lead into gold cause a small meltdown? Would collecting enough power to cast a really big spell like causing ...
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17answers
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For what reasons would an animal species NOT cross a *horizontal* land bridge?

In my worldbuilding project, 2 continents located on roughly the same latitude are connected by a land bridge. Both sides of the bridge are surrounded by a temperate grassland, and the lack of seasons ...
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18answers
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Why did dragons evolve to be smart?

Before you comment "dragons can't happen", we've been there before. Based on the question linked above, assume dragons are scientifically plausible. You may change what you need about the ...
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18answers
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City made of glass in a desert?

My world has a city of glass found along the outskirts of a desert. I decided on this because sand can become glass and so it was a huge resource that could be used for building. However, the concern ...
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10answers
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Electricity free spaceship

Assume there's a spaceship in earth orbit that its crew of 24 want to get to Mars, the crew are all humans and possess all of modern day knowledge and equipment, is it possible for said ship to make ...
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9answers
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How could I scientifically explain ice breath?

I'm sure there have been questions on here about fire-breathing dragons, and I recently saw a question about a lightning-breathing dragon, but back in fifth grade I wrote a 150-page story about a ...
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7answers
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What's the largest body in the solar system that you could destroy without endangering humanity?

You're an alien that really likes pyrotechnics. Nothing that goes boom on your home planet (in a safe and responsible manner) satisfies you any more. Why not blow up a planet and see what that's ...