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Questions tagged [hard-science]

Requires answers backed up by equations, empirical evidence, scientific papers, other citations, etc. Contrast with: science-based and reality-check 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. Review the tag info before using this tag, and flag your question for moderator attention once posted to have the hard-science notice added.

8
votes
1answer
199 views

Bouncing Beads of Blood - Just how cold would it have to be?

My heroine has been stabbed - run through the abdomen by a foot-long dagger - and is bleeding to death. She is currently crawling toward her salvation through a very cold place. She is magically ...
0
votes
1answer
112 views

How would floating islands work? [duplicate]

Soaring among the clouds over an earth-like planet, islands... on which fortresses are built for strategic advantage, on which stations for the dragon air force are built, and which can be relatively ...
0
votes
2answers
216 views

If a Mount Everest-sized mountain had Earth's sea level atmospheric pressure at the top, what would the atmospheric pressure be at sea level?

I'm designing a world with earthlike gravity where the human colonists are intended to live on top of a gigantic shield volcano as tall as Mount Everest. What would the pressure be at the bottom? ...
0
votes
1answer
136 views

What will it cost me to travel through Time? (Part 1: Travelling forwards in Time - Time Dilation)

There are many questions on Worldbuilding about what item(s) a time traveller should take back in time in order to alter past events or even simply to survive. There has never as far as I know been ...
10
votes
1answer
215 views

Could the equator of a world be a closed-time like loop?

Most works of fiction have quite imaginative views of time travel. Mighty machines that teleport in time instead of space. Gaping portals in space that take you to another time. Mystical beings with a ...
6
votes
3answers
191 views

Effects of Explosive Decompression on the Human Body?

Many science fiction stories, movies, and shows involve characters undergoing explosive decompression, the technical term for a rapid drop in pressure, usually all the way to a vacuum. Frequently, ...
3
votes
1answer
138 views

Beer Goggles in the Antarctic

Background A large colony lives in the Antarctic in a network of bases. They have so far evaded the dreadful worldwide plague. When they venture outside their base they don their climate-proof ...
16
votes
3answers
1k views

A Decoy Planet made of expanded polystyrene. How big can I make it?

Note: This is different from the previous question Building a full-sized Lego Earth - what would it look like at various levels?. In that case it was about making a solid full-size Earth from Lego and ...
1
vote
2answers
238 views

Can a planet's atmosphere be in orbit around the planet? [duplicate]

Imagine a planet somewhat like Saturn except that its rings are its atmosphere instead of rocks and ice. Is this theoretically possible? (a) If so, what conditions would need to be true and what ...
1
vote
1answer
137 views

Why would a male marsiupial agree to accept responsibility for carrying half of his mate's joeys?

I'm looking to create a species of marsupial that is heavily K select, which is to say they put significant effort into raising their young after birth (both of them :P ) in which both the male and ...
7
votes
2answers
130 views

Calculating an eccentric enough orbit to allow a dip into atmosphere and escape again

How would I calculate if it is possible to have an eccentric enough orbit around a gas giant to dip the periapsis some depth(how deep?) into the atmosphere of a gas giant like Jupiter or Saturn and ...
-1
votes
0answers
67 views

Would a spaceship be able to stay hidden for some time,if hidden behind an asteroid and running on minimal power output? [duplicate]

Let's say I have a spaceship I want to hide. If the ship had her lights, engine, reactor and non-essential power consuming modules turned off, is covered in a camouflage that reflects light like an ...
1
vote
1answer
133 views

Counteracting Perverse Incentive effects in 1902 Hanoi rat population

A perverse incentive is a reward system that has the opposite effect to the one intended. In Hanoi, under French colonial rule, a program paying people a bounty for each rat tail handed in was ...
17
votes
2answers
430 views

The mass of an economically feasible non-microscopic traversable wormhole

Background In my hard sci-fi settings, there is an advanced Type II Civilization, that are progressing toward Type III Civilization (yes, I am referring to Kardashev Scale). They are sprawling across ...
4
votes
3answers
339 views

Building a full-sized Lego Earth - what would it look like at various levels?

Lego representations of Earth have been made at various scales, for example this one: Suppose Slartibartfast made a full-size Earth from Lego (including the oceans being represented as solid blocks. ...
5
votes
5answers
273 views

Ultrapowerful chemical propellant for guns

I'm building a moderately hard scifi future setting that focuses on space and land warfare and I'm trying to decide what would be the most realistic from an engineering standpoint of artillery tech ...
30
votes
10answers
8k views

In theory, could all mammals be wiped out by a single pathogen?

Pathogen Note: For the purpose of this question I define a pathogen to include viruses and/or bacteria. Edit: I don't exclude other biological agents such as fungi that might have the same effect. ...
8
votes
7answers
388 views

A possible solution to stealth in space

I'm sure most worldbuilders will have heard the aphorism that in space "Everyone sees Everything", or that "There Ain't No Stealth In Space". I'd like to propose a possible solution to this. The ...
3
votes
3answers
223 views

A planet that cannot be orbited [duplicate]

I'm wondering if it is possible for a planet to be impossible to orbit stably over a significant length of time. The shorter the length of time the planet can be orbited for, the better. It should ...
13
votes
2answers
3k views

Square thrusters on spaceships

My question is pretty basic, would square thrusters and RCS ports have any real drawbacks over round ones? I know that angles on windows for airplanes is a problem because of the pressure, so I don't ...
5
votes
3answers
131 views

Could Multicellular Life Evolve Sans Cryogenian?

Prior to the Cambrian, there have been three separate ice ages--the Huronian, from 2.4 to 2.1 billion years ago; and the two Cryogenian ice ages, from 720 to 635 million years ago, split in such by a ...
8
votes
2answers
133 views

Tolerable range of surface gravities for interplanetary colonists?

Human physiology is adapted for life at 1G, but planets colonised by future humans will likely have different surface gravities. What is the range of values for surface gravity that humans can ...
0
votes
2answers
177 views

What is the limit of an immortal being's memory? [closed]

-In my story, my main character comes across an immortal being, chained and isolated under a mountain for countless years; subsequently losing memories from her past over time, while still being ...
0
votes
1answer
75 views

Are Planets with mainly one climate Biome Plausible? [duplicate]

So i'll start by saying it feels like a somewhat stupid question in the sense that the answer is no, but im wondering if (for back story of races in a story) its realistically possible for a planet to ...
29
votes
13answers
6k views

Can a planet have a day that's always longer than night?

This question has been rewritten to incorporate all clarifications. On Earth, half the planet is illuminated at any time (let's ignore eclipses). Axial tilt lets day lengths vary, but over the course ...
9
votes
1answer
110 views

What are the fundamental limitations of echolocation in Earth's atmosphere?

I'm writing a cyberpunk novel where one of the characters has an augmentation that allows them to echolocate. The idea is that there is a device on the center of his forehead (is there a more optimal ...
10
votes
2answers
940 views

What sort of acceleration would I need for my space ship to reach Eris in 3 months

I have been working on a sci-fi story for a little while now, and have recently discovered that I made a very big error in assuming the position of Eris. The main issue is that I had forgotten to take ...
6
votes
1answer
303 views

What size would a planet have to be such that I could throw a tennis ball into orbit?

If I was affixed to the surface of some solid spherical body in space (so as to ignore effects like me floating away), would it be possible for me to throw a tennis ball so that it went into orbit ...
13
votes
5answers
460 views

Solar recycling or: How to keep your star from dying

I was in the shower the other day thinking about the sun going Nova, you know...like you do, and a thought occurred to me: Could you turn the sun into a stable, mostly closed system? Some details ...
-3
votes
6answers
428 views

Can magnetism be what causes my flat Earth to accelerate?

It has been determined by observation of the stars that the gravity on Flat Earth is due to it accelerating upwards at 1G. This is what holds people and objects to the surface. It has also been ...
0
votes
1answer
39 views

Approaches that could be used to define a given bacterial strain as a new species [closed]

I would like to know what are the possible approaches a scientist could use to identify a given bacterial strain as a new species.
5
votes
1answer
110 views

Explaining a Low-Mass Brown Dwarf

Considering the well-established relationships between stellar mass, surface temp, and luminosity, how unusual would it be to find a star (or brown dwarf) that possesses about half the mass of an ...
4
votes
1answer
70 views

Visual Cortex, superficial Brain Implant - Biological feasibility

In another question Everybody has a brain implant. What measures can a criminal take to escape justice? I assumed that a brain implant would be possible in the future for surveillance. In this ...
6
votes
2answers
274 views

Is a Titan-like planet with Earth-like gravity plausible?

For my hard sci-fi story, I would like to have a planet similar to Titan (very cold, nitrogen atmosphere, methane seas) but with a surface gravity in the region of 1g. Could this occur, or would the ...
10
votes
4answers
220 views

Is it possible to make high-compressive-strength cement on Mars?

I was having fun reading this article about making cement on the moon when I asked myself (and now you), is it possible to make a suitably high-compressive-strength cement on Mars? Since concrete is ...
10
votes
2answers
558 views

Planetary cave: Gravity inside a non-concentric shell

There are several previous questions concerning concentric shells. I won't reference them here because this is different. I understand that there is no gravitational effect inside a concentric shell*....
27
votes
6answers
7k views

Would one atom of antimatter be lethal if annihilated inside the brain?

I am dealing with a dystopian story that tries to come up with some kind of total surveillence or control from higher authorities. The authorities threaten to kill those who disobey them by simply ...
14
votes
5answers
491 views

How much energy did it take for God to part the Red Sea?

EDIT Why this is a world-building query. If I had framed this as, "In my world where magic requires the expenditure of energy, a powerful wizard decides to open a path through a large lake,etc. The ...
5
votes
1answer
126 views

Scale model solar system in interstellar space - will it work?

Now that FTL travel is here there are all sorts of family outings we can go on. One of these is a scale model solar system lovingly made by hobbyist Barty Slartfast. In full scale Sedna is three ...
6
votes
2answers
3k views

What is the minimum size for the Sun?

How small could our Sun be and still "burn" with nuclear fusion and emit the same spectrum of light and other radiation as the real Sun does? Edit: The goal is to have a small sun inside a huge ...
2
votes
2answers
284 views

Dimensions of an O'Neill cylinder with gravity and coriolis force like surface of Earth

What would be the diameter and rotational speed of an O'Neill cylinder on the inside surface of which centrifugal and coriolis forces are equal to "gravity" and coriolis force on the surface of Earth ...
16
votes
8answers
1k views

How can spacecraft manufactured on the moon be powered?

Background: The moon has been selected as the base for human space exploration. Rather than ship tonnes of material out of earth's gravity well, interplanetary space-craft and space stations will be ...
12
votes
2answers
307 views

How to predict the color of this sky?

How can I predict the color of the sky based on the information provided? Atmospheric composition: | 2% Trace gases | 58% Nitrogen | 26% Oxygen | 11% Argon | 3% Carbon dioxide | Average ...
7
votes
1answer
203 views

How close can a ship get to Sagittarius A?

Assuming that the only fancy available technology is FTL drives (to get there) plus anything needed to protect and sustain a crew during the journey from Earth to Sagittarius A (whether it takes a few ...
4
votes
3answers
210 views

Could you liquefy an asteroid to collect its resources?

Suppose you could pump a load of energy into an asteroid at a safe distance. As energy gets added to the object, does it make sense that this could be done in a way to get the asteroid to ...
1
vote
2answers
119 views

Finding the size of tides

I have a planetary system in which there is a huge planet and a moon orbiting it which has an atmosphere and water (and actually everything needed to sustain life). Thing is that I'm sure the mass of ...
5
votes
1answer
116 views

How does the n-body-problem affect a star system around a red dwarf?

So my story is set in the TRAPPIST-1-system and a rogue planet enters the system. When it's still far off, a scientist discovers that one of the numbers is slightly off. (She has some tables that ...
5
votes
2answers
125 views

What is a reasonable energy solution for a proposed solar system wide Laser Propulsion array?

In my fiction I'm setting up a civilization which uses Laser Propulsion for moving things between bodies within a solar system (assume Earth/sun analogy). Laser Units have been set up anchored to ...
3
votes
1answer
422 views

How to maximize cancer growth? [closed]

Given the modern knowledge of human anatomy and biology what are the things one must hypothetically do in order to maximize human colorectal cancer proliferation?
0
votes
7answers
265 views

What are the options to incorporate teleportation in my story in a realistic fashion that adheres to the laws of physics?

I'm currently outlining my science fiction novel which deals with humanity reaching Type 3 civilization status. My goal is to place an emphasis on hard science fiction while featuring fantastic ...