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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.

0
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1answer
144 views

Creating a wormhole connecting two universes with different spacetime metrics?

A civilization wishes to create a wormhole connecting its universe to a universe with a different spacetime metric. For instance if we describe a timelike dimension with $+$ symbol and a spacelike ...
0
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0answers
61 views

Would air rise quicker in pressurized water (like at the bottom of the ocean) [closed]

If the air was in a ball that was strong but lightweight, allowing the air to not be compressed.
13
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3answers
1k views

Black holes as heat sinks

Cooling in space is a well known difficulty. There are many unpleasant consequences like no stealth in space, difficult space battles which turn into a short wars of attrition (because you have to ...
5
votes
2answers
174 views

Atmosphere of a terraformed 10 km planetoid with Earth gravity

Bernal spheres and other O'Neill cylinders are complicated, maintenance-high and fragile beasts. Someone started to make micro-black-holes and put them in asteroids, in order to have 1 to 10+km rock ...
7
votes
4answers
220 views

Aliens in a 4D universe try to explore our 3D spacetime fabric: How can they do it?

They do not necessarily meet humans and try to interact with them. This question is more about the technical possibility/impossibility of 4D aliens being able to "analyze" the inner structure of our ...
3
votes
2answers
169 views

Making iron tools from blood [closed]

So, I read a while ago several threads about making iron objects/blades from blood. In my conworld there are giant predators that would, according to my calculations, have enough blood so that 12 of ...
3
votes
1answer
199 views

Can you forge iron from oxide dust?

I've been looking over the internet and on here to find some kind of evidence for this, but nothing conclusive, so I was hoping for people with a better understanding of smelting, chemistry and ...
4
votes
3answers
151 views

Calculating Wormhole Wind Speeds

Here's something I've never noticed anyone asking when it comes to wormholes/portals: If they allowed air to pass through them, how fast would the wind be? Should atmospheric pressure differences be a ...
6
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2answers
129 views

Ice-World / Cryo-World Settlement (amorphous cryolava / cryomagma)

I was watching a program about the New Horizons space probe and was fascinated by the new revelations about cryolava/cryomagma, and the amorphous planes covering Pluto(98% nitrogen ice). I'm ...
7
votes
1answer
81 views

Visibility of a Red Dwarf Companion Star

An interstellar traveller stands upon the surface of an alien planet beneath the light of an unfamiliar sun. The planet upon which he stands orbits one star of a binary system in which one is a G-...
19
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8answers
11k views

Car headlights in a world without electricity

In a world like ours in the 1980s, but which for whatever reason does not use any form of electricity. (Either it does not exist or batteries and generators etc have not been invented.) For purposes ...
3
votes
4answers
158 views

Would a monster size aquatic lizard be possible?

So, I am writing a comic which will perhaps grow into an entire series about a group of aquatic heroes. One of those heroes is a monster size aquatic lizard. The story of how this lizard came about is ...
0
votes
1answer
79 views

How much colder would that asteroid make my planet?

I've seen some posts here (for example this one) for the effects of certain sizes of impactors, but I'm not finding any definite answer and all my google and google scholar searches have not turned up ...
19
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3answers
4k views

The One-Electron Universe postulate is true - what simple change can I make to change the whole universe?

The one-electron universe postulate, proposed by John Wheeler in a telephone call to Richard Feynman in the spring of 1940, hypothesises that all electrons and positrons are actually ...
8
votes
3answers
182 views

How to calculate the thickness of the ice-layer of a frozen ocean planet/moon?

How do I calculate the thickness of the upper ice layer on cold ocean worlds like Europa, Enceladus, Ganymede, ...? I'm asking this for a programm I'm currently writing. Given/Known is: mass, radius, ...
14
votes
10answers
4k views

Could solar power be utilized and substitute coal in the 19th century?

Would it be possible for a nation with 19th century to very early 20th century technology and history and hot desert climate to utilize solar power for electrical generation as a substitute for coal ...
-5
votes
3answers
137 views

Preventing the Big Bang

I travel back in time to the Big Bang in my time machine. I am equipped with all the present day equipment I need. I locate the infinitesimal 'point' where the Universe would come into existence and ...
2
votes
4answers
314 views

How would a Type I civilization not cook itself?

A type 1 civilization is defined as a civilization that can utilize the maximum amount of energy equal available to its entire planet, roughly 1017 watts for Earth. This is equal to the amount of ...
2
votes
0answers
71 views

What is the minimum tech level for manned flight? [closed]

For instance, a hot air balloon is really pretty simple; I suspect that even thousands of years ago, it would have been possible to make - steam engines existed in 1AD, after all. So, just how far ...
0
votes
1answer
117 views

What would the moon look like if its orbit was highly inclined?

How would the phases of the moon change depending on the inclination of its orbit with respect to its primary's equatorial plane? Earth's moon has an orbit that is rather close to the ecliptic, but ...
14
votes
4answers
5k views

Would mining huge amounts of resources on the Moon change its orbit?

Imagine that humanity builds mining facilities on the moon. We know that the moon has Helium-3 which could be used as fuel for fusion reactors. Also, there are a lot of other resources which could be ...
2
votes
5answers
550 views

Death from old age has stopped, but fertility window is the same. What is the new population equlibrium?

I'm imagining a near-future world where a process can be undergone that will halt all future aging of the body, but the approach causes infertility. Those undergoing it will not have (biological) ...
4
votes
1answer
166 views

Super Strong robotic prosthesis steampunk Style

I'm thinking of a character that has the magical ability to transform parts of his body into technology, similar to Generator Rex or Bleeding armor iron man, but only with the technology that he "...
-7
votes
3answers
243 views

Focused Earthquake by Remote Jumping up and down - Destroy the Palace!

This question draws on an old idea but it is different. The original question is, "If everyone in the world jumps at the same time, will the Earth move?" My question is,"If everyone in one hemisphere ...
9
votes
1answer
180 views

To make a blue moon, what element does it need?

We know that Mars has a reddish color, because its ground consists of iron-based compounds. The moon is grey-whiteish because it consists mostly of silicon-based compounds. What element should the ...
2
votes
1answer
387 views

Splitting the atom with a hammer

In a world of superheroes the job of blacksmith is given to the very strongest of them. Question Is splitting an atom in a human-scale piece of work by using a human-scale tool even theoretically ...
6
votes
1answer
124 views

Feasibility of an Antimatter-Catalysed Ram Augmented Interstellar Rocket (AC-RAIR)

A fictional starship that I am designing functions via a form of Bussard ramjet that uses hydrogen from the interstellar medium as reaction mass, not as fuel. In order to accelerate the propellant, ...
-1
votes
2answers
155 views

Could implanting false memories change someone's perception immediately? [closed]

This question is about how the brain works in that aspect, if it's even known. I mean with the question that a person might react to something with fear, happiness, disappointment, or whatever other ...
6
votes
2answers
285 views

How hot is my dragon?

Little side project on fantasy story with dragons (or wyverns to be exact, but they're equivalent for the purpose). I have dragons roaming the country side, laying waste and ruin in their wake. As ...
10
votes
2answers
304 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
138 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
241 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
157 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
232 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 ...
7
votes
3answers
295 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
152 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
247 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
159 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 ...
8
votes
2answers
141 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
vote
1answer
139 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 ...
19
votes
2answers
483 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
383 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
292 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 ...
31
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
441 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
233 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
163 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
143 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 ...