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.

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Exoplanet sky with suspended ice crystals

I'm envisioning a planet around a sunlike star, with gravity and temperature similar to Mars, but covered with a thin shell of water ice (with CO2 ice at the poles). The atmosphere's pressure and ...
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7 votes
4 answers
1k views

Can Mars disintegrate entirely in this scenario?

I have a hypothetical scenario in which Mars flies over Jupiter at close range. I want to make Mars disintegrate entirely in this scenario while keeping the scenario scientifically accurate (please ...
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1 vote
1 answer
114 views

Can kinetic energy be converted into cooling?

In a hypothetical scenario, I'm trying to design an object where, the faster it moves, the more it cools something it comes into contact with it. There's all kinds of materials that can convert energy ...
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18 votes
13 answers
4k views

What would a spacefaring race use as fuel for their matter-to-energy reactors?

Imagine that we invent the technology to convert matter directly to energy, and capture most of the output for doing work. We can convert any matter to energy in this way, i.e. the matter does not ...
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2 votes
1 answer
97 views

What Would Be The Consequences of An Asteroid Literally Falling Onto An Ice Sheet?

On this alternate Last Glacial Maximum Earth powerful psychics bring an asteroid into near earth orbit and deorbit it using entirely laser ablation. Bringing it carefully down onto the Laurentide Ice ...
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6 votes
1 answer
157 views

The immediate and long term effects of slashing wounds in microgravity

What would be the specific long term and short term outcomes of slashing wounds in microgravity? The scenario is that a normal adult is slashed with a knife in a microgravity environment. Assume ...
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1 vote
0 answers
50 views

Could non-avian dinosaurs survive if introduced into modern world? [duplicate]

Lets say Jurassic park somehow came to existence and someone cloned dinosaurs genetically identical to ones of the past and tried to keep them in a zoo. Could the dinosaurs survive as is? I'm ...
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5 votes
2 answers
91 views

Could a tether be used to boost Phobos’s orbit?

Background: Phobos, the innermost moon of Mars, is in a decaying orbit which will either crash into Mars or break up in a few million years. It is a very valuable staging port in my universe, due to ...
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8 votes
2 answers
545 views

How would a sky with extreme kessler syndome look like?

A few decades ago the Third World War destroyed Earth. Space infrastructure was considered a priority target by both sides. Orbital space was in the years before the war was filled with skyhooks, ...
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1 vote
1 answer
78 views

Optimal Fuel for GyroJet Handheld Weapon? [closed]

Is there optimal fuel for gyrojet weapons? Specifically, what fuel would best propel gyrojets from a hand held launcher (read gun -- ex: pistol, rifle, volley gun, etc.)? I'm looking for velocity -- ...
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-3 votes
1 answer
73 views

What alternate propellants could be used for firearms? [closed]

What propellants could be used to increase the damage or injury caused by firearms? Answers may include propellants that decrease the service life of the weapon (the weapon should be able to fire a ...
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5 votes
5 answers
1k views

Is it possible to build a transmitter small enough to fit inside of a .45 caliber bullet?

Is it possible to build a transmitter inside of working .45 caliber bullet? Specifications: The bullet must be fireable from a .45 semi-automatic pistol Transmitter must function after firing ...
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4 votes
2 answers
172 views

How large must a solar furnace be in order to sweep a planets surface melting everything in its path?

To melt a planets surface erasing all traces of civilisation, I figured a solar furnace would do the trick. It is more elegant than nuking a planet, not to mention leaves no nuclear fallout. Perfect ...
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6 votes
1 answer
581 views

Industrial scale Tritium production from Helium3?

Currently Tritium is produced by neutron bombardment of Lithium. I was looking into alternatives and learned that Helium3 has a rather large cross section for reacting with thermal neutrons. From what ...
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-2 votes
1 answer
90 views

Can a button cell battery power car cigarette lighter (in the shape of a ring)?

Is it possible to make a fake golden ring which can light a candle on the push of a button and power it with button cell battery (either coin cell or watch button size)? I have a fraud guy trying to ...
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5 votes
2 answers
187 views

How to make a pump for lots of molten lead?

If I had a steady and powerful wind source and wanted to run a continuous flow of liquid lead, what method would work best to lift the fluid? One benefit of this fluid is that the machinery will be ...
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6 votes
6 answers
2k views

Where could you store the energy from a tornado?

Assuming a very large device was constructed which could harvest up to 20% of the mechanical energy of a tornado. It is a mobile platform of some sort, and one or several of these are ready to deploy ...
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  • 5,864
7 votes
1 answer
253 views

How to "miraculously" light any candle? By chemical or technological means

There is a Mystery Busters team that is solving mysteries and catching criminals (like Scooby Gang from Scooby Doo). There is no magic in the setting, the solution is always mundane, a trick done with ...
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-2 votes
1 answer
56 views

Major moon on a geosynchronous orbit of a planet (20 hours)

So, here are the characteristics of the planet: 1.14 times earth radius. 1.16 times earth mass. rotational period of 20 hours. it orbits a star of 1.1 solar masses at 1.02 AU. I want to know if it ...
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3 votes
3 answers
182 views

Zero propellant interplanetary travel [closed]

I am creating a world where there is an interplanetary network that allows planetary commuting to and from all planets and major moons in the solar system with 0 propulsion being supplied by the craft ...
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2 votes
5 answers
176 views

Igniting a biological H$_2$ fueled pulse jet engine?

A squid-like organism uses gravity powered flight but relies on jet propulsion for launch, pouncing, and evasive tactics. It’s aerodynamically based on the way a true squid flies however it has ...
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-1 votes
1 answer
85 views

Short and long term effects of an Earth sized planet entering Earth's orbit [closed]

In this scenario a Earth analog planet is accidentally pulled into Earth's orbit through the creation of a wormhole. The planet would orbit Earth at about 80,000 miles (128747.52 Km). The planet has ...
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2 votes
5 answers
156 views

What will be the best battery solution for keeping electrical power a tradable commodity in an industrialized star system?

On Earth, electricity became a tradable commodity thanks to Chile in the 1980s, it has since become a staple of international economic markets. One would assume the same outcome to happen on the ...
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1 vote
3 answers
153 views

How would a futuristic robot soldier look like? [closed]

I feel that whenever I search for something like “futuristic robot soldier”, the results are always similar and they look like designs and concepts made by ARTISTS, not ENGINEERS. As far as I know, ...
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4 votes
1 answer
74 views

How to make terrestrial biochemistry more acid-resistant?

So, I'm designing a race of sapient extraterrestrials for a series of short stories, and I've gotten to the point of designing their basic biochemistry, but I have a problem: Both their environment ...
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2 votes
2 answers
101 views

How to replace glucose with ethanol?

So, I'm designing a species of sapient extraterrestrials for a series of short stories, and I've gotten to the point of needing to find a significant biochemical difference between life on their world ...
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2 votes
4 answers
170 views

How can my character cool her tea quickly? [closed]

Let's say I have a character that is obsessed with drinking warm tea (or cider, or...). Tea needs to be steeped at a high temperature; say, 90°c. However, drinking it at that temperature will result ...
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1 vote
1 answer
79 views

Muzzle velocity of a metallic hydrogen firearm

Related and linked to Metallic Hydrogen Propellant and Barrel length of a metallic hydrogen firearm. In the two previous questions, I've explored different properties of a firearm that uses metallic ...
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  • 3,209
1 vote
5 answers
159 views

What are some hypothetical specs for Elon Musk's next generation Starship for 2060?

Elon Musk's Starship, formerly known as the BFR (then the ITS), is planned to be the workhorse to transport people and goods to Mars. Theoretically, the rocket could be ready for orbital testing ...
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2 votes
1 answer
74 views

Barrel length of a metallic hydrogen firearm

A overdue follow up for the question Metallic Hydrogen Propellant. One of the points that was brought up on the post was that since the gas propelling the bullet would be atomic hydrogen, the ...
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13 votes
4 answers
321 views

How Big Can An Ancient Bird Powered Glider Get?

What are the practical limitations of a glider made of bronze age materials and pulled by well trained birds? Due to psychics able to control animals, and a cultural fixation with domestication, ...
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6 votes
5 answers
1k views

How much gunpowder (or other materials) it would be required to accelerate 4mm Tungsten Sphere to 50 km/s? [closed]

I don't understand much about physics and ballistics, so I hope I don't make too many incorrect assumptions here. So, I just saw this video where a 4 mm tungsten sphere hits a 85 mm steel armor, and ...
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  • 1,031
4 votes
1 answer
97 views

Would These Three Actions Allow the Ecoregions to Regrow?

This scenario begins with multitudes of vanishings from around the world, at the same time. All of the domesticated animals (dog, goat, pig, sheep, European cattle, zebu, cat, chicken, Guinea pig, ...
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  • 14.3k
-1 votes
5 answers
162 views

Could a active rotational bullet increase accuracy?

I don't know where I should ask this, on History, Aerodynamics, Physics or here. But here we go. So, from what I could see on youtube videos (not the best source, I know), the bullets on rifles and ...
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  • 1,031
-4 votes
2 answers
165 views

Please Check My Fictional Calculus (Halting Problem, Incompleteness)

For a story, I'm having a character invent a new kind of calculus. Halting Problem The new math efficiently solves the Halting Problem. What is the Halting Problem? Provided you have code like this -- ...
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3 votes
3 answers
164 views

Can a new geological material (specifically, a metal) be formed no older than 56 million years ago?

There is an alternate Earth that I've been building and rebuilding for years. The canonized point of departure is 56 million years ago, specifically a Paleocene-Eocene Thermal Maximum that is four to ...
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  • 14.3k
3 votes
2 answers
238 views

Would a locomotive on ice (like in The Polar Express) move?

In the Polar Express film, there is a scene where the Polar Express runs off the tracks onto a frozen-over lake, which supports it and doesn't collapse even after the locomotive tilting and hitting ...
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5 votes
1 answer
126 views

Designing A Ring World For A Science-Fantasy Setting

Why Am I Doing This To Myself? Because I'm designing a surreal pulp science-fantasy tabletop roleplaying game, and I want to take the coolest elements of hard sci-fi and mix it with the punchiness of ...
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6 votes
2 answers
1k views

Help Fix My Space Elevator - Untapered Steel Cable

I think I have made a mistake somewhere in my design of an untapered steel cable space elevator down to Earth. I was building this as a design reference to figure out how much stronger "stronger&...
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6 votes
1 answer
457 views

Is a fall into a high-pressure atmosphere survivable?

In my question What is the largest achievable oxygen-atmosphere world?, my answer suggests an atmosphere of standard terrestrial air with a sea-level pressure of 20 ATM and platforms at an altitude ...
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4 votes
1 answer
219 views

Hard Science Superhumans [closed]

For my story, I want to create a group of superhumans- to be clear, not humanns with powers, but just humans who have been bioengineered beyond normal human capabilities. This can be something with ...
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5 votes
2 answers
389 views

What is the largest achievable oxygen-atmosphere world?

I am trying to calculate the largest world that will meet the following criteria: Exists within the Goldilocks zone of a G2V star similar to our sun. Is survivable long-term by anatomically modern ...
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  • 45.4k
6 votes
2 answers
464 views

How big an asteroid to hold a ship in stable orbit?

A derelict space craft, 1MKg in mass is in a 100km (more or less) orbit above the surface of an asteroid out in the asteroid belt. How big should the asteroid be to have the ship maintain this orbit ...
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8 votes
3 answers
400 views

Preventing black hole formation in a water-filled universe

Imagine a universe full of water. A comfortable 22 degrees Celsius warm, density of about 998 grams per liter, and it fills up everything for as far as can be observed. There's nothing else; neither ...
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  • 13.1k
0 votes
1 answer
128 views

Implanted device in human body that can transmit over long distance

Previously linked question (which is closed but already has answers). Say we have a type of implanted device in human body (say, ear) used to communicate over a distance. I am thinking about a ...
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4 votes
2 answers
230 views

Collect powers from human body via miniature implantation

How much energy can we draw from miniature implanted device that collects energy from human body? The goal is to design a type of implanted device in human body used to communicate over a distance, ...
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  • 87
-3 votes
1 answer
135 views

My alloy plausibility

My armour is able to take temperatures upto 500°c and tensile strength of 17 MPa . It is made with some knowledge of physics and material science. My suit is made of mono-crystalline iron and coated ...
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2 votes
3 answers
300 views

How might other civilizations discover irrational numbers

The first number shown to be irrational in our world was supposedly the square root of 2. I know that the irrationality of π is likely out of reach for a civilization that hasn’t discovered ...
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19 votes
5 answers
3k views

Making stillsuits less fantasy - how to dump the heat?

As we all know1, stillsuit as described in the books would cook the user. Water would carry heat away from the body, but then it would be caught again, and again with the heat. Assuming energy is not ...
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  • 32.7k
5 votes
1 answer
130 views

Equipotential liquid surfaces in a universe which uses the infinity norm as a metric

Premise On viewing this question, I wondered what the small-scale behavior of drops of liquid in that world would be. What would happen to small volumes of liquids in an atmosphere? Calculations For ...
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