Questions tagged [gas]

For questions about chemical substances in gaseous form, and their interactions with other elements of a world. Consider also [atmosphere].

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Keeping the global average temperature at current levels if the Earth moves away from the Sun. What is the limit?

Suppose that due to an encounter with a rogue planet, the Earth is propelled out of the Solar system. It will then get gradually colder on Earth. We can try to restore the global temperature to the ...
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14 votes
5 answers
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Are there any heavier-than-air gases that could be made using medieval tech and have military applications?

I am trying to find a gas that would be used as a weapon, which could also be made by someone in a medieval setting. The gas doesn’t have to be explicitly deadly, but anything that would incapacitate ...
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0 votes
5 answers
230 views

Gas lighter than air

I'm in the process of creating flying creatures big enough to be mounted, but there's a problem: the bigger the size, the heavier the weight, the heavier the weight, the more difficult (or even ...
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3 votes
10 answers
388 views

What could a weakness be for a gaseous species?

I am currently working on a space opera setting, and I wanted to include a gaseous species of sapient aliens that hail from a gas-giant reminiscent of Jupiter. Before I ask my question, I wanted to ...
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11 votes
16 answers
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What kind of substance that existed in the Middle Ages could, when ignited, potentially destroy everything within several miles?

I am a DM for a homebrew D&D 5e game. In terms of technology, the time period loosely takes place somewhere between 1100 and 1400 CE (so High Middle Ages to Late Middle Ages). The villain of my ...
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5 votes
2 answers
129 views

How could fluoride salts occur naturally?

I've been looking around the internet but I can't seem to find out how fluoride salts would form naturally. My end goal is for my planet to have a mildly high concentration of hydrofluoric acid pools, ...
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1 vote
1 answer
126 views

Calculating the Atmospheric Properties of an Exoplanet

I am developing a double-star system filled with several planets, a few of which will be habitable. I also have a spreadsheet file full of all the planets information, from Semi-Major Axis, orbital ...
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1 answer
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How strong would the wind have to be to strip away flesh?

How fast would air have to move for the gas molecules to strip away at a person's body until nothing is left? I would prefer that actual formulas are used and that it takes less than a few seconds for ...
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7 votes
4 answers
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Vacuum airships

Airships fly thanks to their weight. The m3 you occupy should be lighter than the m3 of whatever you want to float around in (bit of a simplification). To achieve this they make a big balloon and fill ...
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Could the vaporization of all the oceans push away most of the air in the atmostphere?

You may remember my question here, part of which assumed that all humans would die in one way very quickly, with minimal destruction to the planet. This question will ask about the way humans would ...
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7 votes
4 answers
372 views

What would be the effects of changing the composition of air in order to increase its density?

In another question, I asked how airships could be made more viable. The first (and so far only) promising solution I came up with is to increase the density of air. In the real world, air (on Earth) ...
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8 votes
5 answers
2k views

How can a monster infested dungeon keep out hazardous gases?

There is a newly discovered dungeon believed to be made up of a series of interconnected tunnels and caverns that runs deep beneath the ground, the place is thriving with all kind of terrifying ...
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5 votes
4 answers
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If an astronaut could remove their helmet in space, would Flight Control hear any sound during depressurization?

I assume it all comes down to how long would it take for the oxygen in an astronaut's helmet to evacuate. I figured it would happen in less than a second, and no sound would be picked up by the ...
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3 votes
2 answers
119 views

Effects of Tear Gas on Miniature Drones

In this setting, most if not everyone has one or more personal drones. Think robotic hummingbird: same mode of flight, same speed and maneuverability, but no lungs. Instead of internal organs, they ...
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7 votes
3 answers
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Shaped Wind Charges

I have a character that can create compressed air spheres. If you were to create just a normal sphere of compressed air, it would expand in all directions equally at a speed and force that would ...
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4 votes
2 answers
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Is a human body more dense (higher mass/volume) if acclimated to a higher ambient pressure (like in saturation diving)?

Say we are a person sitting in a diving bell and have saturated (acclimated) to an ambient pressure of 5 MPa = 5,000,000 $kg/m/s^2$, breathing a mixture of 99% helium, 0.8% oxygen, and 0.2% impurities ...
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2 votes
4 answers
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How much neon would need to be in an Earth-like atmosphere to tint it considerably orange/red?

I'm creating a planet for a game I'm making that has orange-red skies. My explanation that I've currently come up with is that the atmosphere has a much higher neon content than Earth does. At the ...
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11 votes
3 answers
2k views

Where could you obtain neon/argon in 1931 Las Vegas?

First question ever asked, so apologies if I've done this incorrectly! My current predicament: characters in 1931 Las Vegas are looking to get their hands on some neon/argon (for use in neon signs). ...
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4 votes
2 answers
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Resources to justify the use of musical instruments in an alien planet?

Well, basically I was thinking on a planet where humans live above clouds/a certain atmosphere level, because down there is (darker and colder? hotter and harder to breath? full of creatures?) ...
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1 vote
2 answers
293 views

Calculating average sea-level air pressure

Right now I'm currently trying to calculate the average surface pressure at sea level of an atmosphere, but I'm having a struggle finding the relevant formulae with which to determine this number. ...
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7 votes
3 answers
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Navigating a sea of sulfur hexafluoride

Sulfur hexafluoride is pretty awesome. It is a gas six times denser than regular air, and thus you can actually make tinfoil "boats" float on it. It also makes your voice deep when you breathe it in. ...
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4 votes
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How does composition change if you extend an Earthlike atmosphere 50km below sea level?

I'm working to design the atmosphere of a fictional planet inspired by Venus (let's call it Cael). Cael's atmosphere at an altitude of 50 km is essentially identical to Earth's atmosphere at sea ...
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  • 553
3 votes
1 answer
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What could cause Fluorocarbons to be present in an Earth-like atmosphere?

Pretty simple (in theory that is) question for one of my worlds. I heard carbon fluorides are intense greenhouse gases but otherwise harmless and didn't lead to large issues (atleast none that I could ...
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1 vote
1 answer
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Imagine a well functioning atmosphere on the terraformed moon

Just assume we are long into the future, all other parameters have been met and we have the technology, will and money to terraform our moon and keep it so. Atmosphere, as commonly agreed on, would ...
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2 votes
2 answers
317 views

Nonflammable flight gas

What would be a lighter-than-air gas that is also not flammable, and would be fairly easy to produce in a modern-style world?
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25 votes
9 answers
9k views

How could an animal "smell" carbon monoxide?

Carbon monoxide (CO) is a colorless, odorless, and tasteless flammable gas that is slightly less dense than air. So begins Wikipedia's article on carbon monoxide (CO). To the best of my internet ...
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8 votes
5 answers
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Can you make a star from other gases, and how long would they last?

In my Conworld, the inhabitants have discovered a type of star they cannot identify. I would like it to be a star made not from just hydrogen and helium, like our sun and countless others. But my ...
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5 votes
2 answers
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Hot air balloons lifting bridges in volcanic areas are possible?

In this world, there is a land isolated by a lava line, and the only way to get in there, is across a bridge levitated by hot air balloons. I had the idea of making a wooden bridge being supported by ...
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6 votes
3 answers
359 views

Separating light gases from heavy without chemistry

How do steampunk civilizations get lifting gas? Inspired by the above question I was tempted to suggest collecting the gases rising from public toilets. I know that human gaseous emissions contain ...
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4 votes
8 answers
3k views

What gas can I use to incapacitate pesky heroes?

Supposing I have a room currently occupied by Jedi Knights, or some other force that I can't defeat with battle droids and brute strength. I wish to incapacitate the occupants of this room with a gas, ...
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2 votes
2 answers
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Fantastic gas, part 2: what would be the source of a subterranean gas that's not organic in origin?

Natural gas comes can be found in the underground, but its origin are the organic rests of a long time ago. However, my gas doesn't come from dead trees or anything like that. So what's an alternative ...
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5 votes
1 answer
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Fantastic gas, part 1: could a gas be 'polluted', 'rarified', or otherwise react negatively to electricity, excluding methane-like explosions?

I previously asked a broad enough question about designing a fictional gas but it was advised by two users to split it into smaller questions. So here I am. The main property I want this gas to have ...
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6 votes
3 answers
595 views

Can you have reduced visibility (due to fog) but an atmosphere that is still breathable?

Is it possible to have an atmosphere that is essentially fog, but still be breathable by humans? I'm basically looking to have an environment where visibility is very low (for suspense reasons) even ...
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3 votes
5 answers
255 views

Chemical element made with alternative particles

In my earlier question, regarding airships, I mentioned fictional gas, as light as hydrogen but non-flammable. Is it possible to make chemical element, with atoms made not from nucleons, but with some ...
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19 votes
1 answer
2k views

Could this bubble float with a person inside? [closed]

Related to this previous question: Could a city be built out of Balloons? Remember in Oz where the witch is riding in on a bubble. I began to think how could I make this as real as possible. You ...
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5 votes
2 answers
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Looking to optimize the atmospheric gas mix and pressure for humans for minimal cellular degeneration

To build another world, I would want a perfected atmosphere that would sustain the air cycle and yet optimize a decreased cellular degeneration. i.e.: increase quality and length of life. Would we ...
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4 votes
4 answers
427 views

How do you get a thick atmosphere with less than earth-like gravity?

Basically: I want a highly viscous atmosphere but I want people to be able to walk around. I was thinking earth's gravity * 0.6 or similar. I was thinking that an atmosphere of Sulfur Hexafluoride ...
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2 votes
2 answers
93 views

Airborne gas capable of paralyzing or "getting high"?

Writing a science fiction where the air outside is not breathable for long periods of time. Some characters get high from the air, but large amounts of it cause the user to become paralyzed or black ...
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19 votes
5 answers
2k views

Could a microbe plausibly generate lift gas for manned balloon flight?

QUESTION I was thinking about ways of justifying practical balloon flight for a pre-industrial civilization, when I remembered that some microorganisms produce methane, and better yet, hydrogen. ...
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1 vote
3 answers
239 views

Can this world invent gas cylinders early?

QUESTION I'd like a nation in the world I'm working on to be able to transport natural gas and hydrogen, for fuel and possibly ballooning. Natural gas pipelines and cylinders were first invented in ...
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-3 votes
1 answer
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Can liquid nuclear fuel be injected and ignited like petro from a fuel injector?

[![enter image description here][5]][5] Model Lightcraft under laser power While sadly the funding for this research has not been forthcoming, there have been proof of principle flights and open air ...
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1 vote
2 answers
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Viability of laughing gas as a weapon

How effective would it be? Presume that the nitrous oxide is freely available to the user (e.g. "magically" [hand-wave] produced) and that they are immune to any effects. How far would it really ...
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2 votes
3 answers
844 views

Using Solid Oxygen for a Rebreather

I'm designing an environment suit for humans to wear while interacting with a benevolent alien species while in alien space. Here's my question: How much solid oxygen (by mass and volume) it would ...
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38 votes
6 answers
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How could steampunk civilizations get lifting gas?

Steampunk airships typically use either helium or hydrogen as a source of lift (depending on the specific world). However, the source of the lifting gas is often not fully explained, or frequently ...
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-3 votes
2 answers
528 views

What conditions would cause electricity to create carbon monoxide?

I've been mulling whether the local gaseous makeup of air is changed by electricity running along a wire. My previous question is on hold, and this one is different anyway. I couldn't find exactly ...
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0 votes
2 answers
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Meteorology spreading problem [closed]

It is known that in WW1 "battle" gas was used for the first time. This information is used in a plethora of sci-fi stories and comics. For example it is used in Wonder Woman. What if the substances ...
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8 votes
5 answers
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Is there dense, non flammable gas that I can cover the Earth in?

This question is related to Deadly, Heavier than Air Gas, and Is a world with two different types of air possible? but has several different criteria. I've also looked at https://chemistry....
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2 votes
5 answers
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A predator that uses an airborne chemical to make prey not be afraid of it

There is a predator that lives in the forest. It is roughly the size of a large bear, and moves quite slowly - a person could outrun it at a light jog. Nor is it agile - although its arms and jaws ...
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2 votes
2 answers
687 views

Floating airships in planet with helium layer? [closed]

A planet's lowest atmospheric layer is breathable for humans, with approx 21% oxygen and 78% nitrogen or other stable gas. The next atmospheric layer has large amounts of helium. On this planet could ...
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20 votes
9 answers
6k views

Real-life substance that causes humans to behave similar to Zombies

In my scenario, people behave after a certain "transformation" similar to Zombies. However they are not "undead", meaning that they cannot raise again after their body functions completely are out of ...
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