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20 votes
Accepted

Space with a breathable "atmosphere" - How to make it kind-of believable?

This works best as an accretion disk, although there's still going to be a bunch of hand-waving if you want the science to be hard: Viscosity of the gas is going to be significant on interplanetary ...
Sarah Messer's user avatar
19 votes

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

Because that's not how physics works to begin with From a physical standpoint, humans do just fine at higher pressures. The deep diving record is around 600 meters, where the pressure is equal to ...
Chris's user avatar
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18 votes
Accepted

How deep under water could a vessel go?

For starters, your assumption of constant temperature is not too far off: considering that water has a maximum density at around 4 C, the bottom of any ocean, far from any appreciable heat source, ...
L.Dutch's user avatar
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14 votes
Accepted

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

Their Internal Body Pressure can Reduce When in Lower Pressure Environments Perhaps these aliens have a way of decreasing internal body pressure. They aren’t able to completely acclimate to Earths ...
Kal Madda's user avatar
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10 votes

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

Frame Challenge Well, sort of... The Venusians have an extremely dense outer skin and musculature system that works in their native Venus to resist the Pressure of their own atmosphere, despite the ...
TheDemonLord's user avatar
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9 votes

What types of adaptations might alien life have to survive high atmospheric pressure?

Ten atmospheres is not going to require any serious changes in size, area, or volume. The primary changes that will be required are concentration setpoints. Breathing involves exchange of gases. ...
BillOnne's user avatar
  • 2,535
9 votes

Space with a breathable "atmosphere" - How to make it kind-of believable?

Get rid of gravity. I think the biggest issue is gravity. Like you mentioned in your post, the dense gas will tend to collapse under gravity. There's enough mass in a solar system full of STP air to ...
BMF's user avatar
  • 6,798
7 votes

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

Their home planet has a wide variance of pressure While they prefer being at high pressures, their native environment includes higher up 'skies' which are lower pressure, low enough for them to swim ...
Nepene Nep's user avatar
7 votes

How would atmospheric pressure change in a giant hole through the earth?

Equator to equator or pole to pole will be roughly the same as the centrifugal force difference is only about 0.3% that of gravity. My calculus is not up to the maths, but it would be fairly easy to ...
Slarty's user avatar
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6 votes

Space with a breathable "atmosphere" - How to make it kind-of believable?

You can try making it not a stationary state, but a long lasting transient. Somewhere there is a source of gas and somewhere else there is a well sucking in all that gas at the same rate which it is ...
L.Dutch's user avatar
  • 291k
6 votes

What key invention allows the exploration of my hot humid world?

Refrigeration: Out of all of the problems on your world, the heat and humidity are the largest. So with the invention of refrigeration, you should be able to counter these twin problems. The first ...
DWKraus's user avatar
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6 votes

Lighting system for early submersibles such as the Nautilus

Verne's divers (before their undocumented demise from caisson disease) used battery powered Ruhmkorff coils (auto-induction high voltage suppliers, similar to modern ignition coils) to provide high ...
Zeiss Ikon's user avatar
  • 45.9k
6 votes

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

The only part of your question that might have an answer relates to pressure. Just consider the problem of traveling from an environment with an atmospheric pressure of 93 Bar to an environment with ...
Mon's user avatar
  • 17.4k
5 votes

Space with a breathable "atmosphere" - How to make it kind-of believable?

Frame challenge: How do I breathe in space? That's the neat part, you don't There are fewer issues entailed by redesigning the biology of the creatures in your world than by redesigning all ...
wokopa's user avatar
  • 4,735
5 votes

What key invention allows the exploration of my hot humid world?

Digging. Underground is gonna be the average temperature of the world, winter and night included, so it's gonna be a fair bit cooler. As such, humans will get very good at digging. This means they can ...
Nepene Nep's user avatar
5 votes
Accepted

How to calculate temperatures on my world given different pressures and altitudes

The spherical cow in a vacuum approach: 70-80°C Ok, here we will use simplifying assumptions. Big ones: The air is an ideal gas and g is constant with altitude (those ones are fine) The atmospheric ...
Barbaud Julien's user avatar
4 votes
Accepted

What should be the dimensions and pressure used in the 5 ton Hydraulic McKibben artificial muscles in my 2,55 meter mechs?

The McKibben artificial muscle is made from a cylinder of braided fibers closely surrounding an inner inflatable tube. When the tube is inflated, the cylinder of fibers expands in circumference, ...
David Moews's user avatar
4 votes

How would atmospheric pressure change in a giant hole through the earth?

About 6 billion atmospheres This is a bit more nuanced than it seems. On the surface of the Earth, we approximate a linear relationship between height and pressure, but even that can be seen to be ...
Cristobol Polychronopolis's user avatar
4 votes

How would atmospheric pressure change in a giant hole through the earth?

Some Approximations I invoke the holy mathematical rite of symmetry to reduce this problem down to 1 dimension: depth. As you may recall, the standard equation for pressure-at-depth in a fluid is $$P=\...
PipperChip's user avatar
  • 32.3k
4 votes

What would a dead body look like after spending 20 minutes at 1500 PSI?

The main issue is not the absolute pressure, but the pressure differential: have you ever experienced ear pain when diving or during an airplane landing? That pain is not caused by the pressure, but ...
L.Dutch's user avatar
  • 291k
3 votes

How deep under water could a vessel go?

Alright time to add my 2 cents. Its not that simple. By which i mean you cant make any definite statements here because so many factors come into play. Everything from Gravity, Water salinity, ...
ErikHall's user avatar
  • 2,481
3 votes

On a planet with a 2 atm atmosphere, how would atmospheric pressure affect plant evolution?

The main effect of a higher atmospheric pressure would be the higher partial pressure of oxygen and carbon dioxide, and the increased density of the atmosphere. While plants would still be evolving to ...
Monty Wild's user avatar
  • 62.2k
2 votes

What key invention allows the exploration of my hot humid world?

I think this is much harder than other answers suggest. As written in DWKraus answer the first step would be airships. This can happen around 1800 to 1850 in Earth technology. These would not actually ...
quarague's user avatar
  • 1,621
2 votes

What key invention allows the exploration of my hot humid world?

One large issue core body heat, and not being able to use sweat and evaporation to keep the body cool. The other is how long the surface of the body can withstand the heat. As a rule of thumb a hot ...
UVphoton's user avatar
  • 6,912
2 votes

Lighting system for early submersibles such as the Nautilus

The fundamental problems normal light bulbs would experience under high pressures combined with an incandescent or combustible light source are related to compressive and tensile forces acting on the ...
Vogon Poet's user avatar
  • 8,169
2 votes

What key invention allows the exploration of my hot humid world?

Pumps. One of the great advantages of exploring your world at sea level is, by definition, the sea. It's right there. In our world these are known as Sea Water Air Conditioning (SWAC) systems, and ...
Roger's user avatar
  • 6,161
1 vote

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

Hyperventilation causes a Pufferfish like Stress Response. Many other answers have already explained how divers can make this kind of transition; so, your Venusians should be able to survive the ...
Nosajimiki's user avatar
  • 95.9k
1 vote

Why won't Venusians just explode in our own atmosphere when they're not even wearing protective suits?

As long as they don't boil or sublimate, Solids and liquids don't really change much with pressure, and gasses are mostly found in the lungs, as long as the pressure change is gradual they will vent. ...
Peter Green's user avatar
1 vote

Space with a breathable "atmosphere" - How to make it kind-of believable?

If you were willing to borrow a bit fantasy you could replace air with something like the classical interpretation of aether as posited by Greek philosophy In particular Plato and Aristotle both held ...
AllSeeingEye33's user avatar
1 vote

Space with a breathable "atmosphere" - How to make it kind-of believable?

The early universe was a lot denser than it is now and at one point would have been warm, wet and opaque during it's transition to hot, light and filled, to cold, empty and dark (I forget the time ...
Alex Dawn's user avatar

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