27
votes
Accepted
An atmosphere that gets denser with increasing altitude, to support these flying creatures
Get rid of the planet
Rather than a planet, your story can take place on an enormous space station. The cylindrical space station is under spin to simulate gravity by centrifugal force. The people ...
- 2,232
22
votes
Accepted
How stable would a rogue star system be?
It could certainly be stable; it's possible for a star to be ejected from a galaxy and still have other objects be gravitationally bound to it. Observations of the hypervelocity star HE 0437-5439 ...
- 99.6k
17
votes
Accepted
Is it possible to store the gravitational energy between planets somewhere in space?
OK, the question is formulated a little bit loosely, so let's try to understand the implications of what you are asking. I will focus solely on extracting gravitational potential energy from the sun-...
- 1,345
16
votes
An atmosphere that gets denser with increasing altitude, to support these flying creatures
Not within the constraints of our physics: as we are taught in primary school, gases tend to occupy all space in their container.
This means that in an atmosphere, using a language a bit above primary ...
- 272k
16
votes
Could a planet orbiting a star have a habitable moon and this moon have its own moon orbiting it?
A moon orbiting a moon is called a submoon. It's possible for them to have a stable orbit, but it's more constrained than for a normal moon. None have been observed so far.
The conditions for stable ...
- 1,123
16
votes
Accepted
Could a planet orbiting a star have a habitable moon and this moon have its own moon orbiting it?
Yes, it is possible for a star to have an orbiting body (a planet) which has a habitable body as its satellite (a moon), and it is possible for such a habitable body to have its own satellites (the ...
- 52.6k
12
votes
How might planet size affect volcanic activity?
Rayleigh number
Copying from a thing I did on Astronomy SE on this very subject:
The competition between forcing by thermal buoyancy and damping by
viscosity and thermal diffusion is characterized by ...
- 11.3k
12
votes
Accepted
How possible is a habitable, liquid ocean-planet at temperatures below 0°C?
Similar to the other answers, yes there are lots of liquids that melt below freezing and at a pressure of 1 atmosphere.
Liquid Possibilities
Butane and Pentane
You said that your planet had ...
- 652
10
votes
How possible is a habitable, liquid ocean-planet at temperatures below 0°C?
The lower the atmospheric pressure, the lower the temperature at which water boils and becomes water vapor. At a low enough atmospheric pressure liquid water is not possible since water will be either ...
- 29.1k
9
votes
An atmosphere that gets denser with increasing altitude, to support these flying creatures
Your problem is that the nature of the universe is for heavy/dense things to be at the bottom of a gravity well and light/thin things are at the top. You can violently mix that up (see Jupiter's storm ...
- 114k
9
votes
Is this ocean-planet stable?
Pure ethanol and pure water are miscible--ethanol and salt water are not. So you would not have an ocean of alcoholic salty water--you'd have an ocean of salt water with a separate layer of ethanol ...
- 41.4k
7
votes
Could a captured planet end up in the habitable zone of a new star system?
A captured planet would enter the system with at least escape velocity.
Circularizing its orbit would require a series of carefully calibrated swing-byes.
So, yes, theoretically it's possible, but ...
- 272k
7
votes
How to make a hybrid mapping system for aircraft on barren planets without celestial or compass use?
Light houses and Nazca Lines
You mention a group pirates in your scenario but no other groups or communities. However since a bunch of pirates with no one to actually commit acts of piracy upon is ...
- 14.9k
6
votes
Accepted
Is this ocean-planet stable?
https://en.wikipedia.org/wiki/Supercooling
It could lead to intersting pehenomena though.. were at the poles, supercooled ice structures could appear. Imagine a world, were the smallest turbulance can ...
- 1,125
6
votes
How possible is a habitable, liquid ocean-planet at temperatures below 0°C?
There are many substances which are liquid below 0°C (and 1 atm pressure):
methane (melts at −182 °C, boils at −161.5 °C),
methanol (melts at −97.6 °C) and
ethanol (melts at −114 °C)
are just three ...
- 272k
5
votes
How to make a hybrid mapping system for aircraft on barren planets without celestial or compass use?
I think 3 gyroscopes and 1 clock can do.
At a reference point, set the gyroscopes to a starting configuration, e.g. with their spinning axis mutually orthogonal and take the time.
Any change to that ...
- 272k
4
votes
Can a tidally locked planet with two counter-orbit moons exist for at least 100,000 years?
So, obviously this depends a lot on the initial conditions. For simplicity, lets assume the ideal case of two moons, one half as massive as the other, on circular orbits around a central body. Like ...
- 1,087
4
votes
Could a captured planet end up in the habitable zone of a new star system?
For reference, there is an hypothesis according to which Venus is a captured planet. Evidence for this is her weird angular momentum (spins so that the Sun rises on the west, one sol lasts 224 Earth ...
- 134k
4
votes
Accepted
Could humanoid life survive the violent formation of a planetary ring system?
I think you are glossing over the points that would actually cause the extinction event.
You can probably engineer some sort of trajectory for your quasi-Theia such that it won't immediately shower ...
- 1,087
3
votes
An atmosphere that gets denser with increasing altitude, to support these flying creatures
Not possible, as others have mentioned, however, it appears your goal is to have the animals you show able to exist in the air / more exotic / more biodiverse set of animals in the air other than just ...
- 1,051
3
votes
An atmosphere that gets denser with increasing altitude, to support these flying creatures
Atmospheric layer with high viscosity
An atmospheric layer of a gas with extremly high viscosity might be a possible solution. Viscosity and density of gases are not neccessarily related, so a gas ...
- 994
3
votes
Is it possible to store the gravitational energy between planets somewhere in space?
We are stealing the kinetic energy of the earth's moon -- that's what tidal power generation is.
By taking energy out of the tidal flow, the water is held back, which gives a slight offset to the ...
- 993
3
votes
Is it possible to store the gravitational energy between planets somewhere in space?
Physics is all about transforming one form of energy in another form of energy. That said, if you let something that is orbiting a planet go orbit in a lower orbit, it will lose some energy that must ...
2
votes
How to make a hybrid mapping system for aircraft on barren planets without celestial or compass use?
Navigation
There are a lot of options for navigation, but I suspect the real answer is to how to navigate is "all of these and then some".
Dead reckoning is maybe actually fine?
You know ...
- 288
2
votes
How stable would a rogue star system be?
Should be fine
Your safest bet for causing a rogue star would be a galactic collision event in which all the stars that pass through the equilibrium point of the 2 galaxies will shoot off in a more or ...
- 87k
2
votes
An atmosphere that gets denser with increasing altitude, to support these flying creatures
You would not be able to do this at all according to fluid dynamics. Your best be for having an atmospheric ocean environment while still having humans is either having the humans be genetically ...
2
votes
How possible is a habitable, liquid ocean-planet at temperatures below 0°C?
You say it doesn't have to be an ocean of water, but... if you want an atmosphere with oxygen and an ocean that won't produce toxic-to-humans vapors, you really don't have a lot of options. It has to ...
- 41.4k
1
vote
An atmosphere that gets denser with increasing altitude, to support these flying creatures
How about you just add more gas to the atmosphere?
For example, Earth has 20% O2, 80% N2 at 1 bar. Increase the nitrogen by a factor of ten. Now it's 2% O2, 98% N2, but 10 times denser. So a lungful ...
- 513
1
vote
How possible is a habitable, liquid ocean-planet at temperatures below 0°C?
I know you asked for a liquid, but have you considered a ocean of sand?
Sand can be fluidized with air, as certain other particles can. You could have an ocean that contains no water, and cannot ...
- 193
1
vote
How stable would a rogue star system be?
If your star travels at ~1000 km/s, you should reach Andromeda in about 600 million years. Give or take.
The sun has an expected lifespan of around 10 billion years, with about 5 billion years left. ...
- 119
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