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3

You can make a decent approximation of the surface pressure $p_0$ of a planet just knowing its mass $M$, radius $R$ and atmospheric mass $M_{\text{atm}}$: $$M_{\text{atm}}=\frac{p_0}{g}4\pi R^2=\frac{4\pi R^4p_0}{GM}\implies p_0=\frac{GMM_{\text{atm}}}{4\pi R^4}$$ Therefore, we can split your work in half and just ask what the mass of the atmosphere will be ...


1

Ash and boxcartenant's answers both claim that there will be a constant wind on the habitat, perceived as anti-spinward by residents, due to "resistance" against the spinning. However, after some long conversations, I am reasonably sure that this is a misunderstanding, and will add my own answer: Thermal equilibrium Note that this ignores thermal ...


4

Same as normal shadows Shadows are created by blocking of light. If an object is bigger than the light source, the closer it'll get the more of the light source it'll block. Further away this effect becomes smaller until it nearly just creates a shadow as big as itself. If an object is smaller than the light source, it is the reverse. The closer it gets to ...


15

You don't need to make sophisticated calculations to get the size of the shadow in this configuration. Australia is about 4500 km across from East to West and 3700 km from North to South. As compared to the 9 km on top of the Everest, the border effect can be neglected, and the size of the shadow is practically the size of the object producing it. For a ...


0

It won't be a planet. There can be no celestial bodies at 10.000 earth mass, with room temperature at the surface. Jupiter has about 800 Earth masses and an object 3-4 times Jupiter mass would become a dwarf star, burning deuterium. Pressure is in the right order, but the surface is too hot to accommodate the O8. I think you'd be talking a cooled down larger ...


-1

Octaoxygen forms from oxygen at a pressure of ten gigapascals, or a pressure equal to 10,000 standard atmospheres. Since atmospheric pressure is directly related to gravity, you would need an oxygen-rich atmosphere on a planet with gravity 10,000 times stronger than that of the Earth. Edit: Gravity is a significant factor, but it is not the only one. The ...


2

Different fine structure constant It has been reported that the fine structure constant varies throughout the universe. The fine structure constant affects things like how many elements can be found in the periodic table. Whether this variation could change the rules of chemistry so much that octaoxygen would work more like our sulfur, be something close ...


3

I read once that the unaided human eye can see a single candle on a hill 30 miles away, on a clear night. Per Alexander's link: the farthest distance a human eye can detect a candle flame is 2.76 kilometers. That's 1.71 miles, in filthy Imperial units. A bonfire emits more light, and its light will also reflect off nearby objects. However, a simple search ...


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