# Tag Info

Accepted

### What would a 1.5 km wide, 20 km tall spire look like?

If you were at sea level (e.g. on a boat), the tower would disappear over the horizon at approximately 505km away. Horizon calculations are generally dealt with as simple right-angle triangles; a ...
• 3,638
Accepted

### What does a solid, 1 mile diameter subterranean glass sphere look like?

If the glass is unflawed, the opening will look like a flat, nearly-black (but possibly also greenish) mirror . When you look at glass, you see a combination of the light reflecting off the surface ...
• 3,768

### Hiding a subterranean alien megastructure

Consider the following: The diameter of the Earth is 12,742 kilometers. Our planet's crust thickness is anywhere from 30 kilometers on the continents, to 5 - 10 kilometers on the ocean floors (which ...
• 34.7k

### What would a 1.5 km wide, 20 km tall spire look like?

Interesting side effect: Astronomers would kill for a tower like this. Middle of the ocean is where you find lowest light pollution levels on Earth 20km up the atmosphere is rather thin further ...
• 23.8k

### Hiding a subterranean alien megastructure

The Earth is better surveyed than is generally realized. It is probable that geophysical survey techniques would have revealed the existence of an underground megastructure. Geophysical surveys may ...
• 38.5k

### Are there any benefits to a large body of water in a space habitat?

Radiation shield There is lots of radiation in space. There are few better shields than water. Due to its hydrogen bonds and large dipole (that is, the oxygen is negatively charged, the hydrogen ...
• 85.7k
Accepted

### What to do with all the heat in a Dyson Sphere?

I think the best solution would be a Matrioshka Brain. This is effectively a layered set of Dyson spheres. Once it reaches equilibrium, each shell has a particular temperature differential across it,...
• 133k

### What would a 1.5 km wide, 20 km tall spire look like?

There would be a lot of local climate effects caused by the tower. One of the most visually dramatic would be clouds. It would likely have a cloud wake, the most dramatic of which are Von Kármán ...
• 809

### Are there any benefits to a large body of water in a space habitat?

Depends on your definition of benefit. In the case of Rama the lake wasn't just a lake, it was also a machine reclamation (and presumably construction) yard where machines from anywhere in the habitat ...
• 66.4k

### Minimising the environmental effects of my dyson brain

Give your Dyson sphere an equatorial window All of the inhabitable parts of the solar system lie along a single plane meaning that we don't need any of the sun light escaping above or below this ...
• 101k
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• 16.4k

### Are planetary orbits absolutely necessary?

You won’t find an arrangement of 3 or more stars in a stable configuration to begin with, other than those having vastly different sizes so the little ones orbit the big one like planets, or a ...
• 69.7k
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### How do 21st century C.E. submersibles enter an underwater dome swiftly and safely?

You can use the concept of a decompression chamber with two doors, one to the outer, one to the inner environment. When it is open to the outer environment it is closed to the inner. Submersible can ...
• 296k
Accepted

### Life on the Broken Ring - an issue of size

If there is a gap between the sections of the ring, it would allow all the atmosphere to spill through the gap, like so: The question really isn't one of how long of segments you need (the answer ...
• 1,560