Hot answers tagged

142

The ocean is a dynamic and very large place, so it's unlikely to have many large-scale effects unless humans overreact. I'll focus on the local, immediate effects of this saucer from a physical, biological, and chemical perspective. Some things to consider about the location of the saucer- it's suspended in the middle of the Atlantic Ocean, almost directly ...


90

The climate of Earth has been roughed up quite a bit last century. But it has no idea what it's got coming with this portal of yours. Earth turns into Venus. Update: As R.M. pointed out, the amount of energy is not 'maybe a long term thing', it's the Major Issue. This has been fixed now. How much water are we talking? Let's say your portal is 10km below ...


86

My question is, would it be physically possible to do that with the air tank? No. Source: Tried it. We've actually been taught to breathe off a tank without a regulator. You can do so by feathering the valve. But even when you fully open it, the thrust is simply not enough to propel you at a speed comparable with even relaxed finning. Much worse than ...


81

will the presence of large volumes of water inevitably result in some of the oxygen making its way into the atmosphere? No The Earth has oxygen in its atmosphere because of cyanobacteria which produced most of earths oxygen through photosynthesis. However, your planet has "has no native life forms". Without any kind of life, it would be very unlikely for ...


73

It's even conceivable that all ballast tanks, vents and control systems were completely compromised, and so the sub sank with no attitude controls (bow planes & stern planes completely inoperative) but some of the crew stayed alive long enough to isolate the control room & conning tower base (equivalent to the bridge on a ship or surface boat) in ...


59

Normally, a lake will have a fresh water river flowing into it from higher ground, and a river flowing out of it to the sea. Fresh water source \ \ --- Lake --- \ \ Ocean If you do it the other way ...


54

Here is a way to bypass the issue Our hero removes his air tank, points it away from himself and starts fumbling to undo the top. It's not working! He's never opened one of these things himself let alone underwater, let alone uninstructed first time around while being attacked by a shark, and these things probably have safety mechanisms to prevent stupid ...


54

Give your planet two moons with different orbits, and once a year for about 30-60 days they align on the sides of the planet perpendicular to the twin islands. The tidal forces draw enough water away to lower the sea in that area, bringing out the island.


53

You can do it if the sea conditions are favourable (read dead flat calm), otherwise having the ships that close together, tied or not, is a danger to all concerned. Banging hulls weighing tens to hundreds of tonnes together even at relatively low speeds is never something you want to do if you can avoid it, you'd need at least as many mechanisms keeping the ...


47

No. Jellyfish are osmoconformers Osmoconformers are marine organisms that maintain an internal environment that is osmotic to their external environment.[1] This means that the osmotic pressure, or osmolarity, of the organism’s cells is equal to the osmotic pressure of their surrounding environment.... Most osmoconformers are marine invertebrates ...


47

You have problems, and it isn't food Food is easy. The ocean is full of fish. So long as your story places the aircraft carriers in the right place, food is irrelevant. Your problem is nuclear fuel. Those aircraft carriers are big, sealed, bathtubs. Without ventilation, the CO2 resulting just from human breathing would slowly make the lower decks ...


46

Consider two substances with refractive indices $n_1$ and $n_2$. The reflectivity can be calculated as $$R=\left|\frac{n_1-n_2}{n_1+n_2}\right|^2$$ For air, $n\approx1$, and for water, $n\approx1.33$. Therefore, for a ray of light reflecting off of water, we have a reflectivity of $$R=\left|\frac{1-1.33}{1+1.33}\right|^2=0.02$$ The refractive index is often ...


46

Waves, on Earth wave height is, in large part, constrained by the fact that waves meet land relatively quickly in most of our oceans. On a water world there's very few chances for surface waves to break, so they'll keep building until they reach monstrous heights and swamp habitats floating on the surface. The base of globe circling wave trains will probably ...


39

Why is it that in questions like this about something blocking light, everyone seems to forget that the Earth rotates? To simplify the geometry, we'll use the following assumptions: the saucer has a flat bottom (it doesn't curve to follow the Earth), so the 2 km altitude is measured from the center of the saucer; the saucer is located on the equator, and it'...


37

Possibly. There are two mechanisms for producing oxygen on Earth (and other similar planets) Photosynthesis. Water is split and combined with CO2 to make (roughly) CnH2nOn and O2n. Some reduced carbon ends up buried to give a net contribution of O2 to the atmosphere. Note that the combination of photosynthesis and metabolism - using carbohydrates for fuel -...


36

The best reason to build submerged cities is the same reason to build subterranean cities; protection from surface threats. Specifically radiation. Water provides amazing protection from radiation. Nuclear powerplants store their recently-spent fuel in big pools while it cools off. Water is so good at stopping radiation, divers routinely do maintenance ...


35

Absolutely! It's great that you said Cold War era. The Soviets actually made a submarine with a titanium-alloy hull during the Cold War era. Titanium is highly anti-corrosive, strong, light, non-ferrous, etc. It's corrosion in sea water is only slightly worse than in air, meaning 50 years is no issue. With an intact hull, you only need to figure out why ...


32

I spent some time considering how you might even start forming an ocean of blood. Mammal blood is out of question because it would coagulate. It would probably end up with rocks made of blood crust separating from watery plasma and pus. If you were sailing on an ocean of pus, any stars you'd see on the surface of the ocean would be the result of ...


32

Less land It's actually pretty easy. There are two ways to make an ocean less salty. The first way is to remove salt, and the second is to add fresh water, both of which are possible, but takes a lot of effort and won't really occur naturally. But the better question is, what makes an ocean salty in the first place and can we prevent that from happening? ...


31

You can have tectonic plates even on a water world, that is still "land" under there, you just have enough water to cover it all. In your case, any tectonic plates carrying enough land to break through water are all adjacent to each other; just like our continents were once all adjacent. Look at early Earth and Pangaea for an example. With multiple plates ...


30

If a river flows from ocean into lake, you better have another river that flows out of the lake into someplace else, otherwise that ocean is quickly going to fill the lake, the surrounding area, and continue until everything below sea level is filled up, at which point it will stop flowing. If you have a second river flowing to somewhere else to drain the ...


29

First observation: The portals as described in the question create a perpetuum mobile. Salt water under high pressure (from the ground of the Mariana trench) wells up at some point in the Sahara desert, becoming a fine source of hydroelectric power. It will create a river of salt water that may fill up some basins and eventually reaches the sea (either the ...


29

First of all, holding your breath while emerging from a deep dive is a really bad idea: the air in your lungs will expand as you approach the surface and will turn you into a balloon, probably killing you faster than gaseous embolism would do.* Then, coming to your real question, to get propulsion from a rocket in air we use a Venturi tube to accelerate the ...


29

There's a lot that goes into answering this, and the answer could turn into either yes or no depending on what assumptions and trade-offs you make. Firstly, nuclear carriers have an operational lifetime of 50 years, and get a overhaul and refueling at the 25 year mark. This is assuming that the carrier is actively being used for military purposes, if you'...


28

The idea of an ocean planet isn't too far-fetched. There are several moons in the Solar System - Enceladus and Europa, for instance - that have subsurface oceans. If the ice covering their surfaces melted, they'd be just what you're looking for. Extrapolating that to a larger, planetary-mass body isn't too hard. Creating an ocean planet isn't too difficult: ...


26

There are a number of issues with eliminating our planet's oceans... Our planet's gravity holds onto our water pretty tightly. The energies needed to evacuate several oceans worth of water out into space would probably also take our atmosphere along for the ride. You could send the water deeper into the planet's crust, but that leads to other issues... ...


26

The thing about water is that it is pretty much indestructible. If you don't want it in the sea you need to put it somewhere else. The usual reason for lowered sea levels is glaciation. For example, at present Earth is in an ice age, with a lot of water trapped as permanent ice; as a consequence, sea levels are some 90 meters lower that what is usual in ...


25

Would the makeshift platform be doomed as soon as they hit a storm or strong winds, or is there a way that they survive indefinitely (assuming plentiful food)? It would be doomed. Disclaimer: I've based my answer on real ships, not hypothetical pontoon-like vessels. A ship that is not able to steer its bow into the waves will take on a lot of water if a ...


24

Your structure would definitely need to be spherical, since that shape supports so much more pressure than hard angles. (The human part of the bathyscaphe which descended to the bottom of the deepest trench in the ocean was the little sphere at the bottom of the picture. The rest was gasoline, water and iron to regulate buoyancy.) Since we've gone to the ...


24

Although Clay Deitas took my first suggestion, of a shallow island with extreme tides, here's a weaker alternative: The island is actually a large rock made of an aggregate of pumice/scoria and basalt, trapped within the caldera of an underwater volcano. Periodically, the volcano or geothermal vents give out enough gas that gets trapped under/in the rock, ...


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