First scenario, sound.

Because you are in a plane you are in a fairly sealed environment. The air around you is traveling roughly at the same speed you are traveling. As such, all sound and speech within the plane would appear normal to you as would the look of everything around you.

Second scenario, speed of light.

You, the plane and the person sitting ten rows back would be converted into energy. No speech no hearing.

Second scenario (b), just below the speed of light.

Because you are in a plane you are in a fairly sealed environment. The air around you is traveling roughly at the same speed you are traveling. As such, all sound and speech within the plane would appear normal to you. Things would look normal within the plane. Outside the plane, everything would seem to be speeding up compared to you (and the plane). By how much? Depends on how close to the speed of light you moving.

Roughly speaking; yes.

We lose a few tons per year from the atmosphere, we gain a few from debris falling onto Earth. But basically you can consider it constant.

The bigger problem tends to be water mixing with other materials so that we can’t readily use it as water. Or components of water being tied up in other materials.

It seems like we have less because of several major factors. 1. Lakes, rivers, and aquifers take a while to filter the water. 2. We have introduced new materials that need to filtered (pollution), in which some of these sources are not capable of filtering. 3. We have a lot more people and demands on these water sources than even a short time ago.

Ergo, same amount of water, harder to get water in the condition you want for your needs.

1′x10′

2′x5′

A little more than 3′x3′

Hold your arms out. That far all around you is about 10sqft.

This is a highly subjective question.

By scale:

The great wall of China

Three Gorges Dam

By cultural significance:

The Eiffel tower

The empire state building

Toyko tower

The great pyramids

Probably the best answer is any building/structure a small group of people could name off the top of their heads. But, I don’t think that was quite what you wanted.

The granite sink is carved or hollowed out granite. The composite will be a cement/concrete type construction using granite or similar material as the aggregate or filler.

The carved granite will be considered more luxurious, but composites tend to be better sinks, all other things being the same.

Simple answer, yes. This is called the heat island effect.

This is caused by a number of factors:

Albedo – The amount of reflected light (including UV and IR). This generally affects radiant heat in the area.

Thermal storage/ thermal lag/ insulation (also embodied heat/energy and specific heat) – The amount of heat present materials can absorb along with the rate at which they then release said heat back into the surrounding area. This is a complicated subject known as thermodynamics which gets really nasty at this level of complexity. This generally affects convection, contact and radiant heat in the area.

Wind change – Air will tend to get compressed between and above buildings causing wind speed changes. Changes in the air temperature will greatly affect the wind. This generally affects convection in the area.

Shade and shadow – By changing or denying areas to direct light you are changing the which objects get which heat/energy going into them. this greatly affects the radiant and contact heat in the area.

Great, what does all this mean?

We are replacing existing environments with increasingly higher reflective surfaces and better thermal storage systems. So, you get more energy shared during the day; more heat. And, better energy release during the night, more heat.

Most of the existing systems either just stored more energy, used the energy, or slowly transferred it into the ground. Modern materials either reflect it onto something else or release it back into the environment as soon as the temperature outside changes below its surface temperature.

Surface winds should decrease in both strength and velocity as the total temperature change is decreased.

Basically, if the total temperature range is smaller you should get less and slower wind.

Any height provided you met the emergency egress requirement.

In North American jurisdictions you need an emergency exit from bedrooms. If there is no exterior door, then you use a window. If you a window it can’t be more than 44″ from the floor.

There are many reasons why, but I’m going to assume you are asking about highrises for living and offices.

One of the better reasons is to allow more people on the same amount of ground.

Second, for economics.

Let’s say a given area currently has 1 family per acre. These are nice fairly open areas. But, if all the areas fill up with 1 family per acre, but more people want to come it stars to make since to place more families per acre.

Once you get to about 16 families per acre you need to change how you are placing people. The simple answer is to go up (usually going up is about 10 times easier than going down).

Again once go 5 levels up things change again.

Right now most conventional construction can take you up to about 60 levels above ground or about 15 levels below ground. Beyond that you start needing to get creative.

So, back to the question, the reason we build highrises is to allow more people to get together than would be possible standing on the ground.

There are several ways to answer this question.

In general: vertical. Literally, 8″-9″ depending on use and jurisdiction.

For most publicly use spaces most designers will use a 7″ riser (vertical) and 11″ tread (horizontal) or 6″R and 12″T as the general layout with adjustments for the final heights and materials used.

For lower steps a portion is used based on a typical human stride of roughly 23″-24″.

Private stairs can go down to 9″R and 6″T, but this is typically uncomfortable to most people and would require use of handrails.

Stairs that have a rise higher than 9″ is called a ship ladder and require handrails along its length for additional support.

Vertical to near vertical systems would usually be called a ladder. Steps or rungs tend to be between 9″-12″ apart.