Officially, where does the sky start?

Question

A plane flies in the sky.... a child's balloon floats into the sky... but is there a boundary where the sky actually starts?

Answer 1

uh...are you kidding?

Answer 2

Thats just like saying Were does the air start or were does the space start. But i really dont know.

Answer 3

At the edge of the Earth.

Answer 4

In observation it would start at the horizon but in reality it would be anything above the ground

Answer 5

Sky started about 4.4 billion years ago when the atmoshphere was formed.

Answer 6

if you look around yourself in a 360 view, anything above the horizon is considered sky. the sky is what you yourself can see, and the only boundry is were it meets the horizon. the sky is based on were someone is standing,and is different for everyone

Answer 7

There are two definitions:

In the US, space begins 50 miles (80 km) above the mean sea level.

For the rest of the world, space begins 100 km (62.5 km) above the mean sea level.

Conventional airplanes (and balloons) cannot get that high because the air density is way too low.  

A plane generates lift by having air flow rapidly under and over its wings; when there is not enough air, the flow does not generate enough lift to keep the plane flying.

A balloon (helium filled) floats by buoyancy. As long as the balloon is lighter than the air it displaces, the balloon floats upwards.  The difference must account for the weight of the rubber (that is usually the limiting factor).  There is also the problem that as the pressure, outside the balloon, diminishes, the inner gas keeps pushing the rubber skin outwards -- it would eventually burst (another limiting factor as burst balloons no longer float).

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Above 100 km, there is still some air -- albeit not much.

The International space station is in an orbit with an average height of 350 km (220 mi).  Outside the station, space is a better vacuum than what we can get in many labs on Earth.  Yet, there is enough air molecules to slow down the station.  That's why it needs to be "boosted" back up, every once in a while.

Answer 8

The sky is the part of the atmosphere or of outer space visible from the surface of any astronomical object. The sky is sometimes defined as the denser gaseous zone of a planet's atmosphere.

therefore, the child's balloon will float toward the sky, but flies in the air. there is most probably no scientific definition for it, because it is too vague and atmosphere would be a better term.

Answer 9

the horizon.

it sounds right.

Answer 10

The sky never starts or stops. The EARTH is a sphere (3D circle) so it'll go around forever. Understand? OK, I'll explain it:

Hey, get a ring, put your finger on the ring & follow the ring-line. Does it stop? No. So the EARTH doesn't stop, too. Hoped I helped.

Answer 11

havent gt a clue

a ballon floatss in the air not the sky it would pop coz of the temp

it looks like it coz it soo far way

Answer 12

1mm above the ground. I'm sure that's what the majority of life on earth would tell you-The Insects.

Answer 13

I've seen low flying planes and also I've witnessed a childs balloon floating aimlessly along barely off the ground. So I would say as soon as no contact is being made with the ground then the sky begins

Answer 14

Interesting question, I haven’t come across any officially defined starting point from any books or research materials, but I can assume the sky starts from the horizon.

The sky (from earth point of view), can be classified as the ‘Thermosphere’, anywhere above the earth’s surface @ app. 90km above our head, and below that (nearer to earth surface, still very far high above us) @ about 50km – 90km is termed the ‘Mesosphere’, and below that @ about 12km – 50km is the ‘Stratosphere’.

And anywhere below app. 12km from earth average surface is the ‘Troposphere’ is what we perceive the sky to as far as our eyes can see, the horizon.

This Troposphere is where the convection takes place since warm air is less dense and tends to rise and maxes with the gases in this troposphere environment determine the weather we enjoy.

The most interesting part is the ‘stratosphere’ (like thermosphere), the temperature increases with height, but not in the case with ‘Troposphere’.

Answer 15

Sky is an abstract concept, so there's no identifiable boundary. If you wanna speak scientifically, call it atmosphere. Atmosphere starts immediately off the ground.

Answer 16

Sky is anywhere that is not on earth