how much sky weigh? and why is sky blue?
Answers
There is no sky to weigh, much like there isn't a shadow to weigh, or a rainbow to weigh. The sky is just a name we give to something we see.
We (the whole Earth) are surrounded by air. We call that air the atmosphere. At night, we cannot see that air and when we look up, what we call the night sky is just the moon, the stars and the whole universe we can see.
During the day, the light from our sun is scattered by the air and it looks blue. The blue of the sky is just the light from the sun bouncing around the air. The day sky also has the sun, which is a star really big and really far.
Night or day, we also have clouds, smoke, fog, rain, snow, birds, bugs, airplanes and a whole lot more that can all be part of the sky, as drawn by smart and curious people with color pencils.
All those parts of the sky have weight. We know how much the air in the atmosphere weighs, the sun, the moon, the bugs, the stars, the airplanes, the clouds. If we added all that up, then the answer is that the sky weighs a lot. How much? A huge lot. More than most of the smartest people can easily imagine.
But the sky is just the name we give to all the stuff we see over our heads. Could you say how much does a ballet weigh? You can weigh the dancers, the musicians (but not the music, although you could weigh the music sheet), the costumes, the curtains, the props, the stage, even the theater. But is that the weight of a ballet?