In a science lesson we did that 'bell in a vaccum wont make a sound' experiment.

I understand why it did this, but the concept of the vaccum puzzled me a bit.

So is it an 'empty space' on earth? And how can there be absolutely nothing in there? Why doesn't the glass crack under the pressure?

The power of a vacuum is very obvious. Suction pads can defeat the earths gravity and lift a person up off the ground. So why does the vacuum of space not suck the air molecules away from earth, when the vacuum force is far greater than the earths gravitational pull? Am i overlooking something?

I understand that on earth we feel the heat of the Sun because it radiates light to earth which then gets trapped within our atmosphere and gives out heat.  Space, being a vaccum, would contain no heat as there is no matter to conduct the heat of the Sun, so how close could you get to the sun before you would feel any heat from it?  Also would the sun not be able to radiate heat in the form of light to human skin in the same way as it radiates heat to the earth?

Many Thanks

James Stretton (Colchester)