People can fall: â  from the edge of a completed roof; â  from the edge where work is being carried out; or â  through openings or gaps. Edge protection Unless the roof parapet provides equivalent safety, temporary edge protection will be required during most work on flat roofs.
Why is astronomy considered the original science? Astronomy is the oldest science for our ancients either drew or made structures according to seasons or movements of celestial bodies in our Universe.
Nonetheless, I would agree that astronomy does not have many practical benefits to people's lives. The reason we do astronomy, I think, is that people are interested in learning about it - humans want to know how the universe came into being, what our place in it is, and what other objects exist within it. Basically, we are curious, and astronomy enriches our lives that way.