oldness

[Andy and lou]

how old is the largest window that is not make of sand?

[archbishop]

As glass is made from sand, do you mean the largest window not made from glass? If so I don't know. 

[Alphil_72]

It might have been made of a large single crystal of translucent or transparent material like quartz or mica...don't know, just a guess.

[New Forester]

I should think the largest one would be quite new.  Sheets of mica are used for things like boiler inspection hatches, and I imagine that modern technology is able to make them bigger than natural mica.

 

Oh, and I just thought, what about Perspex and other clear plastic?  There must be great huge giant ones made of that.  What about the large aquaria in Sea Life centres, for a start?

 

In ancient times, I think oiled cloth or skin was used -- those must have had the extra advantage that they prevented your neighbours seeing you naked in the shower...

[Peter Pedant]

what's the context?

dja think they want a cutsey answer like, the window of the world,or the window of the universe?

Both of which are kinda pretty big.

[Numbers]

Windows 95.

[l_h_kings]

are you sure you want to ask that question? Yeah - I Know