Question: What is glass, how is it made?

Karen Reed answered on 19 Jun 2012:

In my mind glass is made from heating sand up really hot – I’m afraid I don’t know any more than that but I did once watch someone blowing glass to make a vase and it was facinating and hard work. The essetially melted a bog blob of something on the end of a long tube, and then blew down the tube to blow up the glass blob (like it was a red hot balloon). As long as they kept the temperature just right (it looked red hot) the glass could be moulded into the shape they wanted – then they had to leave it cool slowly so that is didn’t crack.
Hope that helps.