1×5 / Presented by Marty Jopson

MARTY JOPSON continues in his quest to find the science behind common idioms and this time he want to know if you CAN throw stones in a glasshouse.

This age-old adage means that we shouldn’t criticise others when we have so many faults ourselves. It’s homespun wisdom at its best. But can you really throw stones in a glasshouse? To find out Marty first needs to get to the bottom of what glass is.

An entire building can now be made out of the stuff. To find out how toughened glass gets to be so tough, Marty has come to the factory of Essex Safety Glass. Here the production manager explains that toughened glass is made by sandwiching glass and plastic together. He shows Marty how it’s done.

In the back yard of the factory the production manager has constructed a little house of glass and it’s time to test the saying. A competition level shot putter is going to try to shatter the glass. Will he break it? Or will the toughened glass hold firm?