We have a toaster with a plastic lid. One is supposed to put the lid on only after the toaster has cooled off, to protect the inside of the toaster from dust. But apparently some time ago someone neglected the pictogram and put the lid on while the toaster was still rather hot. Now in the most heat-exposed places, the plastic has become of a clearer transparent color, more irregular shape of surface, and there are a lot of fine bubbles inside, about half a millimeter in diameter. My question is: What is in the bubbles and how did it get there? Did the plastic contain fine dispersed air initially? Or maybe water or some organic components that "boil" at a moderate temperature?

While visiting Magna in Rotherham recently, my son asked me a question I couldn't answer. What is the bucket that pours the molten steel made of? And how is it made? It must be made of an alloy with a higher melting point than steel, so how is it made? And how is the machinery used to make that made? And how is the machinery used to make that machinery made? You could go on for some time with this chain of production, but it all comes down to how do you make machinery for something that has a massively high melting point? What is it made of and how is it made?

Thanks for your help,

Peter and Alfie Finan, Haworth, West Yorkshire

Imagine you heated a room to more than the temperature of a fire and then lit a fire in that room, would the fire heat up the room further or cool it down? I thought of this question when i noticed that you blow on hot food to cool it, and blowing on ice cream melts it.

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)