G4_Air is to Insulator as Copper is to Conductor_Lower_Level_02

Sir James Dewar created the vacuum flask in 1892 at Oxford University. He knew that in outer space, where there are no tiny air bits, there is a vacuum that by nature cannot pass on heat energy by conduction or convection. He used this idea to make a perfect insulator. The silver layer on the inner bottle stops heat transfer by radiation, and the vacuum between its double walls prevents heat moving by convection. Back then, his creation was known as a vacuum flask. Today, we call it the thermos. You can thank him for keeping Mom’s soup nice and hot.