It’s not magic. It’s science! Sulfur hexafluoride (SF6) is a colorless, odorless gas that is more dense than air at 6.12 g/L (at sea level). This density is why you can pour it into a glass container and float a light-weight aluminum “boat” on its gas “sea.” Watch this 2007 demonstration at the Physikshow of the University of Bonn.
“According to the Intergovernmental Panel on Climate Change, SF6 is the most potent greenhouse gas that it has evaluated, with a global warming potential of 23,900 times that of CO2 when compared over a 100-year period. Sulfur hexafluoride is inert in the troposphere and stratosphere and is extremely long-lived, with an estimated atmospheric lifetime of 800–3,200 years.”