Fact: A snowball can survive in hell.
To round off this 4-part series, I give you the possibly the craziest experiment of all – dunking a snowball into a vat of molten metal and expecting it not to melt.
Molten metal (or slag) reaches about 1,700°C, making a metal foundry the closest thing to ‘hell on earth’ I can think of. To beat these massive temperatures, the scientists had to protect the snowball with a huge amount of insulation to keep things nice and cool.
To start with, they protected the snowball from being crushed by placing it in a 3D-printed sphere. Then, they surrounded that sphere with dry ice (solid carbon dioxide – which is around -80°C). They then wrapped all that in 2 inches of high-grade insulation; an expensive version of what you have in your loft to keep your house warm in winter. This is essential to trap a layer of insulating air, since solids conduct temperature far better than air does (think about putting your hand on piece of ice vs near a piece of ice).
This freezing bundle was then wrapped in a special alloy normally used in jet engines, which can withstand incredibly high temperatures, and dunked into the molten slag. When they pulled it out, in a magical moment, the snowball had beaten the odds and survived the harshest environment you can think of.
If a snowball can survive in hell, imagine what you could do?
This series of posts is based on the General Electric ‘Unimpossible’ video series currently on Youtube – check it out, its awesome:
‘Another one of Mr Shaunak’s Little Bites of Science.’
Image under creative commons license.