A very Daring tube journey!
QUESTION Was the Hyperloop magnetic train predicted by the Eagle comic in 1950?
A HYPERLOOP is a long tube that’s had the air removed to create a vacuum. Passengers sit in i ndividual or group pods, which are accelerated with magnets.
The pods float on air skis, using the same idea as an air hockey table, or use magnetic levitation to reduce friction. Theoretically, you could travel at speeds of 760 mph.
In 1950, a Dan Dare story in the Eagle comic described the Electrosender, a mode of transport used to shuttle around Venus, which bears a close resemblance to the Hyperloop.
Dan and his trusty batman Digby have been captured by scientific automatons called The Treens. The adventurers are to be transported to their capital, Mekonta, for trial and one of the aliens explains the technology:
‘The Electrosender, gentlemen! The car is drawn along by a series of electromagnets. The tube is a vacuum and we reach speeds of up to 15,000 Earth miles per hour!’
As t hey fly over Venus, Digby exclaims: ‘By gum, I never thought I’d be Electrosent!’
Tesla founder Elon Musk floated the concept of vacuum travel in 2012. He launched The Boring Company in 2016 to build a circular network of vacuum tubes under Los Angeles, hence the name Hyperloop. The concept has been made freely available, allowing other companies to copy the idea, including Virgin Hyperloop One.
The idea of using low pressure or vacuum tubes as part of a transport system is not new. In 1864, the Crystal Palace pneumatic railway used air pressure to push a wagon uphill and a vacuum to drag it back down.
Harold Thomas, Berwick-upon-Tweed, Northumberland.
QUESTION What chemical reaction causes popcorn to pop open when heated?
THE hull of a popcorn kernel is hard, non-porous and composed partly of cellulose, a polymer of glucose. Inside the kernel there is a seed, soft starch granules that serve as food during germination and microdroplets of water.
During heating, the corn shell acts like a pressure cooker that locks in moisture. This leads to a build-up of pressure until, at 180c, the kernel ruptures. The audible ‘pop’ is created by the rapid escape of pressurised water vapour rather than the cracking of the hull.
The molten starch bursts through the shell and then rapidly cools, giving popcorn its fluffy appearance.
Dr Ian Smith, Cambridge.
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