Asked by Jono80

The main reason why rain clouds are dark is due to their particulate density. As clouds are formed from minuscule water droplets and/or ice crystals, the denser they are packed, the more light radiating from the Sun is scattered and dispersed by them, lending a darker appearance to their lower sections.

This is best visualised by a trip on an aeroplane, with clouds on an overcast day seeming grey/black in colour when viewed on the runway, yet a bright white when viewed from above during flight. Essentially, the deeper and denser a cloud formation is, the less light will pass through it.

HIW

Oily times

Autopilots, while made famous by aeroplanes, are actually used to automatically control all sorts of vehicles, including cars, trucks and boats. In fact, the first ship to use a basic autopilot was the J.A. Moffett oil tanker in 1920.

Eight days

The first pilot to fly around the world solo, the games Wiley Post, used a Sperry Corporation autopilot in his record-setting eight-day journey in 1933. Sperry is credited as the company to have officially invented the autopilot in 1912.

Under pressure

Autopilots are used on board spacecraft to counteract minor disturbances caused by micrometeorites, radiation pressure from the Sun, and minor irregularities in the gravitational fields of nearby planetary bodies.

CAT-egories

The International Civil Aviation Organization breaks down autopilot landings into five categories, dependent upon visibility levels and the degree of automation. Categories range from CAT I through to CAT IIIb.

Failure

Autopilots are built to be fail-safe, with manual overrides always given precedent over the system’s actions. the major cause of autopilot failure is with an aircraft’s servomotors, the machines that physically adjust its components.

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This video illustrates how a simple child’s toy can defy everything we think we know about gravity. Discover how spinning the wheel of the gyroscope enables it to stand up on its own, balance on a piece of string, and generally appear to levitate – all due to the effects of angular momentum. This video also refers to the advanced application of gyroscopes for stability and navigation on the Mars Rover, aeroplanes, helicopters, ships, and robots. There’s also an article on gyroscopes coming up in issue three so don’t miss it.

The second issue of How It Works goes on sale today. Also on this day in history onlookers enjoyed the magnificent spectacle of Concorde flying into Filton airport in the Midlands for her final voyage in 2003. After enjoying her first supersonic flight on 1 October 1969, Concorde went on to become one of the most recognisable aeroplanes in the world.