Popular Mechanics South Africa July - August 2021

The South African edition of Popular Mechanics was launched in 2002 and has fast become the acknowledged voice of science and technology in South Africa. Underpinning its rich sci-tech content is an ever-changing mix of articles covering everything from automotive news and outdoor adventures to DIY projects. In essence, it explains how our world works

South Africa
RamsayMedia (PTY) Ltd
12 Issues

in this issue

2 min
at the wheel

I’M NOT AN IDIOT. I can assure you. Okay, that’s not an objective opinion, but I hope you can take my word for it. However, the evidence might show otherwise – an error crept on to page 87 of our previous issue, stating that the new Land Rover Defender has a 20 litre fuel tank. It doesn’t, I promise. A vehicle of that size and power with a 20 litre fuel tank would make no sense, and the design engineers are smarter than that. The correct figure is 85 litres. Apologies for the mistake. I have been test-driving new vehicles since about 2005, all as part of the various magazine jobs I’ve had. It’s certainly been one of the most fun aspects of doing what I do. Some tests have been…

7 min
a flair for solar

WRITE TO US popularmechanics@ramsaymedia.co.za I’m a great fan of POPULAR MECHANICS. When I read your editorial entitled ‘What’s your plan B?’, I thought I’d share with you and the other readers the details of my solar installation solution that I had put in at our home. My wife works in the financial world, on a full-time basis from home, and because of the deals and contracts at stake she can’t afford to be offline at any point. I’m in the electronics field, so, having some firsthand knowledge on the subject, I started researching alternative energy-storage solutions other than batteries for our home off-grid power supply. I didn’t want to have batteries, because their efficiency fluctuates in hot and cold conditions. Also, over-charging of lead-acid batteries can produce hydrogen sulphide, a poisonous gas that’s…

1 min
time machine

1 JULY 1966 ▶ The Coldest Swim in the World The cover story from this issue was told by an expedition diver who was part of a research team that ventured to Antarctica on two occasions to capture audio recordings of the Weddell seal. In addition to divers deployed below the ice in sub-freezing waters, a sub-ice observation chamber (SOC) was positioned below the surface, allowing scientists to study their subjects from the relative safety of the reinforced cylindrical cabin. 2 JULY 1968 How Engineers will save Niagara Falls A full-colour illustration and black-and-white photos accompanied this detailed write-up, which explained how a large-scale construction project was going to rehabilitate the famous waterfalls on the United States-Canada border, preventing erosion from further damaging the base rock layers. 3 AUGUST 1970 ▶ How to do a complete Disc…

4 min
the magnetic north pole is racing towards russia

THE MAGNETIC North Pole just isn’t where it used to be. Scientists have measured the location of the Magnetic North Pole since James Clark Ross first identified it in Canada’s Nunavut territory in 1831. The pole has moved several kilometres annually, but in recent decades, it has been racing towards Siberia at an unprecedented rate. A team of researchers from the UK and Denmark say they’ve uncovered the cause of this rapid shift: Two writhing lobes of magnetic force are duking it out near Earth’s core. Our planet’s protective magnetic field, which keeps deadly cosmic rays at bay and serves to orientate our navigation systems, is generated in Earth’s outer core, more than 2_900 km below the crust. ‘You’ve got these sorts of swirling hot masses of molten iron, bubbling and moving…

3 min
uncovering the hidden secrets of procedural generation

MATHEMATICIANS from the California Institute of Technology have solved an age-old problem related to ‘random walks’, a mathematical process that traces a path based on random decisions at various junctions. If you’ve played a procedurally generated video game such as Minecraft or Stardew Valley, you’ve encountered a random walk in the form of a dungeon or terrain. Biologists use random walks to model how animals move and behave, and physicists use them to describe how particles behave. In a random walk, the ‘walker’ can move in any direction at any point, so there’s an assumption that the walker will eventually revert to the mean and end up near its place of origin (because it’s less likely that chance would urge the walker in a single, focused direction over and over). Some…

1 min
take a random walk

Imagine you are sitting in a circle of n + 1 friends, and positions are labelled 0, 1, … n, and so on. The B in Fig 1 represents a pizza box held by person 0, who can pass the pizza to the person on their left or right with equal probability. That person randomly passes the pizza to their left or right, and so on. After a given number of passes, everyone in an arc of the circle has touched the pizza, and everyone outside the arc has not. The arc grows until all but one person has touched the pizza – and they are the winner. Where in the circle should you position yourself to maximise the probability that you win? Source: Mathematics for Computer Science/MIT OpenCourseWare Answer: You should…