Jack Kilby’s revolutionary idea was to make all the different components of a circuit out of the same flat block of semiconductor material. Not only would this get rid of wires and faulty connections, it would make the entire circuit much more compact. Kilby demonstrated his first “integrated circuit” on Sept. 12, 1958.

Six months later, in California, another engineer, Robert Noyce, independently came up with the idea of making an integrated circuit. Noyce’s chip was better suited to be manufactured in large numbers, and soon he was part of a young company called Intel.

Thus was launched a revolution. The first chip-based computer was the first U.S. Air Force computer, built in 1961. The true potential of the integrated circuit was shown when Texas Instruments unveiled the pocket calculator. Previously calculators had been bulky devices that needed to be plugged in to electrical mains. The pocket calculator, small enough to hold in one’s palm, had a chip inside and batteries were adequate to power it.

Progress was rapid thereafter. Many have already heard of Moore’s law, which has become a mantra of the digital age. First put forward by the Intel co-founder Gordon Moore in the 1960s, it says that the processing power of a chip doubles every two years, while the price falls by half. For more than four decades, Moore’s law has held, driving incredible growth and miniaturization — and wealth.

The question is whether the semiconductor industry can sustain this pace. Further increasing the processing power of chips is proving to be problematic as certain fundamental physical barriers are being reached. At the same time, new frontiers are opening up. The quest is on to make chips that are powered by light instead of electricity, which will enable much faster computers.

Saswato Das. The Chip that Changed the World. Internet: <www.nytimes.com> (adapted).

In May 2021, a hole was found in a robotic arm aboard the International Space Station (ISS). The suspected culprit was a piece of rogue space junk. While thankfully no astronauts were injured, it has re-focussed attention on the growing problem of orbital debris.

How did we get here?

It’s easy to forget that just seven decades ago the Moon was the only thing orbiting the Earth. On 1 January 2021 there were 6,542 satellites in orbit. Tellingly, only just over half of them were active. That’s a lot of useless metal careering around the planet at 28,000 kph — ten times faster than a bullet.

How bad is the problem?

Very bad and getting worse. Estimates suggest there are currently half a million pieces of debris the size of a marble or larger and 100 million pieces of debris above one millimeter across. Yet only 27,000 pieces are actively tracked by the US Department of Defense.

What is Kessler syndrome?

It’s a catastrophic chain of events in which a satellite is shattered by a piece of space junk (or a collision with another satellite) and the resulting debris destroys more satellites creating more junk and so on in a never-ending cascade. It’s a domino effect – one piece falls and then takes the rest with it – and is named after NASA scientist Donald Kessler, who outlined the dangers back in 1978.

What can we do about it?

Better regulation of new launches would help, as right now it’s a bit of a free-for-all. There are existing regulations in place to try and mitigate the dangers, such as a 25-year de-orbit rule for missions in low-Earth orbit. However, ESA’s Space Debris Environment Report says that less than 60 per cent of those flying in low-Earth orbit currently stick to the rules.

Colin Stuart. Space Junk: Is it a disaster waiting to happen?
Internet: <www.sciencefocus.com> (adapted).