Human ingenuity demolishes historical barriers – but not all

We keep pushing the boundaries, but there are some limits that will remain out of reach, writes Alan Finkel.

GREG WOOD / AFP / Getty Images

When accepted limits are broken, I am astonished. Often what I thought were hard limits turn out to be the limits of our collective imagination, not the imposition of physics.

Surprisingly, this demolition of apparently immovable limits happens often. Here are a few examples from my lifetime. See if you can think of a few of your own.

When I studied electrical engineering, it was generally accepted that copper telephone wires couldn’t carry electrical signals that oscillated faster than about 5,000 cycles per second. That was good enough for voice signals, but made for very slow digital communication. As a rule of thumb, you could expect to transfer twice that rate as bits of data and, indeed, for a long time 9.6 kilobits per second was the standard.

But with the advent of new signal-processing techniques for modems, more sophisticated error-correction algorithms and circuitry improvements at telephone exchanges and distribution nodes, digital communications over the copper telephone network became progressively faster.

Today’s high‑speed data modems deliver download speeds of 10 megabits per second – 1,000 times faster than what I naively understood would be the upper limit of the ordinary copper telephone wires.

Moving on to water sports, when my sons were young I explained to them that the maximum speed of a sailboat is proportional to the square root of its waterline length. According to the hull‑speed formula, the 27-metre boat used in the America’s Cup race should have a maximum speed of 24 kilometres per hour.

Incredibly, the current generation of America’s Cup sailboats average speeds of nearly 75 kilometres per hour, often running at twice the wind speed. How did they achieve this breakthrough? By changing the nature of sailing so that instead of ploughing through the water, the boats rise up on a hydrofoil and skim along the surface.

As a very amateur photographer and a manufacturer of scientific imaging systems, for decades I accepted that in order to get high-resolution, high-contrast images, you needed a large optical lens. The rule was “bigger is better”.

Nowadays I see astonishing pictures from smartphone cameras that have tiny lenses only a few millimetres in diameter. I was stuck in the wrong paradigm. In the past, because conventional film – containing silver halide crystals – is inherently granular, it needed to be at least 35 millimetres wide to achieve high resolution.

I am sure that fundamental laws of physics such as the speed of light will never be broken.

When electronic sensors replaced film, they started off the same size in order to operate with standard-sized cameras and lenses. I never foresaw that, aided by clever image‑processing software, high-resolution electronic sensors could shrink to fit into smartphones with a tiny matching lens. This breakthrough was achieved by accepting a compromise: smartphone cameras only operate well in bright conditions, with stationary subjects.

Finally to aeroplane wings. When you look at the massiveness of an A380, it is hard to believe that it can fly! Things have changed. Each square metre of the Wright Flyer biplane built in 1903 could lift seven kilograms. With today’s technology, each square metre of an A380 can lift 663 kilograms. The reasons for this astonishing increase have to do with speed, materials strength and wing design.

I am sure that fundamental laws of physics such as the speed of light will never be broken.

But technological limits are no match for the march of human ingenuity. Developed millions of years ago to cope with the challenges of living on the African savannah, today this ingenuity is channelled into the efforts of scientists and engineers across the planet, sometimes converging in surprising breakthroughs.

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Alan Finkel is an electrical engineer, neuroscientist and Chief Scientist of Australia.
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