Quantum computers: technology’s next frontier

Breakthrough: New computers could “win elections, boost wealth and save lives”. © IBM

IBM has announced plans to build the world’s first commercially available quantum computer. The technology could completely change how the world works. Would it be a good thing?

Quantum mechanics is one of the most mysterious branches of science. It deals with the very small — the intricacies of atoms where the usual rules of physics no longer apply. But it has a huge effect on the world around us.

So when International Business Machines (IBM) announced that it would make its fledgling quantum computer commercially available, it was hailed as a huge step forward for the future of computers. According to Professor Winfried Hensinger, building a successful quantum computer is “the Holy Grail of science”.

To understand why this is so important, it is necessary to understand the key differences between quantum mechanics and classical mechanics.

It all comes down to how atoms work.

Atoms are surrounded by electrons, and it was previously thought that the electrons circled around the atom, just as the Earth orbits the sun. In classical mechanics, objects exist in a specific place at a specific time.

However, in quantum mechanics, objects instead exist in a haze of probability; they have a certain chance of being at point A, another chance of being at point B and so on. They are able to occupy two places at once.

Conventional digital computers function on a series of 0s and 1s. But quantum computers are not just more powerful than normal computers; they are fundamentally different, because they use quantum bits, or qubits, to encode information as 0s, 1s, or both at the same time.

So what could all this mean?

Quantum computers could discover distant planets by quickly analysing the vast amounts of data collected by telescopes. They could even boost a country’s GDP by improving personalised advertising, thus encouraging consumers to spend more money. Its computer models could help detect cancer earlier.

The implications for transport are also huge. Quantum computers could make aeroplanes safer by efficiently testing complex software. And in their efforts to create a driverless car, Google are using the technology to design software that can distinguish cars from landmarks.

Quantum leap

This sounds fantastic, say some. If quantum computers become truly widespread it could be one of humanity’s greatest leaps forward. The technology could save lives and boost wealth and productivity. And humanity must never shy away from technological progress. We must adapt, and we will.

But there are great concerns that this technology could be used for nefarious means. Take hacking, for example. On its first day of operation, a fully functioning quantum computer would be capable of cracking the Internet’s most widely used codes with ease. Quantum computers may sound great, but they would unleash new demons into the world of technology.

You Decide

  1. Will quantum computers be good for humanity?
  2. Will this be the most important invention of the last 100 years?


  1. Draw a diagram illustrating the difference between classical mechanics and quantum mechanics.
  2. If you had a quantum supercomputer, what would you do with it? Write a science fiction story imagining what might happen.

Some People Say...

“If quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet.”

Niels Bohr

What do you think?

Q & A

How close is this from being reality?
A long way. Quantum computers cost roughly $10m, so only seriously big companies would be able to afford them. And much of the technology is still in its infancy. One of the challenges associated with quantum computing is instability. Because calculations are taking place at the quantum level, the slightest interference can disrupt the process.
I don’t understand. How can an electron be in two places at once?
Well, no one really understands — and that is why quantum mechanics is so fascinating. And it is not just that simple law of physics that is defied at atomic level. Things can also travel back in time and information can teleport across space. It really is bizarre.

Word Watch

International Business Machines
An American multinational technology company based in New York. Its inventions include the automatic teller machine (ATM), the floppy disk, the hard drive disk and the magnetic stripe card.
Holy Grail
An artefact in Christian mythology. It is the cup or the plate used by Jesus at the last supper, which was later used to catch his blood when he died on the cross. The term is often used as a metaphor for the ultimate goal of a mission.
Classical mechanics
Put very simply, classical mechanics says what happens when forces act on things. It is one of the largest and most ancient subjects in science, engineering and technology and is also called Newtonian mechanics.
A negative elementary electric charge. The opposite is a proton, which has a positive charge.


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