Meanwhile, in the USA, Thomas Alva Edison was creating his own electric light bulb. In 1882, Edison set up the Edison Electric Light Company in London and immediately started legal proceedings against Swan for patent infringement. The lengthy court battle ended with Swan and Edison agreeing to join forces in 1883.
Power stations were set up in a few towns to supply nearby houses, but restrictive legislation and erratic supply meant most people who wanted electric light had to generate their own electricity. One of the problems with the small local power stations was that the extra demand at night was often just too much for them.
For some time in the late 1880s, electrical engineers disputed bitterly over how to supply electricity in what became known as the Battle of the Currents. On one side were the DC (direct current) crowd, including Edison, Lord Kelvin and others who favoured a DC supply because it was safe at the low voltages suitable for domestic use and could be stored in batteries. For them, the power drop-off that occurred at distance from the power station was a minor problem. On the other side were men such as George Westinghouse, Charles Parsons and Charles Metz who believed in AC (alternating current), which, with the aid of transformers, could be transmitted at high voltages over long distances without losing any power.
At the heart of the battle was the bitter personal rivalry between Edison and a one-time employee of his, the brilliant Serbian-born inventor Nikola Tesla. Highly practical and lacking the maths to appreciate Tesla’s sophisticated work on AC, Edison got rid of Tesla without compensation, saying: ‘[Tesla’s] ideas are splendid, but they are utterly impractical.’ Edison launched an intensive publicity campaign against AC, including spreading misinformation about supposed dangers. In 1902, his film crew made a film showing the electrocution by AC of Topsy, a circus elephant which had killed three men. Even more gruesomely, Edison secretly funded the development of the first electric chair, used on 6 August 1890 to execute condemned murderer William Kemmler. The execution was so badly botched that Westinghouse, commented grimly: ‘They would have done better using an axe.’
In the end, despite Edison’s efforts, Westinghouse and Tesla, who became known as ‘The Wizard of the West’, had the last laugh. On 16 November 1896, electric power generated by hydropower at Niagara Falls was sent 30 miles to the city of Buffalo without any detectable power drop-off, using Tesla’s innovative polyphase AC system. Suddenly, big power was available for industry. Moreover, it became possible to get massive economies of scale by generating power at a single big power station, then transmitting it over huge distances with no significant power loss, by changing the voltage with transformers – something that can’t be done with DC.
A few small power stations continued to supply local domestic use with DC. But as ever more homes switched on to electric light, and industry began to exploit this wonderful new source of on-tap energy, the pattern of electricity supply became dominated by the big power stations and AC delivery.
By the 1920s, a good electricity supply across the nation, for both domestic and industrial use, was seen as a basic necessity. The fragmented and uncoordinated networks, though, were not well equipped to supply it. So in the late 1920s, the UK, for instance, embarked on an ambitious plan to create a nationwide electricity network which became known as the National Grid. Before the Grid was in place, in 1931, barely 30 per cent of UK houses had an electric supply. Just seventeen years later, 85 per cent did. Similar grid systems were set up in most industrialised nations.
But the coordination of electricity supplies hasn’t stopped there. Now ‘synchronous grids’ have been set up to link supply networks across national borders. The largest in the world is the synchronous grid of Continental Europe, formerly known as the UCTE, which covers most of the European Union and supplies over 400 million homes.[1] There is even a proposal to set up a SuperSmart Grid covering all of Europe, northern Africa, Turkey and the Middle East. It’s called a ‘smart’ grid, because it would use two-way digital technology both to control appliances at people’s homes and to adjust the flow of electricity in the supply system to make sure its efficiency is maximised. The point of linking the European and African networks is that most of Europe’s huge energy demands could be met not from polluting, carbon-producing oil- and coal-fired power stations in Europe, but at much lower cost from Africa’s vast, clean renewable hydroelectric resources. One day, switching on a light in Glasgow might draw instantly upon power generated on a dam on the Nile.
This is the great beauty of electricity grids. They not only ensure that every corner of the country has a good electricity supply but they are so interconnected that they can instantly spread and balance supply and demand throughout the network. When there is a blip in UK demand, for instance, a massive hydropower station under the North Wales mountains kicks in, or power is drawn across the channel from the Continental Grid. Moreover, when production in one power station drops, others far across the country can instantly take up the slack to ensure the supply stays astonishingly constant right across the grid.
The electricity supply is so silent, so invisible and so readily available that it is easy to forget just how amazing it is that it is there so reliably. Everything from high-tech gadgets to basic lighting depends on the constant supply of electricity delivered to every house night and day by the grid. The idea of every home in the developed world being supplied together and instantly is quite astonishing when you think about it. The everyday miracle involved only becomes apparent if you get to see one of the computerised maps of the grid at a National Grid centre, showing the state of the supply. The grid visibly links every corner of the nation and supplies it with vital energy, just as surely as the blood circulation delivers life-giving oxygen to the body.
[1] In 2020, China will complete a grid that will cover the whole country and dwarf the European grid.
#21 Quantum Theory
‘If anybody says he can think about quantum problems without getting giddy,’ Danish physicist Niels Bohr said, ‘that only shows he has not understood the first thing about them.’ Niels Bohr was one of the chief architects of quantum theory, and he was right; quantum theory is one of the most bizarre, mind-blowing theories of science ever devised. A century after its creation it still sounds so weird that it seems like science fiction rather than the long-established branch of physics it is. Indeed, it is so weird that it has prompted even philosophers to question the whole nature of reality.
Quantum theory is based on the discovery that at the very smallest scales, smaller than atoms, things behave very differently. The classical rules of physics, the rules that govern everything from how an ant crawls to how the universe expands, just don’t work at the sub-atomic scale, it seems. In classical physics, things behave according to a strict pattern of cause and effect. Quantum theory shows that at the sub-atomic level, we have to abandon this strict cause-and-effect relationship.[1] Instead, it is all about probabilities. It means you can never say where something is (and by something we mean, essentially, a sub-atomic particle); you can only say where it probably is. Its position is fixed only once you observe it.
This is far more unsettling than it sounds at first. Even though it was Einstein’s insights into the interaction of light and atoms that sparked the creation of quantum theory, Einstein hated it. It was not just that the universe was suddenly governed by not one set of laws, but two – one for the sub-atomic world and one for all the rest. It was the whole chancy nature of quantum theory that disturbed him.
Einstein’s theories of relativity might seem extraordinary, but they always assumed that the universe behaved with certainty. He just couldn’t relate to a universe directed by probability. ‘God doesn’t play dice,’ he famously said,[2] and devised a thought experiment to prove quantum theory wrong. This experiment, known as the Einstein-Podolsky-Rosen (EPR) experiment, envisaged a pair of particles emitted simultaneously from an atom. According to quantum theory, Einstein said, the ‘spin’[3] of the two particles is not fixed until they
are observed. Yet the instant one is observed, quantum theory would predict, the other’s spin becomes fixed too – even if it is on the other side of the universe.
Einstein thought this patently absurd since information can, according to classical physics, travel no faster than the speed of light.[4] So quantum theory must be wrong. Then in 1982, amazingly, French physicist Alain Aspect showed that the EPR demonstrates a real effect. The two particles are said to be ‘entangled’. It’s as if they are twins that can telepathically communicate across space.
Astounding though it sounds, entanglement has been demonstrated again and again over the last few decades and can be used to create that science fiction marvel, the teleport. If you attach another particle to one of an entangled pair, the attachment is instantly recreated, seemingly magically, by the other one of the pair, no matter how far apart. In 1997, photons were teleported across a laboratory in Rome like this, and since then molecules as big as bacteria have been teleported. Some scientists, of course, talk of teleporting entire objects across the world, but that’s a long way off. Nevertheless, even though no one has even the vaguest idea how entanglement works, it’s real and it does.[5]
Another astounding effect is ‘quantum tunnelling’. Because the location of a quantum particle is only probable, sometimes the improbable can happen. The particle can sometimes appear on the far side of an impenetrable barrier, as if it has tunnelled through in an instant.
Quantum tunnelling is involved in the latest hard-disc drives in computers. It’s what allows you to clear data rapidly from flash drives. Mobile phones and computers may soon have touch-screens that are pressure-sensitive, thanks to quantum tunnelling. And the effects are observable in nature. It’s how the sun gives out light. It’s how enzymes often speed up organic processes. In fact, the more scientists delve, the more widespread its effects seem to be, ‘explaining’ phenomena that no one quite understood before. Yet no one knows how it works. Scientists working in the field of quantum mechanics have simply to accept that it’s real and go on exploring its effects without any real notion of how it works on a ‘common sense’ level.
The origins of quantum theory lie back in the late 1800s, when scientists were trying to figure out how light is emitted from atoms. Most agreed that light travelled in waves and that each colour has a different wavelength. They knew that each kind of atom emitted a particular range of wavelengths – a particular spectrum of colours. And they knew that the energy in light increases from the red end of the spectrum to the violet. It was the hunt for an equation that summed up this increase that led to the idea of quanta. In 1900, German scientist Max Planck found that he could create an equation that worked only by treating the emitted light not as waves but bite-sized chunks of energy which he called ‘quanta’, from the Latin for ‘how much’.
For Planck, this was simply a mathematical trick. But Einstein soon showed it was much more than that. In 1902, Hungarian physicist Philipp Lenard noticed something rather strange about the photoelectric effect – the way a little electricity is created when certain kinds of light hit metal atoms and knock electrons off. The energy of the electrons knocked off doesn’t vary with the light’s intensity at all, only its colour. This seemed weird; it was as if waves washed exactly the same amount of sand away on the beach no matter how big the wave.
Einstein, in the third of his great papers of 1905, showed what was going on. Even though at the time the consensus was that light is a wave, Einstein realised that Lenard’s observation made complete sense if light consists of chunks of energy like Planck’s quanta, and that quanta were not a mathematical trick but actual particles of light, later known as photons.
Eight years later, the young Niels Bohr was puzzling over the structure of the atom. Recent experiments by Ernest Rutherford had revealed that atoms are largely empty space, with tiny electrons orbiting a minute, dense nucleus. But why, Bohr mused, did each kind of atom seem to emit light only at certain wavelengths (known as spectral lines) and not others? And why didn’t electrons just gradually spiral in towards the nucleus like a roulette ball?
Then it dawned on Bohr. It all made sense if you thought in terms of quanta. Electrons must only occupy certain orbits or ‘energy levels’ around the nucleus, as if each has a ticket to sit only in certain tiers in a stadium. When photons hit atoms, they bump electrons up a few tiers; light is emitted when electrons drop down an energy level or two. The colour emitted depends on the size of the drop. Each atom has a unique pattern of energy levels, and so emits its own unique range of colours.
This extraordinary insight rightly earned Bohr the 1922 Nobel Prize in physics and gave us the basis of the model of the atom we have today,[6] although it has been modified considerably since then. Yet it threw up as many problems as it solved. Now we had light, which everyone had thought of as a wave, behaving like a particle. And then, in the 1920s, French physics student Louis de Broglie showed that electrons, which everyone had thought of as a particle, could behave like a wave. What’s more, light and matter seemed to switch between the two according to how you observed them. It all seemed horribly contradictory.
Gradually, physicists realised that the contradiction disappeared if you thought in terms of quanta and probabilities. An ingenious German physicist, Werner Heisenberg, realised a puzzling fact. You can measure, for instance, the momentum of a photon as it moves as a wave. Or you can measure its position as a particle. But you can never be sure of both at the same time because, as soon as you try to pin a photon down as a particle, it starts behaving like a wave, and vice versa.
This insight, called the Uncertainty Principle, is not just a problem with measuring. It is a basic property of all sub-atomic particles. It means that quantum scientists have to think in terms of probabilities, not certainties. This assumption became the heart of the new science of quantum mechanics developed principally by Heisenberg and Bohr in Copenhagen in 1927.
Over 80 years on, quantum mechanics, the field of science founded on quantum theory, has now branched out into every field of science, affecting chemistry, biology, optics, electronics and much more. It’s been observed to work again and again, and predictions made on the basis of quantum theory have proved to be amazingly accurate. So scientists have no doubt that the basic thinking behind it is right. Yet repeated attempts to join it with classical physics in Grand Unified Theories have so far failed, and ideas such as the many-worlds theory (which suggests that all the possibilities of the quanta are actually realised, but in different worlds) remain nothing more than ideas.
For the moment, scientists accept that it works and use its rich insights to push their exploration of the sub-atomic world further and develop some amazing new technology. But a real understanding of how it works is as yet beyond us.
Because it seems to upturn the traditional laws of physics and the clockwork, entirely deterministic universe that they depict, some people have found all kinds of extraordinary things in quantum theory. The deterministic nature of classical science laws, for instance, makes it very difficult to see how humans could have free will – since every action is entirely predetermined by those that go before. Quantum theory, with its infinite possibilities, seems, to some, to permit it.[7] Others see the operation of mystical forces, and use (and misuse) quantum theory to explain or justify all kinds of outlandish ideas, some of which may be valid, but most of which are fluff. Some even see quantum theory as a way to finally unite scientific and religious, mystical thought. That seems unlikely, but there’s no doubt that our journey into the extraordinary quantum world has barely begun.
[1] Quantum theory doesn’t mean that there is no such thing as cause and effect; it simply works in a different way. The effect is probable, not predetermined.
[2] What he actually said was: ‘It seems hard to sneak a look at God’s cards. But that he plays dice and uses “telepathic” methods … is something that I cannot believe for a single moment.’
[3] Spin is a special quantum quality o
f all sub-atomic particles, but it’s a mathematical concept rather than a physical rotation.
[4] English poet Arthur Buller gently mocked Einstein with this limerick:
There was a young lady named Bright
Whose speed was far faster than light;
She set out one day
In a relative way
And returned on the previous night.
[5] Recently, scientists in Singapore and the USA suggested that DNA, the master molecule of genetic instructions inside every living cell, is held together by quantum entanglement.
[6] Amazingly, many science text books still depict the atom with a ball-like nucleus orbited by electrons like planets around the sun. This image was created by Japanese physicist Hantaro Nagaoka in 1904, and was outdated a century ago. In fact, electrons are not like orbiting planets at all, but more like multiple whirring propeller blades spinning so fast they seem to be everywhere at once.
[7] But quantum theory doesn’t actually allow any more control than classical laws; it simply switches you from the straightjacket of a programme to being the victim of chance.
#20 Printing
Printing has changed the world as much as any idea in the last millennium. Its effects are subtle. It’s not like technology such as the aeroplane which you can see and hear. It’s not even like banks which have a tangible effect on our lives all the time. But the impact of printing has been nonetheless profound, because of the way it has shaped our entire way of thinking and communicating.
The World's Greatest Idea Page 18
