A Short History of Nearly Everything

by Bill Bryson

A few astronomers continue to think there may yet be a Planet X out there8 – a real whopper, perhaps as much as ten times the size of Jupiter, but so far out as to be invisible to us. (It would receive so little sunlight that it would have almost none to reflect.) The idea is that it wouldn’t be a conventional planet like Jupiter or Saturn – it’s much too far away for that; we’re talking perhaps 4.5 trillion miles – but more like a sun that never quite made it. Most star systems in the cosmos are binary (double-starred), which makes our solitary sun a slight oddity.

Second sun in our solar system beyond Puto

The Kuiper belt was actually theorized by an astronomer named F. C. Leonard in 19309, but the name honours Gerard Kuiper, a Dutch native working in America, who expanded the idea. The Kuiper belt is the source of what are known as short-period comets – those that come past pretty regularly – of which the most famous is Halley’s comet. The more reclusive long-period comets (among them the recent visitors Hale–Bopp and Hyakutake) come from the much more distant Oort cloud, about which more presently.

Kuiper Belt

The best speeds yet achieved by any human object are those of the Voyager 1 and 2 spacecrafts, which are now flying away from us at about 56,000 kilometres an hour13

Fasted man made object

Most schoolroom charts show the planets coming one after the other at neighbourly intervals – the outer giants actually cast shadows over each other in many illustrations – but this is a necessary deceit to get them all on the same piece of paper. Neptune in reality isn’t just a little bit beyond Jupiter, it’s way beyond Jupiter – five times further from Jupiter than Jupiter is from us, so far out that it receives only 3 per cent as much sunlight as Jupiter. Such are the distances, in fact, that it isn’t possible, in any practical terms, to draw the solar system to scale. Even if you added lots of fold-out pages to your textbooks or used a really long sheet of poster paper, you wouldn’t come close. On a diagram of the solar system to scale, with the Earth reduced to about the diameter of a pea, Jupiter would be over 300 metres away and Pluto would be two and a half kilometres distant (and about the size of a bacterium, so you wouldn’t be able to see it anyway). On the same scale, Proxima Centauri, our nearest star, would be 16,000 kilometres away. Even if you shrank down everything so that Jupiter was as small as the full stop at the end of this sentence, and Pluto was no bigger than a molecule, Pluto would still be over 10 metres away.

Scale of solar system

The basic unit of measure in the solar system is the Astronomical Unit, or AU, representing the distance from the Sun to the Earth. Pluto is about 40 AUs from us, the heart of the Oort cloud about fifty thousand. In a word, it is remote.

Unit of measurement in solar system - Astronomical Unit

About 4.6 billion years ago, a great swirl of gas and dust some 24 billion kilometres across accumulated in space where we are now and began to aggregate. Virtually all of it – 99.9 per cent of the mass of the solar system21 – went to make the Sun. Out of the floating material that was left over, two microscopic grains floated close enough together to be joined by electrostatic forces. This was the moment of conception for our planet. All over the inchoate solar system, the same was happening. Colliding dust grains formed larger and larger clumps. Eventually the clumps grew large enough to be called planetesimals. As these endlessly bumped and collided, they fractured or split or recombined in endless random permutations, but in every encounter there was a winner, and some of the winners grew big enough to dominate the orbit around which they travelled. It all happened remarkably quickly. To grow from a tiny cluster of grains to a baby planet some hundreds of kilometres across is thought to have taken only a few tens of thousands of years. In just 200 million years, possibly less22, the Earth was essentially formed, though still molten and subject to constant bombardment from all the debris that remained floating about. At this point, about 4.4 billion years ago, an object the size of Mars crashed into the Earth, blowing out enough material to form a companion sphere, the Moon. Within weeks, it is thought, the flung material had reassembled itself into a single clump, and ...

How Earth was created

Newton was a decidedly odd figure – brilliant beyond measure, but solitary, joyless, prickly to the point of paranoia, famously distracted (upon swinging his feet out of bed in the morning he would reportedly sometimes sit for hours, immobilized by the sudden rush of thoughts to his head), and capable of the most riveting strangeness. He built his own laboratory, the first at Cambridge, but then engaged in the most bizarre experiments. Once he inserted a bodkin – a long needle of the sort used for sewing leather – into his eye socket and rubbed it around ‘betwixt my eye and the bone4 as near to [the] backside of my eye as I could’ just to see what would happen. What happened, miraculously, was nothing – at least, nothing lasting. On another occasion, he stared at the Sun for as long as he could bear, to determine what effect it would have upon his vision. Again he escaped lasting damage, though he had to spend some days in a darkened room before his eyes forgave him. Set atop these odd beliefs and quirky traits, however, was the mind of a supreme genius – though even when working in conventional channels he often showed a tendency to peculiarity. As a student, frustrated by the limitations of conventional mathematics, he invented an entirely new form, the calculus, but then told no-one about it for twenty-seven years5. In like manner, he did work in optics that transformed our understanding of light and laid the foundation for the science of spectroscopy, and again chose n...

Issac Newton - Brilliant but Paranoid character

The Principia’s production was not without drama. To Halley’s horror, just as work was nearing completion Newton and Hooke fell into dispute over the priority for the inverse square law and Newton refused to release the crucial third volume, without which the first two made little sense. Only with some frantic shuttle diplomacy and the most liberal applications of flattery did Halley manage finally to extract the concluding volume from the erratic professor. Halley’s traumas were not yet quite over. The Royal Society had promised to publish the work, but now pulled out, citing financial embarrassment. The year before, the society had backed a costly flop called The History of Fishes, and suspected that the market for a book on mathematical principles would be less than clamorous. Halley, whose means were not great, paid for the book’s publication out of his own pocket. Newton, as was his custom, contributed nothing9. To make matters worse, Halley at this time had just accepted a position as the society’s clerk, and he was informed that the society could no longer afford to provide him with a promised salary of £50 per annum. He was to be paid instead in copies of The History of Fishes10

Principia -Newton's mathematics book - Struggle in getting it published

Because the British were the most active in the early years of the discipline, British names are predominant in the geological lexicon. Devonian is of course from the English county of Devon. Cambrian comes from the Roman name for Wales, while Ordovician and Silurian recall ancient Welsh tribes, the Ordovices and Silures. But with the rise of geological prospecting elsewhere, names began to creep in from all over. Jurassic refers to the Jura Mountains on the border of France and Switzerland. Permian recalls the former Russian province of Perm in the Ural Mountains. For Cretaceous (from the Latin for chalk) we are indebted to a Belgian geologist with the perky name of J.J. d’Omalius d’Halloy24.

Why abundance of British words in Geological terminiogies

Originally, geological history was divided into four spans of time: primary, secondary, tertiary and quaternary. The system was too neat to last, and soon geologists were contributing additional divisions while eliminating others. Primary and secondary fell out of use altogether, while quaternary was discarded by some but kept by others. Today only tertiary remains as a common designation everywhere, even though it no longer represents a third period of anything. Lyell, in his Principles, introduced additional units known as epochs or series to cover the period since the age of the dinosaurs, among them Pleistocene (‘most recent’), Pliocene (‘more recent’), Miocene (‘moderately recent’) and the rather endearingly vague Oligocene (‘but a little recent’). Lyell originally intended to employ ‘-synchronous’ for his endings25, giving us such crunchy designations as Meiosynchronous and Pleiosynchronous. The Reverend William Whewell, an influential man, objected on etymological grounds and suggested instead an ‘-eous’ pattern, producing Meioneous, Pleioneous and so on. The ‘-cene’ terminations were thus something of a compromise. Nowadays, and speaking very generally, geological time is divided first into four great chunks known as eras: Precambrian, Palaeozoic (from the Greek meaning ‘old life’), Mesozoic (‘middle life’) and Cenozoic (‘recent life’). These four eras are further divided into anywhere from a dozen to twenty subgroups, usually called periods though sometimes known ...

Epochs in geoogical history

Originally, geological history was divided into four spans of time: primary, secondary, tertiary and quaternary. The system was too neat to last, and soon geologists were contributing additional divisions while eliminating others. Primary and secondary fell out of use altogether, while quaternary was discarded by some but kept by others. Today only tertiary remains as a common designation everywhere, even though it no longer represents a third period of anything. Lyell, in his Principles, introduced additional units known as epochs or series to cover the period since the age of the dinosaurs, among them Pleistocene (‘most recent’), Pliocene (‘more recent’), Miocene (‘moderately recent’) and the rather endearingly vague Oligocene (‘but a little recent’). Lyell originally intended to employ ‘-synchronous’ for his endings25, giving us such crunchy designations as Meiosynchronous and Pleiosynchronous. The Reverend William Whewell, an influential man, objected on etymological grounds and suggested instead an ‘-eous’ pattern, producing Meioneous, Pleioneous and so on. The ‘-cene’ terminations were thus something of a compromise. Nowadays, and speaking very generally, geological time is divided first into four great chunks known as eras: Precambrian, Palaeozoic (from the Greek meaning ‘old life’), Mesozoic (‘middle life’) and Cenozoic (‘recent life’). These four eras are further divided into anywhere from a dozen to twenty subgroups, usually called periods though sometimes known ...

Geological division of Historical time

Although there was no reliable way of dating periods, there was no shortage of people willing to try. The most well known early attempt30 was made in 1650, when Archbishop James Ussher of the Church of Ireland made a careful study of the Bible and other historical sources and concluded, in a hefty tome called Annals of the Old Testament, that the Earth had been created at midday on 23 October 4004 BC, an assertion that has amused historians and textbook writers ever since.fn2 There is a persistent myth, incidentally – and one propounded in many serious books – that Ussher’s views dominated scientific beliefs well into the nineteenth century, and that it was Lyell who put everyone straight. Stephen Jay Gould in Time’s Arrow cites as a typical example this sentence from a popular book of the 1980s: ‘Until Lyell published his book, most thinking people accepted the idea that the earth was young31.’ In fact, no. As Martin J. S. Rudwick puts it, ‘No geologist of any nationality whose work was taken seriously32 by other geologists advocated a timescale confined within the limits of a literalistic exegesis of Genesis.’ Even the Reverend Buckland33, as pious a soul as the nineteenth century produced, noted that nowhere did the Bible suggest that God made Heaven and Earth on the first day, but merely ‘in the beginning’. That beginning, he reasoned, may have lasted ‘millions upon millions of years’. Everyone agreed that the Earth was ancient. The question was simply: how ancient?

Dating earth - Earliest attempts using religious ideas

One of the better early ideas at dating the planet came from the ever-reliable Edmond Halley, who in 1715 suggested that if you divided the total amount of salt in the world’s seas by the amount added each year, you would get the number of years that the oceans had been in existence, which would give you a rough idea of Earth’s age. The logic was appealing, but unfortunately no-one knew how much salt was in the sea or by how much it increased each year, which rendered the experiment impracticable.

Dating earth - Salt in sea method

The first attempt at measurement that could be called remotely scientific was made by the Frenchman Georges-Louis Leclerc, Comte de Buffon, in the 1770s. It had long been known that the Earth radiated appreciable amounts of heat – that was apparent to anyone who went down a coal mine – but there wasn’t any way of estimating the rate of dissipation. Buffon’s experiment consisted of heating spheres until they glowed white-hot and then estimating the rate of heat loss by touching them (presumably very lightly at first) as they cooled. From this he guessed the Earth’s age to be somewhere between 75,000 and 168,000 years old34. This was of course a wild underestimate; but it was a radical notion nonetheless, and Buffon found himself threatened with excommunication for expressing it. A practical man, he apologized at once for his thoughtless heresy, then cheerfully repeated the assertions throughout his subsequent writings.

Dating Earth - Rate of cooling method - French geologist 'Georges-Louis Leclerc'

By the middle of the nineteenth century most learned people thought the Earth was at least a few million years old, perhaps even some tens of millions years old, but probably not more than that. So it came as a surprise when in 1859, in On the Origin of Species, Charles Darwin announced that the geological processes that created the Weald35, an area of southern England stretching across Kent, Surrey and Sussex, had taken, by his calculations, 306,662,400 years to complete. The assertion was remarkable partly for being so arrestingly specific but even more for flying in the face of accepted wisdom about the age of the Earth.fn3 It proved so contentious that Darwin withdrew it from the third edition of the book.

Dating Earth - Charles Darwin's estimate

Unfortunately for Darwin, and for progress, the question came to the attention of the great Lord Kelvin (who, though indubitably great, was then still just plain William Thomson; he wouldn’t be elevated to the peerage until 1892, when he was sixty-eight years old and nearing the end of his career, but I shall follow the convention here of using the name retroactively). Kelvin was one of the most extraordinary figures of the nineteenth century – indeed, of any century. The German scientist Hermann von Helmholtz36, no intellectual slouch himself, wrote that Kelvin had by far the greatest ‘intelligence and lucidity, and mobility of thought’ of any man he had ever met. ‘I felt quite wooden beside him sometimes,’ he added, a bit dejectedly. The sentiment is understandable, for Kelvin really was a kind of Victorian superman. He was born in 1824 in Belfast, the son of a professor of mathematics at the Royal Academical Institution who soon afterwards transferred to Glasgow. There Kelvin proved himself such a prodigy that he was admitted to Glasgow University at the exceedingly tender age of ten. By the time he had reached his early twenties, he had studied at institutions in London and Paris, graduated from Cambridge (where he won the university’s top prizes for rowing and mathematics, and somehow found time to launch a musical society as well), been elected a fellow of Peterhouse, and written (in French and English) a dozen papers in pure and applied mathematics of such dazzling ...

Accounts of Lord Kelvin, alias, William Thomson - Founder of absolute scale of temperature

He had really only one flaw and that was an inability to calculate the correct age of the Earth. The question occupied much of the second half of his career, but he never came anywhere near getting it right. His first effort, in 1862 for an article in a popular magazine called Macmillan’s, suggested that the Earth was 98 million years old, but cautiously allowed that the figure could be as low as 20 million years or as high as 400 million. With remarkable prudence he acknowledged that his calculations could be wrong if ‘sources now unknown to us are prepared in the great storehouse of creation’ – but it was clear that he thought that unlikely. With the passage of time Kelvin would become more forthright in his assertions and less correct. He continually revised his estimates downwards, from a maximum of 400 million years to 100 million years, then to 50 million years and finally, in 1897, to a mere 24 million years. Kelvin wasn’t being wilful. It was simply that there was nothing in physics that could explain how a body the size of the Sun could burn continuously for more than a few tens of millions of years at most without exhausting its fuel. Therefore it followed that the Sun and its planets were relatively, but inescapably, youthful. The problem was that nearly all the fossil evidence contradicted this, and suddenly in the nineteenth century there was a lot of fossil evidence.

Dating Earth - estimates by Lord Kelvin

Chemistry as an earnest and respectable science is often said to date from 1661, when Robert Boyle of Oxford published The Sceptical Chymist – the first work to distinguish between chemists and alchemists

Robert Boye - Inventor of chemistry -1661

Perhaps nothing better typifies the strange and often accidental nature of chemical science in its early days than a discovery made by a German named Hennig Brand in 1675. Brand became convinced that gold could somehow be distilled from human urine. (The similarity of colour seems to have been a factor in his conclusion.) He assembled fifty buckets of human urine, which he kept for months in his cellar. By various recondite processes, he converted the urine first into a noxious paste and then into a translucent waxy substance. None of it yielded gold, of course, but a strange and interesting thing did happen. After a time, the substance began to glow. Moreover, when exposed to air, it often spontaneously burst into flame. The commercial potential for the stuff – which soon became known as phosphorus, from Greek and Latin roots meaning ‘light-bearing’ – was not lost on eager business people, but the difficulties of manufacture made it too costly to exploit. An ounce of phosphorus retailed for 6 guineas2 – perhaps £300 in today’s money – or more than

Hennig Brand - German Chemist - 1675 - Story of accidenta discovery of phosphorous from urine

In the 1750s a Swedish chemist named Karl (or Carl) Scheele devised a way to manufacture phosphorus in bulk without the slop or smell of urine. It was largely because of this mastery of phosphorus that Sweden became, and remains, a leading producer of matches. Scheele was both an extraordinary and an extraordinarily luckless fellow. A humble pharmacist with little in the way of advanced apparatus, he discovered eight elements – chlorine, fluorine, manganese, barium, molybdenum, tungsten, nitrogen and oxygen – and got credit for none of them3. In every case, his finds either were overlooked or made it into publication after someone else had made the same discovery independently. He also discovered many useful compounds, among them ammonia, glycerin and tannic acid, and was the first to see the commercial potential of chlorine as a bleach – all breakthroughs that made other people extremely wealthy. Scheele’s one notable shortcoming was a curious insistence on tasting a little of everything he worked with, including such notoriously disagreeable substances as mercury and hydrocyanic acid (another of his discoveries) – a compound so famously poisonous that 150 years later Erwin Schrödinger chose it as his toxin of choice in a famous thought experiment (see here). Scheele’s rashness eventually caught up with him. In 1786, aged just forty-three, he was found dead at his workbench surrounded by an array of toxic chemicals, any one of which could have accounted for the stunned an...

Unlucky Swedish Chemist - karl Scheele - Real dicscovery of oxygen, chlorine, and lot other elements and compounds

The one thing Lavoisier never did was discover an element. At a time when it seemed as if almost anybody with a beaker, a flame and some interesting powders could discover something new – and when, not incidentally, some two-thirds of the elements were yet to be found – Lavoisier failed to uncover a single one9. It certainly wasn’t for want of beakers. Lavoisier had thirteen thousand of them in what was, to an almost preposterous degree, the finest private laboratory in existence. Instead, he took the discoveries of others and made sense of them. He threw out phlogiston and mephitic airs. He identified oxygen and hydrogen for what they were and gave them both their modern names. In short, he helped to bring rigour, clarity and method to chemistry. And his fancy equipment did in fact come in very handy. For years, he and Mme Lavoisier occupied themselves with extremely exacting studies requiring the finest measurements. They determined, for instance, that a rusting object doesn’t lose weight, as everyone had long assumed, but gains weight – an extraordinary discovery. Somehow, as it rusted the object was attracting elemental particles from the air. It was the first realization that matter can be transformed but not eliminated. If you burned this book now, its matter would be changed to ash and smoke, but the net amount of stuff in the universe would be the same. This became known as the conservation of mass, and it was a revolutionary concept.

Lavoisier - French chemist couple - Law of conservation of mass in chemical reaction.

Because chemists worked for so long in isolation, conventions were slow to emerge. Until well into the second half of the century, the formula H2O2 might mean water to one chemist but hydrogen peroxide to another. C2H4 could signify ethylene or marsh gas. There was hardly a molecule that was uniformly represented everywhere. Chemists also used a bewildering variety of symbols and abbreviations, often self-invented. Sweden’s J.J. Berzelius brought a much-needed measure of order to matters by decreeing that the elements be abbreviated on the basis of their Greek or Latin names, which is why the abbreviation for iron is Fe (from the Latin ferrum) and for silver is Ag (from the Latin argentum). That so many of the other abbreviations accord with their English names (N for nitrogen, O for oxygen, H for hydrogen and so on) reflects English’s latinate nature, not its exalted status. To indicate the number of atoms in a molecule, Berzelius employed a superscript notation, as in H2O. Later, for no special reason16, the fashion became to render the number as subscript: H2O.

Development of wrting convention of chemical formulas

in 1869, at the age of thirty-five, he began to toy with a way to arrange the elements. At the time, elements were normally grouped in two ways – either by atomic weight (using Avogadro’s Principle) or by common properties (whether they were metals or gases, for instance). Mendeleyev’s breakthrough was to see that the two could be combined in a single table. As is often the way in science, the principle had actually been anticipated three years previously by an amateur chemist in England named John Newlands. He suggested that when elements were arranged by weight they appeared to repeat certain properties – in a sense to harmonize – at every eighth place along the scale. Slightly unwisely, for this was an idea whose time had not quite yet come19, Newlands called it the Law of Octaves and likened the arrangement to the octaves on a piano keyboard. Perhaps there was something in Newlands’ manner of presentation, but the idea was considered fundamentally preposterous and widely mocked. At gatherings, droller members of the audience would sometimes ask him if he could get his elements to play them a little tune. Discouraged, Newlands gave up pushing the idea and soon dropped out of sight altogether. Mendeleyev used a slightly different approach, placing his elements into groups of seven, but employed fundamentally the same premise. Suddenly the idea seemed brilliant and wondrously perceptive. Because the properties repeated themselves periodically, the invention became known a...

MandeleyesVand Newlands - law of octaves and periodic table of chemistry

Helium, the second most abundant element, had only been found the year before – its existence hadn’t even been suspected before that – and then not on the Earth, but in the Sun, where it was found with a spectroscope during a solar eclipse, which is why it honours the Greek sun god Helios. It wouldn’t be isolated until 1895.

Why helium named so

The nineteenth century held one last important surprise for chemists. It began in 1896 when Henri Becquerel in Paris carelessly left a packet of uranium salts on a wrapped photographic plate in a drawer. When he took the plate out some time later, he was surprised to discover that the salts had burned an impression in it, just as if the plate had been exposed to light. The salts were emitting rays of some sort. Considering the importance of what he had found, Becquerel did a very strange thing: he turned the matter over to a graduate student for investigation. Fortunately the student was a recent émigré from Poland named Marie Curie. Working with her new husband, Pierre, Curie found that certain kinds of rocks poured out constant and extraordinary amounts of energy, yet without diminishing in size or changing in any detectable way. What she and her husband couldn’t know – what no-one could know until Einstein explained things the following decade – was that the rocks were converting mass into energy in an exceedingly efficient way. Marie Curie dubbed the effect ‘radioactivity’24. In the process of their work, the Curies also found two new elements – polonium, which they named after her native country, and radium. In 1903 the Curies and Becquerel were jointly awarded the Nobel Prize in physics. (Marie Curie would win a second prize, in chemistry, in 1911; the only person to win in both chemistry and physics.)

Marie Curie - Accidental Discovery of Radioactivity

At McGill University in Montreal the young New Zealand-born Ernest Rutherford became interested in the new radioactive materials. With a colleague named Frederick Soddy he discovered that immense reserves of energy were bound up in these small amounts of matter, and that the radioactive decay of these reserves could account for most of the Earth’s warmth. They also discovered that radioactive elements decayed into other elements – that one day you had an atom of uranium, say, and the next you had an atom of lead. This was truly extraordinary. It was alchemy pure and simple; no-one had ever imagined that such a thing could happen naturally and spontaneously. Ever the pragmatist, Rutherford was the first to see that there could be a valuable practical application in this. He noticed that in any sample of radioactive material, it always took the same amount of time for half the sample to decay – the celebrated half-lifefn3 – and that this steady, reliable rate of decay could be used as a kind of clock. By calculating backwards from how much radiation a material had now and how swiftly it was decaying, you could work out its age. He tested a piece of pitchblende, the principal ore of uranium, and found it to be 700 million years old – very much older than the age most people were prepared to grant the Earth. In the spring of 1904, Rutherford travelled to London to give a lecture at the Royal Institution – the august organization founded by Count von Rumford only 105 years befo...

Rutherford - Dating earth with radioactivity

For a long time it was assumed that anything so miraculously energetic as radioactivity must be beneficial. For years, manufacturers of toothpaste and laxatives put radioactive thorium in their products, and at least until the late 1920s the Glen Springs Hotel in the Finger Lakes region of New York (and doubtless others as well) featured with pride the therapeutic effects of its ‘Radio-active mineral springs27’. It wasn’t banned in consumer products until 193828. By this time it was much too late for Mme Curie, who died of leukaemia in 1934. Radiation, in fact, is so pernicious and long-lasting that even now her papers from the 1890s – even her cookbooks – are too dangerous to handle. Her lab books are kept in lead-lined boxes29 and those who wish to see them must don protective clothing.

Radiation sickness tok Marie Cruie

What Michelson and Morley did, without actually intending to, was undermine a longstanding belief in something called the luminiferous ether, a stable, invisible, weightless, frictionless and unfortunately wholly imaginary medium that was thought to permeate the universe. Conceived by Descartes, embraced by Newton, and venerated by nearly everyone ever since, the ether held a position of absolute centrality in nineteenth-century physics as a way of explaining how light travelled across the emptiness of space. It was especially needed in the 1800s because light and electromagnetism were now seen as waves, which is to say types of vibrations. Vibrations must occur in something; hence the need for, and lasting devotion to, an ether.

Idea of Luminoferous ether filled in empty space of universe

They are also fantastically durable. Because they are so long-lived, atoms really get around. Every atom you possess has almost certainly passed through several stars and been part of millions of organisms on its way to becoming you. We are each so atomically numerous and so vigorously recycled at death that a significant number of our atoms – up to a billion for each of us, it has been suggested3 – probably once belonged to Shakespeare. A billion more each came from Buddha and Genghis Khan and Beethoven, and any other historical figure you care to name. (The personages have to be historical, apparently, as it takes the atoms some decades to become thoroughly redistributed; however much you may wish it, you are not yet one with Elvis Presley.) So we are all reincarnations – though short-lived ones. When we die, our atoms will disassemble and move off to find new uses elsewhere – as part of a leaf or other human being or drop of dew. Atoms themselves, however, go on practically for ever4. Nobody actually knows how long an atom can survive, but according to Martin Rees it is probably about 1035 years – a number so big that even I am happy to express it in mathematical notation.

Life of an Atom

The realization that atoms are these three things – small, numerous, practically indestructible – and that all things are made from them first occurred not to Antoine-Laurent Lavoisier, as you might expect, or even to Henry Cavendish or Humphry Davy, but rather to a spare and lightly educated English Quaker named John Dalton, whom we first encountered in Chapter 7. Dalton was born in 1766 on the edge of the Lake District, near Cockermouth, to a family of poor and devout Quaker weavers. (Four years later the poet William Wordsworth would also join the world at Cockermouth.) He was an exceptionally bright student – so very bright, indeed, that at the improbably youthful age of twelve he was put in charge of the local Quaker school. This perhaps says as much about the school as about Dalton’s precocity, but perhaps not: we know from his diaries that at about this time he was reading Newton’s Principia – in the original Latin – and other works of a similarly challenging nature. At fifteen, still school-mastering, he took a job in the nearby town of Kendal, and a decade after that he moved to Manchester, whence he scarcely stirred for the remaining fifty years of his life. In Manchester he became something of an intellectual whirlwind, producing books and papers on subjects ranging from meteorology to grammar. Colour blindness, a condition from which he suffered, was for a long time called Daltonism because of his studies. But it was a plump book called A New System of Chemical...

John Dalton - First person to understand scale od atom

The work made Dalton famous – albeit in a low-key, English Quaker sort of way. In 1826, the French chemist P. J. Pelletier travelled to Manchester7 to meet the atomic hero. Pelletier expected to find him attached to some grand institution, so he was astounded to discover him teaching elementary arithmetic to boys in a small school on a back street. According to the scientific historian E.J. Holmyard, a confused Pelletier, upon beholding the great man, stammered8: ‘Est-ce que j’ai l’honneur de m’addresser à Monsieur Dalton?’ for he could hardly believe his eyes that this was the chemist of European fame, teaching a boy his first four rules. ‘Yes,’ said the matter-of-fact Quaker. ‘Wilt thou sit down whilst I put this lad right about his arithmetic?’ Although Dalton tried to avoid all honours, he was elected to the Royal Society against his wishes, showered with medals and given a handsome government pension. When he died in 1844, forty thousand people viewed the coffin and the funeral cortège stretched for two miles9. His entry in the Dictionary of National Biography is one of the longest, rivalled in length among nineteenth-century men of science only by those of Darwin and Lyell.

Low key life of john dalton

By the early twentieth century it was known that atoms were made of parts – Thomson’s discovery of the electron had established that – but it wasn’t known how many parts there were or how they fitted together or what shape they took. Some physicists thought that atoms might be cube-shaped21, because cubes can be packed together so neatly without any wasted space. The more general view, however, was that an atom was more like a currant bun or a plum pudding: a dense, solid object that carried a positive charge but that was studded with negatively charged electrons, like the currants in a currant bun.

Earlier thoughts about the shape and structure of Atom

As Cropper has put it, if an atom were expanded to the size of a cathedral, the nucleus would be only about the size of a fly – but a fly many thousands of times heavier than the cathedral25

Analogy of Density of nucleus , and enormous empty space in atom

Midgley was an engineer by training and the world would no doubt have been a safer place if he had stayed so. Instead, he developed an interest in the industrial applications of chemistry. In 1921, while working for the General Motors Research Corporation in Dayton, Ohio, he investigated a compound called tetraethyl lead (also known, confusingly, as lead tetraethyl), and discovered that it significantly reduced the juddering condition known as engine knock. Even though lead was widely known to be dangerous, by the early years of the twentieth century it could be found in all manner of consumer products. Food came in cans sealed with lead solder. Water was often stored in lead-lined tanks. Lead arsenate was sprayed onto fruit as a pesticide. Lead even came as part of the composition of toothpaste tubes. Hardly a product existed that didn’t bring a little lead into consumers’ lives. However, nothing gave it a greater and more lasting intimacy than its addition to motor fuel. Lead is a neurotoxin. Get too much of it and you can irreparably damage the brain and central nervous system. Among the many symptoms associated with over-exposure are blindness, insomnia, kidney failure, hearing loss, cancer1, palsies and convulsions. In its most acute form it produces abrupt and terrifying hallucinations, disturbing to victims and onlookers alike, which generally then give way to coma and death. You really don’t want to get too much lead into your system. On the other hand, lead was ea...

Thomas Midgey - use of tetraethyl lead to stop engine knocing

Refrigerators in the 1920s were often appallingly risky because they used insidious and dangerous gases that sometimes seeped out. One leak from a refrigerator at a hospital in Cleveland, Ohio, in 1929 killed more than a hundred people4. Midgley set out to create a gas that was stable, non-flammable, non-corrosive and safe to breathe. With an instinct for the regrettable that was almost uncanny, he invented chlorofluorocarbons, or CFCs.

Thomas Midgley - Inventor of CFC gas

Chlorofluorocarbons are also not very abundant – they constitute only about one part per billion of the atmosphere as a whole – but they are extravagantly destructive. A single kilogram of CFCs can capture and annihilate 70,000 kilograms of atmospheric ozone5. CFCs also hang around for a long time – about a century on average – wreaking havoc all the while. And they are great heat sponges. A single CFC molecule is about ten thousand times more efficient at exacerbating greenhouse effects than a molecule of carbon dioxide6 – and carbon dioxide is of course no slouch itself as a greenhouse gas. In short, chlorofluorocarbons may ultimately prove to be just about the worst invention of the twentieth century.

Dangers of Choroflurocarbons

Libby’s idea was so useful that he would be awarded a Nobel Prize for it in 1960. It was based on the realization that all living things have within them an isotope of carbon called carbon-14, which begins to decay at a measurable rate the instant they die. Carbon-14 has a half-life – that is, the time it takes for half of any sample to disappear – of about 5,600 years, so by working out how much of a given sample of carbon had decayed, Libby could get a good fix on the age of an object – though only up to a point. After eight half-lives, only 0.39 per cent of the original radioactive carbon remains9, which is too little to make a reliable measurement, so radiocarbon dating works only for objects up to forty thousand or so years old.

Willard Libby - Discovery of Carbn 14 dating

Curiously, just as the technique was becoming widespread, certain flaws within it became apparent. To begin with, it was discovered that one of the basic components of Libby’s formula, known as the decay constant, was out by about 3 per cent. By this time, however, thousands of measurements had been taken throughout the world. Rather than restate every one, scientists decided to keep the inaccurate constant. ‘Thus,’ Tim Flannery notes, ‘every raw radiocarbon date you read today is given as too young by around 3 per cent10.’ The problems didn’t quite stop there. It was also quickly discovered that carbon-14 samples can be easily contaminated with carbon from other sources – a tiny scrap of vegetable matter, for instance, that has been collected with the sample and not noticed. For younger samples – those under twenty thousand years or so – slight contamination does not always matter so much, but for older samples it can be a serious problem because so few remaining atoms are being counted. In the first instance, to borrow from Flannery, it is like miscounting by a dollar when counting to a thousand11; in the second it is more like miscounting by a dollar when you have only two dollars to count. Libby’s method was also based on the assumption that the amount of carbon-14 in the atmosphere, and the rate at which it has been absorbed by living things, has been consistent throughout history. In fact it hasn’t been. We now know that the volume of atmospheric carbon-14 varies dep...

Flaws in carbon 14 dating

Because of the accumulated shortcomings of carbon-14, scientists devised other methods of dating ancient materials, among them thermoluminescence, which measures electrons trapped in clays, and electron spin resonance, which involves bombarding a sample with electromagnetic waves and measuring the vibrations of the electrons. But even the best of these could not date anything older than about two hundred thousand years, and they couldn’t date inorganic materials like rocks at all, which is of course what you need to do if you wish to determine the age of your planet.

Thermoluminisense method of dating materials

Holmes was heroic as much for the obstacles he overcame as for the results he achieved. By the 1920s, when he was in the prime of his career, geology had slipped out of fashion – physics was the new excitement of the age – and had become severely underfunded, particularly in Britain, its spiritual birthplace. At Durham University, Holmes was for many years the entire geology department. Often he had to borrow or patch together equipment in order to pursue his radiometric dating of rocks. At one point, his calculations were effectively held up for a year while he waited for the university to provide him with a simple adding machine. Occasionally, he had to drop out of academic life altogether to earn enough to support his family – for a time he ran a curio shop in Newcastle upon Tyne – and sometimes he could not even afford the £5 annual membership fee for the Geological Society.

Struggles in Arthur Holmes life

The technique Holmes used in his work was theoretically straightforward and arose directly from the process first observed by Ernest Rutherford in 1904 by which some atoms decay from one element into another at a rate predictable enough that you can use them as clocks. If you know how long it takes for potassium-40 to become argon-40, and you measure the amounts of each in a sample, you can work out how old a material is. Holmes’s contribution was to measure the decay rate of uranium into lead to calculate the age of rocks, and thus – he hoped – of the Earth. But there were many technical difficulties to overcome. Holmes also needed – or at least would very much have appreciated – sophisticated gadgetry of a sort that could make very fine measurements from tiny samples, and, as we have seen, it was all he could do to get a simple adding machine. So it was quite an achievement when in 1946 he was able to announce with some confidence that the Earth was at least three billion years old and possibly rather more. Unfortunately, he now met yet another formidable impediment to acceptance14: the conservativeness of his fellow scientists. Although happy to praise his methodology, many maintained that he had found not the age of the Earth but merely the age of the materials from which the Earth had been formed.

Arthur Holmes - method of dating rocks using rate of decay of uranium to lead

Patterson began work on the project in 1948. Compared with Thomas Midgley’s colourful contributions to the march of progress, Patterson’s discovery of the age of the Earth feels more than a touch anti-climactic. For seven years, first at the University of Chicago and then at the California Institute of Technology (where he moved in 1952), he worked in a sterile lab, making very precise measurements of the lead/uranium ratios in carefully selected samples of old rock. The problem with measuring the age of the Earth was that you needed rocks that were extremely ancient, containing lead- and uranium-bearing crystals that were about as old as the planet itself – anything much younger would obviously give you misleadingly youthful dates – but really ancient rocks are only rarely found on Earth. In the late 1940s no-one altogether understood why this should be. Indeed, and rather extraordinarily, we would be well into the space age before anyone could plausibly account for where all the Earth’s old rocks went. (The answer was plate tectonics, which we shall of course get to.) Patterson, meanwhile, was left to try to make sense of things with very limited materials. Eventually, and ingeniously, it occurred to him that he could circumvent the rock shortage by using rocks from beyond Earth. He turned to meteorites. The assumption he made – rather a large one, but correct as it turned out – was that many meteorites are essentially left-over building materials from the early days of ...

Clair Patterson - dating earth to 4.55 billion years by studying meteors

Almost at once, Patterson turned his attention to the question of all that lead in the atmosphere. He was astounded to find that what little was known about the effects of lead on humans was almost invariably wrong or misleading – and not surprisingly, since for forty years every study of lead’s effects had been funded exclusively by manufacturers of lead additives. In one such study, a doctor who had no specialized training in chemical pathology17 undertook a five-year programme in which volunteers were asked to breathe in or swallow lead in elevated quantities. Then their urine and faeces were tested. Unfortunately, as the doctor appears not to have known, lead is not excreted as a waste product. Rather, it accumulates in the bones and blood – that’s what makes it so dangerous – and neither bone nor blood was tested. In consequence, lead was given a clean bill of health. Patterson quickly established that we had a lot of lead in the atmosphere – still do, in fact, since lead never goes away – and that about 90 per cent of it appeared to come from car exhaust pipes18; but he couldn’t prove it. What he needed was a way to compare lead levels in the atmosphere now with the levels that existed before 1923, when tetraethyl lead began to be commercially produced. It occurred to him that ice cores could provide the answer. It was known that snowfall in places like Greenland accumulates into discrete annual layers (because seasonal temperature differences produce slight changes ...

Clair Patterson campaign to ban Tetraethyl Lead from petrol

In 1911, a British scientist named C. T. R. Wilson1 was studying cloud formations by tramping regularly to the summit of Ben Nevis, a famously damp Scottish mountain, when it occurred to him that there must be an easier way. Back in the Cavendish Lab in Cambridge he built an artificial cloud chamber – a simple device in which he could cool and moisten the air, creating a reasonable model of a cloud in laboratory conditions. The device worked very well, but had an additional, unexpected benefit. When he accelerated an alpha particle through the chamber to seed his make-believe clouds, it left a visible trail – like the contrails of a passing airliner. He had just invented the particle detector. It provided convincing evidence that subatomic particles did indeed exist.

Invention of Particle detector by CTR Wilson

Today accelerators have names that sound like something Flash Gordon would use in battle: the Super Proton Synchrotron, the Large Electron-Positron Collider, the Large Hadron Collider, the Relativistic Heavy Ion Collider. Using huge amounts of energy (some operate only at night so that people in neighbouring towns don’t have to witness their lights fading when the apparatus is fired up), they can whip particles into such a state of liveliness that a single electron can do 47,000 laps around a 7-kilometre tunnel in under a second3. Fears have been raised that in their enthusiasm scientists might inadvertently create a black hole or even something called ‘strange quarks’, which could, theoretically, interact with other subatomic particles and propagate uncontrollably. If you are reading this, that hasn’t happened. Finding particles takes a certain amount of concentration. They are not just tiny and swift but often also tantalizingly evanescent. Particles can come into being and be gone again in as little as 0.000000000000000000000001 of a second (10−24 seconds). Even the most sluggish4 of unstable particles hang around for no more than 0.0000001 of a second (10−7 seconds). Some particles are almost ludicrously slippery. Every second the Earth is visited by ten thousand trillion trillion tiny, all-but-massless neutrinos (mostly shot out by the nuclear broilings of the Sun) and virtually all of them pass right through the planet and everything that is on it, including you and ...

Enormous Economics and size of large particle detector and accelerator - Challenges with Subatomic particles.

In the 1960s, in an attempt to bring just a little simplicity to matters, the Caltech physicist Murray Gell-Mann invented a new class of particles, essentially, in the words of Steven Weinberg, ‘to restore some economy to the multitude of hadrons15’ – a collective term used by physicists for protons, neutrons and other particles governed by the strong nuclear force. Gell-Mann’s theory was that all hadrons were made up of still smaller, even more fundamental particles. His colleague Richard Feynman wanted to call these new basic particles partons16, as in Dolly, but was over-ruled. Instead they became known as quarks.

Murray Gell-Mann - Theory of Quarks

The fundamental simplicity of quarks was not long-lived. As they became better understood it was necessary to introduce subdivisions. Although quarks are much too small to have colour or taste or any other physical characteristics we would recognize, they became clumped into six categories – up, down, strange, charm, top and bottom – which physicists oddly refer to as their ‘flavours’, and these are further divided into the colours red, green and blue.

Subdivisuon of Quark

Eventually out of all this emerged what is called the Standard Model17, which is essentially a sort of parts kit for the subatomic world. The Standard Model consists of six quarks, six leptons, five known bosons and a postulated sixth, the Higgs boson (named for a Scottish scientist, Peter Higgs), plus three of the four physical forces: the strong and weak nuclear forces and electromagnetism. The arrangement essentially is that among the basic building blocks of matter are quarks; these are held together by particles called gluons; and together quarks and gluons form protons and neutrons, the stuff of the atom’s nucleus. Leptons are the source of electrons and neutrinos. Quarks and leptons together are called fermions. Bosons (named for the Indian physicist S. N. Bose) are particles that produce and carry forces18, and include photons and gluons. The Higgs boson may or may not actually exist; it was invented simply as a way of endowing particles with mass.

Building blocks of subatomic pafticles - Quark, Gluons, Leptons and Bosons

When we last met Edwin Hubble, he had determined that nearly all the galaxies in our field of view are flying away from us, and that the speed and distance of this retreat are neatly proportional: the further away the galaxy, the faster it is moving. Hubble realized that this could be expressed with a simple equation, Ho = v/d (where Ho is the constant, v is the recessional velocity of a flying galaxy and d its distance away from us). Ho has been known ever since as the Hubble constant and the whole as Hubble’s Law. Using his formula, Hubble calculated that the universe was about two billion years old31, which was a little awkward because even by the late 1920s it was increasingly evident that many things within the universe – including, probably, the Earth itself – were older than that. Refining this figure has been an ongoing preoccupation of cosmology.

Hubble's law - Hubble constant - age of universe

Except conversationally, astronomers don’t use light years. They use a distance called the parsec (a contraction of parallax and second), based on a universal measure called the stellar parallax and equivalent to 3.26 light years. Really big measures, like the size of a universe, are measured in megaparsecs: 1 megaparsec = 1 million parsecs. The constant is expressed in terms of kilometres per second per megaparsec. Thus when astronomers refer to a Hubble constant of 50, what they really mean is ‘50 kilometres per second per megaparsec’. For most of us that is of course an utterly meaningless measure; but then, with astronomical measures most distances are so huge as to be utterly meaningless.

Parsec - very big unit of measuring distances