Human Universe - Brian Cox, Andrew Cohen (2014)

WHAT IS OUR FUTURE?

I can hardly wait

To see you come of age

But I guess we’ll both just have to be patient

’Cause it’s a long way to go

A hard row to hoe

Yes it’s a long way to go

But in the meantime

Before you cross the street

Take my hand

Life is what happens to you

While you’re busy making other plans

John Lennon

MAKING THE DARKNESS VISIBLE

They must have descended into the darkness for a reason. Their burning dry-grass torches would have filled the caverns with acrid smoke, sucking the oxygen from the wet air. They would have moved carefully, fearfully perhaps, enveloped in a dim, flickering sphere of red, fading into a profound silent dark, the like of which I don’t experience. A child held her hand against the rock, and blew a red-pigmented mixture across it with a straw. She smiled – ‘my hand’. Her companions reached into the pigment and, in careful movements, inked a line of dots beside the handprint. The precision of a young imagination. A retreat to the lightness of the cave mouth. ‘Perhaps we’ll come back someday,’ she thought.

Over 40,800 years later, I held my hand next to hers, because the experts on the Upper Paleolithic told me that the handprints are always those of children, and most likely always female. El Castillo in northern Spain contains some of the oldest cave-art in the world. It is not known precisely how old, because the pigments themselves cannot be dated. The art is covered in calcite, which dripped and crystalised across the handprints and dots as the whole of recorded history played out above. Calcite contains uranium-234 atoms, which decay with a half-life of 245,000 years into thorium-230, which in turn decays with a half-life of 75,000 years. Thorium is not soluble in water, so there was none when the limestone formed. By measuring the concentrations of the uranium isotopes 234 and 238, and the thorium-230, a precise date for the formation of the calcite can be measured. This gives a minimum date for the art, since of course it must have been created before it was covered. The limestone covering the red dots formed 40,800 years ago. The oldest handprint was covered 37,300 years ago.

These dates are significant, because before 41,000 years ago there is no evidence of modern humans in Europe. Homo sapiens arrived tantalisingly close to the minimum age of the art in the darkness of El Castillo, leading some anthropologists to suggest that the art is not human. Rather, it may have been created by our close cousins, the Neanderthals, who dominated Europe at the time. I find this possibility profoundly interesting, and moving. It is interesting because the creators of this art had all the attributes that we might lazily refer to as ‘uniquely human’. The retreat into the deep caves was undoubtedly a sophisticated response to the world. This is not mere decoration, because cave-art like this is not found near the cave entrances where these ‘people’ lived. Its creation is highly ritualised. The darkness is integral. One of the most beautiful pieces in El Castillo is a bison, half-carved out of a column of rock and shaded with pigments to emphasise the arch of its back. When illuminated by torchlight, the rock casts a flickering, animal shadow onto the cave wall. The interaction of light and dark was important to the rituals carried out here before history, perhaps before humans. The cave resonates with ideas, curiosities and fears. It represents a border; the transition from existence to living. If this is a human place, it is a record of the first stumbling steps towards humanity. But if it is Neanderthal, it is a record of an ending, an ascent cut short. ‘Perhaps we’ll come back someday,’ thought the little girl in my imagination. Not long afterwards, her species became extinct, out-competed by their incoming cousins. Perhaps. It is possible that the date coincides with the migration of Homo sapiens into Europe because the art is indeed human. Some anthropologists believe that the art may have been a response to the native Neanderthal population; a sort of prehistoric shock and awe, asserting cultural dominance and engendering a sense of community and superiority in the nascent human population. Things never change. If this is the case, the Neanderthals inadvertently played a role in our ascent. The roles may have been reversed, however. Perhaps our ancestors found a young, emerging and more sophisticated culture when they crossed the Mediterranean. A species distantly related to us whose desire to explore the darkness we assimilated. Perhaps our intellectual climb was, in part, a response to them. Intellectual superiority does not guarantee survival; witness the fall of classical civilisation.

Yet from those flames, no light; 
but rather darkness visible.

John Milton.

Paradise Lost 1, 63.

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This possibility is illustrative of a fact that we modern humans often subconsciously rest in the shadows. Things can end, for ever. Species become extinct, and that doesn’t only apply to animals with feathers and no feelings. The Neanderthals became extinct, and they may have begun to imagine a future before they lost it. The red handprints of El Castillo are overwhelming in this context. Go there. Hold your hand up to hers, hear the giggles, picture the smiles, imagine the beginnings of hope, and listen to the silence.

At least 40,800 years later, we can use our knowledge of nuclear physics to move backwards through time to piece together her story. Science is a time machine, and it goes both ways. We are able to predict our future with increasing certainty. Our ability to act in response to these predictions will ultimately determine our fate. Science and reason make the darkness visible. I worry that lack of investment in science and a retreat from reason may prevent us from seeing further, or delay our reaction to what we see, making a meaningful response impossible. There are no simple fixes. Our civilisation is complex, our global political system is inadequate, our internal differences of opinion are deep-seated. I’d bet you think you’re absolutely right about some things and virtually everyone else is an idiot. Climate Change? Europe? God? America? The Monarchy? Same-sex Marriage? Abortion? Big Business? Nationalism? The United Nations? The Bank Bailout? Tax Rates? Genetically Modified Crops? Eating Meat? Football? X Factor or Strictly? The way forward is to understand and accept that there are many opinions, but only one human civilisation, only one nature, and only one science. The collective goal of ensuring that there is never less than one human civilisation must surely override our personal prejudices. At least we have come far enough in 40,800 years to be able to state the obvious, and this is a necessary first step.

‘We’ve woken up at the wheel of the bus and 
realised we don’t know how to drive it’

SUDDEN IMPACT

On 15 February 2013 at 9.13am a 12,000-tonne asteroid entered Earth’s upper atmosphere travelling at 60 times the speed of sound. It came from the direction of the Sun, so there was never any chance of seeing its approach. The rock broke up at an altitude of 29 kilometres, depositing over twenty times the energy of the Hiroshima bomb into the sky above the Russian town of Chelyabinsk. Thousands of buildings were damaged by the shockwave and 1500 people were injured, mainly by flying glass as windows smashed in multiple cities across the region. Sound waves from the explosion rattled around the globe twice, and were detected by a nuclear weapons monitoring station in the Antarctic. The Russian parliament’s foreign affairs committee chief Alexei Pushkov took to Twitter: ‘Instead of fighting on Earth, people should be creating a joint system of asteroid defence.’ Naïve idealism? Overreaction? Hollywood? Not really. Sixteen hours later, a 40,000-tonne asteroid named 367943 Duende streaked by at an altitude of 27,200 kilometres, well within the orbits of many of our satellites, although it missed them all. This one had a name, because it was discovered by astronomers in Spain in 2012. There is a 1 in 3000 chance that Duende will strike the Earth before 2069; if it does, it could destroy a city, which isn’t too bad.

Before Chelyabinsk, the last recorded large impact was the Tunguska event over Siberia in 1908. The shockwave created by the airburst flattened 2000km2 of forest in an energy release close to that of the United States’ most powerful hydrogen bomb test at Bikini Atoll in March 1954. Events on this scale are thought to occur on average once every 300 years, and could easily wipe out a densely populated region. The best-known impact in popular culture was the Chicxulub event in Mexico’s Yucatan Peninsula 66,038,000 ± 11,000 years ago, which wiped out the non-avian dinosaurs. Precision is important when available. If they’d had a space programme, Carl Sagan once quipped, or perhaps lamented, the dinosaurs would still be around, although in that case we wouldn’t. The Chicxulub asteroid was probably around 9.5 kilometres in diameter, and the energy release of such an object exceeds that of the world’s combined nuclear arsenal by a factor of a thousand. Or, if you like scary statistics, that’s 8 billion Hiroshima bombs. Such events are estimated to occur on average every 100 million years, give or take, and are quite capable of destroying human civilisation and possibly causing our extinction. At the other end of the scale, rocks of around a millimetre in diameter hit the Earth at a rate of two a minute.

Alexei Pushkov was right. It is absolute idiocy not to pay attention to the danger of impacts from space, and fortunately our space agencies have begun to do so. NASA’s Near Earth Object Program created the Sentry system in 2002, which maintains an automated risk table continually updated by new observations from astronomers around the world. I am writing these words on 3 September 2014, and there are currently no high-risk objects in the table, although there are 13 asteroids with the potential to impact Earth that have been observed within the last 60 days. The risk posed by an asteroid is quantified on the Torino Scale.

Every known near-Earth asteroid is assigned a value on the Torino Scale between 1 and 10, calculated by combining the collision probability with the energy of the collision in megatons of TNT (see diagram for here 1–10 of the Torino Scale). Asteroid 99942 Apophis reached level 4 on the Torino Scale in December 2004. Initial observations and calculations suggested this 350-metre-wide asteroid had a 1 in 37 chance of a potential collision with the Earth on 13 April 2029 and a further chance of hitting us seven years later if it missed first time around. This would not have been a civilisation-threatening event, but it could have laid waste to a small country. Subsequent observations have effectively ruled out the risk from 99942 Apophis, but statistically speaking such an impact is expected to occur every 80,000 years or so. Although the Sentry table is currently benign, there are at least two very good reasons why we shouldn’t relax and forget about impact risks. Firstly, we haven’t detected all of the threatening objects by any means, as the Chelyabinsk event so effectively reminded us. And secondly, we don’t currently know precisely what to do if we do observe an asteroid with our name on it, which could happen tomorrow. In 2015 a new early warning system called ATLAS (Asteroid Terrestrial Impact Last Alert Sytem) will come online.


TORINO SCALE

The Chicxulub impact, believed by many to be a significant factor in the extinction of the dinosaurs, has been estimated at 108 megatons, or Torino Scale 10. The impact which created the Barringer Crater and the Tunguska event in 1908 are both estimated to be in the 3–10 megaton range, corresponding to Torino Scale 8. The 2013 Chelyabinsk meteor had a total kinetic energy prior to impact of about 0.4 megatons, corresponding to Torino Scale 0. In all cases their impact probability was of course 1, as they actually hit Earth. As of May 2014, there are no known objects rated at a Torino Scale level greater than zero.

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Eight small telescopes will scan the sky for any sign of faint objects that may pose a threat to the Earth. ATLAS will give up to three weeks’ warning of an impact, which is enough time to evacuate a large region, but probably not an entire country. The cost of our global insurance policy? One third of the annual wages of Manchester United striker Wayne Rooney. Such comparisons always sound childish of course; I’m well aware of how capitalism functions, and I know that Wayne Rooney generates income for the Manchester United corporation in excess of his wages. But the aim of this chapter is to argue that there is a flaw in the majestic edifice of human civilisation: our myopic and cavalier disregard for our long-term safety. In my view, the reason for the shortsighted approach is that nothing catastrophically bad has happened to humanity in recorded history that we haven’t inflicted upon ourselves, unless of course you believe in Noah’s Ark, and even that was presumably down to us because one assumes that God is usually quite a patient sort. One of the central themes of this book has been to argue that the human race is worth saving because we are a rare and infinitely beautiful natural phenomenon. One of the other themes is that we are commonly and paradoxically ingenious and stupid in equal measure. I do not personally think that there is anyone out there to save us, and so it follows that we will have to save ourselves; at least, that would seem to me to be a good working assumption. This is why I don’t feel naïve, idealistic or like a particularly radical member of the Student Union in a Che Guevara T-Shirt when I ask the question ‘Is it reasonable to spend less on asteroid defence than on a footballer’s annual salary?’ When I look in the mirror and think about that, my face assumes an interesting shape – you should try it.

NASA is working hard in the face of apathy to do something to close the gap between the capabilities of the dinosaurs and us. Twenty metres beneath the surface of the Atlantic Ocean, 8 kilometres off the coast of Key Largo, Florida, is the Aquarius Reef Base. Originally constructed as an underwater research habitat to study coral reefs, it is used by NASA to train astronauts for future long-duration space missions. The base allows for saturation diving, which greatly increases the length of time a researcher can spend exploring the reefs. On a normal scuba dive, a diver can spend a maximum of 80 minutes at a depth of 20 metres without having to go through decompression. The diver can remain at this pressure for several weeks, however, as long as they decompress when they return to the surface – a process that takes almost a day. Since the air pressure inside Aquarius is the same as the pressure outside in the water, researchers living inside the base can spend many hours a day exploring the sea bed using standard scuba equipment, but with the important caveat that they cannot return to the surface a few metres above their heads. If anything goes wrong, they must return to Aquarius and deal with the problem inside the base. For all practical purposes, therefore, they are isolated; it’s not possible to panic or simply loose patience and return to civilisation above. This is why NASA uses the Aquarius base to train astronauts to work in a hostile environment and test their psychological suitability for long-duration space missions.

Filming inside Aquarius was a personal highlight of Human Universe. We didn’t want to have to decompress of course, so we had a strict time limit of 100 minutes inside the base spread over two dives. The ex-US Navy diver in charge of our dive was wonderfully clear as far as timings were concerned. ‘If I say leave, you don’t smile and take one more shot – you leave! Otherwise you stay, for a long time. Your choice. I know you media types.’ Aquarius has the look and feel of a spacecraft from a science fiction film. There are six bunk beds piled three-high at one end, and a galley area complete with microwave and sink at the other. In between, there are control panels, some books on marine life, and a laptop computer station. Above the table, there is a single round window looking out across the reef. Through an air-lock-style exit, there is a dive platform with access to the scuba tanks and the open sea. NASA’s Extreme Environment Mission Operations (NEEMO) team had just completed a nine-day mission when we arrived. Led by Akihiko Hoshide of the Japanese Aerospace Exploration Agency, the mission was part of the long-term goal of landing astronauts on an asteroid, and developing the capability to deflect one, should the need arise. There are strong scientific and commercial reasons for exploring asteroids: they are pristine objects that will allow us to better understand the formation of our solar system over 4.5 billion years ago, and rich in precious metals precisely because they are pristine. On Earth, heavy metals such as palladium, rhodium and gold migrated into the Earth’s core, leaving the accessible crust depleted. Asteroids are too small to have separated in this way, leaving the primordial abundances of these valuable metals untouched and accessible.

Whether for commercial, scientific or practical reasons, learning how to land on asteroids, exploit their resources and manipulate their orbits is clearly an eminently sensible thing to do. And make no mistake, we will have to move one at some point.

SEEING THE FUTURE

In the year 35,000 CE the red dwarf Ross 248 will approach the solar system at a minimum distance of 3.024 light years, making it the closest star to the Sun. Nine thousand years later it will have passed us by, ceding the title of nearest neighbour to Proxima Centauri once again. Coincidently, in 40,176 years, Voyager 2 will pass Ross 248 at a distance of 1.76 light years. We know this because we can predict the future.

We’ve encountered Newton’s laws several times in this book. In Chapter 3 we used them to calculate the velocity of the International Space Station in a circular orbit around the Earth. At a distance r from the centre of the Earth, the velocity v is

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Let’s look at this equation in a different way by rewriting it as

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Here, we’ve used the notation of calculus. That may strike fear into your heart if you haven’t done any mathematics since school, but don’t worry. All we need to know is the meaning of the symbol

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In words, this denotes the rate of change of the position of the space station with respect to time, otherwise known as its velocity v. You have an intuitive feel for this even if you’ve never done any mathematics. If you get into your car and drive it away from your house in a straight line at a velocity of 30 kilometres per hour, then in one hour you will be at a position 30 kilometres away from your house in the direction in which you drove the car. The equation is telling us what the position of the Space Station will be at some point later in time, given knowledge of where it is and how it is moving in the present. It predicts the future. This sort of equation is known as a differential equation. In Chapter 4 we wrote down the ‘rules of the game’ – Einstein’s General Theory of Relativity and the Standard Model of particle physics. The notation is a little more complicated, but in the Standard Model you’ll notice the symbols Dµ and δµ, which are more complicated versions of

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In Einstein’s equations, there are also these so-called derivatives hidden away in the compact mathematical notation. The known fundamental laws of physics all function in this way. Given knowledge of how some system or collection of natural objects is behaving now, we can compute what they will be doing at some time in the future. The system in question may be a solar system, a collection of atoms and molecules, or the weather. There are practical limitations, of course, and the weather forecast is a good example. Earth’s climate system is very complicated, with many hundreds of thousands of variables. Ocean currents in the Pacific might affect future rainfall in Oldham, and so long-term forecasting of local weather conditions comes with increased uncertainty.

People do of course make statements, often based on human experience rather than science, which are more likely to be right than wrong. Red sky at night, Shepherd’s delight. Red sky in the morning, Shepherd’s warning. This is often true in countries like the UK whose weather is dominated by westerly winds, because a red sunset is usually a sign of high pressure to the west, which is associated with fine weather. But if you’re doing well in a statistically significant sense using ‘folklore’ or ‘ancient wisdom’, it’s because the patterns and regularities you are using to make your predictions emerge from underlying physical laws, which are described by differential equations. The laws of physics in essence reflect the underlying simplicity of nature and the regularity with which it behaves. They are not magic. We can describe the natural world using mathematics because it is regular and behaves consistently. It is my opinion that we must observe a universe that behaves in a regular and consistent way because such behaviour is necessary for complex structures like brains to evolve. A universe of anarchy, with subatomic particles interacting without some sort of framework or rules, would surely not support life, or indeed any structures at all. This is known as a selection effect. We observe a universe whose behaviour can be described by a limited set of differential equations because we wouldn’t exist if it were not so. This is my opinion, and there are scientists and philosophers who might disagree. It could be the case that there is no simple underlying framework to the universe, and our success to date has deceived us. Or perhaps the ultimate laws are and will forever remain beyond human understanding. We might simply not be smart enough to figure them out. There are also systems that cannot be described using differential equations. The patterns generated in Conway’s Game of Life are an example, where algorithmic rules are used to generate complex patterns and even computing devices such as Turing machines. But what can be said with certainty is that, as far as we can tell, the natural world does behave in a way that is amenable to a description based on the differential equations of physics, and these allow us to predict the future, given knowledge of the present. This is why our asteroid defence system will work if we make enough high-precision observations of the sky. Sort of.

Ahhh, caveats. There are always caveats.

SCIENCE VS. MAGIC

We should be confident in science. It works. But it has limitations, some of which are fundamental. We’ve encountered Newton’s laws of motion and gravitation time and again in this book. They are very simple –the archetypal physical laws – and are used every day by engineers, navigators and asteroid watchers. One of the simplest imaginable real-life systems to which Newton’s law of gravitation can be applied is a single planet orbiting around a single star. For this case, Newton’s laws allow for a precise prediction of the future position of the planet. The orbit is predictable and periodic, which is to say the planet returns to precisely the same position around the star every orbit. It’s clockwork – the way the solar system is often pictured. If a third object – a moon, say – is introduced, it was proved in the late nineteenth century by Heinrich Burns and, later, Henri Poincaré that no general solution to Newton’s equations can be found. There are a handful of special cases, which are still being discovered, for which there are repeating solutions, but in general, the orbits of three bodies acting under gravity never repeat; their motion around each other traces out a tremendous ever-changing mess! This isn’t a failure of mathematics. Natural systems really do behave in this way. The solar system is a case in point. The planets orbit like clockwork on timescales of millions of years, but we are currently unable to predict the Earth’s orbit for more than 60 million years into the future. Beyond that, the sensitivity of the predictions to uncertainties in our current knowledge of the Earth’s orbit, and the gravitational influence of other bodies in the solar system, become too great. This isn’t only a reflection of our lack of knowledge. It also reflects an important fundamental point, which is that solar systems such as ours are unstable over long timescales. Their behaviour is chaotic; the apparent clockwork can break down into a whirling unpredictable swarm. Recent simulations suggest that Mercury could be wrenched out of its orbit and collide with the Sun, and that even the Earth may have a close encounter with Venus or Mars on time periods of 3–5 billion years. The words could and may are italicised for a reason. These predictions are statistical in nature – it is estimated that there is a 1 per cent chance that Mercury will be thrown into a much more elliptical orbit during the next 5 billion years. The uncertainty is down to the extreme sensitivity of the predictions to what physicists call the initial conditions – the current knowledge of precisely where everything in the solar system is at this instant, and how everything is moving at this instant. Other errors are caused by our precise knowledge of the mass and shape of all the objects in the solar system, not to mention the slight perturbations from incoming comets and the ever-shifting asteroids. The area of physics and mathematics concerned with such systems is called chaos theory, and as the pioneer of the field Edward Norton Lorenz put it, nature’s complexity usually leads to a situation in which approximate knowledge of the present, which is in practice all we ever have, does not approximately determine the future.

Chaos: When the present
determines the future, but
the approximate present 
does not approximately determine 
the future.

Edward Lorenz


EQUINOXES AND SOLSTICES

When the Sun is crossing the celestial equator, day and night are of nearly equal length at all latitudes, which is why these dates are called the equinoxes (‘equal nights’). In March, as the Sun is moving northwards along the ecliptic, this is called the vernal equinox, and in September as the Sun is moving southwards we refer to it as the autumnal equinox. The times when the Sun is at its furthest from the celestial equator are called the summer and winter solstices. The world ‘solstice’ comes from the Latin meaning ‘Sun stands still’ because the apparent movement of the Sun’s path north or south stops before changing direction.

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For the asteroid hunters, this is an intensely problematic truth. It is not possible to observe an asteroid once, and then pop its position and velocity into a computer to work out whether it will ever hit us. Instead, a gravitational keyhole system is used. A keyhole is a small volume of space close to the asteroid’s current orbit. If an asteroid passes through the keyhole, perhaps because of a gravitational nudge from some other object in the solar system, then it is highly likely that it will impact the Earth on its next pass. 99942 Apophis was assigned such a keyhole in 2004 when it was classified at 4 on the Torino Scale. Fortunately, it didn’t pass through, and this is why it is currently classified as harmless. The keyhole system reflects the fundamental unpredictability of complex physical systems over long timescales. This is why we have to keep observing and retain a keen understanding of the fundamental limits of our calculational prowess. Science isn’t magic. This realisation is of course important in a practical sense if one is interested in saving the planet from asteroid impact. But it is also very important to embed caution and humility into our/my polemical celebration of the power of science. Scientific predictions are not perfect. Scientific theories are never correct. Scientific results are always preliminary. Whole fields of study can be rendered obsolete by new discoveries. But, I insist, science is the best we can do because it is not simply another arbitrary system of thought based on dreamt-up human axioms. It is the systematic study of nature, based on observations of the natural world and our understanding of those observations. Scientific predictions are not matters of opinion. At any given time, science provides the best possible estimate of what the future might bring, given our current understanding. The predictions may be wrong, they may be inaccurate, the errors may be fundamental in origin, but there is simply no other rational choice than to act according to the best available science, imperfect though, by necessity, its predictions will always be.

THE WONDER OF IT ALL

As of September 2014, in a population of 7.24 billion, 545 people have been to space, 24 people have broken free of the Earth’s gravitational pull and 12 have landed on another world.

In 2013 Charlie and Dorothy Duke, a retired, church-going couple from New Braunfels, Texas, reached their 50th wedding anniversary. With two grown sons and nine grandchildren, Charlie and Dottie must have celebrated a life well lived, captured in photographs adorning the walls and mantelpieces of the family home. There is one Duke family photograph, however, that holds a unique place in history. I myself have a copy of it on my wall at home, signed by Charlie, and it’s one of my favourite things. The photograph, taken in 1972, is an image of Charlie, Dottie and their two young sons Charles and Thomas when they were just six and four years old. The picture itself is of no particular note – a simple portrait of a family in 70s clothes, sitting on a bench in a garden. It’s not dissimilar to one of me and my grandad photographed at around the same time. I was in Oldham, the Dukes were in Florida.

The reason I have a copy of the Dukes’ photograph is not what it is – we are not related – but where it is. Charlie and Dorothy Duke are the only grandparents on Earth who can point their grandchildren’s eyes towards the Moon and tell them there is a photo of Grandma, Grandpa, Dad and Uncle resting on the surface.

Charlie Duke was the Pilot of Orion, the Apollo 16 Lunar Module. At the age of thirty-six he remains the youngest human ever to have walked on the Moon. Together with Commander John Young, my childhood hero, the two astronauts spent three days in late April 1972 exploring the Descartes Highlands, covering almost 27 kilometres in the Lunar Rover.

The primary scientific aim of the mission was to explore the geology of the lunar highlands. It was thought that the unique rock formations around the landing site were formed by ancient lunar volcanism, but Young and Duke’s exploration demonstrated that this explanation was incorrect. Instead, the landscape had been forged by impact events, scattering material outwards from the craters and littering the surface with glass. After three days on the lunar surface and setting a lunar land-speed record of 17km/h, Charlie Duke removed his family portrait from his spacesuit pocket, placed it on the lunar surface and snapped it with his Hasselblad. Inscribed on the back are the words ‘This is the family of Astronaut Duke from Planet Earth. Landed on the Moon, April 1972.’

I remember being four years old in Oldham when Apollo 16 was on the Moon. Forty-two years later I talked to Duke for hours in a diner in Texas, with absolutely no regard at all for the film crew trying to make Human Universe. ‘When I stepped onto the Moon it occurred to me that nobody had ever been here before. You looked out onto the most pristine desert – the most incredible beautiful place I’ve ever seen. No life, nothing like Earth, the rolling grey lunar surface with the blackness of space above.’

How ambitious was Apollo, I asked? ‘They gave us eight and a half years to do it and we did it in eight years and two months. Nobody even knew how to do it,’ replied the test pilot, who was used to doing things that nobody can do. ‘Yeah sure. Fifteen minutes in space and we’re going to land on the Moon in eight and a half years? But the remarkable part is that we did it, and I had a part in it.’ Would it be possible now? ‘No. We don’t have the manpower to do it. Four hundred thousand people and unlimited budget and you can do a lot, and that’s what we had!’ What do you say to people who criticise manned exploration? There is surely more to human exploration than just science. ‘It’s the wonder of it all,’ replied the astronaut. ‘And that’s what we bring – what manned flight brings to the human spirit, the human being – the wonder of it all. The beauty of the universe, the orderliness of the universe, and you see it with your own eyes and it just captures your imagination. Let’s see it, let’s do it and let’s discover it – that’s been the human spirit all along.’

I think Apollo is the greatest human achievement. People argue with me of course. Gil Scott-Heron wrote a song called ‘Whitey’s on the Moon’. ‘A rat done bit my sister Nell, with Whitey on the moon. Her face and arms began to swell, and Whitey’s on the moon. I can’t pay no doctor bill, but Whitey’s on the moon. Ten years from now I’ll be payin’ still, while Whitey’s on the moon.’ The economics of Apollo are interesting. As Charlie said, the budget was whatever it had to be to get to the Moon by 1970. At the peak of spending in 1966, NASA received 4.41 per cent of the federal budget, equivalent to around $40 billion today. That’s a lot of money – almost half of the United Kingdom’s annual debt interest bill. That’s meant to be sarcastic, of course. The total cost of Apollo was in the region of $200 billion at today’s prices, which is around a quarter of the cost of the UK’s bank bailout programme initiated in October 2008. That’s unfair, a City-type might splutter over a glass of Dom Ruinart, because that money was an investment in financial stability and has been repaid, give or take the odd £100 billion, which is neither here nor there. My reply would be yes, but Apollo was probably the most savvy investment in modern history. In 1989, the then US President George Bush said Apollo provided ‘the best return on investment since Leonardo da Vinci bought himself a sketchpad’. Many academic studies have been carried out, and the most commonly quoted figure is that for every $1 spent on Apollo, $7 was returned to the economy over the period of a decade. Why? Because Project Apollo was conceived and executed in a tremendously smart way, distributing high-technology jobs and R&D projects across the country. It was also unarguably inspirational, propelling thousands of kids into science and engineering. The average age in Mission Control, Houston, on 20 July 1969 when Neil Armstrong landed on the Moon was 26. The old man in charge, Gene Kranz, was 36, and the old man flying the lunar module was 35. What happened to all those brilliant engineers? They went out into the economy of course, took the technology and expertise developed for the Moon landings and invented the modern world. The kids they inspired became known as Apollo’s Children; the generation of optimists steeped in possibility who powered the United States economy through the last third of the twentieth century. The world loves this America, the one that flies to the Moon not because it’s easy but because it’s hard.

I think America has lost its way, which might seem rich from a citizen of a small island that spends more on the wages of Premier League footballers annually than it does on research into the physical sciences and engineering, including its contributions to CERN, the European Space Agency and all UK-based scientific facilities. We’ve lost our way too, and so has the world. The World Bank defines R&D as ‘current and capital expenditures (both public and private) on creative work undertaken systematically to increase knowledge, including knowledge of humanity, culture, and society, and the use of knowledge for new applications’. The United States spent 2.79 per cent of its GDP on increasing knowledge in 2012 – the UK spent 1.72 per cent. It has been estimated that the return on R&D spending in today’s world economy is approximately 40:1. Imagine what we could do if we took these figures seriously.

My grandad, sitting behind me in that 1972 family Christmas photograph, was born in 1900. He was three years old when, on 17 December 1903 at Kill Devil Hills in North Carolina, Orville Wright took the controls of the Wright Flyer and lifted off the ground for twelve seconds. He was 68 when he saw Neil Armstrong walk on the Moon. Orville Wright himself died in the year that Neil Armstrong began studying aeronautical engineering at Purdue University, Indiana. I still find it hard to believe that I have spoken to someone who was born before powered flight, and to someone who walked on the Moon. It is important to notice that this sentence can’t be followed. Someone who walked on the Moon, comma, and someone who … What? Where will the next generation of Apollo’s Children come from? Perhaps a new superpower will take America’s place as the great exploring nation. China and India, those re-emergent cradles of civilisation, have ambitions in space. As Jacob Bronowski wrote in The Ascent of Man, ‘Humanity has a right to change its colour.’ But I share his regret that the retreat of Western civilisation may leave Shakespeare and Newton as historical fossils, in the way that Homer and Euclid are. If that is the case, it will be our choice.

Two more astronauts followed Duke and Young onto the lunar surface. They left at 10.55pm GMT on 14 December 1972. Commander Gene Cernan, as he prepared to step on to the ladder of the Lunar Module, quietly spoke the final words from the Moon.

… I’m on the surface; and, as I take 
man’s last step from the surface, 
back home for some time to come – but 
we believe not too long into the future 
– I’d like to just say what I believe 
history will record. That America’s 
challenge of today has forged man’s 
destiny of tomorrow.

And, as we leave the Moon at Taurus-
Littrow, we leave as we came and, God 
willing, as we shall return, with peace 
and hope for all mankind.

Godspeed the crew of Apollo 17.

Gene Cernan, Taurus-Littrow Valley, 
14 December, 1972.

DREAMERS: PART 1

Apollo was about many things. It was about winning a race against the Soviets. It was about national pride. It was born out of fear as well as optimism. It was about laying the foundations of American dominance in the late twentieth century. It was about economic stimulus. It was about dreams. It succeeded on all fronts. Was it really about dreams? ‘Well, space is there, and we’re going to climb it, and the Moon and the planets are there, and new hopes for knowledge and peace are there. And, therefore, as we set sail we ask God’s blessing on the most hazardous and dangerous and greatest adventure on which man has ever embarked.’ I think so. Kennedy was a politician, but I believe he meant it.

So what of the dreamers now? Is the twenty-first century the era of pragmatism? The era in which we believe, because we have to, that the interests of shareholders are aligned with the interests of humanity? Innovation funds the shops on New Bond Street, but is that all? A common governmental lament is that new knowledge is not converted efficiently enough into economic growth. Is that what knowledge is for? Who pays for progress? Who should pay for progress?

Human Universe is a piece of documentary television, and this book is based on the series. Television is about stories; examples that illustrate a point. Human Universe is also at heart optimistic, because I am optimistic. I think we as a civilisation could do better, as I’m sure you’ve gathered, but it would be ridiculous to suggest that we are not doing some things right. In the final episode, we found two stories that demonstrate that long-term thinking is not dead; one almost Apollo-like in state-funded grandeur, and the other more modest but equally important. The first was a project I’d visited once before, back in 2009, known as the National Ignition Facility at the Lawrence Livermore National Laboratory in California. The aim is to make a star on Earth.

Nuclear fusion is the power source of the stars. The Sun releases energy in its core by turning hydrogen into helium. Two protons approach each other at high speed, because the core is hot. The core became hot initially through the collapse of the gas cloud which formed the Sun. Protons are positively charged, and therefore repel each other through the action of the electromagnetic force, but if they get close enough, the more powerful nuclear forces take over. The weak nuclear force acts to turn the proton into a neutron, with the emission of a positron and an electron neutrino. The proton and neutron then bind together under the action of the strong nuclear force to form a deuterium nucleus, which is an isotope of hydrogen (because it contains a single proton) with a neutron attached. Very quickly, another proton fuses with the deuteron to form helium-3, and finally two helium-3 nuclei stick together to form helium-4, with the emission of the two ‘spare’ protons. The important result in this convoluted process is that four protons end up getting converted into a single helium-4 nucleus, made of two protons and two neutrons, and the helium-4 nucleus is less massive than four free protons. This missing mass is released as energy, in accord with Einstein’s equation E=mc2, and this is why the Sun shines. The energy released in fusion reactions is colossal by terrestrial standards. If all the protons in a cubic centimetre of the solar core were to fuse into deuterium, enough energy would be produced to power the average town for a year. Or to put it another way, one kilogram of fusion fuel produces as much energy as 10 million kilograms of fossil fuel, which is approximately a hundred thousand barrels of oil, with no CO2 emissions; the waste product is helium, which can be used to fill party balloons.

Energy is the foundation of civilisation. Access to energy underpins everything, from public health to prosperity. Access to clean water is surely more fundamental, you might say, but this requires energy. Even in the most arid regions, desalination plants or deep wells can deliver water in abundance if sufficient energy is available. It isn’t, of course. Profligate energy use has a bad name today, but consider this. In every country in which the per capita energy use is greater than half the European average, adult life expectancy is greater than 70 years, literacy rates are greater than 90 per cent, infant mortality rates are low and more than one in five of the population is in higher education. The reason energy use has a bad name is not because it is bad in itself. It is good, it is the foundation of modern civilisation, and modern civilisation is a good thing. I don’t want to live on a subsistence farm, sleep in stifling heat, run the risk of dying of malaria and have no access to clean water or cutting-edge medical care. I am lucky. I live in a city, I buy all the food I want from nice shops, I have a fulfilling job in a university and I get to do research at places like CERN, which is interesting. I want everyone in the world to have choices, like I have, and that means I want everyone in the world to have access to energy, like I have. In 2011, 1.3 billion people lacked access to electricity. Yes. Energy use is good. The problem with energy is how we produce it.

The world produces more than 80 per cent of its energy by burning fossil fuels. This is expected to fall to 76 per cent by 2035 as nuclear and renewables grow in importance. Burning things is humanity’s oldest technology. The energy sector is responsible for two-thirds of global greenhouse gas emissions. The most recent scientific modelling suggests that global average temperatures will rise by around 2–2.5°C above the average of the years 1986 to 2005 by 2100. The rise could be less – as low as 1 to 1.5°C, or it could be 4°C or more. Some of the uncertainty depends on our actions, and so there are assumptions about future behaviour built into the predictions. But over 90 per cent of computer models agree that global temperatures will have increased by 2100 as a result of greenhouse gas emissions from fossil fuel burning.

Nuclear fusion, then, is a good idea. If it can be made to work in an economically viable way, it will provide limitless, clean energy for everyone. It is not the only way of achieving this goal. One can make a case for solar power, and indeed an increased contribution from other renewables and nuclear fission. But it is a possible way to solve the world’s energy problems for good, in principle, and is therefore worth exploring.

The challenge is technical rather than fundamental, in the sense that we know fusion works because the Sun does it. Fusion is difficult to achieve on Earth primarily because of the colossally high temperatures and pressures required. There are two approaches being followed, and each is Apollo-like. In Europe, a worldwide collaboration involving Russia, USA, the European Union, Japan, China, Korea and India is in the process of constructing ITER. This machine is in effect a magnetic bottle, which can store a plasma at temperatures in excess of 150 million °C – ten times that of the solar core. ITER will use deuterium and tritium, which is another isotope of hydrogen comprising one proton and two neutrons, to make helium-4. This bypasses the slow initial weak interaction in the Sun that makes deuterium out of hydrogen, making ITER a lot more efficient than our star. Deuterium is extracted from seawater, and tritium is made inside the reactor itself by irradiating a lithium blanket with the spare neutrons produced during the fusion reaction. An 800MW fusion power station of this type would consume around 300 grams of tritium fuel per day. ITER is not particularly telegenic at the moment because it is under construction and will not be commissioned until 2019. This is why we chose to focus on the US National Ignition Facility, which is already up and running.

NIF is pure science fiction; in fact, it was used as a set for Star Trek: Into Darkness. It is the world’s largest laser system by an order of magnitude. The laser delivers 500,000 gigawatts of power onto a target smaller than a peppercorn in a series of increasingly powerful hammer blows, tuned to arrive with a precision of better than a tenth of a billionth of a second. That is 1000 times the peak energy-generating capacity of the United States. This, as you can imagine, creates a bit of a bang. The peppercorn-sized target contains deuterium-tritium fuel, just like ITER. The laser pulses raise the temperature of the pellet’s gold container, and the X-ray radiation produced drives a rapid collapse of the fuel, initiating fusion. The devil is in the detail; the precise timing and duration of the laser pulses, and the shape of the gold container, all contribute to the chances of success and the efficiency of the process. Despite the tremendous engineering difficulty, in September 2013 more energy was released from a deuterium-tritium fuel pellet than the pellet absorbed, although this was only 1 per cent of the total energy input to the lasers. Nevertheless, this demonstrates that so-called inertial fusion works in principle. The inertial fusion power station of tomorrow would use far more efficient laser systems – NIFs are now more than a decade out of date – and the fuel pellet technology being developed by NIF. The technology has been demonstrated to work, at least on a vast, government-funded research scale, and this is how difficult things like space exploration have to begin. Commercial companies will rarely take such enormous risks, and this means that we, the taxpayers, must pay for the creation of this type of knowledge. As with Apollo, we will be repaid, but the investment horizon is beyond that of the average accountant.

It therefore appears that there is no technical reason why such power stations could not be constructed. There is much research to be done, but the barriers are likely to be budgetary rather than fundamental; the United States spends more on pet grooming than it does on fusion research. There is a serious point behind that cheap shot. I think one of the primary barriers to progress is education. I am a believer in the innate rationality of human beings; given the right education, the right information and the right tuition in how to think about problems, I believe that people will make rational choices. I believe that if I said to someone: ‘Here’s the deal. You can have limitless clean energy for your lifetime, for your children and grandchildren’s lifetimes and beyond, in exchange for grooming your own cat’, then most people would reach for a comb. I have to believe that, otherwise this book is a futile gesture.

DREAMERS: PART 2

The second of our stories couldn’t be more different. It involves no high technology and very little cash, but it may have a tremendous impact. Securing the future isn’t all about money; it’s also about action.

The Svalbard Global Seed Vault is modest and beautiful from the outside. In common with all publicly funded construction projects in Norway, the simple door on an Arctic hillside is a work of art, created by Dyveke Sanne. In the summer, it reflects the eternal Sun. In winter, fibreoptic cables shine in the perpetual night. The doorway leads into a converted coal mine, deep in the permafrost. There are three caverns, each maintained at a temperature of -18°C by a cooling system. The temperature was chosen very precisely; it is the temperature at which seeds metabolise slowly, but do not die. At -18°C, the most hardy seeds remain viable for over 20,000 years. Only one of the caverns is in use; the other two are for the future. Inside, there are over 800,000 populations of seeds from almost every country in the world. All the seeds are agricultural crop varieties – the raw material for and the foundation of global food production. Seeds from America and Europe nestle next to those from Asia and Africa. Syrian seeds, rescued from the recent troubles in Aleppo, the home of a local seed bank, sit beside those from North Korea, South Korea, China, Canada, Nigeria, Kenya, and so on around the world. The vault contains virtually the whole history of human agriculture, stretching back to its origins in the Fertile Crescent all those years ago. Each seed population reflects some choices that were made, some environmental challenge or perhaps simply the taste of a farmer or his village. There are varieties manipulated by multinationals, or carefully cultivated and cherished by isolated tribes. The boxes are food for the imagination, time capsules, the stuff of dreams. They are also of fundamental importance.

Why protect agricultural seeds? The answer is that biodiversity is a very good thing. Life on Earth forms a tangled web, a great genetic database distributed across hundreds of thousands of extant species of animals, plants, insects and countless single-celled organisms. The more species there are, the more data there is in the database, and the more chance the whole biosphere has of responding to challenges, be they from disease, natural or human-induced climate change, loss of natural habitat or whatever. This is obvious. If there are genes somewhere in the great database of life that allow wheat to grow with less water, and the climate becomes more arid, then those genes will be valuable to us. If we lose particular genes, then we lose them for good. Today, fewer than 150 species of crop are used in modern agriculture, and 12 of these deliver the majority of the world’s non-meat food supply. There is diversity in the form of different varieties, of course; there are estimated to be more than 100,000 varieties of rice. But the overwhelming majority of crop species used throughout human history are no longer cultivated. They are stored, however, in seed vaults, ready for use if needed. The Svalbard Global Seed Vault is a back-up; our insurance policy, ensuring that even if countries lose their seed vaults through natural disasters, war or simple neglect, then irreplaceable parts of the great genetic database of life will not be lost with them.

The Norwegian government owns the seed vault, but the depositors own the seeds. A charitable trust, the Global Crop Diversity Trust, meets most of the operating costs through an endowment fund. Cary Fowler was the executive director of the Trust during the establishment of the seed vault. He was a pleasure to speak to when we filmed in Svalbard – a dreamer, yes, but a dreamer who gets things done.

‘Those of us in my field, we live in a world of wounds,’ said Fowler. ‘We see the injuries, we see the loss of diversity, the extinction, and at a certain point, enough is enough, and you try to figure out what can we do that’s not just stop-gap? That really is long term and that puts an end to the problem of crop diversity. Because we know that we are going to need this crop diversity in the future, it’s the biological foundation of agriculture. We’ll need it as long as we have agriculture.’ Which is as long as civilisation exists, I added. Fowler nodded. ‘After that, we won’t be bothered, will we!’

The Svalbard Global Seed Vault is built, effectively, for eternity, or at least for tens of thousands of years. It is supported by practically all the governments of the world, and is a genuine investment in our future based on sound science and an understanding of the potential challenges and risks that we may face as a single, global civilisation. It’s not big, flashy or expensive, but it’s important and, perhaps as importantly, somebody actually did it. I find that inspiring.

So where does all this leave us? All I can do is give you my view. I want to be honest. We didn’t set out to make a love letter to the human race when we started filming Human Universe. We set out to make a cosmology series, documenting our ascent into insignificance. Things changed gradually as we chatted, debated, experienced, photographed and argued our way around the world, and we realised that, for all our irrational, unscientific, superstitious, tribal, nationalistic, myopic ignorance, we are the most meaningful thing the universe has to offer as far as we know, and when all is said and done, that’s a significant thing to be. It is surely true that there is no absolute meaning or value to our existence when set against the limitless stars. We are allowed to exist by the laws of nature and in that sense we have no more value than the stars themselves. And yet there is self-evidently meaning in the universe because my own existence, the existence of those I love, and the existence of the entire human race means something to me. I think this because I have had the remarkable luxury of spending my time in education. I teach, I am taught, I research and I learn. I have been fortunate. I believe powerfully that we who have the power should strive to extend the gift of education to everyone. Education is the most important investment a developed society can make, and the most effective way of nurturing a developing one. The young will one day be the decision makers, the taxpayers, the voters, the explorers, the scientists, the artists and the musicians. They will protect and enhance our way of life, and make our lives worth living. They will learn about our fragility, our outrageously fortunate existence and our indescribable significance as an isolated island of meaning in a sea of infinite stars, and they will make better decisions than my generation because of that knowledge. They will ensure that our universe remains a human one.

THE END

What a piece of work is a Man. So certain, so vulnerable, so ingenious, so small, so bold, so loving, so violent, so full of promise, so unaware of his fragile significance. Someone asked me what they thought was a deep question: What are we made of? Up quarks, down quarks and electrons, I answered. That’s what a Man is. Humanity is more than that. Our civilisation is the most complex emergent phenomenon in the known universe. It is the sum of our literature, our music, our technology, our art, our philosophy, our history, our science, our knowledge. I have a recording of Mahler’s Ninth Symphony conducted by Bruno Walter made on the eve of the Anschluss. It is suffused with threat. Walter and the Vienna Philharmonic knew what was coming. Hope fades with the last vanishing note, which Mahler marked ‘ersterbend’ – ‘dying’ – in the manuscript. It is Mahler’s farewell to life, presaging Old Europe’s farewell to peace. None of this depth is present in the physical score itself; those black ink dots on white paper can be digitised using a scanner and stored in a few kilobytes on a mobile phone. The fathomless power of the recording emerges from a finite collection of bits because the performance contains the sum total of the fears, dreams, concerns and anxieties of a hundred lives, played out against a backdrop of a million more. The personal history of each of the musicians, the conductor and the composer, and indeed the history of civilisation, hangs upon the supporting framework of the notes, resulting in a work of infinite complexity and power, because each human being is possessed of infinite faculties, emergent from a finite number of quarks and electrons. Our existence is a ridiculous affront to common sense, beyond any reasonable expectation of the possible based on the simplicity of the laws of nature, and our civilisation is the combination of seven billion individual affronts. This is what my smiling seems to say: Man certainly does delight me. Our existence is necessarily temporary and our spatial reach finite, and this makes us all the more precious. Mahler’s great farewell to life can also be read as a call to value life with all your heart, to use it wisely and to enjoy it while you can.