Martin Rees is a British astronomer and astrophysicist who looks rather like Richard Gere (see https://en.wikipedia.org/wiki/Martin_Rees); he holds or has held all sorts of high positions in British science and academia. He’s published several books, of which the half dozen that I have are rather short, because, it turns out, they are often based on series of lectures he’s given. This present 2018 book is partially based on a series of 2010 lectures (already published in a previous book).
This book was preceded by the 2003 OUR FINAL HOUR, which explored various ways humanity might be doomed, through its own actions or through various cosmic catastrophes. That and this new book look superficially similar, but this one has a broader scope.
Much of what he says is familiar, and I’ll try to highlight those points where he comes down on one side or another of some contentious issue – or where he makes some crucial issue pointedly clearly. He handily numbers the issues in each section.
His theme, stated in the preface: “the flourishing of the world’s growing population depends on the wisdom with which science and technology is deployed.”
Ch1, Perils and Prospects.
- Scientists are rotten forecasters; recall space travel is bilge comment. His earlier book was inspired by Wells, a mix of optimism and anxiety, p14.
- Natural threats exist – asteroid strikes, earthquakes etc – but haven’t changed. But new threats have arisen
- 1.2 Nuclear. Recall how close we came in the ‘60s. the threat is less only in that there are fewer nukes; but political situations can change.
- 1.3 Eco-threats. The population should level off to about 9 billion in 2050, with most living in mega-cities of 30 million or more. The issue is sustainability; means to bring that about include GMOs, insects and artificial meat, greater equality…leading to political issues.
- 1.4 The Anthropocene. Our expanding population puts pressure on the environment. Recall E.O. Wilson’s 2006 book THE CREATION: AN APPEAL TO SAVE LIFE ON EARTH; quotes p33. To save the Earth we can rely on religious allies. The Paris agreement was significant, but needed are attitude changes across the population, e.g. that conspicuous consumption is tacky. Logos help – the bear on the ice floe.
- 1.5 Climate change. No question CO2 is rising. We can agree, p41, that extreme weather events will become more common, and if ‘business as usual’ prevails, catastrophic warming could occur by the end of the century. Some, like Bjorn Lomberg [e.g. Cool It: The Skeptical Environmentalist’s Guide to Global Warming, 2007], ‘discount’ effects past 2050 and so downplay climate change.
- 1.6 Clean energy. Perhaps we can smoothly transition to other forms of energy. Three win-win measures should be agreeable to everyone: 1, improve energy efficiency, and save money; 2, target cuts of secondary polluters, like methane; and 3, expand R&D to all forms of low-emission energy. Electric cars; solar power; geothermal; tides, etc., have different niches of effectivity. More advanced nuclear plants.
- What will actually happen? Most likely, by 2050 not much will have been done, but models will have improved so we know much more about specific effects and where to take action. Controversial is ‘geo-engineering’ e.g. placing reflective aerosols in the atmosphere, etc.; these would be hard to control and politically dangerous.
Ch2, Humanity’s Future on Earth
- 2.1 Biotech. The advances of biotech, of cheaply sequencing the genome. Ethical issues of measures to take in extreme old age, or about nonviable infants. Issues about assisted dying, antibiotics, the dangers of biohacking. Mentions a 2003 bet with Steven Pinker about whether a bio error or terror would cause a million deaths by 2020. Potentials to create new organisms as with a chemistry set, and Silicon Valley notions to preserve youth or save people through cryonics.
- 2.2 Cybertechnology, Robots, and AI. The penetration of the internet and web services has been faster than anyone expected. Example of how technology can improve lives around the world. Indians use iris recognition. Such applications use machine-learning enhanced by increased computer power and brute force data crunching. DeepMind and AlphaGo, chess masters. They consume lots of power. And such machines can make decisions for reasons we can’t necessarily understand. And there are privacy concerns.
- 2.3 What About Our Jobs? So will the new machine age create as many jobs as it destroys? Machines can replace many kinds of jobs; others, like plumbing and gardening, not. How about truck drivers? There is debate about whether automated vehicles would be desirable. Driving, and airline flight, has gotten amazingly safer. Arguments on both sides. Would driverless cars replace train use? [[ Harari addresses such issues. ]]
- And issues of universal income [see Rutger Bregman, UTOPIA FOR REALISTS]; perhaps subsidizing some types of jobs would work better. Such as caregivers, which is where the wealthy spend their money. Workweeks could be shortened. Arts and crafts will resurge. Life-long learning via online courses. Yet people in disadvantaged parts of the world will see what they’re missing. Migration patterns will change. International tensions will rise. [[ This is already happening and our politicians don’t realize this. ]] There are concerns about automated weapons and killer robots.
- 2.4 Human Level Intelligence? No consensus about prospects. Machines can’t interact with people as fast as they can run simulations. Questions about goals and common sense. If humans can ‘download’ their thoughts, what about personal identity? Some say it doesn’t matter whether machines can ‘think’. Once a machine becomes more intelligent than humans, that would be the last invention humans need make. The singularity. Even if it takes centuries, that’s very fast in evolutionary terms.
- 2.5 Truly Existential Risks? We depend on elaborate networks. A collapse would be global. It could lead to the collapse of civilization. Are there other such extreme risks? Perhaps particle research could trigger the destruction of earth, or the universe. Conversion of quarks into strangelets. Or conversion of space into some other phase. Such possibilities are beyond current experiments. We may not understand the risk for such events. Should physicists avoid such potentially catastrophic experiments? We might consider the threat to all possible future people. These issues raise ethical concerns, and questions about the extent we can understand the physical world…
Ch3, Humanity in a Cosmic Perspective
- 3.1 The Earth in a Cosmic Context. Recalls Apollo 8, Sagan’s pale blue dot. Darwin. We understand Darwin’s ‘simple beginning’ as going back 4.5 billion years. P122. We’ve learned much in recent decades; and the public is fascinated. Everyone wonders about life on other worlds; aliens. From the 17th to 19th century it was supposed even planets in our solar system were inhabited—on theological grounds, p126. [[ I did not realize this supposition was so wide-spread. ]] All the way up to the supposed Martian canals. The space age revealed the truth. Europa, perhaps Mars, are still chances. Knowing of one other independent example would change our conception of the universe.
- 3.2 Beyond Our Solar System. We now know that most stars are orbited by planets. How they are detected p130. Kepler. New large telescopes have the potential to see these planets directly. We estimate a billion earth-like planets in the galaxy. And the problem of the origin of life is seeming tractable.
- 3.3 Spaceflight—Manned and Unmanned. Recalls childhood and watching the early spaceflights. The space station is anticlimactic. Unmanned satellites abound. And tiny satellites are being developed for continuous monitoring and exploring the solar system. Settlements on the moon, or a telescope, might still happen. NASA has been risk averse. Maybe the Chinese. Or privately funded. Author would not favor NASA missions—rather let them be by private companies and volunteers. Not space tourism—they are not low risk. Space travel would be more efficient with nuclear power, or by space elevator, or solar sails. But author doesn’t foresee space colonies on Mars; they’re no escape from Earth’s problems.
- 3.4 Toward a Post-Human Era? Such explorers would have greater incentive to redesign themselves. They will spearhead the posthuman era. It might be easier to survive weightless in zero-g, if transitioning to inorganic intelligence, and far surpass their biological ancestors. But would they be conscious? In any case, they would live long enough to spread throughout the galaxy. We humans would have started it.
- 3.5 Alien intelligence. But is there alien intelligence out there already? Life might be common, but not advance life, due to various evolutionary bottlenecks. SETI is still worthwhile, because the stakes are high. By the arguments above, such contact might well be with electronic brains. And such signals might easily be accidental and incomprehensible. We would understand only the small subset of messages that came from creatures like ourselves. We would likely be able to understand them, but communication would be slow. We might also look for artificial molecules, or Dyson spheres. Even objects in our solar system. Two maxims, 162.6 [ worth quoting: “Extraordinary claims will require extraordinary evidence” and “Absence of evidence isn’t evidence of absence”. Whatever happens, it seems our cosmic habitat has been designed, or tuned, to be an abode for life.
Ch4, The Limits and Future of Science
- 4.1 From the Simple to the Complex. The most useful ‘tweet’ to send to some past scientist would be how everything is made up of only 100 or so atoms. Complexity emerges from simple underlying laws. John Conway’s Game of Life, in 1970. Mandelbrot used PCs to generate fractals. It’s been noted how remarkable it is that the universe is comprehensible through mathematics. Dirac realized that following where math leads, led to discoveries in the real world. Hypercomputers might simulate entire universes.
- 4.2 Making Sense of Our Complex World. Paradoxically the whole is sometimes more easily understood than the tiny parts; eclipses vs. weather. Complexity can be measured by the length of a full description of it, 172b. Crystals are simple. Even stars, and black holes, are simple. Silicon chips and living things are complex. It takes 3 billion links of DNA to generate a human. Our brains are the most complex things we know. Some complexities are understood via simple rules—e.g. evolution by natural selection to explain the diversity of life. Science is a hierarchy from particle physics to the human sciences. The ones at the bottom are most fundamental; scientists are reductionists. At the same time, macroscopic systems have ‘emergent’ properties that are best understood by concepts at those levels. Complexity emerges. P177. [ This recalls Sean Carroll’s levels of complexity. ]
- 4.3 How Far Does Physical Reality Extend? By the time the sun dies, in 6by, witnesses will be utterly unlike us. Consider the future over astronomical timescales. In 4by our galaxy will merge with Andromeda. Expansion will leave our Local Group alone in view. Dyson figured the maximum thoughts would be conducted at low temperatures and slowly. Understanding ‘empty’ space, string theory, the idea of the multiverse. In a finite universe some rare events will almost never happen. But if the universe is very big, everything could happen—it would have to be 10 to the power 100, a googol. Even that may be just a component of a multiverse. Our local concept of reality would be constricted as a plankton in a spoonful of water. Would all these universes have the same physics? Perhaps we will have these answers in another 50 years. Such ideas have shifted since author’s 1997 book Before the Beginning. Frank Wilczek has been involved…
- 4.4 Will Science ‘Hit the Buffers’? Science keeps expanding; there are always unknown unknowns. But are there things we’ll never know because our brains are incapable of understanding them? Perhaps, just as monkeys are unaware of stars and galaxies. And aliens might have different perceptions of reality. P190. Already we can do virtual experiments inside computers. Computers might make their own discoveries. E.g. to find superconductors, or new drugs. David Deutsch takes a different view, in The Beginning of Infinity—anything can be computed. That doesn’t mean understood. We can understand simple equations without realizing what patterns they describe. “Some fundamental truths about nature could be too complex for unaided human brains to fully grasp.” P193.7 [[ This touches a science-fictional speculation: would alien intelligence perceive things we could not? Surely we perceive things dogs cannot, despite allowing a certain degree of intelligence to dogs. ]]
- 4.5 What About God? A question commonly asked of astronomers. Author does not believe in God, “but that I share a sense of wonder and mystery with many who do.” We learn from science that even the basic atom is quite hard to understand. “This should induce skepticism about any dogma, or any claim to have achieved more than a very incomplete and metaphorical insight into any profound aspect of existence.” Creationists; can’t even refute the claim that the universe was created an hour ago, 195.7. Intelligent designers find details that remain mysterious and ‘explain’ them by invoking supernatural intervention. But such explanations are useless if they don’t integrate various phenomena to unifying principles. Gravity was the first. Recall Paley; now we have John Polkinghorne who claims the fine-tuning of the cosmos to be the creation of a Creator. Author often wonders about the ‘bottom line’ for a follower of some faith. Author is a practicing but unbelieving Christian; he participates in the rituals of the Anglican church. Hard-line atheists spend too much time seeking evidence of the supernatural in the physical world; they drive away potential scientists, 200t. Most religions prioritize ritual over belief, rituals that bind communities.
- Can we narrow the gap between the world as it is, and the world we’d like to live in?
- 5.1 Doing Science. Summary. What is the role of scientists? By science, technology and engineering is included. The notion of the scientific method should be put to rest; scientists think like everyone else. A few philosophers resonate with scientists. Karl Popper, that a theory should be refutable. Medawar thus dismissed Freudian psychoanalysis. But interpretation depends on context, p204. And judgment applies how compelling contrary evidence might be.
- Then there’s Thomas Kuhn, with his idea of paradigm shifts. But that idea is overused; Einstein didn’t overthrow Newton; he transcended him.
- The sciences are as diverse as sports. Some projects require international cooperation. Varieties of scientific work. Conventional wisdom is that scientists ‘burn out.’ But there are three destinies for a scientist: diminished research; unwise diversification into other fields; or to continue to do what one is competent at, accepting that some new ideas are better assimilated by the young. Very few are late-flowering exceptions. But the demographics are changing. The expansion of wealth and leisure might lead to a resurgence of citizen-scientists.
- 5.2 Science in Society. Our future depends on making wise choices—but not just by scientists. We need a better educated public. Science is the one culture that’s global. The key ideas of science can be accessed by everyone. The public is still in denial about two kinds of threats: the collective harm to the biosphere, and the vulnerability of our interconnected world. Unlike past ‘collapse’ events, a collapse could be global. No one understand the smartphone, or even basic iron age technology; thus Lovelock, and Lewis Dartnell’s book The Knowledge. We need to better assess global hazards and plan outside the short-term interests of politicians. We may need global organizations outside the sovereignty of nations, like the AEA, WHO. Issues about nation-states, threats to security, regulations. And gaps in wealth must be addressed…
- 5.3 Shared Hopes and Fears. Scientists should be aware of the consequences of their experiments. Atomic scientists in the past. Rachel Carson and Carl Sagan were preeminent concerned scientists. Etc. The Long Now Foundation, 224b.
- It’s easy to seem pessimistic. Threats have to be tackled internationally. Planning needs to be long-term, and global. Quote by Peter Medawar: “The bells which toll for mankind are—most of them anyway—like the bells on Alpine cattle; they are attached to our own necks, and it must be our fault if they do not make a cheerful and harmonious sound.”