What do you think?
Rate this book
320 pages, Hardcover
Published October 18, 2022
‘What’s the point of this story? Well, like Apollo 13, we can think of planet Earth as a damaged spacecraft hurtling through the emptiness of space. Unlike Apollo 13—planet Earth holds many billions of human astronauts—Planet Earth has not been damaged because of some design flaw, as was the case for Apollo 13; it has been damaged by its astronauts.’
‘This strikingly paralleled strategies on tackling climate change: try to cut emissions and get to net-zero as quickly as possible, or do little that might threaten economic growth. As far as I could tell, those who advocated minimal restriction to the economy during the pandemic tended to also advocate minimal restrictions on the use of fossil fuels.’
‘As with global warming, this means that the expected number of deaths cannot be reliably estimated using a model simulation run with the most likely values of the uncertain parameters—The expected number of deaths is higher than the number predicted using the most likely values of the parameters. In the case of the second, more laissez-faire policy, the estimated cumulative number of deaths at day three hundred using the most likely value of the parameters is around 25,000. However, the expected number of deaths based on the full ensemble with perturbed parameters is significantly larger than this, around 40,000.’
‘—exascale computing would be needed to even contemplate building a digital ensemble of planet Earth, and perhaps it won’t really be a serious option until we have zettascale computers, capable of performing one billion trillion computations a second—quantum computers, or photonic processors as well as silicon processors, and high-performance low-power imprecise chips that produce noise in hardware—And since handling uncertainty underpins all sciences, the project to build a digital ensemble of global society would bring together the various approaches to representing uncertainty that have developed in the different subdisciplines. This project really would recognise the primacy of doubt.
A first step in this direction is the European Union’s Destination Earth (DestinE) project4. Evolving from an earlier EU flagship project proposal, ExtremeEarth, that some colleagues and I developed a few years ago—DestinE is the first step towards building a digital ensemble of global society. Sadly, the UK having left the EU5, UK scientists will not be contributing to DestinE.’
‘The mathematician and physicist John von Neumann, based at Princeton University, put together a team of meteorologists led by Jule Charney. Since these models are based on laws of physics such as the Navier-Stokes equation, I will henceforth call them “physics based”, to distinguish them from statistical-empirical models (sometimes called data-driven models) of the type that Fitzroy, Blanford and Walker developed. To run their physics-based models, Charney’s team used the first fully programmable electronic digital computer, known as ENIAC, which stood for “electronic numerical integrator and computer”.’
“Ulam and von Neumann decided—“Monte Carlo”—a simple example of the Monte Carlo method at work. Suppose you want to estimate the value of p / 4 without using a calculator. The area of a circle is (π / 4) × D2 where D is its diameter. The Monte Carlo way to estimate π would be to take a sheet of paper and draw on it a square (of area D2) which just contains the circle. You then randomly scatter a number of small seeds on the sheet of paper. It is the random scattering of small seeds that is the repeated operation mentioned earlier. Now count the total number, N1, of seeds that lie inside the square. Of these count the number, N2, that also lie within the circle. If indeed the seeds are randomly distributed inside the square, then the ratio N2 / N1 will get closer and closer to p / 4 the greater the number of seeds that are scattered on the sheet of paper. The circumstances of Ulam’s eureka moment are similar to those of many other eminent scientists. The moments occurred when they were relaxing—Why do eureka moments seem to occur during moments of relaxation?’
‘There’s an old North English saying: “There’s nowt so queer as folk!” For sure, there’s nowt as uncertain as folk—I discussed the representation of unresolved scales in models of fluid turbulence using random noise. Such noise can in principle also provide a representation of some of the uncertainty associated with structural model error—even with the uncertainty of folk. Now whilst models like COVIDSim do have some inherent stochasticity in their equations, the associated noise processes do not contribute much to the ensemble spread.’
‘We concluded in the previous chapter that noise in the brain is a necessary part of the answer. But is it sufficient? Is consciousness a necessary part of understanding, as Penrose argues it must be? I don’t know for sure, but if it is, then developing creative AI will require a close synergy between quantum and classical computing, in addition to the synergy discussed in the previous chapter between power-intensive and low-power classical computing.
If this is so, then we have a long way to go before we create truly intelligent machines. “The singularity”, the day when machines completely take over, is likely not a few years away, as some commentators believe; it is many decades, potentially centuries away. We will need our creative brains for quite some time yet.’
‘For many people it seems implausible that the works of Mozart, Shakespeare and Einstein could emerge from such a collection of particles. Following ideas formulated by Plato and Descartes, maybe there really are two different worlds: the physical world and the spiritual world. As a physicist, I would find it hard to accept such a notion since it would imply there is a core aspect of the world that cannot be studied by the scientific method. Of course, this might be the case, but I am not currently inclined to give up the idea that science can explain such matters. Nevertheless, I completely understand why the idea of emergence of conscious creative creatures from elementary particles seems completely implausible. As one scientific colleague put it, do the electrons and protons in the brain somehow know that Mozart was a superior composer to Mendelssohn?’
‘We are edging towards a topic which some people might feel is taboo. How much is a human life worth?—there were just short of 25,000 people killed on the UK roads in 2020. If we valued a human life as literally priceless, then it would make sense to impose a ten-mile-per-hour speed limit on all roads. However, most of us probably feel that the extra time it would take to travel is not justified—That is to say, we implicitly put a value, in terms of our time, on a human life.’
‘Sabine Hossenfelder put it in a rather graphic way (apparently referring to something that drunken Germans do from railway bridges): science does not tell you not to pee onto high-voltage electricity lines; it tells you that urine is a good conductor of electricity.
Just as with weather prediction, a cost-loss analysis can help you make a decision about whether to take anticipatory action regarding climate change—this requires putting a value on things which do not have an unambiguous value, like living in a future hell on earth.’