General Relativity: a theory that posits the warping effect of gravity on space-time. In the imagined experiment, left, a signal beamed from a satellite bends round the sun
“A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists,” said CP Snow in his celebrated “Two Cultures” lecture of 1959. “Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. Yet I was asking something which is the scientific equivalent of: Have you read a work of Shakespeare’s?”
It is hard to believe that Snow would meet with much more comprehension were he to repeat his questions in today’s House of Commons. It is nevertheless interesting to consider a few ideas from contemporary science with which every politician and civil servant really ought to be comfortable.
1 The Second Law of Thermodynamics
We can start with Snow’s example. The Second Law of Thermodynamics postulates that entropy—disorder, if you like—will always increase in a closed system. It has a wider philosophical significance that politicians would do well to note.
The Second Law emphasises that, over time, without intervention (which can break open a closed system), things will degrade and get worse. Yet it also shows that there will always be waste. As Lord Kelvin explained, heat can never be completely converted into work.
2 The meaning of mass
Snow also wondered whether his audience would have been able to answer the question: “What do you mean by mass?” He considered this a little like asking whether or not someone could read.
Mass is perhaps best described as a measure of how much matter an object contains. But if this is simple, its origins are more opaque. The standard model suggests that it emerges from a mechanism proposed by Peter Higgs, the Edinburgh physicist. But the existence of the particle predicted by this hypothesis—the celebrated Higgs boson—remains uncertain, though that uncertainty should soon be reduced. The Large Hadron Collider at Cern is expected to confirm or rule out the badly nicknamed “God particle” within the year.
3 Evolution by natural selection
“Nothing in biology makes sense except in the light of evolution,” said the Russian biologist Theodosius Dobzhansky. The theory of evolution by natural selection is among the greatest ideas to emerge from any branch of science. Yet it is easily misunderstood.
Evolution is often portrayed as progress, a process that ends in a goal. It is nothing of the sort. Darwin’s genius was to realise that random mutations could drive great change, as those mutations that confer survival advantages in particular environments are preserved, while those that are deleterious are eliminated over time. The process is entirely blind, and anything but teleological.
4 The Theory of General Relativity
Published in 1916, this was Albert Einstein’s crowning achievement. It proposes that the gravitational force that objects exert on one another occurs because of the way their masses warp space and time.
It isn’t “only a theory,” any more than evolution is. In science, a theory has a precise meaning: a hypothesis that has been confirmed by a large volume of evidence. It has acquired the status of a theory because it makes predictions—such as anomalies in the movements of planets—that have been confirmed by experiment again and again.
Relativity has displaced Newton’s view of gravity as the best explanation because it is a better approximation of the truth. Newton’s system works well most of the time—most of the predictions it makes are borne out by experiment—but relativity does better. This, again, is how science works: theories that explain observations well are provisionally accepted, but can always be improved upon. Just as relativity will be. It has yet, for example, to be combined successfully with quantum mechanics.
5 We are all Africans
The evidence from both the fossil record and the human genome is perfectly clear: it is incontrovertible that the origins of humanity lie in Africa. Go back just a few tens of thousands of years, and all of us have African ancestors. There is more genetic diversity within the continent of Africa than there is among all non-African populations—which is to say, a Finn will be genetically more similar to an Australian Aborigine than some African ethnic groups are to one another. Recent research has shown that not all our genetic material is inherited from Homo Sapiens. Some populations have a tiny contribution from Neanderthals as well, introduced when our ancestors interbred with our close evolutionary cousins.
6 Nuclear physics
Atoms are the basic unit of matter, consisting of a nucleus, where the overwhelming majority of the mass resides, surrounded by electrons. The nucleus is formed of positively-charged protons and neutrally-charged neutrons. Electrons are negatively charged. The number of protons in the nucleus determines the element. Elements can have variable numbers of neutrons: these are different isotopes.
In nuclear fission, the atomic nucleus is split, either as a result of natural radioactive decay or collision with a free neutron. The split nucleus releases energy and often free neutrons or protons as well. Neutrons released this way can trigger a chain reaction, as they cascade into other atoms.
Nuclear fusion is a different process, by which hydrogen atoms fuse to produce helium atoms. Though this releases vast amounts of energy, it starts only at intense temperatures. Current technology requires more energy to trigger fusion than the fusion reactions release.
7 The science of climate change
At its root, the question of whether human activities are warming the world is a matter of physics. It is the physical properties of gases such as carbon dioxide, water vapour and methane that cause them to induce the greenhouse effect. When visible light warms the Earth’s surface, much of this is re-radiated at infrared frequencies. Greenhouse gases in the atmosphere absorb some of this thermal radiation, effectively trapping it and raising temperatures.
The existence of this effect is not in doubt: without it, global temperatures would be significantly lower. It is also beyond doubt that human activities since the industrial revolution have increased the concentration of greenhouse gases in the atmosphere. The rest is just physics. There are good political arguments to be had about the best responses to the phenomenon of climate change. But the fundamental science of what is happening is very well understood.
8 Electromagnetism
In the mid-19th century, James Clerk Maxwell, the Scottish physicist conducted research that would eventually make radio transmissions possible. Maxwell’s equations reconciled electricity—the flow of charged electrons—with magnetism. They also showed that both phenomena were aspects of a single electromagnetic force, that also encompassed visible light and radio waves.
Maxwell’s equations are a fine example of the sort of far-reaching implications that often emerge from curiosity-led research, and illustrate why this sort of endeavour must be valued and enabled if technological innovation is to thrive.
9 The building blocks of life
Darwin didn’t live long enough to be introduced to the raw material of evolution: the deoxyribonucleic acid molecule, DNA. Save for a few viruses that only use its chemical cousin, RNA, it is the stuff of all life on Earth. We are cousins to bacteria and beetles, bananas and buffalo, with much of the genome written identically between organisms that look profoundly different. This truth ought to give pause to critics of biotechnology who regard splicing genes between species to create better crops as meddling with nature.
DNA is composed of four nucleotides or bases—adenine, cytosine, guanine and thymine—known by the letters A, C, G and T. Each is arranged with a complementary base in the molecule’s famous double helix structure. Triplets of letters create instructions for the production of amino acids, which in turn build proteins. Only about 2 per cent of the genome, however, comprises genes that code for proteins in this way. The remainder was once dismissed as “junk,” but some of it is now understood to form switches that activate or silence genes, often in response to environmental influences.
This discovery has helped to give the lie to the best-known stupid question in biology: are we the products of nature or nurture? For the most part, we are both. Genes act in concert with the environment to build our bodies and behaviour.
10 The randomised controlled trial
Technologies such as antibiotics, vaccines and monoclonal antibodies have transformed human health over the last century. Yet the greatest discovery of modern medicine is not a treatment, but a test. We know that these different approaches to treatment and prevention of disease are effective, because they’ve been evaluated using the sharpest weapon science has in its arsenal: the randomised controlled trial (RCT).
Take a medicine in isolation, and the act of being treated, rather than the treatment itself, might explain any benefit: this is the placebo effect. The patient might also recover owing to the natural course of the disease. An RCT seeks to discriminate true effects by comparing patients receiving treatment with others taking a placebo or a different drug. Patients are allocated at random to treatment and control groups, so the sickest cannot be channelled to one group or the other. Where possible, neither patient nor doctor knows which group is which, to further reduce potential sources of bias.
Before the RCT, all medicines are equal: small molecules designed by big pharma and folk remedies stand or fall according to their effects. And most alternative medicines—homeopathy, reflexology and so forth—have consistently failed to show benefits beyond those of placebos.
RCTs, too, could be deployed much more often than they are in public policy. If we want to know how best to rehabilitate drug offenders, or to teach children to read, we can use RCTs to guide us.
Ten facts to master:
1. Age of the universe: approximately 13.7bn years 2. Speed of light: 299,792,458 metres per second (186,282 miles per second) 3. Number of chemical elements: 118, of which 98 occur naturally 4. Number of stars in the universe: standard estimates put this at between 10 sextillion (10²²) and 1 septillion (10²) 5. Age of the Earth: 4.54bn years 6. Age of life on Earth: approximately 3.8bn years 7. Age of homo sapiens: anatomically modern humans evolved between 200,000 and 150,000 years ago, and became behaviourally modern 60,000 years ago 8. Number of DNA “letters” in the human genome: 6bn, arranged in two sets of 3bn 9. Proportion of human genes shared with chimpanzees: about 97 per cent, though figures differ according to definitions of genes 10. The current concentration of carbon dioxide in the atmosphere is 397 parts per million (ppm) as measured at Mauna Kea, in Hawaii. The pre-industrial revolution level was 280 ppm.
“A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists,” said CP Snow in his celebrated “Two Cultures” lecture of 1959. “Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. Yet I was asking something which is the scientific equivalent of: Have you read a work of Shakespeare’s?”
It is hard to believe that Snow would meet with much more comprehension were he to repeat his questions in today’s House of Commons. It is nevertheless interesting to consider a few ideas from contemporary science with which every politician and civil servant really ought to be comfortable.
1 The Second Law of Thermodynamics
We can start with Snow’s example. The Second Law of Thermodynamics postulates that entropy—disorder, if you like—will always increase in a closed system. It has a wider philosophical significance that politicians would do well to note.
The Second Law emphasises that, over time, without intervention (which can break open a closed system), things will degrade and get worse. Yet it also shows that there will always be waste. As Lord Kelvin explained, heat can never be completely converted into work.
2 The meaning of mass
Snow also wondered whether his audience would have been able to answer the question: “What do you mean by mass?” He considered this a little like asking whether or not someone could read.
Mass is perhaps best described as a measure of how much matter an object contains. But if this is simple, its origins are more opaque. The standard model suggests that it emerges from a mechanism proposed by Peter Higgs, the Edinburgh physicist. But the existence of the particle predicted by this hypothesis—the celebrated Higgs boson—remains uncertain, though that uncertainty should soon be reduced. The Large Hadron Collider at Cern is expected to confirm or rule out the badly nicknamed “God particle” within the year.
3 Evolution by natural selection
“Nothing in biology makes sense except in the light of evolution,” said the Russian biologist Theodosius Dobzhansky. The theory of evolution by natural selection is among the greatest ideas to emerge from any branch of science. Yet it is easily misunderstood.
Evolution is often portrayed as progress, a process that ends in a goal. It is nothing of the sort. Darwin’s genius was to realise that random mutations could drive great change, as those mutations that confer survival advantages in particular environments are preserved, while those that are deleterious are eliminated over time. The process is entirely blind, and anything but teleological.
4 The Theory of General Relativity
Published in 1916, this was Albert Einstein’s crowning achievement. It proposes that the gravitational force that objects exert on one another occurs because of the way their masses warp space and time.
It isn’t “only a theory,” any more than evolution is. In science, a theory has a precise meaning: a hypothesis that has been confirmed by a large volume of evidence. It has acquired the status of a theory because it makes predictions—such as anomalies in the movements of planets—that have been confirmed by experiment again and again.
Relativity has displaced Newton’s view of gravity as the best explanation because it is a better approximation of the truth. Newton’s system works well most of the time—most of the predictions it makes are borne out by experiment—but relativity does better. This, again, is how science works: theories that explain observations well are provisionally accepted, but can always be improved upon. Just as relativity will be. It has yet, for example, to be combined successfully with quantum mechanics.
5 We are all Africans
The evidence from both the fossil record and the human genome is perfectly clear: it is incontrovertible that the origins of humanity lie in Africa. Go back just a few tens of thousands of years, and all of us have African ancestors. There is more genetic diversity within the continent of Africa than there is among all non-African populations—which is to say, a Finn will be genetically more similar to an Australian Aborigine than some African ethnic groups are to one another. Recent research has shown that not all our genetic material is inherited from Homo Sapiens. Some populations have a tiny contribution from Neanderthals as well, introduced when our ancestors interbred with our close evolutionary cousins.
6 Nuclear physics
Atoms are the basic unit of matter, consisting of a nucleus, where the overwhelming majority of the mass resides, surrounded by electrons. The nucleus is formed of positively-charged protons and neutrally-charged neutrons. Electrons are negatively charged. The number of protons in the nucleus determines the element. Elements can have variable numbers of neutrons: these are different isotopes.
In nuclear fission, the atomic nucleus is split, either as a result of natural radioactive decay or collision with a free neutron. The split nucleus releases energy and often free neutrons or protons as well. Neutrons released this way can trigger a chain reaction, as they cascade into other atoms.
Nuclear fusion is a different process, by which hydrogen atoms fuse to produce helium atoms. Though this releases vast amounts of energy, it starts only at intense temperatures. Current technology requires more energy to trigger fusion than the fusion reactions release.
7 The science of climate change
At its root, the question of whether human activities are warming the world is a matter of physics. It is the physical properties of gases such as carbon dioxide, water vapour and methane that cause them to induce the greenhouse effect. When visible light warms the Earth’s surface, much of this is re-radiated at infrared frequencies. Greenhouse gases in the atmosphere absorb some of this thermal radiation, effectively trapping it and raising temperatures.
The existence of this effect is not in doubt: without it, global temperatures would be significantly lower. It is also beyond doubt that human activities since the industrial revolution have increased the concentration of greenhouse gases in the atmosphere. The rest is just physics. There are good political arguments to be had about the best responses to the phenomenon of climate change. But the fundamental science of what is happening is very well understood.
8 Electromagnetism
In the mid-19th century, James Clerk Maxwell, the Scottish physicist conducted research that would eventually make radio transmissions possible. Maxwell’s equations reconciled electricity—the flow of charged electrons—with magnetism. They also showed that both phenomena were aspects of a single electromagnetic force, that also encompassed visible light and radio waves.
Maxwell’s equations are a fine example of the sort of far-reaching implications that often emerge from curiosity-led research, and illustrate why this sort of endeavour must be valued and enabled if technological innovation is to thrive.
9 The building blocks of life
Darwin didn’t live long enough to be introduced to the raw material of evolution: the deoxyribonucleic acid molecule, DNA. Save for a few viruses that only use its chemical cousin, RNA, it is the stuff of all life on Earth. We are cousins to bacteria and beetles, bananas and buffalo, with much of the genome written identically between organisms that look profoundly different. This truth ought to give pause to critics of biotechnology who regard splicing genes between species to create better crops as meddling with nature.
DNA is composed of four nucleotides or bases—adenine, cytosine, guanine and thymine—known by the letters A, C, G and T. Each is arranged with a complementary base in the molecule’s famous double helix structure. Triplets of letters create instructions for the production of amino acids, which in turn build proteins. Only about 2 per cent of the genome, however, comprises genes that code for proteins in this way. The remainder was once dismissed as “junk,” but some of it is now understood to form switches that activate or silence genes, often in response to environmental influences.
This discovery has helped to give the lie to the best-known stupid question in biology: are we the products of nature or nurture? For the most part, we are both. Genes act in concert with the environment to build our bodies and behaviour.
10 The randomised controlled trial
Technologies such as antibiotics, vaccines and monoclonal antibodies have transformed human health over the last century. Yet the greatest discovery of modern medicine is not a treatment, but a test. We know that these different approaches to treatment and prevention of disease are effective, because they’ve been evaluated using the sharpest weapon science has in its arsenal: the randomised controlled trial (RCT).
Take a medicine in isolation, and the act of being treated, rather than the treatment itself, might explain any benefit: this is the placebo effect. The patient might also recover owing to the natural course of the disease. An RCT seeks to discriminate true effects by comparing patients receiving treatment with others taking a placebo or a different drug. Patients are allocated at random to treatment and control groups, so the sickest cannot be channelled to one group or the other. Where possible, neither patient nor doctor knows which group is which, to further reduce potential sources of bias.
Before the RCT, all medicines are equal: small molecules designed by big pharma and folk remedies stand or fall according to their effects. And most alternative medicines—homeopathy, reflexology and so forth—have consistently failed to show benefits beyond those of placebos.
RCTs, too, could be deployed much more often than they are in public policy. If we want to know how best to rehabilitate drug offenders, or to teach children to read, we can use RCTs to guide us.
Ten facts to master:
1. Age of the universe: approximately 13.7bn years 2. Speed of light: 299,792,458 metres per second (186,282 miles per second) 3. Number of chemical elements: 118, of which 98 occur naturally 4. Number of stars in the universe: standard estimates put this at between 10 sextillion (10²²) and 1 septillion (10²) 5. Age of the Earth: 4.54bn years 6. Age of life on Earth: approximately 3.8bn years 7. Age of homo sapiens: anatomically modern humans evolved between 200,000 and 150,000 years ago, and became behaviourally modern 60,000 years ago 8. Number of DNA “letters” in the human genome: 6bn, arranged in two sets of 3bn 9. Proportion of human genes shared with chimpanzees: about 97 per cent, though figures differ according to definitions of genes 10. The current concentration of carbon dioxide in the atmosphere is 397 parts per million (ppm) as measured at Mauna Kea, in Hawaii. The pre-industrial revolution level was 280 ppm.
