Do You Think You're Clever? Page 8

  Does a snail have a consciousness?

  (Experimental Psychology, Oxford)

  This is such a seemingly simple question, yet it throws up challenges that have baffled both philosophers and scientists. One of the problems, of course, is defining just what consciousness is.

  In commonsense terms, it just means being awake and aware. A snail, like most animals, is able to sleep and wake up. A snail is also, like other animals, aware enough of particular features in its environment to respond to them, choosing where it goes and how it reacts – even if it’s only at its own particularly languid pace. But we know, from our own experience, that there is much more to consciousness than this.

  The problem is how to get inside an animal’s head and know just how it thinks. Consciousness is a very private experience. It’s hard enough to know what consciousness is like for other humans, when we have the benefit of language and many other ways of communicating to tell us. It’s almost impossible with animals, so we have to infer from things they do and the way they react.

  There’s always been a tendency for we humans to regard ourselves as rather special and different from other animals. While it’s clear that physically we have much in common with other animals, we’ve also liked to think that our brains are somehow special, and many thinkers from Aristotle onwards have suggested that we are uniquely conscious. Sometimes human consciousness is described as ‘self-awareness’ – the idea that we know that we are conscious, and are aware of who we are. It used to be a commonplace that only humans recognised themselves in a mirror. But then it was shown that apes, elephants and dolphins do, and more recently even little magpies with their birdbrains have proved they can, too. Even though we might think it’s unlikely, it’s hard to imagine a test to prove for certain that a snail cannot recognise its own reflection. Moreover, there is no reason to assume that an animal, especially one so fundamentally different, experiences consciousness in the same way that we do – so even a proven failure of the mirror test would not prove anything about snails.

  Over the centuries, countless philosophers from Descartes to Daniel Dennett have speculated on just what consciousness is, and for Descartes being aware of thinking was the single basic truth of existence. In recent years, the notion of consciousness has been explored by psychologists and neuroscientists, as well as thinkers about artificial intelligence. While philosophers try to work out just what it all means, scientists such as Francis Crick and Roger Penrose have tried to explain where and how it occurs physiologically in the brain.

  Most thinkers agree that understanding consciousness is one of the hardest of all intellectual problems. In his 1989 Dictionary of Psychology, British psychologist Stuart Sutherland wrote: ‘Consciousness is a fascinating but elusive phenomenon; it is impossible to specify what it is, what it does, or why it evolved. Nothing worth reading has ever been written about it.’ Not everyone is quite as pessimistic as this, and there were small signs of progress at least in spring 2009, when French scientists showed that consciousness is a coordinated activity involving the entire brain – and not located in a particular place.

  Recently, British psychologist Nick Humphrey suggested that animal consciousness may have started with the way a creature keeps track of its response to the environment and then evolved as the ability to privatise and internalise these tracking responses developed into a sense of self and a will to survive that gave the creature a competitive edge. If this is so, there is no reason to think that consciousness cannot have developed right through the animal kingdom, down to the level of snails. If snails have this kind of self-awareness, it’s clearly nothing like as sophisticated as our own, but it might be a mistake to assume that they are simply rather gelatinous automata.

  Thinkers on consciousness have sometimes divided it into two kinds, which were labelled ‘access’ consciousness and ‘phenomenal’ consciousness in 1995 by American linguist and philosopher Ned Block – although not everyone agrees there is such a division. ‘Access consciousness’ is being aware of information in the mind and being able to access it. ‘Phenomenal consciousness’ is simply experiencing things without any physical response. Feeling pain, tasting coffee, hearing music are all such experiences or ‘qualia’, as they are sometimes called. Some thinkers suggest that qualia are the difference between ordinary humans and zombies. Zombies have no qualia, so no inner life, and are thus nothing more than puppets.

  In the 1970s, Thomas Nagel wrote a famous paper, ‘What is it like to be a bat?’ in which he summed up the experience of qualia as ‘what it is like to be’. He then went on to suggest that we cannot yet imagine any way of knowing what it’s like to be a bat (or a slug or any other animal, including humans) – and any physical theory of consciousness cannot be considered until we have some way of understanding this subjective experience of the world. This is sometimes described as the ‘hard problem of consciousness’ (as opposed to easier to understand access consciousness). Other thinkers, such as Daniel Dennett, deny the division of consciousness and the ‘different’ quality of qualia altogether, and believe that there is just one all-embracing kind of consciousness. At the moment, though, the answer must be that we know very little – less than the snail …

  Why is there salt in the sea?

  (Biochemistry, Oxford)

  Well, strictly speaking, there isn’t; there are only dissolved chemicals which combine to make salt when precipitated, and which give seawater a salty taste. So far, 72 separate elements have been found in seawater, and the chances are that nearly every natural element on earth is in there somewhere. However, the most abundant by far are ions of chlorine (about 55.3 per cent) and sodium (about 30.8 per cent), the elements that combine to make common salt. The other relatively common ions are magnesium (3.7 per cent), sulphur (2.6 per cent), calcium (1.2 per cent) and potassium (1.1 per cent). It’s these six elements that make seawater salty or ‘briny’.

  On average, the salinity of sea water is about 35 o/oo, which means 35 parts salt to a thousand water. That’s a huge amount of salt – the equivalent of a teaspoon of salt in a glass of water. Estimating the total volume of water in the oceans, you can work out from this concentration that overall there is a staggering 50 million billion tons of salt in the sea – and that if all the salt were extracted from the oceans it would cover the entire earth to a depth of 500 feet!

  The salt concentration varies from place to place, though – as we know mostly from a worldwide series of chemical tests conducted in 1884 by William Dittmar aboard the British corvette HMS Challenger. It’s highest in the Red Sea and Persian Gulf, and lowest in the Baltic and the Arctic Ocean. This variation gives us a clue about why there is salt in the sea in the first place. Levels are high in warm seas, where evaporation of pure water leaves salt behind in the water and increases salt content; and low in cooler seas, where pure water is continually added from melting ice and rivers.

  The oceans probably formed originally as water vapour ‘degassed’ from the molten rocks that once covered much of the hot early earth, formed clouds and then rained as the earth cooled. The original ocean waters were pretty much freshwater, but the salt content gradually built up as salt was added from three main sources – rivers flowing into the sea, hydrothermal vents on the sea floor and undersea volcanoes.

  Rain falling on the land (and the oceans) is pretty much pure water (made slightly acidic by dissolved atmospheric gases). That’s why rivers are freshwater rather than salt water. Although they are usually fresh-tasting, however, rivers are never completely pure. Instead, they contain tiny traces of salts and other solids – some the fragments of weathered rock, others dissolved directly from susceptible rocks such as limestone as water seeps through the ground on its way to the river.

  It’s estimated that some 4 billion tons of salt are washed into the sea every year from rivers around the world. At that rate, it would take about 200–300 million years to give the oceans their salt content. The rivers don’t dilute the ocean because j
ust as they add freshwater, so freshwater continually evaporates from the ocean surface. That’s why salinity tends to be lowest on the ocean margins where rivers continually flood in freshwater, and highest in mid-ocean. But why haven’t the oceans got steadily saltier and saltier, then, as more salt is added and water evaporates? It’s thought that they have now reached a balance where the salt content stays steady. Each year, much the same amount of salt is precipitated out of the oceans to settle on the ocean floor as is added to them by rivers.

  Interestingly, ‘freshwater’ rivers tend to carry much more calcium, bicarbonate and silica than ‘saltwater’ in the sea. Seawater, however, contains much more sodium and chloride. One of the reasons for this is that marine life plays quite a significant role in the chemical balance of the oceans. A lot of calcium is taken out of seawater by the huge numbers of creatures such as molluscs, crustaceans, foraminifera and corals that use calcium to build skeletons and shells. Diatoms extract silica. Other creatures affect the chemical composition in subtler ways, such as snails that extract lead and sea cucumbers which secrete vanadium.

  What is the point of using NHS money to keep old people alive?

  (Economics, Cambridge)

  As the author Anthony Powell said, ‘Growing old is like being increasingly penalized for a crime you haven’t committed’. After decades of hard labour and long service to the government in the form of taxes, you finally start to get ready for a deserved rest – and what happens? Your body starts to play up and your senses start to weaken – and you can only sleep properly in the middle of a conversation. To add insult to injury, some people start to say that you are placing a burden on the health service. No wonder you might begin to mutter bitterly every now and then!

  Of course, there is a serious point here. Old people are as deserving of health resources as anyone, if not more so, because they have paid their tax contributions all their lives. The ethos of the NHS is that it provides free health care for all, and old people should not be exceptions to this policy. It’s quite simple; if they are ill, they should be treated.

  Unfortunately, the NHS does not always live up to this ideal. A recent survey by the British Geriatric Society of British doctors suggested that more than half would be worried about how they might be treated when they were older – because of the way they see old people being treated now. Most doctors surveyed believe that older people are much less likely to have symptoms properly investigated. When old people feel ill, there is a tendency to assume that the problem is ‘just old age’ rather than examining them properly for signs of a treatable illness. Three-quarters of the doctors asserted that older people are less likely to be properly treated and referred to the right specialists.

  Of course, many of the health problems faced by older people are an inevitable part of growing old. But this does not mean they cannot be treated in any way. Old people may also respond less well to treatment for some ailments than younger people do. It is therefore sometimes suggested that limited NHS resources should be steered towards younger people where they can give more obvious improvements to quality of life. Indeed, there is some evidence that this how the NHS does indeed respond, often treating old people as second-class patients. There are much longer waits, for instance, for hip and knee replacements, which affect primarily old people, than for other operations. Women over 70 are not automatically invited for breast screening as younger women are. And older women with breast cancer are less likely to receive the full range of cancer therapy than younger women.

  In 2005, NICE, the body that produces guidelines on drug policy for the NHS, put the cat among the pigeons when it produced a report saying that, ‘When age is an indicator of benefit or risk, age discrimination may be appropriate’. It fired an angry response from Help the Aged, who retorted: ‘Assumptions that the life of an older person is somehow worth less, or that it is not important if someone who is nearing the end of average life expectancy receives less attention than people in their twenties or thirties, have been widespread. The [NICE] guidelines would run the risk of reinforcing such prejudice.’

  It is perhaps understandable that this happens. On the face of it, it seems so much more worthwhile to pour the best (and most expensive) resources the medical profession can offer into treating a nineteen-year-old with all their life ahead of them, if the treatment is effective, than into treating an 89-year-old who is less likely to thrive, and likely to have only a short time of health before some other ailment strikes. Managers and doctors facing a heavy workload and limited resources may argue that choices have to be made and that such prioritising, though undesirable, is simply unavoidable. There is often an attitude, too, that old people have had their ‘fair share’. More poignantly, sometimes doctors who treat old people with all the skill and dedication they would devote to younger patients are forced to accept that they are fighting a losing battle – that they will not be able to keep their patient alive, let alone restore them to good health. When, then, do they stop fighting?

  But there is a problem with too much ‘pragmatism’. The NHS is an ideal – the ideal of the best available treatment free to all, no matter who – and it’s an ideal that should not be sacrificed lightly. For each and every patient and their loved ones, it’s their health and their life that is precious. The ideal of the NHS means we should not be making choices between one person’s health and another’s. Every patient should be treated to the best of doctors’ abilities. If this principle is compromised, it begins to undermine the important and reassuring comfort of knowing that we will always be treated when we are ill; it also begins to place a very difficult burden on doctors to choose who should be treated and who shouldn’t.

  Yet the NHS budget is rising by the year and the UK has a population that is ageing. Already over 20 million (more than a third of) British citizens are over 50 years old, and old people are more prone to illness. 55 per cent of 75–84-year-olds have some illness or disability and two-thirds of those over 85 do. It is argued therefore that this increasingly aged population will place more and more strain on the NHS’s limited resources – and the ability of younger people to fund it – and that we need to start recognising this before catastrophe strikes. What this argument fails to recognise, however, is that the old people of today are much, much more healthy than those of former years. That is exactly why we have so many old people. And if there are numerically many more frail 90-year-olds now dependent on the NHS than in earlier times, there are also many, many more very fit people in their 60s still actively contributing to society economically, socially and intellectually. More importantly, a society that fails to look after its old people and hold them in any less than the utmost respect may be said to be sick and in need of treatment.

  You have a 3-litre jug and a 5-litre jug. Make 4 litres.

  (Mathematics, Oxford)

  This problem comes up in the movie Die Hard with a Vengeance. At the bidding of the monstrous Simon Gruber (aka Peter Krieg) (Jeremy Irons), John McCain (Bruce Willis) and Zeus (Samuel L. Jackson) are forced to solve this problem in order to disarm a bomb. They succeed just in time. They did it like this (using gallons rather than litres): First they fill the 5-gallon jug. Then they empty 3 gallons from the 5-gallon jug into the 3-gallon jug, leaving 2 gallons in the 5-gallon jug. Then they empty the 3-gallon jug and add the last 2 gallons from the 5-gallon jug. Then they fill the 5-gallon jug and fill up the 3-gallon jug, using just 1 gallon and leaving 4 gallons in the 5-gallon jug. Et voilá!

  This problem is so simple that you can see the solution straight away, and the writers were clearly looking for a riddle that most of the audience would be able to work out or at least understand for themselves. But it’s an age-old arithmetical problem based on the subtraction of relative prime numbers. Relative prime numbers are numbers where the only whole number that both can be divided by is 1. That doesn’t mean that either is a true prime number, just that they can both be divided only by 1. Thus 15 and 16, although not primes, are both relat
ive primes, whereas 15 and 21 are not, because they can both be divided by 3.

  Euclid found a way to solve relative prime number problems like the Die Hard riddle 2,300 years ago. The proof is complex, but the arithmetic relatively simple, and it allows us to solve any similar problem, such as how you would get a 13-minute egg from a 5-minute and a 9-minute egg timer.

  (You ‘calibrate’ the 5-minute timer to 4 minutes, by starting them both off together, stopping when the 5-minute timer runs out – leaving 4 minutes on the 9-minute timer – starting both off together again and stopping when the 9-minute timer runs out, leaving just a minute on the 5-minute timer. You can then cook your egg for exactly 13 minutes by starting with the 9-minute, then reversing the 5-minute timer for the remaining 4 minutes.)

  All these solutions can be expressed by mathematical equations. If one of the measures you have is p and the other is q, you can find the solution you need, k, with the following equation. In this, m is the number of times you need to fill or empty p, and n is the number of times you need to fill or empty q.

  mp + nq = k

  If m or n is negative, it means emptying the jug (or egg timer); if m or n is positive it means filling the jug. In the case of the Die Hard jugs, p is 3 and q is 5. So you would get k is 4 if m is plus 3 and n minus 1.