Sadness perspective
Jessica Marshall examines two alternative views of sadness: that it is a disorder to be treated, or an essential part of human function (17 January, p 36). There is a third view: that it is like physical pain 鈥� indicating an underlying problem that needs to be addressed.
If the problem is addressed, it is reasonable to alleviate the pain. However, attempting to alleviate the pain without addressing the problem is asking for trouble.
From Eleanor Ely
The assumption that sadness is equivalent to depression is not supported by my experience, nor that antidepressants banish sadness. I have found that an antidepressant relieves my mild-to-moderate depression 鈥� an empty, pessimistic, “what’s the use” feeling, combined with pervasive anxiety 鈥� without in any way diminishing my ability to feel appropriate emotions such as sadness, grief or fear.
Has it been demonstrated that antidepressants, even at low doses, blunt normal emotions? I am concerned that an artificial choice between depression and being an insensitive, complacent fool may needlessly discourage people from trying antidepressants who could be helped by them.
San Francisco, California, US
From Frederic Stansfield
Sadness should be addressed by creating a world fit for people to live in. Indeed, satisfying work clearly aimed at this goal would in itself make people happier.
Canterbury, Kent, UK
From Catherine Scott
The article on medicating sadness seems to have been written in blithe ignorance of the double-blind studies that have shown one family of antidepressants, the selective serotonin reuptake inhibitors (SSRIs), to be no better than placebos at relieving moderate depression, or sadness (for example, 1 March 2008, p 7).
Hawthorn, Victoria, Australia
The editor writes:
鈥� SSRIs do seem to work for people with severe depression, so don’t stop taking these tablets without talking to your doctor.
Save the Earth
James Lovelock’s acceptance that 90 per cent of Earth’s human population could perish is on a level with accepting events such as the Holocaust as minor incidents of history that will be forgotten in the course of time (24 January, p 30). This may be true at some point, but it was not the reality then. It is not reality for people in Gaza or Darfur now.
His suggestion that mass extinction is unlikely, since many species survived the Palaeocene-Eocene Thermal Maximum, is optimistic. Then, a 5 掳C rise in temperature likely took 20,000 years: the current change is likely to take under 100 years.
From John Briggs
Lovelock identifies the burial of charcoal from agricultural waste as a promising method of decreasing atmospheric carbon dioxide levels. Soils altered in this way also show an enhanced capacity to retain nutrients, which reduces the need for fertiliser, leading to a decrease in nitrous oxide emissions and nitrate and phosphate pollution of water: see .
Menith Wood, Worcestershire, UK
From Tony Freeman
Burying charcoal or pumping C02 underground (10 January, p 34) will remove carbon from the atmosphere, but the economic case seems weak since it depends on incentives and taxes rather than market forces. Surely the best way to sequester carbon would be to make it into things that we want to keep.
Use more wood as a building material, or develop technology to allow biomass to be used as a feedstock for plastic manufacture.
Carbon taxes are all stick 鈥� the carrot should be for initiatives to use biomass for manufacture.
Slough, Berkshire, UK
From Sandy Henderson
Though initially appealing, James Lovelock’s scheme to bury charcoal wilts a bit in light of the facts. Total annual production of the three staple grains 鈥� wheat, rice and maize 鈥� is about 2 gigatonnes. Even if the same mass of straw and other crop residues were collectable, it would yield about 880 million tonnes of charcoal: less than 3 per cent of our carbon emissions. The huge capital required could be better invested in improving efficiencies by more than 3 per cent.
Braco, Perthshire, UK
From Roger Plenty
I see news reports of stockpiles of waste paper held because it is no longer economically viable to recycle it, and the associated debates about whether it would be better to incinerate it to produce energy: and they got me thinking. Would it not be possible to reduce this paper to a condition like charcoal, and then use it in the same way as charcoal?
Stroud, Gloucestershire, UK
From Clive Hamilton
James Lovelock plans to spend $20,000 on a space flight. No other single action sends a bigger pulse of greenhouse gases into the atmosphere than a rocket launch.
Canberra, Australia
Scrubbers
Robert Kunzig and Wallace Broecker give an interesting account of technologies for scrubbing C02 from the air (10 January, p 34), but they duck the problem of what to do with the captured CO2.
It is theoretically possible to react it with steam or hydrogen to make liquid fuel, but I suspect the energy and other costs would make this much more expensive than the scrubbing process itself.
Sequestration is problematical too. Depleted oil wells can take only a fraction of the gas, and there’s no place to put the rest. Even deep coal mines are not gas-tight. Putting it into the deep ocean is no solution either: that will eventually acidify the seas.
Converting it into calcium carbonate and burying the result would be better, but seems not to have been investigated or costed.
Social contagion
I found Michael Bond’s claims that individuals are unwittingly infected by social epidemics alarming (3 January, p 24).
That individual behaviour is influenced by social networks is beyond dispute: recall the hope and optimism following Barack Obama’s inauguration.
This emotional response was, however, undeniably generated by the long-standing social and economic dishevelment preceding the event. Let us not stereotype people’s emotions and behaviours according to apparent statistical correlations with their friends’ friends, without analysis of the social conditions that give rise to these states.
From Neil Fairweather
Would I be oversimplifying matters unduly if I suggested that happiness is transmitted through people we talk with, whereas obesity is transmitted via the people we eat with?
Risley, Cheshire, UK
Mind and/or body
The mind-body problem is not, as Owen Flanagan says, “about where the mind is located” (17 January, p 42). It is about “mind” and “consciousness” being words flung about without much thought, despite 200 years of discussion by philosophers without any agreement as to what they mean. There can be no solutions until scientists make it clear exactly what they mean when they use these terms.
Science not playtime
It’s good to see Richard Hammond backing the long-standing efforts to get more youngsters to look at science as a career prospect (3 January, p 14). Many years’ experience tells me, however, that simply keeping kids “bouncing along and excited” is not enough. From a young age kids love the entertainment and stimulation that a whiz-bang approach provides. Once they start to grow up a bit (around age 13 or 14) they realise that life isn’t all whiz-bang.
Teenagers are more pragmatic and sophisticated than we realise. How often do you see accountants in schools trying to excite students with accountancy? Yet plenty go on to become accountants.
To encourage teenagers to choose science as a career we need to talk seriously about the prospects available. Introduce them to people working in good jobs and earning good salaries in science. If we can’t do that then what right do we have to attract them to a poorly paid career just to keep the country ticking over?
Newts in space
Eduardo Almeida and his NASA team have ignored a fundamental principle in their interpretation of the data for rate of regrowth of tails in the newt Pleurodeles waltl (3 January 2009, p 12).
The newts use their tails for balance, so a longer, stronger tail is an advantage in a higher gravitational field.
A shorter tail may be adequate in low gravity. It is not necessarily correct to extrapolate these results to say that, in space, regeneration in general does not occur normally.
Where the function of the regenerating structure is not related to balance or weight-bearing, low gravity may not slow down regeneration. I understand that experiments showed that brine shrimp (Artemia salina) grow larger and faster in space.
Were he wrong鈥�
As a teacher I fully agree with A. C. Grayling that the web can be a wonderful source of educational information (17 January, p 44). Many of my teaching resources are derived from it.
He is also right to point out its potential unreliability: I often have to remind my students to discriminate between the sources of information it delivers.
I must, however, take issue with his comments on the Walter de la Mare poem. “Thou have” is a strictly correct use of the English subjunctive mood, forming part of an expression of wish or hope.
Punning stunts
So “botanists are rarely as idiosyncratic” as Godfrey Sykes, who in 1922 named a Mexican succulent after Lewis Carrol’s Boojum (20/27 December 2008, p 63). I offer you: Hebejeebie, a genus close to Hebe in the family Plantaginaceae, described by Michael Heads in 2003; Aquilegia flabellata nana pumila alba “Rama Lama Ding Dong“, a cultivar of dwarf white columbine in the family Ranunculaceae; and Eriogonum inflatum var. deflatum of the Polygonaceae.
You can find more about these and about taxonomy in general at .
For the record
鈥� We said the “Martin Jetpack” was powered by two turbojet engines (24 January, p 44). It is actually powered by
Sadness perspective
Jessica Marshall reports Jerome Wakefield’s assumption that sadness must have some sort of useful evolutionary purpose, because it is entrenched in our biology (17 January, p 36). This is incorrect for a number of reasons.
First, every human being is walking around with a time-bomb in our system called the appendix. This organ has become not just totally useless, but a threat to our very existence. Using Wakefield’s logic we shouldn’t get rid of this organ because it is so much a part of us that it must serve some evolutionary purpose that we can’t survive without.
Secondly, do you know any hay fever sufferers? While the body responses leading to hay fever are necessary for our survival 鈥� for the expulsion of foreign materials that could harm us 鈥� to say that many peoples’ response is totally out of whack with what is actually required is a gross understatement, as demonstrated by the vast amount of pharmaceutical products out there designed to suppress the body’s histamine response.
In Australia in 2003, suicide accounted for 27 per cent of deaths in males aged 25-34, according to the Australian Bureau of Statistics. I would hardly call that a useful evolutionary trait.
If medicating sadness goes some way to alleviating the horribly unacceptable suicide rates in many developed countries, and improves the lives of countless people all over the world, why do so many psychologists and social workers still seem to have such resistance to doing so? Your quotation of Ian Hickie summed it up perfectly: suicide rates appear to have declined as the number of people diagnosed with depression increases.
If depression did serve some use in the past, those days are long gone, and maybe it should go the way of the appendix. As a learning tool it is a slow and ineffective model, and as an evolutionary trait its modern usage appears indiscernible.
Kangaburger
Not only do kangaroos emit fewer greenhouse gases than cattle (20/27 December 2008, p 48) but, like other native fauna, their padded feet do far less damage to fragile Australian topsoils than the hooves of introduced species. Furthermore, kangaroo is healthier than beef or lamb and just as tasty at a fraction of the price (at least in Australia).
There are two huge obstacles to be overcome if macropod is ever to be farmed commercially.
The first is the grazier attitude that if you can’t herd them you can’t farm them. I have no doubt there were sceptics on hand when the idea of domesticating cattle, sheep, goats or whatever was first proposed. We farm salt water crocodiles very successfully without the need for cattle crushes and branding irons, so why not kangaroos? Nearly all of the exotic fauna introduced to Australia have led to feral populations that have become pests. Farming native species nullifies this problem.
The second obstacle is consumer backlash. I have heard that in the UK a consumer group forced a supermarket chain to withdraw kangaroo meat from its shelves. This attitude stems from ignorance. The benefits to the environment of replacing cattle and sheep with kangaroo go without saying. At present, kangaroos and wallabies are culled when they reach nuisance proportions. Some of the meat is sold for human consumption but most ends up as pet food. To give an example, right now there are hundreds of agile wallabies inside the perimeter fence of our local airfield, despite attempts at culling. This prohibits all night flights, including emergency evacuations, so further culls are being proposed. This seems to me to be the equivalent of farming with the end product being thrown away.
Rubber hands
Peter Aldhous’s discussion of some of the techniques used to attempt to replicate the sense of touch in a prosthetic arm (24 January, p 15) interested me very much. When I was fitted with my first prosthetic arm (below the right elbow) 47 years ago, I immediately realised that I could “feel” whenever the split hook 鈥� a wonderfully simple, reliable and effective device 鈥� touched anything. The sensation was slight, transmitted by vibration to the socket and to my residual limb. My brain then very quickly made me “think” that the sensation was in the split hook.
Later, as I was an active radio amateur, I needed to be able to achieve a better “sense of touch” for picking up and holding delicate components. The most successful technique I found involved a miniature pneumatic cuff from a blood pressure measuring device, which was quickly inflated by a small vibrator type air pump. My first pressure detecting device used piezoelectric transducers. While these were very sensitive, they were prone to damage by abrasion and water ingress. However, the biggest problem was due to the difficulty in making the output reliable enough for switching purposes. As this was before the advent of modern interfaces, microprocessors and motors, the system proved unreliable.
To improve it, I lined the inside of the split hook (the transducer actually formed the inner grips of the hook) with lightly pressurised miniature-bore tubing. After opening the hook, by stretching the residual limb forward against a fixed strap, the opening pull triggered the small pump to provide pressure in the “transducer”. On closing the hook, the strong grip squeezed the air in the miniature tube, which ran up on the outside of the limb towards the pressure-operated switch.
With the switch then closed, the vibrator pressure pump inflated the cuff. As the cuff inflated it gently squeezed my upper arm, and I very soon “felt” the pressure as it were directly from the split hook closing action.
It took much experimentation to design a sensible system to stop the air pump. The answer that proved most reliable was a very simple expansion cord switch that open-circuited the pump motor supply as the cuff reached maximum expansion. With the hook firmly closed, the “squeezing” sensation lessened as it deflated but I was assured nothing would drop, because of the hook’s grip.
The system worked well, but my friends and colleagues were surprised 鈥� before they became used to them 鈥� by sounds of the motor running and the gentle hiss as the cuff inflated and deflated.
Later, I used a two-stage pressure switch. The first switch started the inflation and the second increased the pump speed just before maximum cuff pressure was achieved. The resulting cuff inflation pressure stages were “felt” on my upper arm. I soon automatically “thought” of the changes in the grip as actually in the hand that was missing, with sensations interpreted as first touch sensation and a final firm grip.
It was fascinating work, but without modern miniature motors and microprocessors it looked rather Heath Robinson, leading my friends calling me “Robbie the Robot”. I don’t think that such ideas 鈥� even incorporating sensitive transducers in prosthetic fingertips 鈥� are beyond modern research teams and their budgets. I made my test systems for less than 拢100.
Pumping heat
I am happy to be able to answer Tim Douglas’s question about domestic heat pumps (17 January, p 16). We have in our timber-frame, timber-clad house in the glen of Aherlow in Ireland exactly the system that he craves. When air is extracted from bathrooms, fresh air enters through a heat exchanger appropriately placed at a duct crossover enabling heat recovery exactly as he desires. The equipment was supplied by a Canadian company but I would be surprised if it is not available more widely. In any case, development of a system would make development of an electric kettle look positively daunting.
Tim Douglas asks why counter-flow heat exchangers are not used domestically. They are in Canada 鈥� they were one of the requirements for the “R2000” energy-efficient construction standard. I installed one in our house about 20 years ago. I am not sure how much energy it saves, but it controls humidity and air quality when the windows are closed, and modern construction standards have eliminated air leaks. Some jurisdictions now require mechanical ventilation in new construction for this reason.
Methane digested
Two web letters point out that the methane animals produce is made from carbon that had earlier been carbon dioxide in the air (21 January). But that is quite unimportant, because the greenhouse effect of a molecule of methane is much greater than that of a molecule of CO2. Even over a time-scale of 100 years, methane is more than 20 times as powerful a greenhouse gas.
The combination of grass and ruminants converts relatively harmless CO2 into much more harmful methane.