The nature of time has fascinated thinkers for centuries, including
the christian philosopher St Augustine AD 354 to 430, who speculated that
‘hours, days, months or years .. began with the stars’ courses’. Nowadays
physicists might prefer to take things back to the Big Bang for the beginning
of time. But already we have made an assumption here, which is that the
essence of time is directionality, with a beginning, and possibly an end.
This conception of time may be visualised as an arrow, as in this volume’s
title, a metaphor apparently first used by Sir Arthur Eddington in 1927.
This conception is also, of course, the commonsense understanding of time
(though it has not always necessarily been so; the ancient Greeks, for example,
thought that time consisted of a series of cycles, without beginning or
end). For most of us, time marches on; essentially the authors of this volume
want to make a plea for this commonsense view. Their conclusion can be summed
up in these lines from the book’s final chapter: ‘The arrow of time is overwhelmingly
evident when we deal with the world around us. Why not believe what our
senses tell us, and what our poets have described for millennia?’

Not everybody will be entirely satisfied with this recourse to our senses
and the insights of poets. And the authors (Peter Coveney is a physical
chemist and Roger Highfield an award-winning science journalist) are well
aware of this. The problem, as they see it, consists of extrapolating from
the mathematics applicable to the world of subatomic particles to the macroscopic
world of sense experience. At the subatomic level, explanations of the behvaiour
of particles apply within a time-reversible framework; it does not make
any difference if one runs a film of what is happening forwards or backwards,
so to speak, the calculations still work. This had been the case with the
older Newtonian mechanics. At the macroscopic level of explanation, however,
where the behaviour of large numbers of atoms and molecules are being considered
collectively, new laws apply. The tendency of all matter is to break down
to the simple homogeneous arrangemnt of constituent parts – that is, for
entropy to increase – under the Second Law of Thermodynamics. This is a
time-irreversible process. It is what we see going on all around us, for
example, when we leave a cup of tea to go cold. It is such observations
that give us our conception of the unidirectionality of time.

Coveney and Highfield are not content to leave matters there, however.
In answer to those physicists who will want to insist on the powerful explanatory
capacity of quantum mechanics and relativity theory, they point out that
a satisfactory fusion of these two theories has yet to be achieved. Einstein,
for instance, could never accept the merely probabilistic basis of quantum
theory. So something would appear to be lacking with one or both of these
theories. Yet even if a theory were to emerge that accounted satisfactorily
for the apparent incompatibilities between quantum mechanics and relativity,
there would still remain the question, according to Coveney and Highfield,
of emergent properties.

An obvious place to look for examples of mergent properties is in the
world of life. One striking illustration the authors provide of how even
the simplest of organisms seem capable of ‘purposeful’ behaviour concerns
the slime mould, Dictyostelium discoideum. When food is short, groups of
normally free-living cells join together to form a multicellular ‘slug’,
with a discernible head and tail, that wriggles in search of bacteria. ‘Like
the ant hive,’ the authors write, ‘Dictyostelium is a ‘super-organism’,
a genetically homogeneous being composed of autonomous individuals, nevertheless
organised altruistically for the collective good’. It is not easy to see
how such behavour can be considered time-reversible, let alone the more
obviously purposeful behaviour of more complex beings, such as a dog in
pursuit of some quarry, or in much behaviour in our species. In such cases,
Coveney and Highfield argue, it is impossible to understand fully what is
going on at the molecular and ultimately subatomic levels in the organisms
concerned without considering this wider context.

Considering phenomena at the microscopic level only is the reductionist
error. It leads some physicists, apparently repelled by the dizzying complexity
of biological systems, to postulate such impossibilities as Wellsian time-travel.

The absurdity of this idea is dealt with adequately with the paradoxes
that such an activity would entail laid bare fully. (The objection that
time-travel might be possible except to such destinations as the womb and
ultimately infanticide is not a valid one – it simply restates the problems.
Modern chaos theory, is a further difficulty for time-travel). Coveney and
Highfield approvingly quote the American futurist writer Alvin Toffler regarding
reductionism: ‘One of the most highly developed skills in contemporary Western
civilisation is dissection: the spliting-up of problems into their smallest
possible components. We are good at it. So good, we often forget to put
the pieces back together again.’

This is an important book. While it is evidently written with the general
reader in mind, some of its conclusions will nevertheless be controversial,
which the Nobel prizewinner Ilya Prigogine admits in a helpful foreward.
It is generally well written (though there are one or two bloopers – for
example, we learn that ‘the Hydra, a freshwater polyp, was variously reputed
to have 100, 59 or 9 heads’, and that ‘Hercules eventually dispatched it
with the help of his charioteer’), and ranging across the number of disciplines
that it does, from physics to palaeontology, New ÐÓ°ÉÔ­´´ readers should
find something of interest in it whether they agree with the authors or
not. I heartily commend this volume.

John Laurent lectures in the Faculty of Adult Education, Univesity of
Technology, Sydney.

A LIVELY debate in the history of technology centres on the questions
of whether transfer of technology from Western to ‘underdeveloped’ countries
necessarily benefits the latter or whether the benefits are often outweighed
by the costs of disruption of traditional social patterns, environmental
damage and so on. This new volume by Arnold Pacey, author of the well-received
The Culture of Technology, is an attempt to contribute to this debate by
taking a long-term historical view (from about 700 AD to the present day)
of the process of technology transfer. He shows that this process has frequently
been a two-way, or dialectical one, and has often resulted in technologies
emerging that exhibit features characteristic of the two or more cultures
involved.

Pacey backs his case with numerous examples; in fact they are what the
book largely consists of – and this immediately brings problems. Covering
the breadth of history that it does, it is inevitable that Pacey has had
to be selective in his examples. His method appears to have been to concentrate
on some of the important secondary works in the field, such as Joseph Needham’s
multi-volume Science and Civilisation in China, and to utilise the instances
of the his tory of technology that he has been able to view in various museums,
mainly in the north of England. Both sources have provided the bulk of the
mat erial for his illustrations, which are generally excellent. But I cannot
help thinking that he has left much out.

I felt that an important dimension to the history of technology that
has received only relatively slight treatment in this volume is the political
one. For example, we learn how, in the ‘Freedom from Hunger’ campaign of
the early 1960s, irrigation schemes and the importation of tractors and
related technologies in East Africa frequently resulted in spectacular failure.
But one wonders about the kinds of influences brought to bear here. Whose
interests were at stake? Who hoped to gain from this introduction of western
technology? Pacey’s selective approach can annoy as well. As an Australian,
I was chagrined to find no mention of Lawrence Hargrave (who appears on
our $20 note) in his account of the history of glider experimentation before
the advent of powered flight. I was pleased to see mention of the Garratt
articulated locomotive, but Pacey’s remark that this was invented in Australia
in 1907 is incorrect: the first articulated locomotive was built in Tasmania,
but Garratt was English, and had taken out his patent in Manchester.

With often only limited data available to him, there are difficulties
too, it seemed to me, with some of the conclusions which Pacey draws about
some technology transfers. It is so with the development of guns and cannon,
which Pacey convincingly shows owed something to input from China, Islamic
caterpault technology, and iron-making techniques in countries including
China, Sweden and Islamic Spain. The discovery and harnessing of the explosive
power of salpetre found in certain soils was, for example, first demonstrated
by a visiting Indian Buddhist monk.

Pacey’s argument is well supported, not only from ancient literary references,
but also with solid archaeological data. For example, ‘Because of the early
date of the European bottle-shaped gun, and a lack of Chinese evidence until
a little later, it was once thought that guns were a European invention,
made in response to the introduction of gunpowder. With the discovery of
gun barrels in China dating from 1288 and 1332 (the dates of battles where
the barrels have been found) this view is no longer credible.’

So far so good. But Pacey wants to take the argument further, and claim
that since these guns were bottle-shaped, and that similarly shaped barrels
have also been found in Sweden, the route for this ‘idiosyncratic’ technology
was probably from China to the West via the Baltic. Surely one can just
as easily argue that the shape was a common (and commonsense) response to
the need to provide the thickest casing to that part of the gun or cannon
where the explosion of gun powder occurred? There are a number of examples
in Pacey’s catalogue of inventions where he does wish to emphasise the independent
development of certain revolutionary techniques, with a view to showing
that these have not been the prerogative of either East or West. But here,
too, he seems too ready to make confident assertions. For instance, Darby’s
development of the coke-fired blast furnace in 1709 was, we are told, an
‘entirely independent’ invention, owing nothing to China, which used such
methods for centuries.

Overall, however, Pacey’s book is a useful, readable introduction to
an important aspect of the history of world technology: the cross-fertilisation
of ideas between cultures. Covering the period of history that it does,
it is probably unavoidable that the book has a tendency to superficiality
– of the Black Death for example, Pacey explains that ‘the dreadful loss
of populations left psychological scars as well as economic disruption.
A common reaction was to seek reassur ance in traditional values . . . ‘.

Pacey makes up for such passages with fairly detailed treatments of
some of his examples, such as the development of firearms or the important
contributions of Indian artisans to British naval architecture during the
Napoleonic Wars and after. He also mentions the valuable insights that can
be gained from traditional farming methods, such as multi-storey cropping
in countries as widely separated spatially and culturally as India, Indonesia
and certain West African nations. Notwithstanding some of the above reservations,
then, Pacey’s volume is recommended to anybody with an interest in the history
of technology – arguably the most important history of all. It should also,
at its price, make a useful introductory text in undergraduate courses.

John Laurent is in the School of Science, Griffith University, Northern
Queensland, Australia.