Category: Book Reviews

Reviews of books featuring a summary of the book and links to related material

Aug 13 2017

Book review: The Comet Sweeper by Claire Brock

thecometsweeperA return to women in science in this post where I review The Comet Sweeper: Caroline Herschel’s Astronomical Ambition by Claire Brock, a biography of a woman who discovered comets and nebulae and published a catalogue of astronomical objects in the later years of the 18th century. For scientists the name “Herschel” will not be unknown. Caroline Herschel’s brother William discovered Uranus, and was paid as an astronomer by King George III. Her nephew, John was also well known as a scientist. However, relatively little has been written about Caroline.

The Comet Sweeper is based substantially on the autobiographical writing of Herschel. However, she was sufficiently well-known at the time to be referenced elsewhere, and indeed later in her life was bestowed with various honours and medals for her astronomical work.

Herschel was born in Hanover in 1750, her father Isaac was a musician and very much a self-taught man – something he passed on to Caroline. Anna, her mother, gets a less than sympathetic treatment from her daughter and consequently this book. For her early years Anna treated Caroline as a servant, and stopped her education as soon as it appeared it would help her leave the Herschel household in Hanover. She was finally given a means of escape when her brother, William, invited her to Bath to work in music with him in 1771. She had no previous training in music and put herself assiduously to learning what she needed to know. William Herschel was earning up to £400 per year from music lessons and the like when he invited his sister to join him. It seems that Caroline became a significant musician in her own right, at least until her brother dragged her into astronomy.

This is something of a theme through the book, Caroline Herschel is clearly very capable and when given the opportunity can excel in whatever she turns her hand to. But the choices she has are limited. In the first instance her mother controls what she can do, then her brother – switching her from music to astronomy with little regard for her own wishes.

In astronomy Herschel started by assisting her brother in the workshop – at the time, to get the best telescope, you built them from scratch yourself. She supported him in his observations but she also carried out observations on her own. The “sweeping” of the title is the systematic scanning of the night sky with a telescope to identify static features such as stars and nebulae but more specifically to find comets. To a degree the discovery of nebulae was incidental to the main task of finding comets, nebulae were easily confused with comets so recording their locations was an essential part of finding comets. The Herschel’s work followed, but only by a few years, the publication of Charles Messier’s first catalogue of diffuse celestial objects in 1774.

As well as discovering comets and nebulae Herschel was also responsible for publishing Catalogue of Nebulae and Clusters of Stars in 1798, which built on the earlier work of Flamsteed. Ultimately this became the New General Catalogue of stars. Amateur astronomers will know this work, Messier’s catalogue provides information on the 100 or so most prominent objects whose identifying numbers are prefixed with an M- beyond this are the NGC objects – from the New General Catalogue which is the descendant of Herschel and Flamsteed’s catalogue.

Herschel was honoured in her own lifetime with a gold medal from the Royal Astronomical Society, as well as honorary membership and medal from the King of Prussia, at the age of 96. She was the first woman to be published in Philosophical Transactions the journal of the Royal Society. These awards did come until quite late in her life although she was paid £50 per annum by King George III as an assistant to her brother. He was paid rather more, £200, but notably rather less than he earned as a musician.

I found the broader insight that The Comet Sweeper gave into the lives of Georgian women was interesting. Women did not have formal positions within the scientific community of the time but they contributed as wives, sisters, daughters. At the time there was little in the way of formal, paid, scientific community – it was very much a gentleman’s club but there was a place for women in it although not necessarily of equal status.

This was to change later in the 19th century when science became institutionalised, as a result women were excluded by, for example, not being able to receive degrees or even attend lectures at university.

The Comet Sweeper is not a long book, it is readable and casts an interesting light on women in science in Georgian England and the specific contributions of Caroline Herschel.

Aug 01 2017

Book review: Inventing Temperature by Hasok Chang

inventing_temperatureMy next read is more academic in character, Inventing Temperature: Measurement and Scientific Progress by Hasok Chang. As an undergraduate chemical physics student, temperature was important to me. On the chemistry side of the equation, increasing the temperature of a reaction by 10 degrees doubles its rate. Statistical mechanics forms the core of chemical physics, and this is very much about temperature and equilibrium. In a laser, light is emitted when population inversion is achieved which some describe as negative temperature. It’s fair to say that measuring temperature is one of the core activities of any physical scientist, even if all you are trying to do is keep your experiment at a fixed temperature.

The book starts with a discussion of the fixed points used in thermometry. For the familiar Celsius temperature scale these are (crudely) the melting point of ice and the boiling point of water. The temperature difference between these two fixed points is divided into 100 equal divisions, and the scale can be extrapolated above and below these fixed points.

But this isn’t so easy, it isn’t necessarily a given that ice always melts and water always boils at the same temperature – superheating and supercooling are things that will dog you, particularly if you take great care with your experiments! In a theoretical sense we now know that melting and boiling happen at fixed temperatures under fixed conditions. Experimentally exactly how you set your water boiling and your ice melting can change the temperature at which they appear to melt or boil. In the early days of temperature measurement these questions were all consuming and took many years to resolve.

Another question is “what does it mean to measure temperature"?”. Chang proposes a Principle of respect in the development of measurement and also epistemic iteration. That is to say that the development of the measurement of temperature is guided – respects – our perception of temperature but is not dominated by it. Sometimes our perception of temperature is wrong, epistemic iteration allows us to correct that perception or at least make our measurement correct. If you’d like an example of an incorrect temperature perception try testing the same water having run your hand under hot and cold taps – we perceive a different temperature even when there is no difference.

The next step in the process of measuring temperature is trying to make a linear scale which does not depend on the precise nature of the thermometer you use. This is difficult to achieve without having a clear idea of what temperature is. Linked to this is the problem of what the best “working fluid” is for your thermometer – although we are familiar with mercury and alcohol thermometers, from a scientific point of view “air thermometers” are the best behaved. To a 20th century physicist this is unsurprising but in the late 18th and early 19th century this was not obvious. Furthermore, air was more difficult to work with.

After considering the problem of the linearity of the temperature scale Chang turns to temperatures far above and below the fixed points of the scale, below where mercury freezes and above where glass melts. The challenge at low temperatures was attaining low temperatures, the challenge at high temperatures was finding any sort of device that could survive and keep working at high temperatures. For a long time a pyrometer invented by Josiah Wedgewood was used which relied on measuring the shrinkage of clay pellets as a measure of temperature. Joining this temperature scale to one measured at lower temperatures with conventional thermometers was hard.

Finishing the specific sections on measuring temperature is a chapter on theoretical considerations, focusing on the work of Joule and Thomson. Who established an absolute temperature scale, and under what circumstances a gas could be used to measure such a scale.  Epistemic iteration plays a part here as the combatants need to find a concrete system to demonstrate an abstract principle, and show that their concrete system is close to being abstract!

The book ends with two chapters on more general matters in the history and philosophy of science. The first of these is on Chang’s view of how science progresses. The second is on what Chang calls “complementary science”, how the history and philosophy of science could lead to an increase in scientific knowledge. In my view scientific progress would likely be improved if students were taught better in the history of their subject.

I found this book fascinating, as far as I can recall I came across a much abbreviated form of some of this work during my A-levels when I wasn’t really able to appreciate the scale of the challenge in the now simple act of measuring temperature. Once at university measuring temperature was a given but I gained a more sophisticated understanding of what temperature meant – an understanding that was based on theories developed in the late 19th century.

Jun 29 2017

Book review: Numbers and the making of Us by Caleb Everett

numbersMy next read is Numbers and the Making of Us by Caleb Everett. It is a book about our innate numerical senses, and how we developed skills beyond them that are enabled by the language of numbers.

The book starts with an overview of numbers in writing systems. Highlighting that ways of recording numbers, in the form of tallies, appeared before full blown language. Tallies seem to be evident in prehistoric artefacts before being found in the Fertile Crescent where they were used to record quantities of grain and the like in early written languages. Later in the book Everett proposes that “static” agriculture drives the development of numerical language, citing as evidence the fact that the few remaining hunter-gatherer societies have fewer number-words than their agricultural counterparts. He suggests that as specialisation due to agricultural occurs, it becomes necessary to record amounts of food so that they can be bought and sold (or exchanged for other goods).  

I was interested to read that many human number systems are quinary, decimal or vigesimal, or put more simply based on 5, 10 and 20. This relates to the number of fingers and toes we have, our number words are linked to the numbers of our fingers and toes because they are used for counting. In some languages the link to fingers and toes is explicit, whilst in Western European languages it is not. Vigesimal vestiges remain – in English the number 20 has it’s own special word – score. And in French eighty is quatre vingt and ninety is quatre vingt dix. Later in the book, Everett suggests that our bipedalism helps with the development of counting – our fingers being relatively available (unlike toes) and also important because of our use of tools.

Numbers don’t just come into language in the form of numbers, they can be inferred in the plurals of nouns, or in the forms of verbs. In English we are used to the idea of adding an “s” at the end of a word to make a noun a plural. This is common across many languages. Plurals can also be formed with prefixes (at the start of the word), and even “Infixes”. For example in the Tuwali Ifugao language woman is babai but women is binabai. The plural is formed by adding –in- within the word. But not only this, number can be indicated in the conjugation of forms, and pronoun forms. English is a bit sparse in this regard, other languages have pronouns indicating two or three people as well as just the English divisions of one (I) and many (we).

It seems we have an innate, “exact” number sense for numbers up to three. Beyond three we have a innate, fuzzy number sense meaning we can tell when objects groups are more than or less than one another but where we cannot accurately subject the numbers of objects in a group. Beyond these two senses is a matter of learning.

The evidence for this comes from a number of places, the first of these are experiments with people from anumeric Amazonian tribes and Nicuraguan home signers, who are also anumeric. By anumeric, we mean that they do not have number words beyond three. These people are able to distinguish small numbers exactly but become increasingly inaccurate beyond 3.  

A second strand of evidence comes from the investigation of numeric ability in children, some as young as 48 hours old! Although older children can be questioned directly in spoken language regarding numbers, for younger children it is necessary to use indirect methods. In particular, researchers can track gaze, and watch the absence of sucking on a dummy. Children (and adults), turn their gaze to things they find interesting or unusual and will stop chewing/swallowing/sucking as well. An example experiment in this area is to hide an object behind a screen, and then pretend (or not) to add a second object of the same type, or remove the object. If the child shows excessive gaze, or reduced sucking then it is inferred they are surprised by what they see when the screen is dropped again. That’s to say if they see 2 objects when they expected 1, or vice versa. This surprise implies the ability to count.

Evidence for the exact and fuzzy number sense is also found in experiments on animals. Although some animals, following much training appear to be able to count exactly beyond 3 they are rare. Otherwise they show the same types of innate abilities that we have.

Language is the enabler for exact counting beyond three, clearly sometime in the past one or more humans has learned how to count. Embodying this ability into language enabled it to be transmitted to other, less gifted humans.   

I found this book really fascinating, interested, as I am in both words and numbers.

Jun 05 2017

Book review: Women in Science by Rachel Ignotofsky

women_in_scienceWomen in Science by Rachel Ignotofsky is a whistle-stop tour of 50 women in science mainly from the mid-19th century onwards. Each woman gets a double page spread, with a few paragraphs of text on one page and a cartoon drawing of them and some catchphrases on the other. As well as this there is a centrefold of lab equipment, a timeline and some very brief descriptions of 14 further women in science at the end. You can see more on the authors website, here.

Also included are some statistics on women in science, technology, engineering and maths (STEM), I suspect the figures relate to the US but the picture would not be dramatically different in the UK. On the plus side the proportion of women in STEM has increased from 14% in 1970 to 41% in 2011 and it has been rising steadily. The proportion of engineers who are women rose from 3% in 1970 but has been on a plateau at 13% since 1990. In computer work the proportion of women peaked in 1990 and has been dropping since then, it now stands at 27%.

Why is this important? Historically women have been treated as second class citizens. It wasn’t that they tried to do the things that men did traditionally, and failed. They were very actively prevented from studying in their chosen fields. They weren’t allowed into science labs or science lectures. And if by some chance they did manage to train themselves, there were no jobs or facilities for them to continue their work because they were women. This is the legacy we are trying to overcome.

It isn’t a matter of deep history, women alive today will have been refused access to degree courses in their chosen subjects. Cambridge University, for example, only awarded the first full degree to a woman in 1946, which is the year my mother was born. The parents of men alive today would have kept those systems in place. Women only got the vote in the UK during the lifetime of my grandparents. After I was born my mother was denied an application form for an administrative job at a local garage because the owner felt that her place was at home with her young children. Since the 1970s the spirit of the welfare system in the UK has changed to one in which it is seen as best for both parents to work. And yet historically women have been denied access to many careers. This leaves a legacy because people tend to recruit other people like themselves. The aspirations of children and young people are shaped by the roles they see people like them undertaking.

This book provides a set of role models that show that women can be successful in science.

The 50 chosen women are from a range of sources, many of them are from the rather sparse roll-call of female Nobel Prize winners. Some of the names I recognised: Marie Curie, Jocelyn Bell-Burnell, Jane Goodall, Ada Lovelace, Katherine Johnson (through my very recent reading), Dorothy Hodgkin, Rachel Carson, Lise Meitner. Others I had never heard of, like Lillian Gilbreth who worked on psychology and industrial design. Or Patricia Bath, who founded the American Institute for the Prevention of Blindness.

I’ve looked through the book with my son (aged 5), he seemed to like it – although his main questions on each page were “Where was she born?” and “Where did she go?”. Then again in a book on the history of art his questions were “Where’s Jesus?” and “Why are those people naked?”. I suspect it is better suited to children a little older than him.

Currently my son is binge watching “Horrible Histories”, a programme for children about history. It is a string of vignettes from history acted as adverts, as music videos, game shows or just plain acted. It is lively and educational. It strikes me that Women in Science would provide an excellent source for a sister programme.

I don’t think I am the intended audience for this book but it did remind me to put some more biographies of women in science on my reading list. I’m pleased to see there is a biography of Maria Sibylla Merian, 17th century illustrator and entomologist. Ada Lovelace and Mary Anning are also on my list.

Jun 01 2017

Book Review: Scala for the Impatient by Cay S. Horstmann

scala_for_impatientI thought I should learn a new language, and Scala seemed like a good choice so I got Scala for the Impatient by Cay S. Horstmann.

Scala is a functional programming language which supports object orientation too. I’m attracted to it for a number of reasons. Firstly, I’m using or considering using a number of technologies which are based on Java – such as Elasticsearch, Neo4j and Spark. Although there are bindings to my favoured language, Python, for Spark in particular I feel a second class citizen. Scala, running as it does on the Java Virtual Machine, allows you to import Java functions easily and so gives better access to these systems.

I’m also attracted to Scala because it is rather less verbose than Java. It feels like some of the core aspects of the language ecosystem (like the dependency manager and testing frameworks) have matured rapidly although the range of available libraries is smaller than that of older languages.

Scala for the Impatient gets on with providing details of the language without much preamble. Its working assumption is that you’re somewhat familiar with Java and so concepts are explained relative to Java. I felt like it also made an assumption that you knew about the broad features of the language, since it made some use of forward referencing – where features are used in an example before being explained somewhat later in the book.

I must admit programming in Scala is a bit of a culture shock after Python. Partly because its compiled rather than interpreted, although the environment does what it can to elide this difference – Scala has an REPL (read-evaluate-print-loop) which works in the background by doing a quick compile. This allows you to play around with the language very easily. The second difference is static typing – Scala is a friendly statically typed language in the sense that if you initialise something with a string value then it doesn’t force you to tell it you want this to be a string. But everything does have a very definite type. It follows the modern hipster style of putting the type after the symbol name (i.e var somevariablename: Int = 5 ), as in Go rather than before, as in earlier languages (i.e int somevariablename = 5).

You have to declare new variables as either var or val. Variables (var) are mutable and values (val) are immutable. It strikes me that static typing and this feature should fix half of my programming errors which in a dynamically typed language are usually mis-spelling variable names, changing something as a side effect and putting the wrong type of thing into a variable – usually during I/O.

The book starts with chapters on basic control structures and data types, to classes and objects and collection data types. There are odd chapters on file handling and regular expressions, and also on XML processing which is built into the language, although it does not implement the popular xpath query language for XML. There is also a chapter on the parsing of formal grammars.

I found the chapter on futures and promises fascinating, these are relatively new ways to handle concurrency and parallelism which I hadn’t been exposed to before, I notice they have recently been introduced to Python.

Chapters on type parameters, advanced types and implicit types had me mostly confused although the early parts were straightforward enough. I’d heard of templating classes and data strctures but as someone programming mainly in a dynamically typed languages I hadn’t any call for them. I turns out templating is a whole lot more complicated than I realised!

My favourite chapter was the one on collections – perhaps because I’m a data scientists, and collections are where I put my data. Scala has a rich collection of collections and methods operating on collections. It avoids the abomination of the Python “dictionary” whose members are not ordered, as you might expect. Scala calls such a data structure a HashMap.

It remains to be seen whether reading, once again, chapters on object-oriented programming will result in me writing object-oriented programs. It hasn’t done in the past.

Scala for the Impatient doesn’t really cover the mechanics of installing Scala on your system or the development environment you might use but then such information tends to go stale fast and depends on platform. I will likely write a post on this, since installing Scala and its build tool, sbt, behind a corporate proxy was a small adventure.

Googling for further help I found myself at the Scala Cookbook by Alvin Alexander quite frequently. The definitive reference book for Scala is Programming in Scala by Martin Odersky, Lex Spoon and Bill Venners. Resorting to my now familiar technique of searching the acknowledgements for women working in the area, I found Susan Potter whose website is here.

Scala for the Impatient is well-named, it whistles through the language at a brisk pace, assuming you know how to program. It highlights the differences with Java, and provides you with the vocabulary to find out more.