Jan 20 2019

Book review: Hedy’s Folly by Richard Rhodes

Back to some history of technology with hedys_follyHedy’s Folly by Richard Rhodes. This book concerns the patent granted to Hedy Lamarr, Hollywood actress, and George Antheil, experimental musician, for the frequency hopping radio communications system. Originally it was intended to allow secure, jamming resistant communications between torpedoes and their control aircraft or ships, nowadays it is most notably the basis for Bluetooth and WiFi communications.

I’ve previously read Richard Rhodes “The Making of the Atomic Bomb”, which is a massive tome, Hedy’s Folly is a rather more modest affair. It provides some biographical material on Lamarr (born Hedwig Kiesler) and Antheil but only in as much as it leads to the patent of the title.

Hedy Lamarr was born in Austria in 1914, to a wealthy family – her father was banker who clearly cultivated her interest in how things worked. Following a brief career in European theatre and film she married Fritz Mandl in 1933. He was an arms manufacturer and one of the richest men in Austria. He didn’t want to see his wife continue her acting career. On the death of her father Lamarr resolved to leave her husband but in the interim she paid close attention to the technical discussions on armaments which she was party to. In all likelihood she was doing this throughout her marriage, despite his controlling nature Mandl clearly valued her opinions (even if he didn’t like them). Lamarr then moved to the States with Louis Mayer of MGM for whom was to make a number of films. In this milieu she met George Antheil.

Antheil in Trenton, New Jersey in 1900. He travelled to Europe in 1921 where he composed the Ballet Mécanique, originally intended as the score to a film it ended up twice the length of the film. As originally envisaged Ballet Mécanique required 16 player pianos and an aeroplane propeller – amongst many other sound making devices. Essentially Antheil vision was much in advance of what technology in the twenties and thirties could deliver. The player piano plays a part in the story. Player pianos were briefly popular as a way for everyone (who could afford one) to make music, they were automated pianos programmed using a paper roll with holes directing the music. The operator simply had to provide power and rhythm. They were supplanted by radio. The important feature was the ability to control sound automatically.

Antheil returned to the US, to Hollywood, in 1936 where he turned to writing film scores, his experimental music proving rather unpopular. It was here he met Hedy Lamarr.

The spirit of the Second World War in the US was that everyone would do what they could to help. Antheil had a sideline in writing about endocrinology, and made suggests on how to defeat the Nazis by this approach. Later in the war Hedy Lamarr was to do considerable work in encouraging Americans to buy government bonds to support the war effort, as well as volunteering at the Hollywood Canteen – entertainment for servicemen.

Lamarr was an inventor in her spare time, her background meant she knew the problems faced with torpedo guidance. So it was not unsurprising for her to work with Antheil on a frequency hopping patent for torpedo guidance. The central idea of the frequency hopping patent was to transmit radio instructions between controller and torpedo over a series of radio channels at different frequencies switching synchronously between channels. In the original patent the number of channels used is relatively small (less than 10), hops are relatively slow – of order minutes and were controlled by a player piano style roll.

The US Navy chose not to develop the patent, stating that the apparatus was too bulky. This seems to be a bit of a misunderstanding – the player piano inspiration was indeed quite bulky but could easily reduced in size using current technology. More likely was the fact that US torpedo performance at the beginning of the war was abysmal – 60% of torpedos experienced technical failure, so it was likely they had other priorities. 

Lamarr and Antheil’s patent on frequency hopping expired in 1959, the US military implemented several frequency hopping systems from the beginning of the sixties. As technology improved it evolved to so-called spread spectrum techniques. The difference between frequency hopping and spread spectrum is really just one of scale. These techniques finally became public in 1976.

Spread spectrum techniques eventually found important applications in Bluetooth and WiFi. Originally designed to be resistant to jamming – the deliberate use of noise to block signals – it is also resistant to unintentional noise. Furthermore it can be used with very low power transmissions so it can cohabit with other signals used for longer range applications and parts of the electromagnetic spectrum where there is a lot of noise.

Hedy Lamarr’s part in the development of frequency hopping is finally being recognised, and George Antheil’s more experimental music is finally being recognised too – technology has now reached the point where his original vision can finally be realised.

This is a fascinating little book, focused on one small invention with huge consequences. It isn’t a biography of Hedy Lamarr, and it isn’t a biography of her co-inventor George Antheil.   

Jan 19 2019

Book review: The Practical Guide to Modern Music Theory for Guitarists by Joseph Alexander

Continuing with the guitar theme here I reviewguitar_theory The Practical Guide to Modern Music Theory for Guitarists by Joseph Alexander. Reading the Beginner’s Course I felt I was missing out by not understanding why there were the notes there were and how they could be put together. The Beginner’s Course gave me enough knowledge to realise that generally songs were not just made by mashing a whole pile of notes together and hoping for the best.

My background is in physics, so I have very clear ideas as to what I consider to be a theory. Physics covers music somewhat indirectly, during training physicists are taught about “oscillations and waves” and “harmonic oscillators”. So to a degree I approach this book expecting to find a physics-like theory, music theory is not like physics theory.

The book is divided into two parts. The first part covers how musical scales are constructed, how chords are formed and chord progressions. The second part talks about each of the modes of the major scale, with fine names such as the Dorian, Lydian, Mixolydian and the Phrygian. Following some introductory material the second part of the book follows a regular pattern for each of this modes, so has the feeling of a reference section.

I found the first section jumped in a bit fast, I’ve not looked at musical scale notation for a very long time, and would have welcomed a bit more explanation. A guide to guitar tab notation would also fit well in here. The basics of both of these forms are straightforward enough but there are various symbols and conventions which are difficult to search for and could have been usefully collected here.

Indeed the existence of natural, sharp and flat notes is not explained. As I understand the natural notes A,B,C,D etc where discovered in antiquity to provide harmonious music. Although there are hints here that in the Western world we have all been trained to hear harmonious music in tunes composed from natural notes.

The natural notes represent musical sounds which have certain relationships in terms of frequency. The sharps and flats were added some time later based on a uniform division of the octave (a doubling of frequency) into 12 evenly spaced notes (in frequency). The notes on this scale fall approximately onto the natural notes but in addition provide some sharp and flat notes. The notes F flat and C flat do not exist which explains the irregular appearance of a piano keyboard and makes everything more complicated. The interval between a natural note and its sharp or flat is a semitone. The interval between two consecutive natural notes is a tone.

The C major scale comprises all the natural notes starting at C (CDEFGABAC), since natural notes are not evenly spaced in frequency this means that the steps between notes are not equal in size. No problem for a scale starting at C but if we form try to form a scale starting at a different natural note such as A (ABCDEFGA) then it sounds “wrong”, in fact this is a minor scale not a major one. To make a major scale we need to match the pattern in step sizes found in the C major scale which for A is (A, B, C♯, D, E, F♯, G♯). The non-uniform nature of the gaps between notes in the major scale makes the rules for forming scales very wordy.

I’m leaving it as an exercise for me to write Python code that constructs scales, this would help me see music theory as a more physical theory.

Chords are sets of three notes drawn from scale with the same spacing on the scale, so on the C major scale the C chord is formed of the first, third and fifth notes (CEG), similar we can make chords D (DFA) and E (EGB). Where there are whole tones between the first two notes in the chord is a a major chord, if there is only 1.5 tones then the chord is a minor chord. 

Early in the book Alexander makes reference to how the major scale is “too bright” for rock, this comment along with others later in the book discussing different modes and which forms of music they suit was intriguing to me but no expanded upon. Similarly with chord progressions (sequences of chords) there is clearly some theory as to moods that different chord progressions invoke but there’s no discussion of this in the book. This is where musical theory diverges from physical theories. 

Looking back I think I picked up this book too early. It feels like revision notes for someone taking a rather high level music examination. I’ve certainly learnt from it and I can see it as a useful reference in future but for me it raised more questions than provided answers.

Jan 13 2019

Book review: Justinguitar.com Beginner’s Course by Justin Sandercoe

This review is a bit of a departure for me, it is of beginners_courseJustinguitar.com Beginner’s Course by Justin Sandercoe.

I’m a big fan of book learning, so when I decided to learn how to play the guitar a book was the obvious place to start. To be honest I picked the justinguitar.com book largely because it was ring-bound, a quick search reveals many other options but envisaging how I would use the book a ring-bound version seemed to make sense.

It turns out this somewhat arbitrary method of selection has worked out quite well. The book is accompanied by a substantial website (https://www.justinguitar.com/), which includes free video versions of the lessons in this book, amongst much other, mainly video, material. The videos are typically less than 10 minutes long, which is ideal. Looking around similar video courses Justin Sandercoe is, by comparison, clearly a very good teacher. His videos are quite casual in their feel but focussed and well put together. There are also purely app based guitar course but that seemed a bit modern for my tastes.

The book is divided into 9 stages, in each stage new chords are introduced as well as associated techniques, such as rhythm patterns and in the later stages scales and fingerstyle picking. A key element of learning chords is “fingering”, which finger goes where.

I got on really well with the chord change aspect of each stage, you’re invited to record how many chord changes you can do in a minute – which is absolutely my thing! I have a spreadsheet recording how my pace has increased over time. I have made satisfying progress. I also feel somewhat triumphant that I can do apparently notorious F-barre chord although don’t ask me to change to and from any other chord at any great rate.

There is an associated songbook, each stage enables a few different songs. I haven’t made a great deal of use of this yet. I found each stage came with a list of 10 songs but I didn’t know which to focus on to improve my skills. Possibly the answer is “any of them”, choose the ones that appeal to your musical taste.

The emphasis is very much on the rhythm side of guitar playing which isn’t where crowd pleasing showing off lies. Sandercoe does have videos showing you how to play classic guitar riffs (like Smoke on the Water, Seven Nation Army, Creep) but these aren’t included in the book. I found these more motivating than the songbook.

It has taken me a couple of months to get through the first 6 stages of the book. I’ve jumped ahead for a few things – starting to play scales, experimenting with fingerstyle playing and playing a 12-bar blues shuffle. As it stands my chord change rate is a bit lower than the goal for the whole book and I’m not very good at strumming and changing chords, certainly not strumming anything but the simplest patterns.

Learning chords from the book works really well. I found learning strumming patterns required the CD sound tracks at the very least and really needed the video lessons, certainly for the more complex patterns.

Beginner’s Course includes listening exercises at each stage, I must admit I didn’t do well with these. I practiced them using an unrelated app which probably didn’t help – I felt I wasn’t making progress. The focus of the app was very much on the speed at which you could recognise chords rather than accuracy.

There’s a little bit of music theory included in this beginners course – simple stuff relating to where notes appear on the guitar fretboard but there’s no real discussion of how chords are constructed and the relevance of musical scales and chord progressions. I’ve looked elsewhere for this since I’m interested, I think Sandercoe actually introduces quite a lot of this material indirectly.

What I’ve really enjoyed in playing guitar has been managing to do a recognisable rendition of Seven Nation Army by The White Stripes within a couple of weeks, playing the 12-bar blues shuffle from the beginners course book, making a passable attempt at Creep by Radiohead. I think my next task is to hunt out the videos for songs that Sandercoe has done which appeal to me and give me motivation to practice some key skills. At the moment I have my eyes on Smells Like Teen Spirit (power chords), Jolene (finger style playing). Hey Joe (riffs), Thunderstruck (fast, simple riffs). It helps that these tracks will impress the girl in my life (Mrs H, aged the same as me).

This review is different from most of my book reviews, it is more about how this beginners course works for me than a review of the book in itself. Learning to play the guitar competently is the work of years, this book is a good start on the path.

Jan 06 2019

Book review: Mapping Society by Laura Vaughan

mapping_societyMy next review is of Mapping Society: The Spatial Dimensions of Social Cartography by Laura Vaughan. This book covers four broad themes around mapping which are presented in the order in which they first occurred. As well as discussing contemporary material there is some re-analysis in terms of “space syntax”. This is a modern theory of urban spaces which measures things like accessibility and connectedness for road layouts. This feels very familiar to me since I use a similar approach to estimate the age of buildings on the basis of street layout.  

The first theme is the disease map: maps of deaths due to disease, typically during epidemic outbreaks. Snow’s map of cholera deaths around the Broad Street pump in 1853 is the best known of these. His innovation was to use the map to identify the cause of cholera as being waterborne, and to use the map as a device for presenting his case. At the time the prevailing theory of disease was that it was airborne – the miasma theory. Snow’s map was not the first of its type though. Vaughan, wisely, doesn’t get into the discussion of the “first” such map but presents Seaman’s map of yellow fever deaths in New York, dating from 1797 as an early example. She cites a study finding 53 published maps of cholera deaths by 1832.

These maps of disease were used as to motivate the introduction of sanitation laws which became widespread during the middle years of the 19th century.

The second theme is poverty. Maps of disease often included data on sanitation and also poverty. Charles Booth’s work on London towards the end of the 19th century is the most notable in this area, his initial study was repeated 10 years later and then a further 30 years on in a separate survey. The novelty here was to measure levels of poverty in some sort of quantitative way, for this he is sometimes called the first social scientist. The fears of society at the time were that ” the poor” formed a cohesive mass that could rise up. Booth showed this was not the case, the poor were poor in many different ways and for different reasons. Poverty was often found in close proximity to wealth. Work like Booth’s was used to motivate changes in building regulation. Booth observed that irregularity of income was important as well as absolute level. One of the observations from this period is that areas of poverty, often identified at the scale of households, where correlated with inaccessibility – being off the beaten track. The poor were not found on the main streets but rather tucked away in poor housing set back behind better accommodation. New infrastructure such as canals and railways could introduce new pockets of inaccessibility – leading to poverty, or at least attracting the poor to areas thus cut off.

Booth’s work helped to motivate slum clearances and ultimately social security policies such as state pensions. Slum clearances proved to be a mixed benefit, all to often the slum is replaced with more desirable accommodation which displaces the original occupants to be replaced by the slightly more wealthy. The problems that the urban environment engenders can be very persistent. The spatial distribution of deaths in Paris due to cholera in 1849 are quite similar to those from the heatwave of 2003.

The third theme was nationality, race and immigration. These arose around the end of the 19th century, in both San Francisco’s Chinatown area, where the outcome was pretty malign in that Chinese immigration was banned and also in the East End of London, where there was a large influx of Jewish immigrants who came as a result of the Russian progroms. The book cites the Venice Jewish Ghetto, founded in the 16th century and where we get the word “ghetto” from. In the US there were maps of race, W.E.B. du Bois, himself an African-American pioneered this work in Philadelphia.  

The final theme is crime, in fact much of this chapter is about licensed premises. In the latter half of the 19th century the drinking habits of the working classes were of intense concern. In the US this concern eventually led to Prohibition but both the UK and US had temperance movements. In the more distant past, public houses and bars served as the “front room” for poorer families. Their own homes were quite probably overcrowded, unheated and insanitary – the local pub was a warm pleasant place to spend any free time. They were also a place to find work, both legal and illegal.

Vaughan highlights that we don’t see maps of the form found in the 19th century in the late 20th century. Typically maps from this later period are on a larger scale, we don’t see data presented at such high spatial resolution but they cover a wider area. For example, the national census in the UK typically presents data at the Lower Super Output Area scale which covers approximately 1000 dwellings. Sometimes data is available at postcode level, such as the Police.UK crime data, a postcode will typically contain approximately 30 addresses. Devices such as mobile phones mean that high resolution data collection at scale is feasible with more modest resources than previously required. However, we would not publish the data in the manner of the 19th century maps because it is personal information, essentially maps such as Booth’s and Snow’s identify individuals including there health and wealth status.

Mapping Society is a beautifully produced book, with colour figures throughout rather than relegated to central pages, it gives some background to those iconic maps with which many of us are familiar. 

Dec 31 2018

Review of the year: 2018

My reading rate is somewhat reduced this year, 26 books covering both fiction and non-fiction in 2018 compared to 34 and 32 in the two previous years. In the autumn, Thomas and I started learning to play the guitar, Thomas taking lessons at school, me working independently – maybe this is what distracted me from reading. I wrote a blog post on this.

Anyway, to the books. I started the year with a Christmas Extravaganza – short reviews of books on walking, maps, birds, Vermeer and Caneletto. I read some work related books on machine learning, data strategy, and behavioural marketing. This last one was an attempt to read about something a bit different from my usual data science/technology area of interest but it turns out that behavioural marketing is marketing targeted using data which is already my patch. Nabokov’s Favourite Word is Mauve, on the statistically analysis of word frequency distributions, felt like it fitted this category of work-like books.

A couple of the books were quite long: The Devil’s Doctor – Philip Ball’s biography of Paracelsus and The Silk Roads, by Peter Frankopan. Frankopan’s book is a history of the world viewed through the lens of the overland route to China from Europe which has it’s centre of gravity in the Middle East. I was a bit surprised when this coverage came all the way up to the present day. Lucy Inglis’ book Milk of Paradise, on opium and its derivatives, morphine and heroin, had a similar geographic coverage to Frankopan’s book with trade routes passing through the Middle East to China and Asia.

William Armstrong: Magician of the North by Henrietta Heald and Chrysalis: Maria Sibylla Merian and the Secrets of Metamorphosis by Kim Todd were biographies of individuals. Armstrong was a Victorian industrialist famous for his house, Cragside, which was the first to be lit with electricity. Merian was a naturalist and illustrator in the 17th century, she is better known outside the UK – clearly a very remarkable woman. These days I prefer ensemble biographies such as The Philosophical Breakfast Club by Laura J. Snyder which covers William Whewell (pronounced: who-ell), Charles Babbage, Richard Jones and John Herschel, and were involved in the reform of British science in the 19th century. Sentimental Savants by Meghan K. Roberts follows the move from savants as monastic figures into men embedded in families in 18th and 19th century France. What’s your type? by Merve Emre finished the year with a biography of Katherine Myers and her daughter Isabel Briggs-Myers who created the Myers-Briggs Personality Test.

Other Minds by Peter Godfrey Smith is possibly my favourite book of the year, it is the story of thinking and octopuses. Godfrey-Smith’s idea is to understanding thinking better by studying the most radically different thinkers he could find.

Inferior by Angela Saini is the story of scientific studies of women. It is a rather sorry tale of men clearly desperate to find biological basis as to how women are inferior whilst ignoring societal factors. I’m still endeavouring to read more books by women. For most non-fiction and fiction this is no hardship, niche technical books present a challenge since the number of women authors in this area is close to zero.

Finally, we have The Anatomy of Colour by Patrick Baty, a history of paint and interior decoration. Aside from the outright art books, definitely the most beautiful book of the year.

This year we went on holiday to Westendorf in Austria, Thomas’s first trip abroad. We know Westendorf well – we’ve skied there several times and been once in the summer. We went with my mum, who has been going so long the tourist office gave her a “long service” award this time around! The weather in Westendorf was scorching, much like the UK had been for a chunk of the summer. Fortunately the bedrooms in our apartment were in the basement which was nice and cool.

westendorf

On the domestic front, we have had our driveway replaced with resin-bound gravel. Probably the largest construction undertaking that we’ve done, approaching 15 years after moving in we finally got around to replacing the rather uneven gravel and original concrete slabs at the front of the house. It took rather longer than expected, most likely due to the installers discovering that the existing driveways and paths were sitting on sand and other uncompacted material rather than any sort of properly made base. Having completed the driveway, the front garden and fences looked a bit tatty too so we got those fixed too. All it requires now is for Mrs H to get more plants. If you want to enjoy the whole process in pictorial form, there is an album (here). A before and after are shown below.

before

driveway

On a related note: we paid off our mortgage!

Politically I’m in limbo, Brexit  has deeply upset me – it sees my friends and colleagues from other EU nations treated as second class citizens, cast into Kafka-esque Home Office procedures. The future for my son seems less open and outward looking, with reduced opportunities. I gave up listening to the Radio 4 Today programme after getting on for 30 years regular listening. Some of this is specifically to do with the Today programme: John Humphreys has long struck me as greatly over-rated, over-paid, and unprepared – getting by on bluster. More recently outright brexity. More widely the BBC uses its requirement for “balance” as cover. It gets regularly reprimanded by the regulator for bringing in Nigel Lawson to counter climate change scientists. Question Time panels regularly comprise 3 brexiters and possibly one remainer, if that. Its headline news programmes have ignored serious stories about the Leave campaign, or even actively prompted the Leave side.

I’m looking forward to more learning guitar in 2019, more reading and hopefully better mental health. Brexit will have either happened or not happened fairly shortly.

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