Category: Coffee review

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cafe with good nut knowledge Coffee review General Observations Science history slow

Coffee as an art at Briki, Exmouth Market

exterior of Briki coffee London
Briki London on the corner of Exmouth Market

Traditionally made coffee always appeals to my sense of coffee history. Coffee made its way out of Ethiopea via Turkey and the method of brewing the finely ground coffee in a ‘cezve’ or ‘briki’ is one that goes back a long way. It’s therefore always interesting when a new cafe arrives on the scene that offers “Greek” or “Turkish” coffee on its menu. Briki, in Exmouth Market, opened in May last year and so it was only going to be a matter of time before I visited to try it out. Aesthetically Briki appealed to me as soon as I walked through the door. Spacious and with the bar along one wall, there are plenty of seats available at which to slowly enjoy your coffee. The cafe itself is almost triangular and the other two walls have windows running all along them. What better way to sit and enjoy the moment (and your coffee) than to gaze out a window? Still, given that I had gone to a cafe called ‘Briki’ and that it advertised “Briki coffee” on the menu behind the bar, it was obvious that I had to try the briki coffee. The coffee was rich, flavoursome and distinctive, well worth the time taken to savour it. There was also an impressive selection of food behind the counter and the dreaded “does it contain nuts” question was met with a friendly check of the ‘allergen’ folder. I was therefore able to also enjoy the lovely (nut free) chocolate cake. Briki definitely gets a tick in the “cafes with good nut knowledge” box on my categories list.

image from British Museum website
Folio 109b from an album of paintings showing Turkish sultans and court officials. Kahveci. A youth who serves coffee. He is holding a cup in each hand, circa 1620.
© The Trustees of the British Museum

However as I realised later, the coffee was not brewed in the traditional way but in a Beko coffee maker – a coffee maker specifically designed for optimising the brewing of Turkish coffee. The idea of the Beko is that it carefully controls and automates the entire brewing process so that you get a perfect coffee each time. But just how do you make a ‘perfect’ Turkish coffee?

A quick duckduckgo (it’s a mystery to me why has this verb failed to catch on while ‘to google’ is used so frequently) revealed two sets of instructions on how to make Turkish coffee. The first set, (including some otherwise very good coffee brewing websites) suggested ‘boiling’ the coffee repeatedly in the pot (cezve/briki). The second set, which seemed to be more specifically interested in Turkish coffee (as opposed to interested in coffee generally), were much more careful, even to the point of writing, in a very unsubtle way, “NEVER LET IT BOIL“. According to this second set of websites, the coffee in the cezve should be heated until it starts to froth, a process that begins at around 70C, far below the 100C that would be needed to boil it. Warming the cezve to 70C produces these bubbles and the lovely rich taste of the traditionally made coffee. Heating it to boiling point on the other hand destroys the aromatics* that form part of the flavour experience of coffee and therefore makes a terrible cup of coffee.

The contrasting instructions however led me to recall a discussion in Hasok Chang’s Inventing Temperature. Perhaps we all remember from school being taught how thermometers need two fixed points to calibrate the temperature scale and that these two fixed points were the boiling point and the freezing point of water. Perhaps this troubled you at the time: Just as with making coffee in a cezve, just how many bubbles do you need in order to say that the coffee (or water) is ‘boiling’? How were you supposed to define boiling? How much did it matter?

Cezve, ibrik, Turkish Coffee Creative Commons license
Cezve, image © http://www.turkishcoffee.us

It turns out that these questions were not trivial. There is a thermometer in the science museum (in London) on which two boiling points of water are marked. The thermometer, designed by the instrument maker George Adams the Elder (1709 – 1773) marked a lower boiling point (where water begins to boil) and an upper boiling point (where the water boils vigorously). The two points differed by approximately 4C.  So how is it that we now all ‘know’ that water boils at 100C? And what was wrong with Adams’ thermometer? The Royal Society set up a committee to investigate the variability of the reported boiling point of water in 1776. Careful control of the heating conditions and water containers reduced the temperature difference observed between different amounts of boiling. However, as they experimented with very pure water in very clean containers they found that things just became more complicated. Water could be heated to 120C or even higher without ‘boiling’. They had, unintentionally, started investigating the phenomenon that we now know as ‘superheating‘. Superheating occurs when water is heated to a temperature far above its boiling point without actually boiling. What we recognise as boiling is the escape of gas (which is usually a mix of air and water vapour) from the body of the water to its surface. In order to escape like this, these bubbles have to form somehow. Small bubbles of dissolved air pre-existing in the water or micro-cracks in the walls of the container enable the water to evaporate and form steam. These bubbles of gas can then grow and the water ‘boils’. If you were to try to calibrate a thermometer using very pure water in very clean containers, it is highly likely that the water would superheat before it ‘boiled’, there just aren’t the ‘nucleation’ sites in the water to allow boiling to start. The Royal Society’s committee therefore came up with some recommendations on how to calibrate thermometers in conditions that avoided superheating which meant thermometers were subsequently calibrated more accurately and superheating (and improved calibration points) could be investigated more thoroughly.

Perhaps viewed in this way there are even more parallels between Turkish coffee and physics. It has been written that “making Turkish coffee is an art form“. It is a process of practising, questioning and practising again. The Beko coffee machine automates part of the process of making Turkish coffee. When it’s done well though, Turkish coffee is far more than just the temperature control and the mechanics of heating it. There is the process of assembling the ingredients, the time spent enjoying the coffee and the atmosphere created by the cafe in which you drink it. Coffee as art in Briki is something that I would willingly spend much more time contemplating.

 

Briki is at 67 Exmouth Market, EC1R 4QL

“Inventing Temperature”, by Hasok Chang, Oxford University Press, 2004

*Although these aromatics are part of what gives coffee such a pleasurable taste, they decay very rapidly even in coffee that is left to stand for a while, it is this loss of the aromatics that is part of the reason that microwaving your coffee is a bad idea. A second reason involves the superheating effect, but perhaps more on that another day.

 

Categories
Coffee review Observations Science history

Planet Earth is blue (or is it) at Ground Control, Clerkenwell

Ground Control, outside the cafe
Ground Control on Amwell St

Ground Control is a small little cafe on Amwell St. If you are in the Angel/Clerkenwell area it is well worth stopping by this interesting cafe which serves a variety of Ethiopian coffees. Of course they offer the normal espresso, Americano etc. type drinks but if you want to sample their coffee properly, I think it best to try one of their coffees prepared with a V60. Tasting notes are shown on the menu on the wall. Being fairly small, there aren’t that many tables, however if you are lucky enough to get one of the two tables at the window, you will find plenty around you to look at without resorting to checking your phone while you enjoy your coffee. Behind one of the tables at the window is a set of shelves with coffee beans (presumably for sale). Behind the other table is a picture of a lady holding a jug and a basket. Vibrantly coloured circular patterns form the backdrop behind her.

coffee mosaic, colour perception
The coffee mosaic at Ground Control

The picture (shown on the left) has a flow to it, you are almost drawn into the movement of the picture. This movement comes from the many, differently coloured, coffee beans that have been used to make the picture. Each bean is orientated slightly differently so that the lines through the bean flow with the picture, rather than the beans being mere individual pieces of a mosaic. The circular patterns, the lines of her shirt, all of these are produced by orientating coffee beans this way or that. The mosaic is also richly colourful. Many of the colours stand out, but some, arranged next to each other, appear more subdued. How do we see the colours of a picture? How much of our colour perception is due to the pigment of the paint, how much due to the lighting, and how much is due to the individual colouration of the neighbouring beans?

An artist known for his unusual use of colour was Georges Seurat (1859-1891). Seurat developed the technique of pointillism in which small dots of varying colours are painted next to each other. Viewed from a distance, the colour seen by the viewer may be quite different from the multitude of differently coloured dots perceived close up. As with the coffee bean mosaic, direction was given to Seurat’s work through the orientation of the painted dots. Seurat had based his technique on the state-of-the-art science of the day. One of the scientists whose work on colour theory influenced Seurat’s artistic development was Ogden N. Rood, a physicist who’s 1879 book “Modern Chromatics” he seems to have read (in its French translation)*. Rood had carefully distinguished between two types of colour mixing, that of mixing coloured lights and that of mixing pigments. Mixing pigments had been used by all of the old masters. It is the process by which paints are mixed to produce a new paint colour. Rood however showed that if small dots of colour were painted adjacently, when the painting is viewed from a distance such that the eye cannot distinguish the two dots individually but rather mixes them in the eye, the colour produced is that of mixing coloured lights, not coloured pigments. As he explained, colour mixing through adding light of different colours was an additive process, colour mixing through combining pigments was subtractive. More about colour theory and colour mixing can be found here.

Pointillism Seurat
Georges Seurat, 1859 – 1891
The Channel of Gravelines, Grand Fort-Philippe
1890, Oil on canvas, 65 x 81 cm, Bought with the aid of a grant from the Heritage Lottery Fund, 1995, NG6554
http://www.nationalgallery.org.uk/paintings/NG6554

In the late 1880s, Seurat was criticised for relying “unduly on scientific formulae”, though he himself seems to  have viewed his use of science merely as a guide, a way to help control the colour and light seen by the viewer*. The colours that we perceive can be affected by the colours they are adjacent to, as evidenced by many optical illusions. Yet even when everybody is looking at the same photo, we do not necessarily all see the same colour (I saw it as white and gold).

There is indeed a lot to the science of colour perception and some great fun that can be had with it. Seurat was aware of some of this and used science to understand how to best paint his paintings. Note how the (pointillist) border of the Seurat painting pictured on the right is a different colour at the top, do you think that affects how your eye perceives the top compared to the bottom of this painting?

Starting tomorrow, light and colour are to be combined in a three day “Lumiere festival” across London. The event looks as if it will take full advantage of the effects of different methods of colour mixing. If you are outside London, sorry! If you are lucky enough to be in London over the weekend, more details of what looks to be a fascinating science/art/experience event can be found here.

 

Ground Control is at 61 Amwell Street, EC1R 1UR

*”Seurat and the Science of Painting” by William Innes Homer was published by MIT press in 1964

Ordinarily I would have left the title of this post as a type of puzzle to see if anyone got the link (some posts on the Daily Grind have such puzzles, I’ve no idea whether I’m the only one who understands some of them). However, given that he passed away two days ago, here’s a rendition of David Bowie’s Space Odyssey (which is referenced in the title) sung by Cdr Chris Hadfield:

 

Categories
cafe with good nut knowledge Coffee review Science history

Hanging out at J+A Cafe, Clerkenwell

Exterior of J and A cafe (the bar is on the other side of the passageway)
Exterior of J and A cafe (the bar is on the other side of the passageway)

Tucked down a little alley, in the back streets of Clerkenwell is the J+A Cafe. Not just a cafe, but also a bar, J+A is a satisfying place to find, particularly if you happen to find it serendipitously. As you head down the alley, the café is on your right whereas the bar opens up on your left. The café is simply furnished, with bare brick walls adorned with a few impressionist paintings. There are plenty of seats at which to enjoy good coffee and home-made cake. Their website suggests that J+A specialise in Irish baking and so we dutifully had a slice of Guinness and chocolate cake with our coffees. Importantly, the dreaded “does it contain nuts?” question was met with a knowledgable answer and without the ‘frightened bunny face’ that I often encounter when I ask this question. J+A definitely gets a tick in the ‘cafe’s with good nut knowledge’ box on my website.

Lights were suspended from the ceiling, connected by wiring that was allowed to hang down, a section of electrical wire held at both ends and freely hanging. While I’m sure that this was done for aesthetic reasons (and certainly it works on that level), such hanging wires are in fact far more than merely pleasing to the eye. Such hanging wires were a mathematical puzzle just four centuries ago. Indeed, these simple hanging wires form curves that are so important they get their own name; they are catenary curves, from catena, the Latin for chain.

lights at J and A coffee Clerkenwell
Between each lamp, the electrical cord formed a catenary curve.

Galileo had thought that a wire hanging under its own weight and suspended at its two end points formed a parabola. A fairly simple curve that is easy to describe mathematically. It was natural for Galileo to assume that these catenary curves were really parabolic. He had earlier shown that objects that fell with gravity followed parabolic paths, and after all, the hanging wires did look almost parabolic. It fell to Joachim Jungius to show that the curve was not parabolic and then to Huygens, Bernoulli and Leibniz to derive the equations determining the form of the curve. Although the differences between the parabola and the catenary curves are subtle, they have profound consequences.

When a chain, or a wire, is suspended and allowed to hang under its own weight, it forms a catenary. Flipping this around, quite literally, a catenary arch will be self-supporting. This means that a vault made of a series of catenaries or a dome that is made into the shape of a catenary will be self-supporting with no need for buttresses. This property of the catenary curve was used by Antonio Gaudi in his designs of the Casa Mila in Barcelona and also by Christopher Wren. The famous dome of St Pauls is not a catenary, but it is not one dome either. It is in fact 3 domes stacked together. The outer dome is spherical (which is weak from a structural point of view) while the inner dome is a catenary. The dome between these two was designed, using the mathematics of the day, to support the impressive outer dome (more info here and here). Wren, was not just an architect, he was also a keen mathematician, there is maths, physics and beauty throughout many architectural designs.

Mathematics in the city reflected in the lights of J+A.

J+A is at 1+4 Sutton Lane, London EC1M 5PU

 

Categories
Coffee review General Science history

Something in the air at Mace by Coffee Chemistry Signature, KL

3D hot chocolate art on an iced chocolate, Mace, Mace KL, dogs in a chocolate
Drinking an iced chocolate with friends.

Perhaps Mace by Coffee Chemistry Signature in Kuala Lumpur should really have a “cafe-art” review rather than a “cafe-physics” review. Indeed, it was because of its latte art that Mace, which operates from a light and airy building in Damansara Uptown, Kuala Lumpur, had been recommended to me. With a comfortable interior and friendly staff, Mace is an interesting place in which to spend some time. But it is certainly the artistic endeavours that are the striking thing about Mace. Nor is it just ‘latte art’. The cakes at Mace arrive at the table decorated into an artwork. It is interesting that every visit to Mace will provide a different creation to enjoy, providing a place that you could return to again and again.

Nonetheless, this is a cafe-physics review website and there is also plenty of science to be found in latte art. For example, one of our drinks arrived with a 3D latte art sculpture floating on its surface. This piece requires manipulation of the rigidity of the milk foam, a topic that has been covered previously on the Daily Grind. However this time, it may be worth looking a little deeper into our frothy coffee: What makes a bubble?

The answer may seem obvious, inside the bubble is “air” with the bubble surfaces being formed from the water and proteins in the milk∗. But it is the question of what air is, and the implications of that, that is today’s Daily Grind.

Tweetie pie with a cake at Mace, KL
Cakes can be shared with cartoon characters at Mace

It appears that it was Empedocles (492 – 432 BC) who first recognised that air was a substance†. A thing that existed all around us. But it took until the seventeenth century and the invention of the air pump by Otto von Guericke (1602 – 1686) before people recognised that air was heavy. Guericke was responsible for the spheres of Magdeburg demonstration about the strength of a vacuum. He had fashioned two hemispheres of copper. Each hemisphere fitted very closely to the other. He then used his air pump to pump the air out of the spheres (ie. make a vacuum) and tried to pull the two hemispheres apart. Accounts vary but it is said that teams of 8-15 horses tethered to each hemisphere were unable to pull the spheres apart because of the vacuum created within the spheres†.

It was von Guericke’s air pump, together with the work of Boyle on gases and Torricelli’s invention of the barometer that prompted Francesco Lana-Terzi, SJ (1631-1687) to design an ‘air ship’. The idea was simple: If air had a weight and it is possible to make something lighter than air (by making a space inside a copper sphere a vacuum), then it should be possible to make something lighter than air such that it would float, just as objects that are less dense than water float. What differentiates Lana-Terzi’s design from previous fantasies about flight (such as Daedalus and Icarus) was that Lana-Terzi based his ideas on solid principles of mathematics and physics. He calculated how heavy the air was and balanced that with the amount of air that he would have to pump out of four hollow spheres of copper in order that they could lift a gondola full of people.

latte art by Mace, Eiffel Tower and hot air balloon
Art on a cafe latte at Mace

Although there were practical problems with Lana-Terzi’s idea of an air-ship based on four hollow copper spheres, his ideas were correct and eventually led to the development of the hot air balloon. And it is with the hot air balloon that we return to coffee, to Mace and find a connection with a London cafe. The artwork on my cafe latte was not, ‘latte art’ in the sense to which we have recently become accustomed. It was however very much art on a latte, with a scene featuring the Eiffel Tower depicted in chocolate. Just to the right of the Eiffel Tower and suspended in the milky sky was a hot air balloon, floating away exactly as Lana-Terzi had envisaged. Back in 1783, on the corner of Euston Road with Tottenham Court Road, there used to be a pub/coffee house called the Adam and Eve. It was renowned for its cakes and cream and its large tea garden. As far as I can work out, the tea gardens extended to around what is now Brock St and the site of a Beany Green. It was here, in 1783 that the balloonist Vincenzo Lunardi (1759-1806) “fell with his burst balloon, and was but slightly injured”‡. Fortunately for Lunardi, and for ballooning in general, it was only a slight setback. Lunardi went on to make a number of balloon flights, including the UK’s first successful hot air balloon flight.

So next time you are in Kuala Lumpur, why not spend a while at Mace imagining floating in on Lana-Terzi’s air ship gondola while you enjoy a gorgeously frothy iced chocolate. Who knows, one day Lana-Terzi’s air ship gondola may even feature on their latte art, I’d love to see that picture!

Mace by Coffee Chemistry Signature is at Damansara Uptown, Kuala Lumpur.

∗ On Food and Cooking, The science and lore of the kitchen, H. McGee, Unwin paperbacks, 1984

† History and philosophy of science, LWH Hull, Longmans, Green and Co, 1959

‡ Quote from London Coffee Houses, Bryant Lillywhite, 1963

 

Categories
Coffee review Coffee Roasters Observations Science history slow

Waiting for a green light at Alchemy, St Pauls

8 Ludgate Broadway, St Pauls
Alchemy Coffee

Alchemy, “a seemingly magical process of transformation, creation or combination”, is certainly a cafe that lives up to the dictionary definition of its name. The branch, on Ludgate Broadway near St Pauls, is the outlet that ‘showcases’ the coffee of Alchemy Roasters. On walking into this cafe, I was presented with a menu of two types of beans for espresso based drinks or two different beans for filter/aeropress. Both sets of coffees came with tasting notes. After a brief chat with the friendly barista I went for the San Sebastian with aeropress. Notes about the origins of the coffee are dotted around this superbly sited cafe (its location is ideal for people watching). The coffee is directly traded (where possible) and, if lattes or cappuccinos are your thing, there are also details about the farm that produces the milk.

Although there were cakes on the counter, I had just had lunch and so had to pass on what looked to be a good selection of edibles. The coffee though was certainly very good and definitely an experience to be savoured. As, perhaps I should have expected, when the coffee arrived it came in a beaker reminiscent of chemistry laboratories. From my chair in the corner, I could watch the preparation of the coffee behind the counter, the people coming into the shop to order their coffee and the crowds passing by outside.

E=mc2 Einstein relativity in a cafe
Scales at Alchemy. Weights on one side, chocolate on the other, it can only mean one thing: energy-mass equivalence

Close to where I was sitting was an old style set of measuring scales. This see-saw balance had weights on one side and chocolate on the other. Perhaps this connection seems tenuous, but for me weights on one side of the scales and an energy bar (chocolate) on the other side could only mean one thing:

E=mc²

The equation relating energy and mass for a particle at rest derived, and made famous by Einstein. The equation comes from Einstein’s theory of special relativity which states that nothing can be accelerated to faster than the speed of light (in a vacuum). First set down in 1905, the theory has some very odd predictions, among which the best known is probably the twin paradox (details here). The idea is that a moving clock will be observed to run slowly by a stationary observer, a prediction that has been confirmed several times by experiments using atomic clocks (here).

San Sebastian via Aeropress
Coffee is served at Alchemy

Moreover, the equation states that mass and energy are equivalent and that a small amount of mass can produce an awful lot of energy, (details here). A detail which will bring this story of a cafe-physics review nicely back to the Alchemy cafe, to London and to the importance of slowing down. The connection is through a set of traffic lights in Bloomsbury. Back in 1933, Leo Szilard was waiting to cross the road at the traffic lights at the intersection of Russell Square with Southampton Row. Szilard had recently escaped from Nazi Germany and was spending his time as a refugee in London pondering different aspects of physics†. That September day, Szilard was thinking about a newspaper article featuring Ernest Rutherford that he had read earlier. In 1901  Ernest Rutherford, together with Frederick Soddy, had discovered that radioactive thorium decayed into radium. The changing of one element into another could be considered a type of modern day alchemy. However Rutherford did not believe that there could ever be a way of harnessing this nuclear energy. In the article read by Szilard in The Times, Rutherford had dismissed any such ideas as “moonshine”. Szilard was forced to pause his walk as he waited for the traffic lights to change. Those few moments of pause must have helped clear Szilard’s mind because as the light went green and Szilard was able to cross the road, a thought hit him: If every neutron hitting an element released two neutrons (as one element was transmuted into another), a chain reaction could be started. As part of the mass of the decaying atom was released as energy, it would mean that, feasibly, we could harness vast amounts of energy; E=mc².

This idea, a consequence of spending five minutes waiting for a traffic light rather than checking Twitter (not yet invented in 1933), proved to underpin both the nuclear fission which we use in electricity generation and the nuclear fission that we’ve used to develop weaponry. It makes me wonder what alchemy we could conjure in our minds if we stopped to enjoy the transformations of the coffee beans at Alchemy.

 

Alchemy (cafe) is at 8 Ludgate Broadway, EC4V 6DU

† A book that some may find entertaining is:

“Hitler’s Scientists”, John Cornwell, Penguin Group publishers, 2003. The book contains this anecdote about Szilard: As Szilard was of Hungarian-Jewish descent, he fled Germany to Britain via Austria on a train a few days after the Reichstag fire of 1933. On the day he left, the train was empty. One day later, the same train was overcrowded and the people leaving Germany were stopped at the border and interrogated.  An event that prompted him, a few years later, to reflect “This just goes to show that if you want to succeed in this world you don’t have to be much cleverer than other people, you just have to be one day earlier than most people.” Something to reflect on in today’s refugee crisis perhaps.

Categories
Coffee review Observations Sustainability/environmental

Old and new at Sarnies, Singapore

Sarnies, Telok Ayer St, CBD, Singapore
Sarnies, Singapore

It is just possible that the name ‘Sarnies‘ may suggest a speciality at this cafe in Telok Ayer St. Singapore. And the sandwiches are definitely very good (I happened to visit one lunchtime), but don’t let this deceive you, the coffee is very good too and indeed Sarnies has been listed as one of the top 10 cafes to visit when in Singapore. Sarnies operates from an old style ‘heritage’ building near the central business district in Singapore. This style of “shop-house” used to be ubiquitous in Singapore but as Singapore has developed so the tall buildings of the “CBD” now tower over these remnants of Singapore’s past. The authorities though are keen to preserve their heritage and so many of the buildings have been carefully restored so that the exteriors are fairly faithful to the original. The interior has plenty of table space for you to enjoy your coffee (and sandwich of course) and watch the goings-on around you. Complementary water is available at the bar while you wait for your coffee and sandwich to be brought over to your table.

air vent, natural air circulation, air conditioning
The old air vent system and the new air con unit inside Sarnies in Singapore

Inside, you can see how the demands of modern living have changed the architecture of the shop-house. Above the door, and along the window were a series of vertical timber railings.  These date from the construction of the house and were presumably to assist with air ventilation in a time before air-conditioning. They work because hot air rises and so by putting an opening – a vent – near the ceiling, the  hot air in the building will rise and leave the interior to be replaced by the cooler (it is never cool in Singapore) air from outside. Unfortunately, the temperature in Singapore during the day time is in the 28-33C region and so this method of cooling is not as efficient as air conditioning which is why the vents are now covered in glass. The air-conditioned interior also means that the door of Sarnies is kept closed at all times, ensuring that the air conditioning is as efficient and cool as possible (though seats are available outside should you want to sit in the heat).

coffee at Sarnies Singapore
At the end of the day, it’s all about the coffee

Air conditioning of course needs a lot of energy in order to work. The basics of air conditioning work on the same principles as those that cool your coffee: When a liquid evaporates into a gas it takes energy from its environment and thereby cools it (think about alcohol – or sweat – evaporating from your hand). The issue with air conditioners is that this is a continuous process. The liquid that is evaporated within the air-con unit cooling the room is compressed and re-condensed in the air-con unit outside the shop, in a process that consumes electricity and generates heat which is transferred to the environment outside the shop. The process uses a lot of energy (and therefore generates a lot of carbon dioxide emissions), indeed one organisation in Singapore calculated that more than 60% of their energy consumption on one campus was due to air conditioning.

As cities use a lot of energy, clever design and engineering of the buildings in cities can be used to decrease the carbon dioxide emissions of cities and so help to mitigate the problems of climate change. The C40 is a group of more than 75 of the world’s largest cities that work together to find ways to use urban design to combat environmental problems. Perhaps it is in developing more energy efficient lighting systems or, in the case of the UWCSEA in Singapore, designing their new buildings so that they use air conditioning more efficiently and therefore less wastefully, both in terms of CO2 emissions and in economic terms.

As I was sitting enjoying my Sandwich and coffee in Sarnies, a customer coming into the cafe left the door open. As the hot and humid air started to blow in from outside, the woman sitting near the door closed it to keep the cold in. This small gesture, almost completely opposite to that which I experienced in winter in London last year, helped to ensure that the air conditioning unit did not have to work harder to keep the cafe cool. A small action but one that helps save energy and so the planet, even if just a little bit. If only more of us did this.

Sarnies is at 136 Telok Ayer St. Singapore.

Categories
Coffee review Coffee Roasters General Observations slow

Time for a slow coffee?

enamel mug, teh halia, Straits Times kopitiam
This enamel mug connected glass to the Giants Causeway (Straits Times kopitiam)

Every two weeks, the Daily Grind on Bean Thinking is devoted to what I have called a cafe-physics review. The point of these reviews is to visit a café, slow down and notice what has been going on in a cafe physics-wise. I focus on physics because it is my ‘specialist’ area but the point is to notice the connections between the coffee, or the cafe and the world around us. To see how what is going on in your mug is reflected in the science of the wider universe. Realising that things that seem disparate are in fact connected: It is the same maths that describes electrons moving in a metal and the vibrations on the surface of a cup of coffee. That sort of connection to me is mind boggling. Yet there is more. Thinking about the connections between physics and coffee can lead to meditations on the environment and sustainability, or considerations about how our attitude to drinking coffee changes our perception of it.

Everything is connected.

Parquet floor at Coffee Affair
How many people have walked on this floor? The story of evolution at Coffee Affair

It is my strong belief that whenever we go into a cafe, order a coffee and then proceed to sit down with our smart phones or tablets and check our e-mail or our Twitter accounts we lose a fantastic opportunity. It is the opportunity to be properly present and to notice what is going on around us. It is the opportunity to slow down and to appreciate what life has given us and the surprising things that the world has to offer. To look at the beauty and the complexity of the world and to say ‘wow’.

This appreciation is open to us all, provided we seize the opportunity to slow down and take that time to enjoy our coffee.

So, this week’s Daily Grind is an invitation. It is an invitation open to anyone who sits down with a coffee. If you notice anything peculiar, or interesting, that you feel deserves a mention as a cafe-physics review why not write an edition of the Daily Grind? It does not matter where in the world you are or what your level of science knowledge is. If a full Daily Grind article is too much but you have a great observation, write a paragraph review of your favourite cafe and I’ll add it to the cafe-physics review map. Think that you don’t know enough science? Never mind, share your idea with me and we can work on it together.

Hasten coffee, long black, black coffee, espresso base
Sometimes the link with physics/science is a little bit tenuous, as it was at Espresso Base

Your observations need not be physics-based. It would be great if it is based on some aspect of science, but, as past examples have shown, this link can be a little tenuous if the cafe/subject warrants it.

So, over to you. I hope that someone will respond to this invitation. Please do contact me if you would like to pen a review or if you have any questions. It is my hope that you are all enjoying such great coffee in the huge variety of cafe’s that we now have that there will be plenty of opportunities for people to slow down and to notice and then to share it with the Daily Grind.

Please contact me here, or in the comments section below. I look forward to hearing from you.

 

Some brief guidelines for a cafe-physics review:

1) The cafe should, preferably, be a good independent.

2) Any science/history etc. needs to be verifiable but, as mentioned, if you’ve noticed something great but are unsure of the science, get in touch and we’ll work something out together.

3) If you have noticed something fascinating with your coffee but at home and not in a café, contact me anyway.

4) Please do not write a cafe-physics review of any cafe you are financially associated with. I will have to refuse/delete any ‘reviews’ that I find are adverts.

Categories
cafe with good nut knowledge Coffee review Science history

Gravity and Grace at the Wren cafe

Wren cafe, St Nicholas Cole Abbey
Inside the Wren cafe

There is a lot to like about the Wren cafe. Firstly, there is the space that it occupies (inside St Nicholas Cole Abbey). I went at lunchtime when the way that the light came through the stained glass windows made the cafe a very relaxing and open space. The coffee is from Workshop, complementary water came in 3 flavours (mint, cucumber or lemon) while the food is cooked on site. This is important because it means that they have a great nut policy and could tell me which dishes were likely to contain nuts etc. A further nice feature of the lunch menu at the Wren was that you could select your portion size. Food waste is a major issue for our society and is not helped by the ‘one size’ portions served at many food outlets and cafes. Lunch was offered in two sizes (technically as a side or a main) but the ‘side’ was more than adequate for a mid-week lunch. Sofas in the corner of the room meant that you could relax and take in your surroundings in a comfy environment or, if you were just there for lunch, ordinary chairs and tables were dotted around the room.

Of course, a place such as this will have plenty of things to notice about it. Whether your interest is in architecture or science, there is plenty to observe around you. What I would like to focus on though is a bit of science history that connects the name of this cafe with Isaac Newton, John Theophilus Desaguliers and the dome of St Paul’s Cathedral (which you can see from the front of St. Nicholas Cole Abbey).

View of the Dome from the cafe
The Dome of St Paul’s, visible from the side of the Wren cafe.

Perhaps we all remember the story told to us at school about how Galileo dropped two balls of different mass from the top of the leaning tower of Pisa. According to the story, the balls fell to the earth at the same time, thereby showing that the acceleration due to gravity was independent of the mass of the object and paving the way for Newton’s theory of gravity. Sadly, it seems that Galileo may never have actually performed the experiment (even if it was “re-created” in 2009). However there is evidence that Isaac Newton did perform exactly this experiment in 1710 from the dome of the soon-to-be-completed St Paul’s Cathedral.

“From the top of St Paul’s church in London in June 1710 there were let fall together two glass globes, one full of quick silver [mercury], the other of air”¹. The globes fell 67m before shattering onto the cathedral floor (I’d hate to have written the risk assessment for that experiment). To avoid the possibility of human error, a trap-door mechanism had been designed to ensure that both globes dropped simultaneously. According to the story of Galileo told to us at school, we can calculate how long it would have taken those globes to drop to the floor: 3.7 seconds, independent of mass. So is this what Newton observed? No! The heavy glass globes took 4 seconds to fall, but lighter ones took 8-8.5 seconds! A few years later and Desaguliers repeated the experiment from slightly higher in the dome (but this time with hog’s bladders rather than glass) and obtained the same result.

View of St Paul's Cathedral London
Another view of St Paul’s. Hard to believe that Newton actually dropped liquid mercury from the dome.

This surprising result can be explained when we realise that Newton was investigating not gravity, but air resistance. While the gravitational acceleration is independent of mass, the upwards force due to the air resistance depends primarily on the object’s size (and velocity). This means that the deceleration caused by the air resistance will be different for two globes of the same size but different mass (Force = mass x acceleration). Heavy objects will fall faster in air (until the objects reach their terminal velocity).

There is a certain irony in the fact that this result is opposite to what we feel should happen based on what we learned at school of Galileo’s experiments challenging the scientific orthodoxy of the time. However the result of Newton and Desaguliers’ experiments do not contradict the theory of Newton or Galileo, they just add an extra layer to the problem. We do not exist in a vacuum, we need to think about the air around us too.

Both Newton and Desaguliers were regular coffee drinkers albeit at different coffee houses. Desaguliers frequented the Bedford Coffee House in the north east corner of Covent Garden while Newton regularly retired to the Grecian in Devereux Court (just off Fleet Street). Coffee houses were places that the latest science, politics or philosophy were discussed and debated. The Wren describes itself on its website as existing to “serve the ministry of St Nick’s talks“. Sadly I experienced no discussion or debate on my visit (just a very nice, but solitary, lunch and good coffee) but it is interesting to see the tradition of the 17-18th century coffee houses continued in this Wren designed church and cafe.

The Wren cafe can be found inside St Nicholas Cole Abbey, 114 Queen Victoria St. EC4V 7BJ

[1] The Dawn of Fluid Dynamics, Michael Eckert, Wiley-VCH (2006)

Coffee house info: London Coffee Houses by Bryant Lillywhite (pub. 1963)

Categories
Coffee review General Observations Science history

Can you see me? At 123 Gasing, KL

Coffee at 123 Gasing
Latte, Long black and chocolate muffin at 123 Gasing, PJ, KL

There are times when you can sit and observe things for quite a while before noticing the physics that becomes a cafe-physics review. There are other occasions when the subject of the review is staring you in the face indeed, it is practically there written for you, on a noticeboard in black and white. Such was the case at 123 Gasing, a cosy and quirkily decorated cafe located, strangely enough at 123 Jalan Gasing (ie. Gasing Road), in PJ, Kuala Lumpur. We enjoyed a lovely breakfast of scrambled egg, long black and a latte (along with a very rich chocolate muffin). The coffee is from Degayo (according to Malaysian Flavours) which means that it is practically a local food product (originating as it does from neighbouring Indonesia). Coffee with minimal ‘food miles’. The only point of regret about our time at 123 Gasing was that we didn’t manage to spend longer there.

decoration at 123 Gasing
Birds on the wall at 123 Gasing.

It is the decoration that strikes you as you look around this cafe. A couple of painted birds sit on top of an electrical wire, prompting the question “why do birds not get electrocuted when they sit on a wire?”. Another question painted to a notice board on the wall asks “what is it that we need that we cannot see or feel?” (answer at the end of this post). Yet it was another thought on another noticeboard that prompted this cafe physics review. That thought suggested invisibility (see picture below).

The idea of invisibility has fascinated story tellers and philosophers for millennia. Trying to render objects invisible is, understandably, very desirable for the military and the defence industry. Although we have always had access to camouflage and deception, it is only relatively recently that it has become feasible to talk about invisibility cloaks as a real possibility.

A sign at 123 Gasing
Am I invisible?

What has moved “invisibility cloaks” into the realm of reality has been the advent of a field called “metamaterials”. As the name suggests, metamaterials are not materials that occur naturally but materials that we manufacture. Combinations of different materials or repeating patterns of a specific material that interact with light in a way that the material itself would not do. The classic example is a so-called split-ring resonator (SRR). These are rings (that were first made with copper) which have a slice cut out of them. Many such rings are arranged in a repeating, lattice pattern. Due to the engineered pattern of the copper, these lattices interact with light in a way that ordinary copper does not (for details click here). Specifically metamaterials can be engineered to bend light around objects so that it appears that the object is not there.

In order to work, the artificial structures (e.g. the copper rings) must be smaller than the wavelength of light that is to be ‘bent’. This means that microwaves (which have a wavelength ranging from a few cm to a few m) can be manipulated far more easily than visible light (with a maximum wavelength of 700 nm, or about 1/100th of the size of a grain of espresso grind). At first sight this may seem disappointing until we remember that even devices that only work with microwaves would have a clear application for the defence industry (radar).

already disturbed
Hopefully not a comment on current scientific funding

There are many ethical and philosophical questions that follow from the fact that it is now within our reach to render some objects invisible. It is not a scientific question as to whether we should do it, the scientific question is whether we can. Where science and ethics collide though is in the funding issue. A subject such as this with obvious applications receives far more funding than fields that advance our understanding but do not enhance our weaponry. Indeed, one of the researchers involved in this field describes how he was “offered large sums of money (almost on the spot)” when he spoke of the potentials of the “Harry Potter project”¹. Something that is alien to those of us who work in less fashionable subject areas where funding is a constant struggle. Government funded science quickly becomes dominated by a quest for application and technology. In effect we bypass the ethical questions of whether we should do this because it is this that will get funded. Science that is not driven by obvious applications will not get funded.

Is this what we want? Should the humanities and philosophy play a role in helping to determine what research is beneficial for society and so which research receives funding? Should ethical considerations play a part in funding considerations, or should scientific research all be about the devices that we can use? It is certainly something to ponder while sipping on our long blacks.

Answer to the question “what is it that we need that we cannot see or feel? Answer in 1990 – Air, answer in 2000 – Wi-fi (though personally I think maybe this should be the answer in 2015, the given answer of “2000” was still a bit early for widespread wifi).

Further reading and [1]: “The Physics of Invisibility” Martin Beech, New York, Springer, 2012

Categories
Coffee review Observations Science history slow Sustainability/environmental

In the Greenhouse at CoffeeGeek

Coffee Geek and Friends, Coffee Victoria
Coffee Geek and Friends

Earlier this year, a new café opened up in Victoria. Coffee Geek and Friends is located at the far end of Cardinal Place as you enter from Victoria Street. Cardinal Place is an odd sort of shopping centre, a small collection of shops with a glass roof. The building site near Coffee Geek as well as the constant stream of people rushing to and fro make Coffee Geek an ideal place to spend some time watching the world go by. Coffee is by Allpress espresso and is served in very individual mugs. Apparently there is a range of geek-ery in the cafe including a ‘centre piece’ water filter but I admit I missed that as I was too focussed on my coffee. Coffee Geek and Friends is definitely a cafe to keep in mind (along with Irish & June’s) if you need a good place to meet near Victoria Station.

It was a very humid day when I enjoyed my coffee at Coffee Geek and, because the mug had not been pre-warmed before my Americano/long black (my notes don’t specify which) was poured into it, condensation quickly formed around the rim of the mug. The condensation forms for the same reason that dew forms after a cool night: the vapour pressure of the water above the coffee (or the ground) has reached the dew point at the temperature of the mug. The lower the temperature, the lower the vapour pressure has to be for the water in the atmosphere to start condensing into liquid droplets. Hence you will often find that your coffee is more ‘steamy’ on a winter’s, rather than a summer’s day.

Condensation on mug in CGaF
Look carefully at the rim of the mug. Do you see the condensation?

Just over two hundred years ago, William Charles Wells made a study of dew. He observed the weather conditions under which dew formed. He observed on which surfaces dew collected. He noted whether the dew formed on space facing surfaces or ground facing surfaces. After several years of careful study he published his “Essay on Dew” in 1814. His work, showed that the earth radiated heat at night (when it was not being kept warm by the Sun) and therefore that space was cold. Cloud cover reduced the amount by which the ground cooled which implied that cloud cover was acting as a type of blanket for the Earth, keeping the heat trapped inside. Later calculations of the balance between the heat radiated by the Earth and the heat received by the Sun confirmed that, without some heat getting trapped by clouds and ‘greenhouse’ gases in the atmosphere, the earth would be a good 30 C cooler than it is observed to be. Although these calculations are just rough, “back of the envelope” figures, detailed calculations confirm that the Earth is in a delicate balance, heated by the Sun, cooled by radiation and kept warm (and live-able) by a layer of natural greenhouse gases. This “natural greenhouse effect” has been necessary for our development, the problem is that now we are adding yet more greenhouse gases to the atmosphere which threatens to tip the established delicate balance by a few degrees.

Cardinal Place roof, greenhouse
The roof of Cardinal Place shopping centre. A very appropriate place for a meditation on the greenhouse effect

What we now call the greenhouse effect are these extra gases, which are more efficient at trapping heat within our atmosphere. If you can imagine what has been happening over the past three hundred years or so as we have been pumping yet more of these gases into the atmosphere at an accelerated rate, we are in danger of tipping this delicate balance towards further heating of the earth. The 2015 Paris Climate Conference is being held with the aim of requiring all nations to agree to a legally binding commitment to reduce the amount of extra greenhouse gases that we emit to a level that will only result in a temperature increase of 2C. To achieve this requires all of us to work together to reduce our own ‘carbon footprint’. Each of us will have to find our own, individual ways to reduce our emissions but perhaps when we look at the condensation on the rim of our coffee cup, we could remember William Charles Wells and his essay on dew and just think, what can I do, at this moment, to reduce my carbon footprint? Maybe it could be something as simple as turning off that phone (to conserve the battery) and watching what is going on in a café instead. A small gesture but one that would be good for us as well as the earth.

Coffee Geek and Friends is at the northern end of Cardinal Place shopping centre (opposite Westminster Cathedral).

As a Coffee Geek note, I would like to just comment that my notes on Coffee Geek and Friends were written using a “linux-sure” ball point pen. Not particularly environmentally friendly but definitely quite geeky.