glass

A Story with many layers, Clapham Junction

Story Coffee St John's Hill Clapham

The doorway to Story, or a story depending on how you look at it.

A “ghost sign” above the door to Story Coffee on St John’s Hill ensures that you know that you have arrived at the correct place. “Peterkin Custard, Self-Raising Flour – Corn Flour, can be obtained here”, only now it is coffee rather than custard that is sold in the shop beneath. The sign is an indicator to the many tales that could be discerned while exploring the coffee within. I had had a couple of attempts to visit Story Coffee (thwarted for a variety of reasons) before Brian’s Coffee Spot’s review appeared a couple of days after one of my attempted visits. Suitably re-motivated, another trip was attempted (address checked, closing times checked) and this time we were in luck. Although a pour over is listed on the menu, sadly this was not available on our visit and so I enjoyed a lovely long black instead (Red Brick, Square Mile) while looking at the cakes on offer. There was plenty of seating in which to shelter from the rain outside and many things to notice in this friendly café. In addition to the cakes and lunch menu, a box on the counter housed “eat grub” protein bars, protein bars made of cricket powder. Are insects the future for humans to eat protein sustainably?

glass jar at Story

Through a glass darkly?
The distortions produced by the refractive indices of air, water and glass and the shape of the glass produces interesting effects on our view through it.

The tables were well arranged for people to sit chatting while enjoying their beverages and it is always an excellent thing (from a personal point of view) to encounter a café with a no laptop (or tablet) at the tables policy. Complementary tap water was available in jugs placed on each table while it was also nice to note that Story branded re-usable cups were on sale from the counter. Many things we noted can be seen in the gallery pictures in the review on Brian’s Coffee Spot: the funky fans, the egg shaped light shades, the light introduced by the large glass window panes (though it was a much fairer day on Brian’s visit than on ours). Each had its contribution to a thought train, the way the glass water jar bent the light coming through, the concept of a Prandtl boundary layer in fluids (and its connection to both fans and coffee cups). Moreover there were hexagons, which for someone who has worked on the periphery of the graphene craze, are always thought provoking.

Apart from hexagons decorating the top of the stools, there were hexagons lining the counter made of cut logs, each showing the rings from the tree that was felled. Rather than a flat surface, these hexagons were made to be different thicknesses on the wall, rather like the hexagonal columns of the Giant’s Causeway. It is a subtle thing that may have implications for the space that is otherwise surrounded by flat, solid, walls. Such spaces can become echo-y and yet, the music and conversation in Story was not overly distracting presumably because features such as the uneven hexagonal wall reflected the sound waves such that they destructively interfered rather than echoed around the room.

every tree tells a story, but which story

A macroscopic crystal of hexagonally cut logs forms the side of the counter.

Each log in the hexagonal decoration was cut with its cross-section showing a number of tree rings. We know that we can age a tree by counting the rings (though each of these would be underestimated as they have been trimmed into hexagons post-drying), but what more do the tree rings, and the trees themselves have to tell us? The rings are caused by the rapid growth of large cells during spring followed by a slower growth of smaller cells as the year progresses. But this method of growth means that the cut logs have more to tell us than just their age. The spacing between the rings can tell of the weather the tree experienced during that year, were there many years of drought for example? Such clues, from the relative density of the tree rings, can help researchers learn about the climate in previous centuries, but conversely, reading the climate report in the rings can indicate in which year a tree was felled and so the age of a building for example.

coffee at Story

Many stories start with a coffee.

And then there is more, trees will grow at an average rate per year so that, as a rough guide, the circumference of a mature (but not old) tree increases by 2.5cm per year¹. There is therefore something in the idea that you can have a good guess at how old a tree is by hugging it. But this assumes that the tree is growing in its optimum conditions, far enough from any neighbouring trees so as not to be crowded into growing more slowly. So the absolute density of tree rings must also give a clue as to whether this tree was in a dense forest or an open clearing. Which is reminiscent of something else that living trees can tell you if you listen to them closely enough: trees will grow so that their leaves are exposed to the maximum amount of light. For us in the UK, this means that the crown of a tree will frequently tip towards the south (where the Sun is most often) and there will be more leaf growth (and consequently more branches) in a southerly direction². But again, we only see this if the tree has room to grow on its own, without the crowding, and competition, of too many neighbours. A solitary tree helps us to know which direction we are walking in.

empty coffee cup Story St John's Hill

While many coffees could also tell a story. It depends on how you read them.

Which all points to the idea that there are many stories being told all around us all of the time, the ones we hear depend on what we choose to pay attention to. So what about the story behind the ghost sign above the door? The Peterkin custard company was a venture by J. Arthur Rank in an attempt to start a milling company in the mould of his father’s (Rank Hovis McDougall, later bought by Premier Foods). The company failed and Rank went on to form the Rank Organisation that was responsible for many films made throughout the 40s and 50s as well as running a chain of cinemas around the UK. Truly a sign concealing many stories.

 

Story Coffee is at 115 St John’s Hill, SW11 1SZ

¹Collins complete guide to British Trees, Collins, 2007

²The Walker’s Guide to Outdoor Clues and Signs, Tristan Gooley, Hodder and Stoughton, 2014

 

 

 

 

Hear no evil… at the Inverness Coffee Roasters, Inverness

Coffee in Inverness

Inverness Coffee Roasting Company.

Hear no evil, see no evil, speak no evil, so the saying goes and so the monkey, that was sitting on the sofa at the Inverness Coffee Roasting company (and café) indicated. And while I would not like anything evil to be said on this website generally, today it will be taken to an extreme as this cafe-physics review will not say much at all. Not because the coffee was not good, my Americano was a lovely complex dark and very enjoyable brew. Nor because there weren’t things to write about, several avenues suggested themselves for a ‘cafe-physics’ type review. There were also plenty of things to enjoy nibbling on while sitting down in this warm and comfy environment taking in the surroundings. Chocolate from The Chocolate Place was clearly labelled (and so I could enjoy it confident that it was nut-free) with a good variety of interestingly flavoured chocolates. The chocolate/coffee combination always goes well and the salted dark chocolate indeed complemented the coffee. A variety of freshly roasted coffees were in jars ready for selling to the home-brewing crowd and I heard both people behind the counter discussing coffee tastes with different customers to ensure that they could properly recommend a coffee for each of them.

So why, if the coffee was good, the service friendly and the environment interesting am I not going to write much about Inverness Coffee Roasting Company? Well, largely because I had been on holiday and so the preoccupations of the days before would necessarily influence what I noticed about this little café. Although I could happily write about neolithic monuments and considerations about inter-generational solidarity in relation to the re-use of refuse heaps at Skara Brae (as building material) and our own use (or misuse) of refuse in our environmental behaviour today. And it could even fit into a cafe-physics review of this venue as a sign on the wall above the door invited everyone to join the Plastic Free Scotland movement. However, it is not really what a Bean Thinking cafe-physics review is about. The idea behind the cafe-physics reviews is that things are often connected in surprising and beautiful ways and we can generally only see the connections if we slow down and look for them.

hear no evil, see no evil, speak no evil

Monkey on a sofa, but there was much more to notice at the Inverness Coffee Roasting Company if you looked around you.

Therefore, while you may (or may not) prefer to read about my holiday considerations of all things thousands of years old, what I thought I’d do with this café review is suggest a few things that I noticed in the café, things that offered a variety of potential thought-trains and then see what you think, what you notice, what you see (or don’t see). Perhaps you will observe something in one of the photos that clicks into a thought train for you, perhaps you can look around you, wherever you are right now – and think about the connections you could make to things you sense there instead? But whichever you do, it is a great time to sit back with a coffee (or perhaps a tea), breathe in and take in your surroundings.

Back in Inverness, the first thing of course was the monkey. Eyes shielded with an arm, suggestive of those who would prefer not to see what is in front of them. Nancy MacLean in “Democracy in Chains” notes that a training in the humanities perhaps opens students to question their society more than other, more utilitarian, subjects may do. Is it hurt pride that makes me rebel against this idea? Can’t physicists question too?

Perhaps it is connected but a sign by the door, and an identical one by the sofa, was written on the glass front of a box of coffee beans: “in emergency break glass”. This suggested so many avenues for exploration to me, I wonder which occur to others?

Behind our seats, a lizard was painted on/engraved into a stone, suggestive of fossils, geology and how we collect evidence. But a second lizard suggested a different direction. An ornamental lizard was positioned as if climbing up the counter. How do lizards climb? What is it about their feat? What connects lizards to a coffee company? Above our heads and above the door, stereotypical of Scotland perhaps, loomed a deer head complete with antlers. But this one was different: it was made of coffee beans and string. How a bean based diet could replace a meat one? The nature of units and how it would not necessarily be sensible to measure the mass of a deer in units of coffee beans? The mind jumped. Jumping beans?

Deer head in beans

Bean there done that?
Gruesome ornament or vegan friendly?

Finally, the logo of the cafe which was featured on signs around the interior and exterior of the space: a flaming coffee bean. The Maillard process and the changes in coffee as it is roasted? The nature of heat/temperature and the manner in which we measure it? What we hear as fire burns, lightning bangs or on “the first crack” of roasting and what this tells us about our atmosphere, our planet and our coffee is made of?

Whatever you notice, please get in touch, either by Facebook, Twitter, leave a comment or send me an email. But one last thing on coffee thought trains that links to real trains and is perhaps reflective back onto what it means to pause and watch. We left Inverness the day after our visit to Inverness Coffee Roasting by train. Inverness station has a relatively steep (1:60) gradient for 20 miles on leaving the station. It is Scotland in autumn, it had been raining and leaves had been falling on the line. Five or ten minutes out of the station, our train to Kings Cross juddered and came to a halt. A signal failure apparently. As the driver re-started the train, it slipped backwards, and again. We weren’t able to get up the hill. And so we had to return into Inverness station. Once back at Inverness station, the guard came across the tannoy and suggested that the signallers had given us the go-ahead to ‘have another run’ at the hill to see if we could get up it this time. So we tried again, juddering and shaking to a stop a few hundred metres beyond where we had stopped before. Back to Inverness station it was. The ever hopeful guard came across the tannoy again: “Third time lucky, fingers crossed”. This time the train left the station faster, building up speed, moving along more quickly and powering out of the station. The carriage was silent, were we going to make it? Past the first point we stopped at, past the second, a bit further, the family behind clapped, the train continued then slowed down and shook, juddered and then sped up again. We were over the hill and on our way back to London.

A last consideration on the conservation of energy and its relation to coffee and thought trains? Or a metaphor for how we may not find those connections in that cafe come to us quickly but if we persist and keep noticing, we can go on a fascinating journey?

Do let me know your thoughts.

The Inverness Coffee Roasting Company can be found at 15 Chapel Street Inverness, IV1 1NA

Now you see it now you don’t at Bond St Coffee, Brighton

Outside Bond St Coffee Brighton

Bond St on Bond St, Brighton

A couple of weeks back, I tried the lovely Bond St. Coffee in Brighton on the recommendation of @paullovestea from Twitter. It was a Saturday with good weather and it turns out that this particular café is (understandably) very popular and so, sadly, to begin with we could only sit outside. That said, it was a lovely spring day (sunny but a bit chilly) and so it was quite pleasant to watch the world go by (or at least Bond St) while savouring a well made pour-over coffee. All around the café, the street decoration hinted at times past. Across the road what was obviously a pub in times gone by has turned into an oddities store. Air vents to a space underneath the window seating area in Bond Street café itself suggested an old storage space. A seat in the window appeared to have been re-cycled from an old bus seat.

But it was the pour-overs at Bond St. Coffee that had been particularly recommended and they certainly lived up to expectations. I had a Kenyan coffee roasted by the Horsham Roasters. The V60 arrived at our bench seat/table in a metal jug together with a drinking glass. The angle of the Sun caught the oils on the surface of the coffee, reminding me of Agnes Pockels and her pioneering experiments on surface tension. Pouring the coffee into the glass I thought about the different thermal conductivities of glass as compared to metal and how I had put both down on the wooden bench. How was heat being transferred through these three materials? And then, as I placed the metal jug back on the bench I noticed the reflections from the side of the jug and thought, just why is it that you can see through the colourless glass but the metal is grey and opaque?

Metal jug and transparent glass

Metal jug, glass cup. V60 presentation at Bond St Coffee

On one level, this question has a simple answer. Light is an electromagnetic wave and a material is opaque if something in the material absorbs or scatters the incoming light. In a metal, the electrons (that carry the electric currents associated with the metal’s high electrical conductivity) can absorb the light and re-emit it leading to highly reflective surfaces. In glass there are no “free” electrons and few absorbing centres ready to absorb the light and so it is transmitted through the glass.

Only this is not a complete answer. For a start we haven’t said what we mean by ‘glass’. The glass in the photo is indeed transparent but some glasses can be more opaque. More fundamentally though, there is a problem with the word ‘opaque’. For us humans, ‘visible’ light is limited to light having wavelengths from about 400nm (blue) to about 780nm (red). ‘Light’ though can have wavelengths well below 400 nm (deep into the UV and through the X-ray) and well above 780 nm (through infra-red and to microwaves and beyond). We can see the spread of wavelengths of light visible to us each time we see a rainbow or sun dog. Other animals see different ranges of ‘visible’ light, for example, bumble-bees can see into the ultra-violet. So, our statement that glass is transparent while metal is opaque is partly a consequence of the fact that we ‘see’ in the part of the spectrum of light for which this is true.

Sun-dog, Sun dog

Sun dogs reveal the spectrum of visible light through refraction of the light through ice crystals.

For example if, like the bumble-bee, we could see in the UV, some glass may appear quite different from the way it does to us now. Even though the glass in the photo lacks the free electrons that are in the metallic jug, there are electrons in the atoms that make up the glass that can absorb the incident light if that light has the right energy. There are also different types of bonds between the atoms in the glass that can also absorb light at particular energies. The energy of light is related to its frequency (effectively its colour*). Consequently, if the energy (frequency/ wavelength) of the light happens to be at the absorption energy of an atom or an electron in the glass, the glass will absorb the light and it will start to appear more opaque to light of that colour. Many silicate glasses absorb light in the UV and infra-red regions of the electromagnetic spectrum while remaining highly transparent in the visible region. High purity silica glass starts to absorb light in the UV at wavelengths less than approx 160nm†. Ordinary window glass starts to absorb light in the nearer UV†. In fact, window glass can start to absorb light below wavelengths of up to ~ 300 nm, the edge of what is visible to a bumble bee: The world must appear very different to the bumble bee. At the other end of the scale, chalcogenide based glasses absorb light in (our) visible range but are transparent in the infra-red.

Looking at how materials absorb light, that is, the ‘absorption spectrum’, enables us to investigate what is in a material. It is in many ways similar to a ‘fingerprint’ for the material. From drugs discovery to archaeology, environmental analysis to quality control, measuring how a material absorbs light (over a wider range of frequencies than we can see) can tell us a great deal about what is in that material.

Perhaps you could conclude that whether something is opaque or crystal clear depends partly on how you look at it.

 

Bond St Cafe is on Bond St, Brighton, BN1 1RD

*I could add a pedantic note here about how the colour that we see is not necessarily directly related to the frequency of the light. However, it would be fair to say that a given frequency of light has a given ‘colour’ so blue light has a certain frequency, red light a different frequency. Whether something that appears red does so because it is reflecting light at the frequency of red light is a different question.

†”Optical properties of Glass”, I Fanderlik, was published by Elsevier in 1983.