Category: Coffee review

Categories
Coffee review Coffee Roasters Observations

Connectivity at Populus, Singapore

Inside Populus
The cool interior of Populus

A friend recommended that we try a café in her neighbourhood near Outram, in Singapore. So, with some time to spare we walked up the hill and into the welcoming air conditioning of The Populus Cafe in Neil Road. The coffee is roasted by 2º North and there is an extensive menu of both coffee based drinks and a seasonal filter selection. There was also a range of iced drinks on the menu which in the Singapore heat were tempting, but I opted for the 6oz Long Black. Given more time, or a second visit, I would certainly try the filter, but this time an appointment across the island was calling. There seemed too to be a very good lunch selection on the menu, but again, the lunch appointment elsewhere meant that it was just the 6oz long black that day.

It should be possible to take some time back from a busy schedule full of appointments and concerns and sit back and ponder the connections in any café. Having run from one set of concerns and soon to have to go off to another, would this be possible in 30ºC+ heat? The comfortable space of Populus provided a perfect place to test this question. Sitting back while sipping my coffee, the first thing that struck me was the wood, arranged in different geometrical patterns on the walls. The floors too were decorated with hexagonal stone tiles while the door was glass. There was a different pattern on the door, but what was it? Staring at it for a while, I thought about the schematics you sometimes see for a connected world, each of us a point connected to the others (how true is it that we are all 6 hand shakes away from everyone else?). Maybe this fitted with the name of the café? My companion in these reviews instead thought of crystals and the way that crystal structures are represented with lines between the atoms. While loading the photograph of the door onto the website, I saw a pattern of flowers. It seems that the pattern on the door formed and reformed with each new view.

door, Populus
Looking through the door of Populus. What patterns do you see?

Then there was the cup. A black coffee in a black cup, with umbral and penumbral shadows (as pointed out by @Bob_MatPhys on Twitter). A few years ago there was great excitement about a new material that had been made to be blacker than any known material. The substance used a coating of carbon nanowires (of just 20nm diameter which is about 1/1000 the size of a grain of espresso grind) to absorb light across the visible, ultra-violet and infrared spectrum. And just as nano-structuring a material helps it to appear the ‘blackest’ object ever, so changing the structure of a material can make it invisible to other parts of the electromagnetic spectrum such as microwaves. Quite why various defence companies and governments would invest so much into this research I will leave for your imagination (it is not to avoid heating soup). A more peaceful and beautiful side of the effect of nanostructure on optical properties is the way that the feathers of a peacock have a striking green-blue hue. It is another example of light interacting with a structure and so producing different optical effects; all is not as it appears.

coffee cup Populus
A black coffee in a black coffee cup. But what does black mean? And is something that is transparent always so?

And the fact that all is not as it appears gives another connection to the Populus cup. For although it seemed quite black to my eyes, it was clearly shining in the infra-red. The hot coffee inside was radiating through the cup and onto my hands. Which could prompt us to consider what ‘black’ really means? And for that matter, what about transparent? Just as ‘black’ only absorbs light over a certain set of frequencies, so transparent only lets light through over certain frequencies. The door that we can see through with our eyes may be opaque to a different frequency range that we cannot see. Just over two hundred years ago Carl Wilhelm Scheele deduced the presence of the infrared by contemplating how his stove heated him in the winter. Although he could not see them, the ‘heat rays’ seemed to come straight towards him and yet did not cause a candle flame to flicker, clearly the heat was ‘radiating’ like light rather than travelling like a breeze on the air.

The knowledge that structure, as well as pigment, provides the colour to our world, or that what is transparent at some frequencies may be opaque to others, these things give us plenty to think about, scientifically and perhaps more philosophically, while enjoying our black coffee. Which shows that even ten minutes spent sitting with your coffee can result in a series of thought connections that you may not have enjoyed had you rushed from appointment to appointment while checking your smartphone. That we could all enjoy a good ten minutes (or more) in the Populus Cafe!

The Populus Cafe is at 146 Neil Road, Singapore 088875

Categories
Coffee review General Home experiments Observations Science history slow Tea

Noticing at Artisan, Ealing

coffee Artisan Ealing
A good coffee is a solid foundation for any afternoon’s noticing.

A cafe-physics review with a difference. In that, it’s not so much a review as an invitation. What do you notice in a café?

Last week, I had the opportunity to try Artisan’s Ealing branch. Although I had found a lot to notice on my previous visit to the East Sheen branch, I had a very specific reason for visiting the Ealing location of this small chain of four cafés. The coffee (espresso) was reliably good. Smooth and drinkable in a friendly atmosphere. Just as with the café in East Sheen, there were a good selection of edibles at the counter and plenty to notice. The light shades were immediately outstanding as something to notice while a framed ‘hole in the wall’ provided a conversation point. The café was very busy and while there was plenty of seating with many tables, we were still lucky to have got a table for two near the back. Behind us there was a lesson going on in the coffee school while on the wall was the calendar for the space booking downstairs. And it was this that I had come here for.

A couple of months ago, Artisan announced that this space would be available to rent to provide a friendly space (with coffee) for the meetings of local small businesses or charities. This stayed in the back of my mind for a while as it came about at roughly the same time as an idea for Bean Thinking.

Lampshades at Artisan Ealing
First the obvious. Immediately striking, these lampshades could provide several avenues for thought.

There are a couple of us who are interested in meeting, about once a month, to discuss science. As ‘science’ is quite a big subject, we thought we would limit it to science that is associated with coffee or with the café at which we are meeting. Perhaps readers of this website may realise that this is not such a restriction, it is quite easy to connect coffee to the cosmic microwave background radiation of the Universe or to chromatography and analytical chemistry. If we were to meet in a location such as Artisan, there should be plenty more food for thoughts. The lampshades prompted me to consider what made substances opaque or transparent? Where is the link to coffee and methods for measuring the coffee extraction? The hole in the wall suggested thoughts about the algorithms behind cash machines. I’m sure that there is plenty more to notice if we take the time to see it.

And so this is an invitation. Would you like to join us in exploring what we each notice about the science of our surroundings? The plan would be to meet once a month, probably starting late January 2019 or early February (date and location to be confirmed). An afternoon on the weekend is probably better than an evening and we’d probably stay for an hour or two. You do not have to be a practising scientist to come along indeed, it would be great if we could have people from a variety of walks of life. The idea is not (necessarily) to answer scientific questions that we each may have but instead to explore the science behind the questions, to find the connections that form our ideas of the universe. To really notice our surroundings and our coffees (tea drinkers would also be welcome). As a consequence of this, mobile phones/laptops etc. will be discouraged during the afternoon. We’d like to notice things around us and not be distracted by what a search engine suggests about it; if we think a search engine could help us, we’ll use it after we’ve left and come back the following month to discuss the issues further. So, if you are curious, would like to explore what you notice and can tolerate keeping your phone on silent and in your pocket for an afternoon, please do come along, it would be great to meet some of you.

menus and lampshades in Artisan
You may like to look more closely at this photo. How are the menus supported? What does that tell us about the history of science?

In order to understand whether there would be any interest in this idea and to hear your input about the format, content, location, time etc. I have set up a mailing list for these cafe-science-spaces. Please do sign up to the mailing list to hear the latest announcements concerning these events and also to email me back to contribute your opinion. You can sign up to the mailing list using the sign up form below. Alternatively, if you don’t want to sign up to the mailing list but do want to hear more, I will be advertising the events on Twitter and Facebook so please do feel free to follow me there.

 

Please enter your email address here if you would like to hear about future Bean Thinking events.

 

Categories
Coffee review Observations Science history Sustainability/environmental Tea

A post in need of a Curator(s) Coffee, Fitzrovia

espresso Curators
A deliciously intense and fruity espresso from the ‘specials’ menu at Curators Coffee.

Curators Coffee in Margaret St in Fitzrovia has been there for years. A great location just off of Oxford St, with plenty of seating and good coffee, and so it is perfect to pop into, unless you are like me and avoid the Oxford St area as much as possible. Which perhaps explains the rarity of my visits. I first popped into Curators Coffee a couple of years back (before the laws on allergen information came in) when I remember enjoying a lovely long black but couldn’t have a cake because the people behind the counter that day couldn’t tell me which (if any) cakes contained nuts. At the time, I sat upstairs and noticed the graphene type arrangement of hexagons around the back of the space and the Bramah’s 300 years of coffee makers book in a rack at the back. I had wanted to return to properly cafe-physics review the place at a later date (and try the cake) but circumstances (and Oxford St avoidance) meant that I never got round to it. Until very recently.

This time, I noticed that there were three single origin coffees available to try as espresso. Glancing at the tasting notes it was a fairly quick decision: “chocolate”. And although this time I had just had lunch and so passed on the cake, it appears that the espresso choices regularly rotate, offering an incentive to come back again and try something new. Although the café is quite large, with plenty of seating, it seems that it is also very popular. And so there were no spaces remaining upstairs. Fortunately, there were more seats downstairs and so, taking our table number with us, we made our way down the stairs and found a table at the window, as if it was waiting for us.

UFO in Curators Coffee Fitzrovia
A UFO reflected in the window? Why? What? Why (again)? It is small details such as this that reward you as you put down your smart phone and notice your surroundings.

Perhaps it is obvious that a café called Curators should have art work adorning the walls. That, and the spotlights that highlighted the work immediately caught our interest, (although it was odd to see that one of the rows of spotlights was almost devoid of bulbs). The exhibition downstairs seemed to have a tilt towards street art and a couple of decorated aerosol cans were on the windowsill priced at £15 each. Was this the time to consider why an aerosol gets cooler as you spray the walls with it?

Outside the window, a staircase leading up to the street outside had railings in straight lines leading up towards a blue sky. Inside, a space craft was reflected in the window.

Indeed, on checking again, there was a spacecraft, like a cartoon of a stereotypical little UFO, drawn onto the wall behind my accomplice’s head and reflected in the window next to it. What could it mean? Regardless of whether some UFO incidents are associated with visitors from other planets, there are a large number of scientific thought trains we can take when considering a UFO reflected in a window. To start with, how likely is it that we are alone in the universe or that there are many other intelligent life forms in other planetary systems?

The question has been answered on the basis of probability for many years. But recently, we have been finding more planets orbiting stars and crucially, more planets that are in the ‘habitable’ zone around other stars. Assuming that life elsewhere needs similar conditions to the earth’s in order to thrive, the idea of life elsewhere is becoming increasingly real.

canali Curators Coffee
If you see straight lines such as this, it is fairly sensible to infer that they were built by an intelligent life-form. Can you see canals on Mars?

Closer to home, there were even suggestions that Mars may support flowing water, thought to be a host for bacteria based life. And although these interpretations of the flow patterns observed on the Martian surface have more recently been contested (could they instead be flowing sand?), we continue to send probes (such as the Insight probe that landed recently) to the red planet to investigate its geology. Did Mars once host life?  Mars of course has a resonance in science fiction for being the planet hosting extra-terrestrial life. HG Wells imagined the Martians landing just south of London, and eventually being killed off by exposure to bacteria on earth that they had not experienced in their Martian habitat. Could life on Mars suggest a (tenuous) further link to this café on Margaret St?

Perhaps one reason that people started to imagine (intelligent) life on Mars came about because of an interesting mistranslation of an astronomical observation. While gazing at Mars in 1877, Schiaparelli noted ‘canali’ on the Martian surface. The correct translation of this in this context into English is “channels” but what the observation came to be known as was “canals”. Canals imply an intelligent builder, and hence life on Mars. Later observers also saw these ‘canals’ and a popular myth was born. It is a useful lesson for us all, sometimes how we see something can be influenced by the language we use to describe it.

soya hot chocolate, Curators
We photograph our coffee, and share it with our online friends. But would putting down our phone in a cafe be worth something for the planet as well as for ourselves? How many batteries do we need?

And then one final thought train, prompted by photographing the cafe with my mobile phone. The whole probability argument rests on two assumptions. The first is that there are other planetary systems (which we are finding). The second is that life is fairly easy to start, or at least, that the chances of producing life are not restricted to one planet a short distance away from the Sun; we are not unique. As yet we don’t know whether this assumption is justified but discoveries such as the deep sea hydrothermal vents challenge our preconceptions about the requirements for life and suggest that life could start more than once, and so could very well start on other planets, not just ours. In these vents, bacteria are known to convert what we think of as toxic chemicals into energy in a process known as chemosynthesis without the need of sunlight or other ingredients that we had thought essential to life. Could similar hydrothermal vents on other planets host new life forms?

And in a related way, what is going on with these vents? Is new life being created even now in the deep sea? In which case, what do we think about deep sea mining? If our aim is to reduce our carbon dioxide emissions by using more re-usable objects and renewable energy sources, we will require more batteries and batteries require (among other things) cobalt. If we are all to keep using mobile phones to photograph cafés, we too need the batteries which rely on these elements. A number of companies have realised that there is a vast untapped resource under the sea if only we could dredge it up. This may be easier or ultimately cheaper than recycling the old batteries. It may destroy a few hydrothermal vents or stir up the sea bed but what concern is that to us if we can gain access to more cobalt to allow us to have more batteries to allow us to all be ‘greener’.

Indeed, of what concern is that to us?

Curators Coffee is at 51 Margaret St, W1W 8SG

Categories
Coffee review Coffee Roasters Observations Science history slow Sustainability/environmental

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

 

 

 

 

Categories
Allergy friendly Coffee review Observations Tea

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

Categories
Allergy friendly Coffee review Observations Science history slow Tea

Creating an impression at 2Love Coffee House, Clapham Junction

coffee, cake menu, Clapham Junction, monmouth coffee
The menu at 2Love in Clapham Junction and some of the coffee making equipment in the window.

There is a lot of coffee paraphernalia on display in the windows at 2Love Coffee House on St John’s Road near Clapham Junction. Reusable cups, filters, moka pots, Chemex’s etc. Stepping inside, a piano greets you while the counter is on the left. The wall behind the counter is lined with jars of different sorts of tea while the coffee menu is on a blackboard close to the window. Coffee is roasted by Monmouth and is also available to purchase for brewing at home. Moreover, the number of re-usable cups on display meant that I have to admit to a touch of reusable cup envy when I saw the variety of glass cups on sale, have I used my cup enough to justify a second*? One great feature about this café was the care that they have taken to specify the allergens in their cakes on the blackboard, it is a considerate touch for people with allergies. Although we didn’t enjoy a cake on this occasion, it is great to know that I can!

There is definitely a musical feel to the café, with statues of musicians on shelves around the shop and pictures of different singers on each of the walls. Although we managed to find a table, it was rather crowded with the amount of chatter and distractions in the café initially challenging my assumption that all cafés can offer a space to contemplate and consider connections. However, this brief doubt in the idea behind Bean Thinking did not last long. The change in direction started with our discussion over an Americano and a fruit juice: can there be a justification for not eating certain meats if you are not already vegetarian/vegan and if so, what is it? This didn’t seem to go down too well with the table adjacent to us. On the wall behind our table was a metal picture of a horse drawn cart where the figures had been raised out of the picture to form a 3D image. It was reminiscent of the patterns given for stone rubbing as a child. But it was also reminiscent of something else, something that shines a light on an area of manufacturing as well as, perhaps, our conversation about the ethics of meat eating.

Not quite a mirror at 2 Love
3D Metal picture, musician statue and poster at 2Love Coffee House, who is the fairest of them all?

It concerns Chinese (or Japanese) magic mirrors. Known about for millennia (and not just in China, Aulus Gellius (c125 – approx 180 AD) wrote of them in the second century¹), they are slightly convex mirrors made of bronze. One surface appears to be an ordinary mirror but on the reverse surface, images of mythology or special Chinese characters are cast in relief. A Nature paper of 1879 describes why they were considered ‘magical’:

“If a polished surface is looked at directly, it acts as an ordinary mirror, reflecting the objects in front of it, but giving, of course, no indication whatever of the raised patterns on the back; if however a bright light be reflected by the smooth face of the mirror onto a screen, there is seen on this screen an image formed of bright lines on a dark background more or less perfectly representing the pattern on the back of the mirror, which is altogether hidden from the light”.¹

You can see photos of such mirrors and their reflections here but how would such an image be produced? Apart from magic, the first explanations for the effect focussed on it being trickery on the part of the makers of these mirrors. Perhaps the image was patterned onto the front of the mirror using more dense (or less dense) material, covered with a thin layer of lead or tin and highly polished so that you would never notice it by looking at your reflection only by shining light at it? Maybe there was other trickery involved on the part of the mirror makers to deceive us into thinking we could see through the mirror to the back. Later researchers wondered if these mirrors really existed at all as few could be found when they searched for them amongst Japanese mirror workshops. And yet a few mirrors with this magic quality were found and subject to study in the late nineteenth century.

window display 2Love
How much is that cup in the window?
Some of the reusable cups on sale at 2Love coffee house.

The results showed that the image was not formed if projected too close to the mirror but only if the screen were held some distance away from the mirror’s surface. Moreover careful optical experiments showed that the image was formed by the surface of the mirror having thicker regions that were less convex than the rest of the mirror so that these reflected the light differently². Although the image at the back of the mirror had been cast and not stamped on the back, the stresses and strains formed by the pattern on the metal somehow propagated through the (thin) mirrors and produced distortions on the surface of the mirror. Even when highly polished, these minute distortions in curvature remained causing the reflection of the ‘magic’ image under certain lighting conditions.

The theory describing the optics behind the magic mirrors was described as a ‘beautiful fact’ in a fairly recent mathematical description. But exactly how the stress of the pattern at the back gets transferred to the surface of the mirror remains to be understood³. Nonetheless, the fact that imperfections on one side of a material can be revealed by the projected reflections from the surface of the other, a process known as “Makyoh imaging”, is now used to check the integrity of semiconductor wafers before they are used in the manufacturing of devices. A piece of physics based neither on magic, nor on trickery, that is useful for our computer based lifestyles.

When faced with something that seemed improbable, it is interesting that our first explanations were based on magic, deceit on the part of the one who made it or distrust of the phenomenon altogether. It was only by carefully studying something that was too easily dismissed that the beautiful physics and industrial relevance of the property was revealed. For me this has pertinence to the question of our own investigation into what we think about the world. Do we place too much weight in our judgement of what we do not understand merely based on our own experience of how things are? Do we need to look more carefully at what we thought we knew? Great pondering points for a visit to a café and confirmation that, provided you have good coffee and a nice chair to sit on, contemplation directions can be found no matter how popular the venue.

2Love coffee is at 89 St John’s Road, Clapham Junction, SW11 1QY

¹ “The Mirror of Japan and its Magic Quality” Nature, April 10 1879, p 559

² “The Magic Mirror of Japan, Part 1”, WE Ayrton and John Perry, Proc. Royal. Soc, 28, 127 (1878-79)

³ “Oriental Magic Mirrors and the Laplacian Image”, MV Berry, Euro. J. Phys. 27, 109 (2006)

*Although there are differences depending on what you take into account, lifecycle analysis done here, here and here suggest a break-even point of disposable to reusable cups from 15 to 100 re-uses. However, if you consider that part of the solution to our environmental problems involves breaking the consumerist mindset then perhaps, if it ain’t broke, no need to replace it.

 

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

Feeling the Earth move at Pritchard and Ure, Camden

Egg no pales, coffee, garden centre
Fried egg on cactus leaves. Cactus festival at Pritchard and Ure, Camden

Good coffee in a garden centre, in (nearly) central London, with some physics thrown in? Today’s cafe-physics review seems unlikely on several levels. And then it becomes even more unlikely as you realise that this garden centre and café are also a social enterprise where people “disadvantaged in the labour market” are helped back to employment through working here. All in all, Pritchard and Ure represent a great café to have come by.

Pritchard and Ure can be found in the gallery space of a warehouse type shop that houses the Camden Garden Centre. They serve Workshop coffee together with an extensive selection of alternative drinks and food. As it was lunchtime we enjoyed a spot to eat which gave me an opportunity to try cactus (it was cactus festival at the garden centre). Cactus leaves with re-fried beans and a cactus-water mocktail which came together with a reusable metal straw. The straws were being sold (together with brush straw cleaners) at the counter. After lunch there was a very well made long black (interestingly I was given the choice to have it either as a 6oz or an 8oz, ie. more or less water depending on whether I wanted more or less coffee taste) and resisted (somehow) one of the tempting cakes before having a wander in the garden centre.

equations art work coffee Camden
But are they real?
The equations are the writing on the wall at this cafe.

There are of course many things that you can notice and connect with/to in a garden centre. Plants, biosphere, windows and greenhouse effect, the carbon cycle, the nature of colour, the list could go on. In addition to all of these, to the left of the counter was an art piece on the wall with a list of various equations and comments. Were all these equations real? One thing in particular though in this café/garden centre was particularly mesmeric: the disco ball suspended as a pendulum from a beam across the ceiling. Initially we watched as the ball just glinted reflected light as it slowly swayed to and fro in its oscillation. It took 22 seconds to cover 5 oscillations while I estimated it was 7m in length. Knowing that there is a formula for calculating the period of oscillation I wondered, was my estimation any good?*

During the hour it took us to enjoy lunch, the position of the Sun moved in the sky so that the disco ball started to reflect an array of polka dots of light onto the walls surrounding us (you can see these in the photo). Owing to the combined rotation and oscillation of the ball it wasn’t too easy to measure the time period from these oscillations but about 4 seconds per swing (as I had obtained by merely watching the ball) seemed comfortingly correct. The sun slowly moved round and these dots danced until at some point the sun had moved far enough that the glitter ball was no longer in direct light. But had the Sun moved or the Earth rotated underneath it? We all know the answer (or at least we think we do), but we could use the pendulum to prove it (and to calculate our latitude).

discoball cafe
Disco ball pendulum together with polka dot reflected sunlight. The view from the gallery at Pritchard and Ure.

In various science museums around the world, different Foucault pendulums swing to and fro all day above circular patterns on the floor. The pendulums appear to rotate clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere thereby illustrating the rotating earth underneath the pendulum. The idea is of course that the pendulum continues to swing in the same plane as it was when it was started off but as it is swinging the earth is rotating underneath it giving an apparent rotation of the pendulum swing over the course of a day. If we were at the north (or south) pole, the period of one complete rotation of the pendulum through a circle on the floor would take 24h. As most of us are not at the pole (and Pritchard and Ure certainly is not), the period of complete rotation is lengthened by a corrective factor proportional to the sine of the latitude. Consequently, it is perfectly feasible for us to calculate our latitude by observing a pendulum swinging for long enough in the absence of any breeze.

It is a great piece of evidence for the rotation of the earth (and by implication the fact that the earth is not flat and that the sun is not going round the earth each day). It’s also a very simple (hiding some complicated maths) demonstration that anyone could set up if they wished to carefully do so. So next time you see a disco ball suspended as a pendulum in a café, you would have another reason to start singing “I feel the Earth, move, under my feet…”

Pritchard and Ure is in the gallery of Camden Garden Centre at 2 Barker Drive, St Pancras Way, NW1 0JW

*7 m is an over estimate of the length of the pendulum based on the period of the oscillation. A length of 7m would give a time period of 5.3 seconds, whereas 22 seconds for 5 oscillations is about 4.4 seconds for one giving a calculated length of just under 5m. More details about how to calculate this are here.

Categories
Coffee review Observations Science history

Metrology and the Press Room, Twickenham

Press Room coffee Twickenham
The arrival of the pour over at the Press Room, Twickenham.

It is not often that I have an errand to run in Twickenham, but when one popped up just two weeks after reading Brian’s Coffee Spot review of The Press Room, it was obvious where we were going to have a coffee. The Press Room serves pour over coffees (along with a good selection of other drinks). It is always great to find somewhere that serves pour overs well and so I had no hesitation in ordering a Nicaraguan “Los Altos” prepared by V60. Hot chocolate was available as white, milk or dark chocolate and there were a number of alternative non-dairy milks on offer as well as a large variety of tea. A lovely feature of The Press Room is that they offer suspended coffees, the idea being that you buy a coffee now for someone later who may not otherwise be able to afford one. The total number of coffees (given/claimed) is recorded on a blackboard behind the counter. It was nice to see that at the time of our visit 800+ coffees had been paid forward (and just less than 800 claimed), suggesting that the Press Room is having a positive effect on its local community.

clock wall Twickenham coffee
The large clock on the wall at The Press Room in Twickenham.

A great thing about ordering a pour over is watching as the barista expertly prepares your coffee, taking the time to do this properly. To be fair, this is part of the reason that finding a café serving pour-overs is becoming more difficult. After a while, the coffee was brought over to our table together with a bowl ready for me to place the filter cone on it when I was ready to enjoy the coffee. After taking the obligatory photograph, and pondering when would be the best time to remove the filter from the top of the mug and place it onto the empty bowl, the clock next to us took our attention. It is a large time piece that dominates this corner of the room. It is revealing to consider how the accuracy and availability of clocks have changed the way we live as a society.

Considering measurement (of time and other things), I used to be in this area more frequently a few years ago when I worked on a project in collaboration with the National Physical Laboratory (which is down the road, on the same bus route that Brian’s Coffee Spot notes takes you to a few good cafés). Partly, NPL’s work is to ensure that we know how to measure things properly. Take the pour over I enjoyed at The Press Room. A known amount (perhaps 12 g) of coffee was weighed out before 200 g of water was poured slowly over the coffee. But how do you know that the 12 g measured at Press Coffee is the same 12 g as you measure at home? And while perhaps it may not be critical for the coffee culture (even the most extreme home-brewer does not need to know the amount of coffee they are using to the nearest 0.000 002%), knowing accurately how heavy something is can be extremely important. Hence the need for a standard kilogram (and a standard metre, second, Candela etc) so that we have a way of knowing that what you call a kg is the same as what I call a kg.

coffee bowl pour over
The coffee that escaped! But was it a measure of my patience or hesitation?

Oddly, the kilogram is the last fundamental unit still defined with reference to a physical object (the other fundamental units are seconds, metres, Kelvin, Amperes, Moles, Candelas). The kilogram reference block is a PtIr alloy kept at the International Bureau of Weights and Measures near Paris. However all this may change next year depending on a decision due in November 2018. If all goes to plan, from May 2019 all units will be defined with respect to natural constants such as the speed of light etc. For the kilogram, this has meant measuring mass relative to a magnetic force generated by a coil of wire in a device known as a Kibble balance. In this way, the kg can be defined with respect to Planck’s constant and an era in which we measured substances relative to known objects will end.

On a day to day level though, how much do these things matter to us? Sometimes the way we measure things affects how we view them (and therefore what questions we ask next). Take for example temperature. We are used to measuring degrees of ‘hot’, so on the centigrade scale 0ºC is the freezing point of water and 100ºC is the boiling point. But it wasn’t always this way. Celsius devised his original scale to measure degrees of cold so 0º was the boiling point of water and 100º was the freezing point (you can read more about that story here). It is arguable that changing to measuring degrees of ‘hot’ enabled us to more easily conceptualise the idea of heat as energy and the field of thermodynamics. Certainly for a while, considering the idea of ‘degrees of cold’ meant that some looked for a substance of ‘cold’ called “frigorific“¹. There’s a similarity here with the coffee at The Press Room, was the amount of coffee in the bowl used to hold the filter after I removed it from the mug a measure of my impatience before trying the coffee or my hesitation at testing the coffee? How we ask that question affects how we view the coffee and the café (for reference, I would take the positive interpretation: the amount of coffee in the bowl measures my impatience; I was eager to try the coffee).

droplets on the side of a mug
Condensation on the side of the mug. These droplets can reveal many aspects of physics, which do you think about?

Partly this suggests some of the ways in which language, and philosophy, underpin all science. It certainly suggests one further connection with this bright and comfortable café. Erich Fromm in “To have or to be”² considered an interesting linguistic usage that reveals our way of being. Do we “have an idea”, or do we “think”? Are we consumers or people with experiences? Do we wish to have, to acquire, to consume or do we wish to exist, to be. Our language affects how we perceive the world which in turn changes the language we use about it. Linguistically, depending on how we interpret the cafe’s name “The Press Room”, we either have a café that offers a space to read the latest news or one that is reflective of the coffee brewing process (specifically espresso); a space to get up to date or one in which to contemplate? The symbol of the café visible in the frontage of the shop and on the mugs suggests the latter, but maybe it is something we need to experience to truly know?

¹Inventing Temperature, Hasok Chang, Oxford University Press, 2008

²To have or to be, Erich Fromm, Jonathan Cape, 1978

The Press Room is at 29 London Road, TW1 3SW

Categories
Coffee review Observations slow Tea

Hundred House: Wonder what they are?

Dog and Hat, Dog & Hat, Hundred House, Quarterhouse coffee
Look what arrived! The package from Dog & Hat with the distinguished logo.

What would happen if, rather than five minutes taken noticing the surroundings of a café, you were to look closely at the coffee you brewed in the morning? Different roasters, different coffees, an opportunity to notice something new in each brew. And so it was that a couple of weeks ago a package arrived in the post from the coffee subscription site “Dog and Hat“. Together with a note (in answer to a question I had sent them) ‘Recycled box, paper, mail bag’, came two coffees. An Ethiopian honey processed coffee from Hundred House and a Mexican washed coffee from Coatepec via Quarter Horse coffee.

Each time I moved the bag from Hundred House, a lovely aroma was released. So I moved it around quite a lot. While brewing a V60 with it, the morning light poured through the window producing beautiful lensing effects through the bubbles on the coffee surface and reflections from the coffee itself. The brewed coffee had such a sweet, fruity aroma reminding me of cherries that gave way to plums on tasting. What I took as toffee seemed to be described on the tasting notes as “dates” or “molasses”. Close enough I think. A lovely coffee to enjoy slowly.

Hundred House coffee
The Hundred House coffee bag. With that aroma, indeed how I wonder what you are.

Printed onto the bag was a star with extra lines coming out of it, suggestive of a twinkling star at night. Although each star is massive, they are all at such a great distance from us that they appear to us as point sources of light. And since all light gets refracted when it goes from one medium to another (think about the appearance of that paper straw in a glass of water) the star will appear to twinkle from our position on the Earth below our turbulent atmosphere. Although on a clear night we may not notice it directly, regions of relative hot and cool air in the atmosphere are constantly moving. Layers of air move over each other creating waves much like you see on the seashore and it is this turbulent environment that refracts the light from the stars in such a shimmering way. We can see a similar effect in tea (though not so easily in coffee*): When we pour hot tea into a cold cup, the convection in the cup leads to there being areas of hotter and cooler tea. The refractive index of water is temperature dependent and so the light incident on the tea gets refracted (bent) by different amounts depending on whether it encounters a cool region or a warm region. This leads to the lines of light that we see dancing on the bottom of the cup¹.

KH instability, Kelvin Helmholtz instability
Not a great example of a Kelvin Helmholtz instability but it gives the general idea. This one was quickly snapped from a moving car, I’m on the lookout for a better example.

Although atmospheric turbulence is inferred by the twinkling of stars, a beautiful visualisation of that turbulence can be seen in the form of the Kelvin-Helmholtz instability. Named after Lord Kelvin and Hermann von Helmholtz, this instability manifests as a string of waves on a cloud. It occurs when a fast moving layer of air flows over a slower moving one. The phenomenon is fleeting. If you are lucky enough to see it, the pattern manifests only for a very short time. They are definitely worth watching out for.

Depictions of atmospheric turbulence can also be seen in some paintings. It is said that Vincent van Gogh’s depiction of turbulence in his painting “Starry Night” is extraordinarily accurate. Certainly it is striking that the turbulence depicted by van Gogh does look like the turbulence in a coffee cup. However apparently it goes much deeper than this. In a numerical analysis of the turbulent patterns in a few van Gogh paintings, researchers showed that van Gogh’s depiction was very close to the mathematical (Kolmogorov) description of turbulent flow.

Coffee, Van Gogh
Van Gogh in a coffee cup. Reminiscent of his painting “Starry Night”, there are remarkable mathematical similarities between what van Gogh depicted and real turbulent events.

On their website, Hundred House discuss their aim of being a “collective space, where conversation, art and industry meet, over a cup of coffee”. Pouring a coffee, and watching the turbulence in the cup, perhaps pause a while to consider these points of connection and maybe add a bit of science to the mix. This week if you are in the Northern hemisphere, the Perseid meteor shower offers a particularly great time to reflect on turbulence in the atmosphere and the twinkling of the stars. If you locate the “W” of Cassiopeia (currently in the north east viewed from London) and watch, slightly underneath it towards Perseus, you should see a few meteors of the Perseid meteor shower (perhaps 60-70 per hour during the peak of 11th-13th August). While watching for the shooting stars, it is worth looking at those that twinkle. Which twinkle more, the stars of Cassiopeia or the stars toward the horizon? Why do you think this is?

Whether you watch the stars or just prepare your coffee, take the time. Enjoy your brew.

You can find out more about the coffee subscriptions at Dog and Hat coffee, here and more about Hundred House coffee, here. Do get in touch (email, Twitter, Facebook or comments) if you notice anything you want to share.

 

*We don’t see this so often in coffee because coffee, generally, absorbs more light than tea and so it is harder to see the bottom of the cup.

¹Another effect that can lead to these patterns in swimming pools and similar large bodies of water is caused by waves on the surface of the water. Where waves form on the surface of the pool, the curved surface acts as a lens focussing the light to the floor of the pond. As the waves move on the surface, the pattern on the pool floor will change similarly to that in the tea cup.

Categories
Allergy friendly cafe with good nut knowledge Coffee review Coffee Roasters Observations Sustainability/environmental

Bee-ing positive at the Sugar Pot, Kennington

coffee and cake Kennington
Banana bread and coffee with a sugar pot in the background at Sugar Pot, Kennington

What is it that makes a great café? A space to slow down and think? Good coffee and cakes? A local business that forms part of its local community and gives back to that community in different ways? As I was looking around for a new café to try, I was reminded of Sugar Pot in Kennington. Their website suggested that it ticked all of these boxes and so I was eager to try it (so eager in fact that I didn’t note the opening times, they close at 3 on week-days which is a problem when you arrive at about 2.55). So a second attempt at trying Sugar Pot was arranged, this time safely before lunch. This time, in the morning, there were quite a few chairs and tables outside the café in a roped off area of the street. (We hadn’t noticed this on the first occasion we visited as they had all been piled up inside the shop by the time we arrived). Most of these tables were occupied indicating that it is clearly an attractive place for locals to meet and chat over coffee. Fortunately there were also a fair number of tables inside which suited us as a café often offers more to ponder inside than out (though outside offers a different perspective particularly for people watching).

Inside, each table has an individual character and one in particular offered several points to think about both in terms of physics and aesthetics (you will have to visit to understand). However, it was elsewhere that my attention was drawn that day. Coffee is roasted locally by Cable Bakery while the cakes are from John the Baker of the Kennington Bakery. Sugar Pot definitely gets a tick in the “allergy friendly” box because they answered confidently (and with required caveats about traces) my dreaded question “does it contain nuts?” So I was able to enjoy a lovely slice of banana bread with my coffee. Most of the usual espresso based drinks are available (but not listed on the menu) together with a French Press coffee for those who prefer a non-espresso brew.

Interior Sugar Pot, Kennington
Noticeboard, magazines and coffee counter at Sugar Pot in Kennington

The community feel of the café was immediately apparent with a notice board adjacent to the counter being packed with notices of different activities happening around the locality and within Kennington Park which is just opposite. Underneath the counter were books and magazines and an advert for volunteering with the local bee keeping and urban farming organisation Bee Urban. This is indeed another way that Sugar pot gets involved in its local community. The coffee grounds are donated to Bee Urban for use in their Kennington Park based composting facility. Bees of course have an Albert Einstein link with physics as he is alleged to have said

“If the bee disappeared off the surface of the globe, then man would have only four years of life left. No more bees, no more pollinators, no more plants, no more animals, no more man.”

I do not know if he really did say this but it is a sad reflection on our society that rather than address our environmental crimes we are researching pollinating with drones. However, it turns out the the bee has a much more exciting, almost shocking, link with physics and one that I only discovered thanks to the excellent book “Storm in a Teacup” by Helen Czerski¹. The bee is indeed a very positive creature.

ultra violet, bee, bumble bee
The world looks very different to a bee. Image © www.gardensafari.net

Whether or not they have a happy disposition, it seems that 94% of bees are, electrically speaking, positively charged². They pick up a static charge while flying through the air in a similar way to a balloon being rubbed on your hair. Flowers meanwhile have a negative charge meaning that in addition to colour, shape, scent and pattern, bees can recognise flowers by their electric fields. These fields in turn mean that pollen from the flower ‘jumps off’ and adheres to the bees fur before the bee has even landed, increasing the efficiency of the bee as a pollinator. But it turns out that there is much more to it. When the positive bee lands on the negative flower, there is a charge transfer that results in a change of the electric field around the flower for a duration of 100 seconds or so. By constructing artificial flowers held at different voltages containing either a sugar reward or a bitter centre, researchers at Bristol university found that bees could learn to recognise which ‘flowers’ contained the sugar and which were too bitter to be visited by sensing the electric field around the ‘flower’. It suggests that the changing electric field of real flowers provides a mechanism by which the bee can recognise if a flower has been recently visited by another bee and so been recently pollenated. This would mean that by ‘feeling’ the electric field of the flower, the bee may decide that it would be more rewarding to carry on to a differently charged flower. You can read more about the research in the paper here.

It seems to me that learning about how the bee senses its environment reveals even more about the amazing way that nature (and physics) works. And this offers a link back to Sugar Pot. On the shelf behind the counter back at Sugar Pot was a card that had the message “Keep safe, live to be”. What does it mean “live to be”? In the environmental encyclical Laudato Si’, Pope Francis urges everyone to slow down and notice things such as the bee commenting that “If someone has not learned to stop and admire something beautiful, we should not be surprised if he or she treats everything as an object to be used and abused without scruple.” He goes on “… when media and the digital world become omnipresent, their influence can stop people from learning how to live wisely, to think deeply and to love generously… True wisdom, as the fruit of self-examination, dialogue and generous encounter between persons, is not acquired by a mere accumulation of data...”³ Which is one reason that in order to be, we may want to come back and take a closer look at those bees. Taking time to experience our coffee in a relaxing space such as Sugar Pot and to watch and ponder as the bee uses senses of which we are barely aware can never be a waste of our time. Indeed, it is possible that our world may depend on it.

¹Storm in a Teacup, Helen Czerski, Transworld Publishers, 2016

² Clarke et al., “Detection and learning of Floral Electric Fields by Bumblebees”, Science, 340, 6128, 66 (2013).

³The passages quoted are from paragraphs 215 and 225 respectively of Laudato Si which can be read online.

Sugar Pot can be found at 248 Kennington Park Road, SE11 4DA