Tag: slow movement

Categories
Coffee Roasters General Home experiments Observations Science history slow Uncategorized

Chemical extraction in a V60

chromatography, paper chromatography, V60
Brewing a coffee, insight into analytical chemistry

Ever considered the connection between your morning brew and a century old technique that, it is fair to say, revolutionised analytical chemistry?

Last week, a new coffee arrived in the post from the Roasting House coffee club, followed shortly by an email with details about that week’s coffee. This is not unusual, the coffee club means that a different coffee arrives every two weeks. What was slightly unusual was the email which started:

“There are some brief tasting notes on the bag of coffee we sent you, but before you go on and read the more detailed description, have a good taste of the coffee yourself….”

The opportunity to do so finally arrived and I prepared a V60. First measuring out the freshly ground beans, rinsing the filter, watching the bloom, then slowly pouring the remaining freshly boiled water onto the grounds, all the while noting the aroma.

Taking this opportunity to slowly prepare (and appreciate) a coffee, I noticed that some of the soluble elements in the coffee climbed the filter paper during the pour. A few hours afterwards, the paper had gained a circular rim of coffee solubles around the top of the paper. Although in many ways quite different, this effect was very reminiscent of the technique of chromatography.

Roast House coffee, tasting chromatography
The coffee in question. What tasting notes would you get if you slowed down and tried this one?

The biggest difference between the behaviour of the V60 filter and “paper chromatography” is that in the former, the bottom of the filter paper is continuously immersed in both the sample (coffee) and the solvent (water). In chromatography on the other hand, a drop of the sample (e.g. coffee or ink) is put onto the filter paper which is then placed in a solvent (e.g. water, ethanol). Different components within the sample travel different amounts up the filter paper depending on how soluble they are in the solvent and how they interact chemically with the filter paper. So different components will travel different distances up the filter paper before they get stuck while the solvent continues to travel up the paper. All else being constant, each component always travels a certain distance relative to the solvent and so this provides a way of separating chemical components ready for further analysis or identification.

Perhaps you remember using chromatography to separate the colours in an ink pen at school? The ink was spotted onto a piece of filter paper and then immersed in water. We watched as it separated into various colours illustrating the number of different dyes that had been used to make up the ink. When used professionally though, the chromatography technique can be used to investigate trace impurities in soil, air, drinking water etc. It has even been used to analyse the components in coffee. From something that can be done in school science, it is an incredibly powerful chemical technique.

What was surprising was that the technique of chromatography was not invented until 1903, while the idea of using paper in chromatography only came about in 1944¹. Those who first used chromatography as a method to identify chemicals (in plants), did so using columns of powder rather than paper. Paper chromatography was invented to investigate the separation of amino acids and specifically was used to understand the composition of the antibiotic tyrocidin¹. Just as the ink in our school experiments separated into different dyes, so the chemicals that they were investigating would separate into different components, different chemicals would stay at different heights on the filter paper.

Since its invention, the technique had been extended to include gas chromatography rather than just liquid and has been developed to be extraordinarily sensitive. It is now possible to analyse chemicals with a mass of just 10^-15 grammes, a quantity which is too small to even easily imagine. Even just a couple of decades after the invention of the technique it could be said:

“Amino acids… could now be separated in microgram amounts and visualised…. (Paper chromatography) would allow one within the space of a week [to do some analysis]… which until then could very well have occupied the three years of a Ph.D….”¹

V60 chromatography chemistry kitchen
A few hours later and the coffee had travelled up the filter paper with the solvent (water).

However, to return to the coffee. Through tasting rather than chemistry, I obtained a toffee aroma, with earthy notes and hints of redcurrant that evolved as the coffee cooled into a sweet toffee taste. The tasting notes further down the email on the other hand said:

“There’s a rich chocolate base, a kind of woody pine taste, sweet summer fruits, even tobacco. Remember, taste it before you judge it! Tobacco notes and woody pine don’t sound particularly appealing and maybe you don’t taste them at all!”

Much more descriptive than my effort. It seems I need to return to my V60 and improve my tasting ‘chromatography’. There are so many ways to slow down and appreciate a good coffee, what do you notice in yours?

A ‘coffee tasting wheel’ can be found here if you, like me, would like to improve your coffee tasting ‘chromatography’.

¹Chapters in the evolution of Chromatography, Ed. John V Hinshaw, Imperial College Press, 2008

Categories
Coffee review General Home experiments Tea

Communities at Wilton Way

exterior of Wilton Way, Hackney Coffee
Wilton Way cafe on Wilton Way

There are two things that may strike you as you walk past Wilton Way café. The first is the prominent La Marzocco espresso machine on the counter. The second is the “ON AIR” sign in the corner next to the window. Indeed, it is best to look out for these two as there didn’t seem to be any other sign indicating that this café was the Wilton Way cafe, home to the London Fields Radio that is broadcast from here (hence the “on air” sign). In the late afternoon, the café offered some shade on a sunny day and so we popped in for a tea, though there is seating on a bench outside should you wish to enjoy the Sun. Although this website is supposed to be about coffee (which is roasted by Climpson & Sons), sometimes a fresh mint tea is what is needed. This particular mint tea was very refreshing with plenty of mint leaves in the cup. Sadly though, in what seems to be a common pattern at the moment, this was another café at which there were few cakes on offer, presumably as it was late afternoon by the time we visited. However, what is sad for the mind is perhaps good for the waistline, we’ll have to revisit in the morning for the cakes next time.

Corrugated iron supported the counter while the (plentiful) seats inside the café appeared to be made of recycled wood and boxes. Interestingly, this is mentioned in the description of the Wilton Way café on the London Fields Radio website, apparently the interior was designed to be a mix of modern and reclaimed materials. Choosing a seat at the back allowed us to survey the space and people-watch while sipping the tea. On the counter was an old-style Casio cash register while in the far corner at the front of the café, the microphone and broadcasting equipment stood waiting to be used for the London Fields Radio.

the broadcasting equipment at the WW cafe Hackney
London Fields Radio, broadcast from Wilton Way cafe

In the book “Radar, how it all began” the author, Jim Brown reminisced about how he had played with a crystal radio set as a child in the 1920s¹. Many scientists can remember making their own radio sets as children (or indeed as adults). It seems playing with things, taking them apart and building them again is part of the personal-history of many scientists and engineers (particularly experimental ones whether they be ‘professional’ scientists or not). The Lunar Society (which was active at the end of the eighteenth century and into the early nineteenth) featured a group of keen “tinkerers”. These were people who experimented with nature and invented new devices in order to explore their understanding of the world. Though each of them were only doing science ‘on the side’ as they each had other day-jobs, individuals within the group did make some important contributions to our understanding of the world. One such contribution was by Josiah Wedgwood who by observing the “waviness of flint glass” noticed its resemblance to “that which arises when water and spirit of wine are first put together before they become perfectly unified”². The reference is to mixing fluids of different density. Isn’t this experience of tinkering with things similar to our enjoyment and appreciation of coffee? The more we experiment, the more coffee we try (including cupping coffee as with this how-to from Perfect Daily Grind), the more deeply involved in coffee we become and the more we value it. Isn’t it actually true that in order to deepen our relationship with coffee we need to explore it (and experiment with it) more fully? Cannot the same be said for our relation to our world?

interior of Wilton Way cafe
The view from the corner. Spacious and quirky, the Wilton Way cafe has plenty to offer the coffee (or tea) drinker who wishes to slow down and appreciate the moment.

But then a second thought that, to some extent flows from the first. No development would be possible without a community, each contributor bringing a different talent but each contributing to an idea of a greater good. The London Fields Radio would not be possible without the scientists and engineers who design and optimise the broadcasting (and receiving) equipment. But neither would it be possible without talented DJs and musicians, thinkers, poets and performers to give us something to listen to. Two more groups of people are needed for London Fields Radio to be a success. Those who provide the space for the broadcasting equipment (i.e. the café) and those who listen in. Again there is an analogy with coffee. No cup of coffee could be there for us to enjoy without the farmers, the traders, the roasters, the baristas and finally many other people like us who enjoy a good cup. And the more each of us tinker with appreciating another’s work (cupping the coffee like a roaster or tending an allotment to appreciate the growth), the more of a community we become and the better coffee we get for it. We do not imagine while ‘cupping’ coffee that we are really about to take on the role of the coffee trader or roaster, yet by playing at their job we can appreciate their importance and skill more and so realise more effectively our own role too. We could go full-cycle here and consider how playing with radios and experiments can help us to understand the role of technology and science in society and our participation in it, but perhaps that is left as a point to ponder in another café: How can we each contribute to a better society, understand our role in it and appreciate the contributions of others?

One final thought that came from the Lunar society but appears to have a very contemporary relevance. Wedgwood once said to Richard Lovell Edgeworth “But in politics… as in religion, hardly any two people who thought at all, thought exactly alike on everything.” The main thing was “to agree to differ, to agree on impartial investigation and candid argument”.² It appears the Lunar men still have a thing or two to teach us.

Wilton Way cafe can be found at 63 Wilton Way, E8 1BG

¹Radar, How it all began, Jim Brown, Janus Publishing Ltd, 1996

²The Lunar Men, Jenny Uglow, Faber & Faber, 2003

Categories
General Observations slow Tea

Happiness is a cup of coffee

stone recycling, slate, slate waterfall, geology
A cafe with a lovely space to enjoy the coffee. Taking time out at Espresso Base

If you are reading this, you clearly have access to a computer. You are also quite possibly connected through social media to friends, colleagues and others through Facebook, Twitter, Instagram or one of the other numerous ways in which we can now connect with each other. And while I would love for you to continue reading, at least for a couple of moments, I would like to ask you how often you take the opportunity to stop?  To stop and turn off your computer or the notifications on your smart phone and just look at what is around you.

This website is really about slowing down and noticing things. Since I believe that science offers a great way of seeing the connectedness of the world around us, I choose to emphasise the science that you can notice around you. It is most likely that you see the world in a different way, sharing some aspects of my point of view, disagreeing with others. However, it seems to me that slowing down and noticing your surroundings, whether you look at the science or another aspect of those surroundings, makes us in some way happier, or at least, generally, more calm. Having a coffee in a café is a great way of doing this. Whether you are interested in the café or the coffee (or indeed both), there is an awful lot to notice and to appreciate in a café. Noticing it of course does depend on keeping the smartphone (tablet or laptop) in your pocket or your bag. Personally, I find it slightly depressing when I see signs in a café saying “free wifi” (though I suspect I am in a minority on that one). And although if we are not used to it, not checking our email while having a coffee can seem to be enforced boredom, I’d hope that we soon realise that such boredom is in fact creative.

Sun-dog, Sun dog
Walking along while texting could mean that you miss seeing a sun dog

Please don’t get me wrong. It is not that I think social media are a bad thing. I have met (either ‘virtually’ or in person) some great and highly interesting people whom I would never have had the opportunity to meet were it not through Twitter/Facebook etc. Each day, I learn something new through the many people whose experience or knowledge I would otherwise never have had the opportunity to ‘tap’. However, just as sometimes it is great to have such interactions, I have found that it is also vital to have times (perhaps even a day a week) when the smartphone is kept firmly in the pocket (or at least, notifications are turned off).

In the UK, we have just got back from a long weekend. Many cafés were closed over the Easter break. Some of the café-Twitterers I follow went on a long break to the countryside (and Tweeted about it), others just turned off their social media for a few days. Elsewhere in the world you perhaps have different long weekends, Chinese New Year or Christmas. Perhaps during these holidays you manage to get a break in the countryside or by the coast. It is here that there is a link between an interesting recent study and a great use of a smartphone.  The study, by researchers at the University of Surrey and the London School of Economics, attempts to measure your ‘happiness’ while you are undertaking different activities in different locations, in urban environments, at work, or bird watching in the country.

Another great coffee outside, this time at Skylark cafe
Another great coffee outside, this time at Skylark cafe

Called the ‘mappiness‘ project, an app downloaded onto your iPhone (it is, sadly, only for iPhones), prompts the user to answer a question about their own perceived level of happiness at random instants. It then records the location of the phone (through GPS) and further asks the user to describe what they are doing. Over 1 million responses have so far been recorded through 20 000 participants. Perhaps unsurprisingly, the researchers have so far found that people tend to rate their happiness higher when they are outside, in natural environments and particularly in coastal areas. To me, it opens questions as to whether we should be attempting to quantify happiness or whether we should embrace the discussions of the humanities on this issue (less precise perhaps but by that very fact more complete and therefore more accurate). Perhaps these two approaches are complimentary. Nonetheless, the mappiness project remains an interesting study of a way in which you can use your phone in order to get a measure of where you should use your phone less.

Do get in touch and let me know what you think. Do you find it necessary to have some time out from social media or is Facebook your lifeline? Should cafés offer free wifi? Comments are always welcome (below) or you can get in touch by those two social media sites Twitter or Facebook. I do look forward to interacting with you there.

 

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
slow

The importance of going slow

journals in a library
How can we assess the work of scientists? Should we count the number of papers that they write?

In the past few weeks there has been a bit of a media storm about the state of science. A paper that had been published in the journal Science, was retracted because it turned out that the study had, quite possibly, been faked. The retraction highlighted the problem of “publish or perish” which has been a concern for many scientists of late. A second article, this time an editorial in Nature, took a different and perhaps surprising perspective on things. Apparently the public trust scientists much more than scientists think that they do. Why would that be the case?

These two stories should concern us because they lie at the heart of a current problem in science. According to the dictionary, ‘science’ is “systematic and formulated knowledge”. Such knowledge takes time to develop, it takes us time to understand what goes on, both on an individual level and as a society. The ‘publish or perish’ culture acts in opposition to this. Within a ‘publish or perish’ culture, the way that science works is that the more papers that you have, especially those that get cited and are published in (apparently) good journals, the more successful you will be in your career and in your ability to get research funding. It is essential to publish “high impact” papers in order merely to survive in science. In more extreme cases this has led to data being faked and subsequent retractions of the papers (if it is ever discovered). Active faking of data though is only the tip of the iceberg. The pressure to publish high profile papers quickly, can lead to the original paper not having been investigated thoroughly enough. In fact, there are even motivations to publish too quickly. Firstly, if you are wrong, you just publish a second paper a few months later. Two papers, two sets of citations. Secondly, publishing early means getting there first, ie. more citations. It has got to the point where it is advantageous to quickly publish poor quality research with hyped key words than it is to do a thorough job and perhaps be beaten to the publication by a more incomplete work. This cannot be good for science or our society and it suggests that, in order to have a scientific career you must, to a greater or lesser extent, cease to behave scientifically. It is perhaps for this reason that scientists themselves have a doubt as to why the public would trust them, they no longer trust themselves.

lilies on water
Is there symbolism here? There’s certainly a lot of physics.

The ‘publish or perish’ culture has come about partly as a consequence of needing a metric by which to judge the worth of research. In itself this is understandable but it does suggest that we are no longer confident of our ability, as a society, to measure the ‘good’ of something. To judge something as ‘good for society’ necessarily involves many different inputs from many disciplines. Assessing something as good is a value judgement. To redefine ‘good’ purely into something that we measure (by profit, or by number of papers) is to artificially reduce what is good for society to an arbitrary, but on appearance scientific, method. Rather than admit that questions over what is ‘good science’ are, essentially, value judgements, we try to give a false ‘scientific’ measure of their worth, one based on citations and publications. We still have our biases but we have become less conscious of them and instead try to hide them with a false scientism.

How could we change this, how else can we assess who is a ‘good’ scientist or what research will benefit society? This is, I think where it is important for everyone to get involved and to slow down. It is open for everyone to investigate, for themselves, what they think would make a ‘good’ society. Clearly the quest for knowledge, and in particular scientific knowledge, will form part of that good but for us, as a society to realise what is good we need to stop and think about it. There is a need to encourage clear methods of thinking but at the same time everyone must feel eligible to be a part of this natural philosophy, purely as a consequence of their being a citizen of society. On a practical level, this can be achieved by our maintaining a sense of awe and wonder at the beauty of the world, and society, around us. In my own field of magnetism for example, to know the physics behind magnetic attraction is to make it more beautiful. And that is in essence what I am trying to communicate with Bean Thinking; just as an artist does with a painting, I am attempting to share the beauty that I see as a result of seeing physics all around me. The saying of Pierre Duhem that “Physical theory is a mathematical painting of reality” can be taken at many levels. As a scientist, I am to a certain extent, an artist.

rain drops on a tulip
A tulip in spring. The water droplets on the petals suggest some very deep physics. As the flower opens into the sunshine, each layer  (physical and metaphorical) of petals reveals a new level of beauty.

Of course, there is no immediate connection between appreciating the beauty of knowledge and allocating research funds. Yet if we, as a society, appreciate science and beauty where we see it, we are going to slowly move back to a more sustainable, scientific way of doing science. “By learning to see and appreciate beauty, we learn to reject self-interested pragmatism”¹. By allowing ourselves to assess the good of society across many measures, we recover science. Denying the fact that what qualifies as ‘good’ is ultimately a value judgement and instead covering it in false metrics, imperils science. It is in the history of humanity to ask ‘why’. Moving to a predominantly technology driven quasi-science does not enrich us as a species. Good art, good music, great science can. Great discoveries of the past have not been obtained by chasing the latest chimera of a device, they have been uncovered through an insatiable curiosity. A demand to know ‘why’ things are the way they are. We are destroying the very science we are so keen to promote if we conform to the key-word, hype and technology driven ‘publish or perish’ culture. It has got to the point where, in order to save science, it is imperative that we, as a society, recover our ability to appreciate the beauty in science.

I hope that Bean Thinking prompts at least some people to question the world around them. It is not important to agree with what is written in Bean Thinking indeed, perhaps with some things it is more important to disagree. The key thing is to notice the world around. The practise of slowing down and noticing things is the reasoning behind the cafe-physics reviews, as much as anything it enables me to practise slowing down and noticing too. To slow down and to appreciate what is there will mean that slowly, imperceptibly perhaps, we challenge the culture of ‘publish or perish’. To do so may not be too far short of a need to recover our humanity, to quote Laudato Si’ again, “[w]e need to see that what is at stake is our own dignity”².

¹ Pope Francis, Laudato Si’, (2015) #215

² ibid, #160

Further thoughts:

Michael Polanyi “Science, Faith and Society”, Sapientia Press, 1964

Michael Polanyi “Personal Knowledge: Towards a post-critical philosophy”, University of Chicago Press, 1974

Categories
Home experiments Observations

Levitating water

V60 from Leyas
Time to look more closely at the surface of your black coffee.

Have you ever sat watching the steam that forms above a hot Americano? Beneath the swirling steam clouds you can occasionally see patterns of a white mist that seem to hover just above the dark brew. Bean Thinking is about taking time to notice what occurs in a coffee cup and yet I admit, I had seen these mists and thought that it was something that was just associated with the evaporation of the water and that “someone”, “somewhere” had probably explained it. So it was entirely right that I was recently taken to task (collectively with others who have observed this phenomenon and taken the same attitude) for this assumption by the authors of this paper who wrote “The phenomenon that we studied here can be observed everyday and should have been noticed by many scientists, yet very few people appear to have imagined such fascinating phenomena happening in a teacup.”

ineedcoffee.com, espresso grind
The water particles in the white mist are a similar size to the smallest particles in an espresso grind. Photo courtesy of ineedcoffee.com, (CC Attribution, No Derivs). The coin shown is a US nickel of diameter 21.21 mm

The authors of the study show that the white mists (these “fascinating phenomena”) are, in fact, layers of water drops that have a typical diameter of around 10 μm (which is roughly the size of the smallest particles in an espresso grind). Although the white mists exist above tea and even hot water as well as coffee, they are probably easiest to see against the black surface of the Americano.

More surprising than the fairly uniform distribution of water droplet size though is the fact that the authors of this study showed that the droplets were levitating above the coffee. Each water droplet was somehow literally hovering above the surface of the coffee at a height of between 10 – 100 μm (which is, coincidentally, roughly the particle size distribution in an espresso grind).

white mists, slow science
You can (just about) see the white mists over the surface of this cup of tea (which is a still from the video below)

One of the questions that the authors of the paper have not yet managed to answer is what is causing this levitation? Could it be the pressure of the hot coffee evaporating that keeps these particles held aloft? This would explain the observation that the mists form patterns similar to those caused by (heat) convection currents. Alternatively perhaps the droplets are charged and are kept away from the coffee by electrostatic repulsion, an explanation that is suggested by the behaviour of the droplets when near a statically charged object (eg. hair comb, balloon, try it). Perhaps the levitation is caused by the droplets spinning and inducing an air cushion under them? Why not design some experiments and try to find out. It would be great if we can drink hot black coffee in the name of science. Let me know the results of your observations in the comments section below. In the meanwhile, here is a video of the white mists in tea, enjoy your coffee:

You can read the study at: Umeki et al., Scientific Reports, 5, 8046, (2015)

 

Categories
General Science history slow

Of worms and grind

coffee ground, grind, composting
What do you do with your used coffee grounds?

What do you do with your finished coffee grounds? Feed them straight to the plants? Donate them to Biobean to be transformed into fuel? Or perhaps turn them into compost with a worm bin? Ground to Ground is a website dedicated to sharing information about what can be done with old grounds. My preferred option though is the worm bin. Each Chemex of coffee grounds gets put out into the “can-o-worms” compost bin ready to be transformed into compost and plant fertiliser.

I had thought that there could be very little connection between my worms (so to speak) and the Bean Thinking website. However, I recently came across an anecdote about Charles Darwin that, to me at least, unites some of what Bean Thinking is about with my can-o-worms.

can-o-worms, worms, coffee grounds, composting
The top layer of my worm bin. You can just see some coffee grounds but it is mostly cabbage.

Darwin’s last book was “The formation of vegetable mould through the action of worms” published in 1881. After Darwin’s death (in 1882), Edward Aveling (1849-1898) wrote about meeting Darwin years earlier. In “Charles Darwin and Karl Marx: A Comparison” (1897), Aveling wrote: “I remember, in my youthful ignorance, asking Darwin why he dealt with animals so insignificant as worms. I shall not forget his reply, or the look that accompanied it. ‘I have been studying their habits for forty years’.”

By studying what to others looks insignificant, Darwin had made huge progress in our understanding of worm behaviour. This has led to our current knowledge about the contribution of worms to the ecosystem and the benefits of composting our coffee grounds, both for our plants and our planet. It strikes me that we can all benefit from slowing down and noticing what seems insignificant.

Perhaps you do something unusual with your old coffee grounds? Maybe you have noticed something about coffee grounds and worm behaviour. Whatever it is, do let me know in the comments section below.

Categories
Coffee cup science Coffee review General Observations slow

Rain drops at Notes, Covent Garden

Notes Covent Garden, rain, puddles
No one wanted to sit outside when we visited Notes at Covent Garden

It was a cold and wet afternoon in early January when I finally had the opportunity to try Notes (Covent Garden branch). Inside, there were plenty of places to sit while warming up and drying off enjoying a coffee. Although it seems small from the outside, inside, the branch feels quite open, with the bar immediately in front of you as you come through the door. One of the attractions of Notes to me, was the fact that I knew that they served different single estate brewed coffees. I think I tried a “La Benedicion” coffee, or at least that is what I seem to have scribbled in my notepad. We took a stool-seat at the window to look out at the rain as my coffee arrived in a 0.25L glass jar. It is always nice to try different single estate coffees and generally, if I know that a café serves single estate coffees I will seek them out to try them for the Daily Grind.

The reflection of the Notes sign board in a cup of tea
The reflections in a cup of tea

Watching the rain form puddles outside, my thoughts were turned to the reflections bouncing off the water in the puddle. It struck me that the appearance of puddles depends on the water molecules behaving both as individual molecules and as molecules within a group. The rain creates ripples in the puddle which can only occur because each molecule is (weakly) attracted to the other water molecules in the puddle, forming a surface tension effect. A ripple is a necessarily collective ‘action’. On the other hand, the reflection of the lights from the street is the response of each individual water molecule to the incoming light. The reflected image is made from the response of many individual molecules. Reflection is more of an individual molecule thing.

Warning sign, train, turbulence
Such turbulence should be familiar to anyone who has stirred a cup of coffee.

I continued thinking about this when I got home where it occurred to me that there was another connection between rain and coffee. It is often said that “rain helps clear the air”, or something similar. Yet this is not quite true. If you have a coffee in front of you at this instant, take a moment to drag a spoon through it. Note the vortices that form behind the spoon. Such vortices form around any object moving through a fluid. In the case of the coffee it is the spoon through the water. For the rain, as the rain drop falls through the air it creates tiny vortices of air behind it. Just as with the coffee spoon, the size of these vortices depend on the speed and size of the falling drop. These vortices pull and trap the atmospheric dust bringing it down to earth more quickly than rain alone could do. The air is cleaned more by this ‘vacuum cleaner’ action than by the ‘wet mop’ of the rain itself.

I’m sure that there are many other coffee-rain connections that you can make if you sit in a café as I did on a rainy day. Let me know your thoughts on this or indeed, on anything that you notice and think interesting while sitting in a café. There is so much to notice if we just put down the phone or close the laptop while enjoying our brew.

Edited to add: Sadly, this article was posted just as Notes Covent Garden was closing down. Notes still has branches at Trafalgar Square and in Moorgate and is opening new branches in Kings Cross and Canary Wharf in February I believe. Hopefully they will all serve single estate brewed coffee and have good window seats from which to observe the rain when it falls.

Categories
General Science history

Time to enjoy a Beethoven coffee

Portrait bust of Beethoven, Anna EG Hoffman, in the British Museum collection © Trustees of the British Museum
Portrait bust of Beethoven, Anna EG Hoffman, in the British Museum collection © Trustees of the British Museum

It is said that Beethoven prepared his coffee by counting, precisely, 60 beans per cup. Biographies of Beethoven certainly suggest that he had a significant coffee habit. Banned by his doctor from drinking coffee towards the end of his life, there are many references to him frequenting coffee houses in earlier years. Sadly, I have not found the source for the 60 beans story and so would not like to comment on its veracity. Nonetheless, it is a good story and it does link with coffee so, as today (17th December) is the 244th anniversary of his baptism (it is assumed that he was born the day before on 16th December 1770), it is “Beethoven day” on the Daily Grind.

To me, what lends some credibility to the 60 beans story is the fact that, as coffee lovers, we can be very particular about the way we prepare our brew. Some people, for example, weigh the amount of the coffee and the quantity of water and brew their coffee according to instructions from one of the various online brewing tutorials (see here for a good one from Hasbean). Personally, in the morning, I am far too bleary eyed to consider getting the kitchen scales out, nor would I count a certain number of beans. I do however count the number of seconds that I take to grind my coffee with my trusty burr grinder (always set to the same level of grind of course). Can counting the number of seconds for a quantity of grind possibly be a good way of measuring a specific quantity of coffee?

Did Galileo drop balls from the top of the tower?
Did Galileo drop balls from the top of the tower?

Galileo Galilei (1564-1642) died before coffee was properly introduced to Europe. He is relevant to this story though owing to his work on clocks and timing devices. One way that Galileo measured time was to collect water in a jug over the measurement period. It seems that this is almost the reverse of my morning coffee ritual. To check that he was measuring time correctly however, he needed a second, independent method. Of course, Galileo couldn’t use a watch or pendulum because watches hadn’t been developed at the time and Galileo himself was doing the work needed to understand pendulums and make them useful for clocks. So what else could he use to measure time? There is a clue to another method that Galileo used in his experiments on falling balls. Although there are questions as to whether Galileo really did drop balls from the top of the Tower of Pisa, we do know that he did experiments which involved rolling bronze balls down a groove. Along the groove were marks where strings made from gut had been pulled across the groove such that they made a sound as the ball passed, perhaps like the sound of a harp being plucked. By adjusting the position of these strings, the interval between the sounds from different gut strings could be made to match a known rhythm. The time it took for a ball to fall down the groove was being measured by matching its descent to a known tune. This suggests that Galileo sang while he was making his key measurements and that it was this that allowed him to start to understand how bodies fell under gravity. Singing was Galileo’s (surprisingly accurate) method of measuring time.

Which brings me full circle back to Beethoven. Beethoven certainly knew the “mechanician” Mälzel who invented the metronome as we now know it. There are also indications that Beethoven was aware of early versions of Mälzel’s invention. In 1813, the Wiener Vaterländische Blätter wrote “…Herr Beethoven looks upon this invention as a welcome means with which to secure the performance of his brilliant compositions in all places in the tempos conceived by him, which to his regret have so often been misunderstood“.  It seems that in the two hundred years between Galileo and Beethoven, there had been so many improvements to clocks and timing devices that singing, which had started off as a way to measure time, was now itself being regulated by the clocks that singing may have helped to develop.

How many beans go to make your morning coffee?
How many beans go to make your morning coffee?

So how is a Beethoven coffee, assuming that there is any veracity to the legend? Sixty beans works out as 8-10g which, depending on the amount of water in the cup could be weaker (or stronger) than modern brews. In my cup, it was slightly weaker than I am used to. I enjoyed my “Beethoven coffee” while listening to his String Quartet Op 74, “Harp”. As I sipped the coffee while listening to the first movement, I could almost hear the gut strings of Galileo’s experiment being plucked as the balls rolled by. The coffee itself (Costa Rica, Finca Arbar El Manatial, Yellow Honey, Caturra/Catual) was very smooth and rich, as you would expect from a coffee from Has Bean. Described in the tasting notes as “….An amazing caramel and milk chocolate sweetness partnered with delicate peach and apricot acidity…” It was the perfect coffee to enjoy with the Harp quartet piece. Sometimes it is important to take time to go slow and enjoy the coffee.

So why not raise a mug today to Beethoven and savour a Beethoven coffee? Please leave any comments using the form below, especially if you know a reliable reference to Beethoven’s coffee habit or have suggestions as to how to improve my morning brew.

Further reading:

Quotes taken from “Thayer’s life of Beethoven”, Revised and Edited by Elliot Forbes, Princeton University Press, 1967

Information on Galileo and time: “Styles of Knowing, A new history of science from ancient times to the present”, Chunglin Kwa, University of Pittsburgh Press, 2011

Categories
Observations

From a Caravan to the Grecian

It is a Saturday morning as I write this while sitting in Granary Square in Kings Cross, London. I’ve just enjoyed an Ethiopean filter coffee at Caravan. If only more cafes offered the possibility of sampling single estate coffees rather than the espressos that are otherwise so popular in London.

Caravan, Granary Square, coffee, single estate, good cafes in London
The fountains in front of Caravan

In the square outside, people are laughing (and dancing!) in front of the old warehouses that accomodate Caravan. Amongst them all, four sets of ground-level fountains push jets of foaming water 50cm into the air, in patterns that change as you watch. There is so much physics here to observe: The white colour of the water foam, the dance of the water droplets as they emerge from the main jet of the fountain and then fall back to earth, the fact that the wet concrete around the fountains is darker than the dry concrete nearby.

Consider though one more observation. As the water shoots upwards, it is pushed by occasional gusts of wind from west to east making the fountains appear as loops rather than columns of dancing liquid. Although the direction of the wind is determined by local weather patterns, over the UK the prevailing wind direction is Westerly, that is flowing from west to east.

People have wondered about the origin of the winds from ancient times. The Greeks had four wind Gods who had authority over the winds from each direction: Boreas, god of the North wind, Notus of the South, Euros of the East and Zephryos of the West. Pliny the Elder speculated at length on the causes of the winds and yet the start of the modern conversation regarding the origin of the winds had to wait until 1686 with the publication of a work by Edmund Halley.

Grecian, Coffee House, London Coffee House
The Devereux now stands where the Grecian once was

Halley (1656-1742) is now more famous for the comet that is named after him rather than his meteorological work but, as with many scientists of the time, he had his finger in many pies. He also seems to have been a keen coffee drinker, or at least, he regularly spent time in one of London’s coffee houses, the Grecian, discussing science with Isaac Newton, Hans Sloane and others. A pub, the Devereux, now stands on the site of the old Grecian in a little side street off of Fleet Street.

Did Halley ponder cloud formation, rain and the origin of the winds while contemplating his steaming coffee cup on cold days in 17th Century London? Regardless, Halley did recognise that the heat from the Sun was the driving force for the wind system. Halley surmised that as a parcel of air was heated by the Sun and rose upwards, the cold air surrounding it would have to flow in to its place so as to replace the risen air so “..by a kind of Circulation N.E. Trade Winds below will be attended by a S.W. above, and the S.E. with a N.W. Wind above”* The problem for Halley was that his explanation of the wind system could account for a North-South wind direction owing to the Sun’s heating the air at the equator, but not the Easterly direction of the Trade Winds near the equator nor the Westerly direction of the winds over the UK.

A few years later, George Hadley (1685-1768) suggested that it was the rotation of the earth that was responsible for the east-west component; the mass of air, being detached from the earth, would appear to flow in a particular direction as a consequence of the earth spinning below it. The idea was not new, Galileo had proposed it some years earlier while similar arguments were made later by the philosopher (and scientist) Immanuel Kant (1724-1804). At first sight, such an argument looks appealing but there are problems, as John Herschel (1792-1871) pointed out. If this were the explanation for the wind direction, the effect would be “so great as to produce not merely a wind, but a tempest of the most destructive violence”†.

Herschel suggested, as had Hadley before him, that friction could slow the wind to the speeds that we normally observe, but while this may explain the wind speed at ground level, what about the upper circulatory patterns noted by Halley: What friction could slow these down?

Grecian, Devereux, Coffee house London
A plaque outside the Devereux pub

It turns out that this is not the reason for the discrepancy in the wind speed. Hadley’s theory was wrong on a number of issues (if you are interested, I suggest reading this article). The real driving force for the Trade Winds is the Coriolis effect which deflects the warm air rising at the equator towards the right as it travels to the North pole. The majority of this air then cools and descends at about 30 degrees latitude, circling back on itself (as per Halley) as the Easterly trade winds. However the air that continues in the westerly direction north (or south) of 30 degrees latitude becomes those prevailing westerlies of the sort that batter the shores of the UK (see here for more information).

Even if Hadley’s simple model was wrong, its contemplation did lead to an important discovery that is still relevant for us today. The question was: What was it in the upper atmosphere that could cause a friction effect that could slow the winds? The person contemplating this question was taking a walking holiday in the Alps in the first half of September in 1886. Hermann von Helmholtz (1821-1894) observed a layer of clouds which showed “whirls formed by perturbation and rolling up” of the surfaces of two neighbouring layers of air. Helmholtz had observed what became known as “Kelvin Helmholtz clouds”, a beautiful but very rare cloud type, for an example click here. Helmholtz realised that the formation of these clouds required that two layers of air rubbed against each other. In the region between the two layers, the air became unstable, wavy and finally showed the whirls which are actually a series of vortices. As these vortices developed, the two layers of air would get more thoroughly mixed and it was in this way that friction could develop in the upper atmosphere.

Such vortices and “surfaces of discontinuity” are now an important concept in many places including the coffee cup. The video “Coffee Rings” presents another manifestation of the effects of surfaces of discontinuity. So we have returned from contemplation of the wind in a late summer square in London, through a famous Coffee House and back to the coffee.

I have not yet had the opportunity for myself to see a Kelvin Helmholtz cloud. If any reader has been so fortunate please share photos with @thinking_bean. Let me know what you think and what you see around you in the comments section below and most importantly, enjoy your coffee!

*from E. Halley, An Historical Account of the Trade Winds, Transactions of the Royal Society, 1686, p. 133, via “From Watt to Clausius”, DSL Cardwell, Cornell University Press, 1971

†Quotes taken from Anders O Persson, “Hadley’s Principle: Understanding and Misunderstanding the Trade Winds”, History of Meteorology, 3, (2006) p. 17 (linked in article)