Categories
Coffee review General Observations Science history

Can you see me? At 123 Gasing, KL

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

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

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

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

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

A sign at 123 Gasing
Am I invisible?

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

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

already disturbed
Hopefully not a comment on current scientific funding

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

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

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

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

Categories
General Home experiments Observations Science history Tea Uncategorized

Predicting the weather with a cup of coffee?

What do the bubbles on the surface of your coffee tell you about the weather?

weather, bubbles, coffee, coffee physics, weather prediction, meteorology
There is a lot of physics going on with the bubbles on this coffee, but can they be used to predict the weather?

You have just poured a cup of freshly brewed coffee into your favourite mug and watched as bubbles on the surface collect in the middle of the cup. It occurs to you that it is going to be a good day, but is that because you are enjoying your coffee or because of the position of the bubbles?

There are a large number of sayings about the weather in the English language. Some of the sayings have a basis in fact, for example the famous “red sky at night, shepherd’s delight, red sky in the morning, shepherd’s warning“. Others though seem to verge on the superstitious (“If in autumn cows lie on their right sides the winter will be severe; if on their left sides, it will be mild”), or unlikely (“As August, so the next February”).  In 1869, Richard Inwards published a collection of sayings about the weather. “Weather Lore” has since undergone several new editions and remains in print although Inwards himself died in 1937. Amongst the sayings contained in the book is one about coffee:

When the bubbles of coffee collect in the centre of the cup, expect fair weather. When they adhere to the cup forming a ring, expect rain. If they separate without assuming any fixed position, expect changeable weather.

A quick search on the internet shows that this example of weather lore is still circulated, there is even a ‘theory‘ as to why it should be true. But is it true or is it just an old wives’ tale? Although I have consumed a lot of coffee I have never undertaken enough of a statistical study to find out if there could be an element of truth in this particular saying. The number of bubbles on the surface of the coffee is going to depend, amongst other things, on the type of coffee, the freshness of the roast and the speed at which you poured it. While the position of the bubbles will depend on how you poured the coffee into the mug, the surface tension in the coffee and the temperature. It would appear that there are too many variables to easily do a study and furthermore that the mechanism by which coffee could work as a weather indicator is unclear. It is tempting to write off this particular ‘lore’ as just another superstition but before we do that, it is worth revisiting another old wives tale which involves Kepler, Galileo, the Moon and the tides.

tides, old wives legends, Kepler, Galileo, Lindisfarne, bubbles in coffee
The pilgrim path between Lindisfarne and the mainland that emerges at low tide is marked by sticks. But what causes the tides?

Back in the mid-17th century, Newton’s theory of universal gravitation had not yet been published. It was increasingly clear that the Earth orbited around the Sun and that the Moon orbited around the Earth, but why exactly did they do that? Gilbert’s 1600 work De Magnete (about electricity and magnetism) had revealed what seemed to be an “action at a distance”. Yet the scientific thought of the day, still considerably influenced by Aristotelianism, believed that an object could only exert a force on another object if it was somehow in contact with it. There was no room for the heavenly bodies to exert a force on things that were found on the Earth. Indeed, when Kepler suggested that the Moon somehow influenced the tides on the Earth (as we now know that it does), Galileo reproached him for believing “old wives’ tales”: We should not have to rely on some ‘magical attraction’ between the moon and the water to explain the tides!

The point of this anecdote is not to suggest that a cup of coffee can indeed predict the weather. The point is that sometimes we should be a little bit more circumspect before stating categorically that something is true or false when that statement is based, in reality, purely on what we believe we know about the world. We should always be open to asking questions about what we see in our daily life and how it relates to the world around us. It will of course be hard to do a proper statistical study of whether the bubbles go to the edge or stay in the centre depending on the weather (whilst keeping everything constant). Still, there are a lot of people who drink a lot of coffee and this seems to me to offer a good excuse to drink more, so perhaps you have some comments to make on this? Can a cup of coffee predict the weather? Let me know what you think in the comments section below.

 

Weather legends taken from “Weather Lore”, Richard Inwards, Revised & Edited by EL Hawke, Rider and Company publishers, 1950

Galileo/Kepler anecdote from “History and Philosophy of Science”, LWH Hull, Longmans, Green and Co. 1959

Categories
Coffee review Observations Science history slow Sustainability/environmental

In the Greenhouse at CoffeeGeek

Coffee Geek and Friends, Coffee Victoria
Coffee Geek and Friends

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

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

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

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

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

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

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

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

Categories
General Home experiments Observations slow Sustainability/environmental

An opportunity to become a cafe-scientist

coffee, Timberyard, wooden tray
A great place to sit and do some citizen science: Timberyard, Seven Dials has plenty of seats outside.

There are many things to be gained from putting down your smart phone when you enter a café. Firstly, there is the opportunity to fully experience the coffee. The sounds as it is made, the smell, the taste, even the feel of the coffee. Then there is the opportunity for people watching; their behaviour as they order their coffees or have their meetings or try to alleviate boredom while playing with their smartphones. Of course, there is also the opportunity to look at the history of the café and its surroundings, to think about a café-physics review or just slow down and notice things. There’s always something interesting going on.

If you are lucky enough though to be in Athens, Barcelona, Belgrade, Berlin, Copenhagen, London, Manchester, Milan or Rome there is now even more reason to put down that phone while you savour your coffee. By doing so, you could be helping scientists with a few questions that they have about atmospheric pollutants. If you are not in one of those cities, you miss out this time, but you may want to keep reading because if enough people get involved now, perhaps next time the iSPEX-EU project may come near you.

contrail, sunset
What sort of aerosols and pollutants are floating in the atmosphere above your head at this moment?

The question is, what are the atmospheric pollutants that are in the air near where you are now? Perhaps you are in a café on a main road and the answer seems obvious, it is those cars and buses that keep passing by. But there are in fact many forms of atmospheric aerosols or particles and they range in size from a few nanometers to tens of microns (which, in terms of coffee grind is from much smaller than the smallest Turkish coffee to approximately the size of a small particle in an espresso grind). Is it really so clear that where you are, in the centre of that big city, is that polluted? If on the other hand you are on the coast in Barcelona, just how salty is that salty sea air? The iSPEX-EU project allows you to measure it and find out.

These particles of dust, salt and soot etc. can have  an effect on human and animal health, so clearly we want to know more about their distribution and their prevalence. But there are also, more subtle reasons why we may want to know about them. They may have an effect on global warming and they are certainly needed in order for clouds to form, (though as yet we still do not fully understand this process). We need more data about what aerosols are around and where they are to start to know what questions to ask (let alone answer) about health, the climate and cloud formation. Yes, we have satellite measurements and pollution data at specific locations, but what people are missing is that local information. What are you actually breathing? When you look up at the blue sky, what pollutants (or other type of aerosol) are you looking through? Can we get enough data to know how the air quality varies between the cafés of Hackney and those of Hammersmith?

Skylark Wandsworth
Another ideal cafe for iSPEX-EU measurements, great coffee and a lovely outdoor seating area at Skylark cafe, Wandsworth Common

To get this data the scientists involved in iSPEX-EU need people, many people. People who are willing to spend 5 minutes turning their iPhone (sadly it is an iPhone-only project) into a pollution detector. The more people that they can get measuring, the more data that they will be able to obtain. All you need is an app from the App-store and a (free) device that fits over your iPhone camera which you can pick up from somewhere local to you. Then, you just take a seat outside the café on a lovely blue sky day between now and the 15th October, aim your phone at the sky and take a series of photographs which are shared back with the scientists coordinating the project. If you are curious to know how your air quality compares with that in another participating city, you can check the live map to see how the measurements are going across Europe.

The device works by looking at the colour spectrum as well as the polarisation of the light reaching the camera as a function of angle. This information gives tell-tale clues as to the size of the aerosols as well as their prevalence. There is a lot more information on the website of the iSPEX-EU project and so I would recommend that if you do want to know more, you click their link here. In the meantime, why not sign up with iSPEX-EU, take a seat outside in that café and enjoy a great coffee knowing that, as you do so, you are contributing to our understanding of atmospheric science.

If you do decide to participate, please let me know of any great locations that you find, both for the coffee and the measurements, or share your pollution measurements with me in the comments section. I look forward to seeing some great data on the live map.

To get involved with the iSPEX project, you can follow the link here.

 

Categories
Coffee review Observations Sustainability/environmental

Seeing the trees for the wood at OJO Coffee, Bangsar, KL

coffees on display at OJO
OJO Coffee, Bangsar, Kuala Lumpur

It is very easy to sit for a long time watching the people and the surroundings at OJO Coffee in Bangsar, Kuala Lumpur. Initially I had thought that this medium-sized café with an impressive number of power points dotted around it was an independent. However similarities with CoffeaCoffee around the corner and a couple of other clues (CoffeaCoffee t-shirts) suggest that it is actually part of the CoffeaCoffee chain, something that was confirmed when I asked the barista. However, the standard of coffee in this chain should prompt some of the smaller independents to up their game a bit (and certainly all of the UK based chains). Not content with just serving the typical coffees of ‘latte’, ‘cappuccino’ etc. (which are made using their own blend), OJO’s additionally serves about 15 types of single origin coffee made with your choice of method (Hario V60, Aeropress or French press). For a while this summer I became a bit of a regular at OJO and so I would particularly recommend the Indonesian Sumatran prepared by V60, but with so many coffees to choose from (from the relatively local Indonesians to South American coffees from much further afield) there is plenty to try at this café.

wooden mosaic
The wall made of wood at OJO

The interior of OJOs is decorated with many types of wood. Different cuts of wood are made into a sort of wood mosaic on the wall while the tables are made using several types of wood so as to give a symbolism about the Sun that is a type of motif of the café. Much of the floor is wood too and so this got me thinking about the rainforests in this country. Malaysia has a rich variety of wildlife and forest, it is home to the Orangutan as well as many other species. Teak trees that can be used for more expensive furniture grow along the roadside. Much of this timber can be obtained sustainably and in a way that respects the rainforest and I am certainly not suggesting that the wood in OJOs was anything but sustainable. However, perhaps inevitably, there are many pressures on these invaluable forests. Some of these pressures have, in the recent past, resulted in significant deforestation. One such pressure is that of palm oil.

Palm oil is a massively useful commodity. It is now used in food products from margarine to biscuits to raisins (surprising but true, check the ingredients list of a packet of raisins) and non-food products such as soaps. It is literally everywhere. Both Malaysia and its neighbour, Indonesia, have profited enormously from growing and exporting palm oil. Unfortunately, at times the rainforest is cleared to make way for the palm oil plantations. As it is easier to burn felled trees to clear the land rather than to painstakingly pull the roots up by hand, the cleared forest is burned. But the ground is not any ordinary soil, the ground is often peat based which means that the fires on the surface penetrate deep below the ground and produce phenomenal amounts of smoke.

If at this point you were wondering where the ‘physics’ bit of this café-physics review is, I assure you it is coming. It is indeed linked to this environmental story and to OJOs, please keep with me.

Each year, parts of Malaysia, Singapore and Indonesia are enveloped by a haze produced by this burning peat land (It made the BBC in 2013 when it was particularly bad, but some haze is present for a few weeks every year). Haze has the appearance of thick fog but smells of smoke. At times, visibility can be reduced such that the tops of nearby tall buildings are obscured. Each time land needs clearing for new palm oil plantations, this smoke is produced. The haze can be reduced by local weather patterns but on many days, the haze is cleared by the torrential rains that can occur in this part of the world.

the haze is coming in
L-R: The haze comes in over part of KL in 2013 (series of 3 pictures)

It is commonly said that ‘rain clears the air’ but this is not completely true. It is not the raindrops themselves that somehow wash the air free of the dust of the haze, it is the vortices that form behind them*. Just as a spoon dragged through coffee produces vortices behind it, so a raindrop falling through the air forms vortices in its wake. The size of these vortices will depend on the size of the drop and the speed at which it falls through the air; a tea spoon and a dessert spoon pulled at different speeds through the coffee similarly produce different forms of vortex. So the amount of dust that is ‘sucked in’ and falls to the ground will depend on the type of rain that falls. Perhaps if you are in Malaysia, Singapore or Indonesia when this haze is present, you could make a study of which sort of rain clears the air most effectively. I have an idea but not the evidence to see if the idea is correct, it would be interesting to know what you think.

As I left OJO one afternoon, the rain had started to come down. The rain, or at least the vortices behind the raindrops, cleared some of the haze that had been around earlier. It is a temporary solution to a longstanding problem. A more long lasting solution may be to start (or continue) asking manufacturers of those biscuits you are eating: just how sustainable is the palm oil they are using?

OJO is at No 23, Jalan Telawi 3, KL

* JR Saylor and BK Jones, Physics of Fluids, 17, 031706 (2005)