Live long and prosper

I'm having a bit of a clear out. Eating 5 a day, drinking lots of water. Choosing the better food option when things are available. I eat fresh home cooked food anyway and I've virtually given up on alcohol all together. Small changes.

I even thought about taking more exercise. Until I read this. I'm supposed to do five hours of exercise a week. I'd be happy to take a 30 minute stroll a few times a week, do a bit of gardening and play on my nintendo wii. But this means I need to go mad. It's the single most offputting piece of health advice ever put across. It says if you want to maintain weight you're in for it and forget it if you want to permanently lose weight.

Say I live for another 40 years. This means I need to spend 87 days solid doing exercise. That's a quarter of a year or 0.6 % of my remaining life. I know what you'll say; the benefits far outweigh the effort. I'll live far extra than 87 days, I'll have healthier later years (apart from the hip replacement I'll need from running) and I might even enjoy exercise and feel happier and more energetic. But the thought of pulling on my running shoes on those dark cold winter evenings or coming out of the swimming baths when it's blowing an ice cold gale or jumping out of the car on a sweltering hot day to go back out running makes me depressed.

Life, The Universe and Everything

When you think about it the Universe is a pretty odd place. I mean, here we are, stuck on this rock for no paricular reason completely at the mercy of any passing asteroids or black holes. We have little or no idea how the whole Universe thing is put together or how it works and if there is anything looking in from somewhere else and having a giggle at our stupidity. Chances are that it is all meaningless. This thought loop is so depressing that most people choose not to think about it most of the time and just get on with the being alive part or they make stuff up without proof to make them feel better and give them something to do on a weekend. The being alive part consists of breathing, food, drink, sleep, sex, house, job, car, sport, shopping, TV and pyramid teabags. Instead of getting together and working out how to pass things around evenly so we all have it half good the system is rigged so that some people get rich and powerfull and never have to worry about anything other than how to stay rich and powerfull and most of the rest of the world are just slaves of one form or another. The world gets by and keeps itself busy by having wars and terrorism and arguments over territory like two neighbours coming to blows over the height of a hedge. And the number one reason to fight is over which theory of it all based on no evidence is right which surely proves that we are just slightly smarter than chimps and confirms that it is all just meaningless evolution from some gunk in a puddle with no higher purpose. Still, you've got to laugh.

Girls in Science

There are fewer girls studying Physics than boys. Is this a problem? Everyone seems to think so. Cue lots of silly suggestions like lowering the A-Level grades required of girls for admission to University Physics courses. This issue is very similar to the attempts to increase the number of people from working class backgrounds at Oxbridge. Barriers should be removed but positive discrimination should not occur. It should not be a case of 'it's OK that you went to a poor school and didn't learn much because we are going to let you in anyway because we think that if you went to a good school you would have got great grades in your exams'. Then what is the point of exams if subjective judgements and leftish social ironing are going to overrule them? The same applies to girls in science. Don't positively discriminate. Just remove the barriers. Like the notion that Maths and Physics are boys subjects. And Maths teachers who ignore the girls. Physics and Maths are hard subjects and they require a person with a specific set of skills. If a group of people are not studying the subject then so what? Just because there are few men doing womens studies or sociology doesn't mean that there fundamentally should be.

PhD viva success

In my oral exam today I successfully defended my PhD thesis which means I will be able to start calling myself Dr. as soon as it is formally confirmed. I would like to thank my external examiner Prof. Woodruff and my internal examiner Prof. Godby. Even more so I owe a huge debt of gratitude to my supervisors Steve and Matt and the other members of our group who have helped me so much along the way. Also big thanks to my family and friends for keeping me sane. There is one person who has done the most. During this past year my fiancee Nicola has been my stable foundation and I hope to repay her support over many years of marriage. That sounds like a car loan or something doesn't it... Erm I mean I'm glad I had you around Nic to share my highs and lows.

I can't believe I ate the whole thing

My PhD viva exam is approaching and I'm hard at work preparing. My hair is getting long and I need a shave. At the moment I most resemble Homer in his highschool yearbook. During the exam on Tuesday I get quizzed at length about my work over the last four years. I have to convince the examiners that I wrote the 200 page thesis and that I have a good enough overall knowledge of Physics and my field to merit the qualification. Eek. See you on the other side.

Science on TV

Science is in crisis. University Physics Departments are being closed down. Just today we have a talk in our University Department about how to attract more students to study Physics at University. There could be many reasons for the slump but one factor is the way Science is portrayed in the media.

Take the TV. When I first got interested in Science there were three flagship science programmes. Documentaries were shown regularly and on the schools programmes. On the commercial channels there is now no science. We are just left with Horizon on the BBC. This used to be a good show but it has steadily been dumbed down in recent years with more explosions and CG effects. This series, in an effort to chase ratings, the science has been watered down to the point of being pointless.

The nadir is the episode to go out tonight which will examine what the world would be like if the dinosaurs had survived.

WTF

Cue a pointless excuse to show dinosaur CG effects in a modern setting. I am going to watch this show just because I know I will spend an hour shouting at the TV for being pointless. At least it'll make me react.

Coffee

A new study suggests that a morning coffee will not make a person more alert. The buzz is in getting the hit as the withdrawal symptoms kick in after a nights sleep. Nothing we didn't know already then. I don't drink coffee as a stimulant. I like the rich multi-facetted taste. It's nice and refreshing to drink warm liquid in a morning. It wakes the senses. There is a downside to being a coffee drinker; headaches, 50 calories of sugar and milk at a time and the diuretic effects driving me to the mens room every hour. But I can manage these side effects of my addiction. I won't be mugging anyone to pay for my habit. And my mantra of coffee in the morning and tea in the afternoon means I don't lose sleep. Unless coffee has long term mental effects like cannabis then I'll continue cleaning out my French press pot every morning.

PhD Viva

Three weeks today.

Colours of nature (part 2)

The other major colours you see in nature are green from foliage and blue for water. The sea looks blue because it reflects the sky. Water itself is transparent. Small depths of water look transparent (like a bathfull) but if you look through enough water (like when you are underwater and can see a long way) things look blue because there are so many water molecules that they absorb most of the colours completely. The only colours that can can more than about 20 metres are blue and a bit of green - that's why things underwater seem blue-green. From land the sea looks blue because it reflects the sky. So when the sky is grey the sea looks grey.


Plants are green because they absorb all colours except green. They break up water and carbon dioxide molecules and fit them together to make oxygen and sugars. They do this using a molecule called chlorophyll. If you give a chlorophyll molecule just the right amount of energy it will give you an electron. This 'just right' energy just happens to be the same energy of a blue particle of light. You can also get an electron if you give it a red light particle. This will have a different energy to a blue light particle but it turns out that this energy is also just right to get another electron from a different part of the structure. When chlorophyll has all these electrons loose they get passed around between loads of chlorophyll molecules until eventually they hit water and carbon dioxide molecules and help them to break down and reform into sugars. So blue and red light get absorbed by chlorophyll and green gets scattered back - green particles don't have the right energy to release an electron. That's why plants are green. Not all plants use light to make food. Funghi and mushrooms decompose dead or living tissue to make food. They often grow in fields or woods where little animals die and rot or the leaves and bark from trees rot. They don't need light and are rarely green.

Rover and Scientific Research

£270m of taxpayers money was used to prop up the ailing Rover car manufacturing company, which is now Chinese owned. As a result £68m given to the scientific research councils by the DTI will now be taken back to help balance the books. This means that thousands of research grants will be turned down and thousands of PhD and Postdoc projects across all scientific disciplines will never come into being. The worst hit research council is the Engineering and Physical Sciences Research Council (EPSRC) which loses £29m.

Science is the biggest thing in history. It has had a bigger impact than any king, politician, war, disease, political ideology or natural disaster. The changes in the world over the past 100 years have been science driven. Computers, TVs, mobile phones, space flight, electric lighting and much more have come directly from Physics. Hacking away at scientific research budgets in this country will cause it to fall behind. And it may prevent the spark of inspiration that will help find a cure for aids or cancer, develop the electric car or make clean nuclear fusion energy a realistic prospect.

Energy usage

I was given a gadget that will measure the energy use of my electrical appliances and help work out their monetary costs

Kettle 2890 W
Computer 130 W
Toaster 1010 W
Phone charger 0.002 W
Dishwasher 600 W
Big TV 110 W
Small TV 42 W (21 W standby)

Which means that £1 ($1.90) gets me

178 cups of tea (2 cups per boil, 800 ml water)
80 hours computer time
255 slices toasted bread
32000 charges of my phone
9 dishwasher loads (2 hrs per load)
100 hrs big TV
250 hrs small TV

I started a new job today.

Why is the sky blue?

Light particles come in all different colours and what that really means is that each different colour of particle has a slightly different energy. Red light is less energetic than green light which is less energetic than blue light and so on. If you go into space the sky is black and all the stars (including the sun) are white because the light particles they emit come in every different colour and when your eye averages them you see white. The light that they send out does not hit anything on its way to reach you because space is empty.

Down here on the earth we have tonnes of atmosphere between us and the sun. The white light comes in and most of it gets through. Except the blue light. That has a slightly higher energy than the rest and that makes it much more likely that when it hits an air molecule it'll get scattered. All this means that when you look at the sun it looks white MINUS the blue that has been scattered out - this means it looks yellowish. When you look elsewhere in the sky it is blue because the blue light gets scattered around everywhere and it hits your eyes from all directions at once.

Another interesting effect happens when you look near the horizon (when the sun isn't near it)- the sky looks paler here (whiter and not as bright). This is because blue light that goes near to the horizon and then back to your eye has to travel a long way. Chances are it'll get scattered again some other way. So from the horizon some of the blue light is taken out and the sky looks less of a deep blue and paler. When the sun is near the horizon it shines straight at you through more air than if it was above you and all the blue light scatters out so the sky is yellow during sunset. Dust and pollution in the air can take some of the green out too so that the sky becomes red. The same thing happens in the morning - shepherds warning! If you stand on Mars and look up the sky it should be blue but it is always red because there's so much dust in the air.

Clouds are different. They are made up of water and this scatters all colours of light the same. Any colour of light that goes into a cloud gets scattered in any direction so when you look at a cloud you see all the colours at once and it seems white to your eyes. Water weakly absorbs light so clouds don't appear brilliant white - they are a bit dimmer. Big wet stormclouds have more water in them and they absorb more light so they seem darker and greyer. Clouds are also very big and block out a lot of light from hitting their sides or their underbelly. When water freezes it doesn't absorb light very well. It transmits it or reflects it. Snow is white because it reflects all colours evenly and it doesn't absorb much light.

The colour of the moon is white. It reflects a bit of each colour of the light from the sun that hits it down to us. A bit of the blue can get scattered and make the moon yellow. Sometimes particles get into the air that scatter the red light very well and the light from the moon has all its red light taken out and it looks blue - a blue moon. It's a very rare occurence because to get these chemicals into the air you need a forest fire or a volcano. This effect never makes the sun seem blue because the sun is so bright - there is never enough of the chemical in the sky to remove enough of the red light.

The Energy Balance

For a 200lb (14st or 90kg) person the energy burned per hour in kcal on the following activities is

Sleeping 82
Standing 106
Walking (3 mph) 388
Driving 3 *
Billiards 223
Housework 259
Sex (missionary) 376
Swimming 541
Cycling 350
Playing football 894
* not counting background calorie loss

Compare this with the calories in some foods

McD quarter pounder 500
McD fries 224
Pint coke 420
Dominoes Pizza (12") >2000
Pint beer 180
Glass Red Wine 80
Cup tea (milk & sugar) 30
1 chocolate digestive 90
1 mouthful donner kebab 42

So if you walk for about 3 hours each way to fetch your pizza you'll have earned it.

Coffee

Coffee is the second most popular drink (after water) and the second most traded commodity (after oil). There are about 70 species of plant in the genus Coffea but 2/3 of commercially produced coffee comes from the arabica plant because of the superior taste and quality. The remaining 1/3 is mostly from the robusta plant which produces a more harsh flavour with a higher caffeine content. The arabica bush is about 1.5-2 metres tall and it grows in temperate climates. It is very sensitive to its environment and grows best at altitude in soil with low acidity. The plant is native to the highlands of Ethiopia, grows for about 50-100 years and starts to produce fruit after 4 years. The fruit resembles red berries and inside there is a small seed or bean.


The chemicals that give coffee flavour are all introduced during the growth process and nothing can be done to the beans once they have been grown. Coffee cultivation is difficult and involves many variables such as plant genes, soil, rainfall, sunlight and temperature ranges. Coffee is grown in over 70 countries principally Brazil, Colombia, Vietnam, Indonesia, Costa Rica, Mexico, India, and Puerto Rico. Human taste and smell are so sensitive (they evolved to protect us from bad and rotten food) that a single bad coffee bean in a batch of 50 ground to make a cup of espresso will taint the flavour. For this reason the best coffee producers employ workers to hand pick healthy ripe fruits. Coffee pickers can each pick 50-100kg of coffee fruits per day. The coffee cherries are dried and a machine is used to extract the raw green coffee beans. Any beans that are mouldy or defective are removed.

The next step is roasting in which the beans are heated to about 200 degrees C for between two and forty minutes. This drives a series of complex chemical reactions inside the bean that enrich the flavour. Green beans are mostly made of sugars with acids, fats, minerals, caffeine, proteins and amino acids making up the remaining 1/3. The cell wall of coffee beans is very thick and remains intact during roasting. Green beans have a 10% water content which is reduced to 5% during roasting. This water turns to steam and the inside of a bean is like a pressure cooker in which the sugars react with fats, amino acids and proteins to make melanoidins and glycosylamine which are brownish, bittersweet chemicals that give roast coffee its dominant taste. So the roasting process is essentially a caramelisation process. Alongside this a series of volatile, low mass aromatic compunds emerge that give coffee its familiar smell. If the beans are not roasted for long enough the aromas do not emerge and the coffee tastes acidic. Poor quality beans are roasted for longer periods to drive out the poor smells and tastes. This leaves a tasteless, bitter bean. The accepted roasting time for good quality beans is 12 minutes. Instant coffee is made using the leftover, crap beans by dry roasting them. The taste is bitter and there are often all sorts of unwanted products from the harvest thrown in to bulk it up.

Once the coffee is ground it is ready to be brewed. There are many techniques. The coffee can be placed in a filter and have hot water percolated through it over about 5 minutes. It can be placed in a container with the coffee for 5 minutes and then a plunger can be used to strain out the grounds as the liquid is poured out. These two methods allow more caffeine to be extracted but they also result in the dissolution of more of the soluble acids. The espresso techinque is favoured by connoisseurs. Here the grounds are compacted to a dense, fine powder. Hot compressed water is squirted through for about 30 seconds. A thin layer of dense, foamy liquor or crema forms on the surface of the coffee in the cup. If this is too light in colour then the extraction time was probably too short, the grounds too coarse or the water was not hot enough. A dark crema with a hole in the middle signifies over fine grounds in too great a quantity. Overextracted espresso gives a white spot in the center of the cup if the brewing time was too long or a white froth with large bubbles if the water was too hot.

The final result is a colloid of gas bubbles, oil droplets and solid fragments less than a few microns in size with water molecules bound to them. The coffee fluid has lots of body and it is very viscous. It coats the tongue with emulsified oils that sit there for about 20 minutes and continue to release flavours and aromas. A good cup of coffee should stay with you for about a quarter of an hour after the cup is empty.