Personal Blogs

The good news

The day finally arrived yesterday: we received our results for S104: Exploring Science. There was much excitement and anticipation in the land, and verily did we leap into the course website with glee.

I'm delighted actually - I got a distinction! I knew I'd done well, as I have achieved consistently high marks throughout the course - but the end of module assessment was genuinely tricky, so I'm really pleased.

• Overall examinable score (OES): 87%
• Overall continuous assessment score (OCAS): 93%

The self-indulgent navel gazing

The results come at a good time, actually, because I've been dipping - rather self-indulgently - in and out of an existential crisis over the past couple of weeks. It struck me, rather more forcibly than I would have liked, that I'm 32 years old and I am not where I thought I would be.

The fact that 1990 is more than 20 years ago keeps assaulting me in an unnecessarily violent manner. I shouldn't be old enough to remember 20 years ago, surely! I keep thinking of Britpop as a modern phenomenon.

My mortality and the foundations of my existence are at the forefront of my mind, which troubles me. Navel gazing is not becoming, nor - do I feel - is it particularly helpful if it lasts longer than about 15 minutes.

I should have been so much more than I feel that I am at the moment.

Having said that, I would not turn the clock back 15 years for anything; I'm wiser, happier and feel smarter and more attractive than I did when I was but a whippersnapper - I'm just not quite where I thought I was. Either that or the world moved sideways slightly when I wasn't looking.

I've always felt slightly out of time. The 1920s, 1940s or 1950s would have suited me much better than these modern times (female emancipation and general equality notwithstanding). The music, the clothes and the manners of the times delight me. But perhaps we are living in even more exciting times as we prepare to send human beings to another planet...

Getting my Open University results has given me a bit of a kick back onto the right track. It's only a level one course, but it was bloody hard work, and I really feel proud of myself. Roll on S216 - I'm ready for you.

And while I'm waiting for you, I'm diving headlong into books on science to try to get a head start. Dawkins' "The Selfish Gene" is my current literary beau, and a splendid read it is too. I've been advised by a colleague to try a little Stephen Jay Gould as anathema to Dawkins, to see which evolutionary camp I fall into, so Amazon was duly visited, and Gould ordered. We'll see where I end up.

Where I want to be is saving the world, one turtle at a time.

As this blog is following and documenting my adventures in science, it seems that I should say a few words about S104 Exploring Science for any prospective students of the Open University.

I'll start by stating, in no uncertain terms, that this is a Very Difficult Course, particularly if there is no (recent) background in studying science or maths. This is not a light, adult-learning-style, interest-only course: it's full on, in depth and requires an awful lot of hard work.

If any prospective students are not truly interested in science and really committed to learning, it will be extraordinarily difficult. I work full time, and I try to have a social life too - I have struggled to find the hours required for this course.

However, and I can't emphasise this enough, S104 Exploring Science is absolutely bloody brilliant. It is Professor-Brian-Cox-jazz-hands-brilliant. Finding the time to study has not been, in any way, a chore.

Some aspects of the syllabus have been easier than others; some have interested me more than others. But overall, it's fantastic.

Here, I need to pay tribute to my wonderful husband - I could not have done this without him. He has been supportive, interested, helpful (especially with the maths and physics) and he has become a very good cook. Joe's patience is seemingly never ending, and I know he's really proud of me. I am proud of him. And I am so grateful.

Anyway. Enough mush. Here are the facts, figures and ravings of an S104 Survivor.

For those thinking of starting S104, I would recommend that you do some reading first - partly to see if you really are that interested in science, and partly because it will give you a good base to build upon. I found Ben Goldacre's Bad Science to be a great introduction to scientific method, and it's a good read to boot. His blog is fab.

We Need to Talk About Kelvin by Marcus Chown is also a good read. One of the more wonderful moments of this course was when I realised, in a bolt of inspiration, that I actually understood what I had been reading about a few months earlier.

And as preparation for when you arrive, breathless and exhausted, at the bottom of the mountain that is Quantum Physics, give Jim Al-Khalili's Quantum: A Guide for the Perplexed a whirl.

In fact, just read everything you can get your hands on, in the daily media, online and in journals such as New Scientist.

Before beginning, brush up your maths. Maths used to terrify me. It's well worth doing the Open University's freebie maths book to start.

Exploring Science is a nine-month course, and the course team recommends that a minimum of 16 hours per week is put aside for study. I have found this to be fairly accurate, albeit the study time is probably an average. Most people will find some topics require far less work, while others require much more (biology and quantum physics, please stand up!) .

There are eight books covering different topics, and although the order may seem slightly odd when you first see it - it does all fall into place:

• Book 1 - Global Warming. This is a fairly gentle introduction to S104, and jumps feet-first into a subject that is bang up-to-date - climate change and all that goes with it.
• Book 2 - Earth and Space. Geology and geological processes are introduced in part one, while in part two we leave Earth and venture out into the Solar System. Again, this is not too taxing, and is a decent way to ease you in.
• Book 3 - Energy and Light. Physics-lite - I began this book reminiscing about GCSE physics, and remembering a surprising amount. By the end of the book I realised that this was Grown Up Stuff, leading my thoughts in directions they would never previously have contemplated. The maths began to pick up pace; and rather than becoming baffled and afraid, I developed a deep and abiding love for a beautiful and elegant discipline.
• Book 4 - The Right Chemistry. Again, it begins with a recap of GCSE chemistry, then steamrollered into the kind of stuff that makes you wonder if, by the end of the course, you'll be able to run your own meth lab. Fascinating. And if, like me, you were once afraid of the mole, this book will cure your fear.
• Book 5 - Life. Biology. It's the thickest book of the lot, and it's stroppy with it. Life lulls you into a false sense of security, starting with the difference between autotrophs and heterotrophs, looking at prokaryotes and eukaryotes, before steaming into the minute detail of the reactions that make up photosynthesis. Think you know how plants make their food? Think again!
• Book 6 - Exploring Earth's History. An interest in fossils and geology will mean you sail through this book. It's absolutely fascinating, and is a grand illustration of how absolutely everything in our Universe is connected. Our planet is a staggeringly beautiful and complicated place, and I am humble before it.
• Book 7 - Quarks to Quasars. Mind-bending stuff. But give it time, read everything VERY carefully, more than once, and it WILL make sense. I promise. I found that writing notes in my own words was really helpful.
• Book 8 - Life in the Universe. I'm not there yet. But the book promises to pull together all the aspects of S104, enabling us to build a complete picture of how the separate disciplines tie together. All branches of science are connected, and feed into each other. It will be good preparation for the End of Module Assessment.

Everybody's techniques for studying are different, but this is how I approached Exploring Science. As I read through each chapter, I highlighted relevant concepts, ideas and facts, making notes in my own words. I also, as you have probably gathered, began this blog. It is, in part, a method of finding out if I've fully understood what I'm learning: if others understand my tales and explanations, it's a good bet that I have.

Talk to your loved ones: bore them silly! I am lucky to have a husband who is almost as fascinated by this stuff as I am, and many of my friends are crazy about science. (I thank you all so much for listening, reading and generally being interested. I love you guys!)

Use the tools the Open University gives you: do all the activities, because they really do consolidate your learning, as well as being good fun in many cases. The questions dotted throughout the text are brilliant, testing your knowledge and understanding before you come to do the assessments.

And speaking of assessments: at the end of each book, you are required to complete an iCMA (interactive computer-marked assignment) and a TMA (tutor-marked assignment). These contribute to your overall mark, as well as helping to pull together everything you've learned.

A good tactic for the iCMAs is to write them out in rough before you enter the answers. My first one was pretty shameful, purely because I hadn't read the instructions properly! In my excitement at starting the course, I achieved only 80%...

For the TMAs - read the questions really, really carefully! Sometimes the OU examiners do not use language in the way you may expect... I found that leaving the TMAs right until the end of the book meant that I was a little stressed about getting them in on time. The questions helpfully tell you which chapters you should have finished before attempting to answer - I would advise that the TMA is completed as you go along.

Use your tutors, that's what they're there for. They are a great source of support, if you're lucky enough to get a really good, dedicated person. The tutorials are also a good source of support, as well as helping you meet other students.

Use other students too: the tutor forums can be helpful, if you get a good group - or join the S104 group on Facebook. I've made some lasting online friends through that, and it's made me laugh until I cry on more than one occasion. You are not struggling alone.

And finally: enjoy it! It's been a fantastic experience, and I'm genuinely sad at the thought of the course ending (although I cry at the news, so don't let that be a measure of normality...). Good luck, and remember:

"What we have learned is like a handful of earth. What we have yet to learn is like the whole world." Avvaiyar, Indian poet-saint.

Everything is connected. Absolutely everything. From the more obvious water cycle, to the less obvious carbon cycle, to the frankly astounding and mind-boggling fact that we are all made of stardust.

Simple, observable, everyday phenomena tell us an enormous amount about how the Earth works. For example, I found out during my study of Book 6: Exploring Earth's History, where that yellowy-orange dust comes from. You know the stuff, it ends up on your car sometimes after it's rained. That is dust from the Sahara desert, and it only appears after a big sandstorm.

The fine, red dust is carried up into the lower atmosphere by the wind, and - if it's fine enough, and the wind is blowing in the right direction - it is transported to our little island and deposited on our cars (much to the annoyance of my dad - it's an abrasive dust, you see, and if you scrub at it the paintwork is damaged).

In the past, dust from all over the Northern Hemisphere was swept up towards Greenland and deposited on the ice cap in the fresh fall of snow. Millenia later, some of our more extraordinary adventure-scientists (I think that's a reasonable title for them) journeyed to the Arctic and took samples from the ice.

These ice cores tell us, amongst other things, how our climate has changed over the past 140,000 years. They show us the peaks and troughs of temperature, give clues as to how arid or humid the climate was, and tell us about the chemical composition of the atmosphere.

All this comes from the presence of dust in ice, and the proportion of heavy or light isotopes of oxygen (that's 18O or 16O) in the snow that fell on the ice-cap.

Another use for isotopes is in radiometric dating of rocks. The oldest rocks we know about are around 4,280 million years old and occur in Hudson Bay, Canada*. That's not long after the Earth and the other planets of our solar system formed (about 4,560 million years ago). They are pretty rare; rocks tend to get recycled during tectonic activity.

Rocks are, against all probability and expectation, extraordinarily interesting. Not only do they provide humanity with gems such as diamonds and emeralds; they provide us with fossils. Look at the rocks next time you see a cutting by the side of a road. Really look at them. That layering, if you're in an area of sedimentary rocks, is giving you a snapshot of the past. You're looking into prehistory. There may even be fossils in there.

Connected to this geological time-line are deep-ocean cores - the sediments laid down by erosion and the dead organic matter in the seas. They provide another means of establishing a relative time-line - and it's all calibrated by the radiometric dating of rocks.

The study of rocks gave us the cause of the last mass extinction, that of dinosaurs (and a huge number of other families) in the K-T event about 65 million years ago at the end of the Cretaceous Period and the beginning of the Cenozoic Era. It's called the K-T event because scientists are awkward so-and-so's: K comes from the Latin for chalk - "kreta" (for Cretaceous) and T comes from Tertiary (an obsolete - but still used to confuse us students - name for the Cenozoic Era. And here is where I feel old: I'm sure I remember reading in books when I were a wee lass the name Tertiary. Cenozoic is a new one on me).

So what did cause the extinction of the dinosaurs? It probably wasn't one single event (and it's pretty much agreed that the other mass extinctions were not caused by a single catastrophic event, but by a combination of changing conditions). There were two events that happened at around the same time, on opposite sides of the world: a 10km meteor smashed into Mexico (you can see the crater on topographical maps) and in India there was, over the course of a couple of million years, an episode of flood-basalt volcanism.

The consequences of a meteor impact are fairly obvious: shockwaves, quakes, but mainly the dust, debris and gases entering the atmosphere. This would only last for a few months; but a few months of starvation is all that is needed to knock a species to its knees. Or its tentacles, if it has no knees. In short, the knock-on effect would be enormous (everything is connected, you see).

Likewise, the volcanism across the world would have a similar effect in terms of gas and dust - but spread over a longer period. CO2 and SO2 levels would rise, increasing the global mean surface temperature (they're greenhouse gases) - but at the same time, the dust in the atmosphere would increase the planet's albedo (the amount of sunlight reflected back into space). So overall, the planet would cool, and the rain would be acid.

This had the devastating, but on the surface insignificant, effect of collapsing a population of plankton because it couldn't photosynthesise. Of course, everything above it in the food chain suffered as well...

Although these events were natural, they should be a cautionary tale to us humans. Every action has consequences. A change to the atmospheric composition can have far-reaching effects; alter the pH of the sea, and the consequences could be devastating. We don't fully understand how it all works yet; but we know that changing one tiny variable will alter a dozen more in ways that we can't necessarily predict.

Everything is connected, and it can tell us an enormous amount about ourselves; our past, present and future; where we came from, and where we might go.

To those who say that science takes the mystery out of life: you are so wrong - if anything, it deepens it and whets the appetite for knowledge and understanding. And you are missing out on the adventure of a lifetime.

*The image of the Hudson Bay rocks was borrowed from here:http://www.daviddarling.info/archive/2008/archiveSep08_1.html. I thank the photographer, but will certainly remove it if requested!

We in S104 have all been assigned a primate species to research. We are then to have a discussion and decide which of the primate species we would prioritise for conservation, and why.

The species are: Pongo abelii (the Sumatran orangutan); Colobus angolensis (the Angola colobus); Leontopithecus rosalia (the golden lion tamarin); Eulemur coronatus (the crowned lemur); and Tarsius dentatus (Dian's tarsier).

I'm not sure yet which species I would prioritise for conservation, but the discussion on the tutor group forum has raised some interesting points - scientific and philosophical.

When discussing the orangutan, in particular, mention was made of its conflict with humans. The Sumatran orangutan is classed as critically endangered by the IUCN Red List with a decreasing population, and little hope for improvement at present. The major threats to the species are legal and illegal logging; a new road which, if approved, will further fragment the sparse populations; and competition with humans for resources.

One student said that the human populations have a right to live there, raise families and make money. Perhaps. "Human rights" are much talked about, and for the most part, our laws and customs are necessary and enshrined in our basic codes of behaviour for good reason.

However, human rights are a human construct: what marks us out as so special? It is difficult to view the world from a non-human-centred viewpoint, but sometimes this is worth trying. When looked at objectively and in a detached manner, it is not so simple.

Why should humanity have more "right" to resources than any other species? What about other species' "right" to existence?

It has been suggested that other species, competing with us for resources, have a case to answer as to their right to survival. "Does it really matter if tigers survive?" asked a devil's advocate? I would argue that, yes, it does matter. And not just because tigers are beautiful, majestic creatures; but because their disappearance may have far-reaching consequences for humanity. And, in any case, who are we to decide?

If we are competing in so many areas for limited resources, that does rather suggest that the problem lies within human populations. Our world is vastly over-populated - we are not just fighting other species for survival, we are fighting each other. Only by stabilising our own population growth can we begin to make any inroads into stabilising the world's ecosystems.

Education is essential: both in the West and in the developing world. If we do not control our own populations, nature has a tendency to redress the balance. By studying animal populations, we can make predictions as to what may happen in our own populations: overcrowding breeds disease; overuse of antibiotics is producing many new strains of resistant bacteria; competition for resources starts wars.

Extinction, like death, is part of life and nature; there's no denial there. Some species reach an evolutionary dead end. Some may argue that the mass extinctions we are facing are "natural"; I would disagree. Humanity is consuming resources so quickly and on such an unprecedented scale, that the world is shuddering in the face of too many changes. We are not just threatening other species - we are threatening ourselves. Perhaps this would not be such a bad thing for the planet; but people are (can be) amazing, wonderful creatures and we owe ourselves so much more.

The answer is not simple, and like almost everything else in life, the debate is not black and white. If conservation is to work - and it is a worthwhile task! - it will need to involve everyone: from governments, conservation groups and concerned individuals to the indigenous human populations themselves. Change has to come from within, and education is key here.

If we can't find a way to protect and preserve the creatures we share this world with, what hope is there for humanity to improve, grow and evolve?

If it were up to me, resources would be poured into the conservation of those endangered species that have been directly threatened by anthropogenic activity alone. We have no idea what effect mass extinctions may have on the planet, on human health and society. Even if we cannot appeal to those who care nothing for wildlife and conservation, surely there is an argument to be made regarding the potential benefits of species we are losing?

And leaving aside all that, our world is incredibly rich and beautiful. Take a look around, learn a little more about the creatures that we are on the brink of losing. That in itself is a good enough reason for conservation. And it's worth some measure of sacrifice.

Today's topic is the light-dependent reactions of photosynthesis. Now, you may think that it's all fairly straightforward, thinking back to your GCSE biology classes (or O-Level for you oldies).

A bit of light for the leaves provides energy to turn water and carbon dioxide into sugar and oxygen. Simples, I hear you say. That is what I thought too. Just a short chapter, I imagined. How complicated can it be?

Well. Let me tell you that it's very bloody complicated. I've drawn two diagrams, and I'm still not entirely sure I've understood it. And I've only done the light-dependent reactions! The dark reactions are yet to come. I'm expecting them to involve Voldemort in some way.

Here is a short account of the principle reactions involved in this stage of photosynthesis, which I wrote as part of an activity to help us to understand the processes. I would include my diagram, but I'm not drawing it on a crappy laptop. It's not an Etch-a-sketch, you know. So I've pinched this one from my OU course book.

The thylakoids are part of the chloroplast in plants. I apologise for the word "thylakoid". All its consonants are in the wrong place, making it a bit of an assault course for the tongue. It reminds me of trying to learn German at school - I never was very good at German, partly because I had trouble getting my tongue around their words. I do, however, love the phrase: "Schnell, schnell, kartoppelkopf!"

They have an outer membrane, and a really convoluted internal membrane which is stacked into grana - and each little disc (or sac) in an individual granum is a thylakoid. The space inside the thylakoid membrane is called the thylakoid lumen, while the space outside the membrane is called the stroma. As illustrated above.

My summary is as follows. It's supposed to simplify the description of what's going on, and complement the diagram above. I'm not sure I've achieved that; any and all feedback is welcome!

When light strikes a chlorophyll molecule, a photochemical reaction takes place in which the hydrogen atoms of water molecules are split into their constituent protons (H⁺ ions) and electrons. (Oxygen is released as a by-product.) As shown above, the electrons move from the thylakoid lumen through the membrane to the stroma, by means of protein carriers within an electron transport chain (ETC). The protons are left behind, increasing the concentration of protons in the lumen. With me?

In the stroma, coenzyme NADP collects a couple of electrons and combines them with a couple of protons, reducing to NADP.2H (see above). This lowers the concentration of protons in the stroma. This will be important later.

One of the electron carrier proteins in the ETC is a little shuttle that collects protons from the stroma, bimbles across the membrane, and deposits them in the lumen, further increasing the concentration of protons in the lumen.

As a result of these processes, a transmembrane (yes, it's a word!) protein gradient is formed across the thylakoid membrane - this works much like a hydroelectric plant (think of the reservoir at the top, and all that potential energy waiting to be turned into electricity). Now there's an imbalance of proton concentration, enabling the protons to flow down the concentration gradient back into the stroma through channel proteins called ATP synthase (shown on the right of the diagram above).

The flow of electrons through these proteins enables the manufacture of ATP from ADP (adenosine diphosphate) and P_i and their transfer provides the energy required.

The products of these light reactions, ATP and NADP.2H, are used in the dark reactions of photosynthesis by the Dark Lord to reduce carbon dioxide to glucose.

I do apologise for the extreme biology - but this is the third time I've written the process in my own words, and I do believe it's finally beginning to sink in. In a manner that ensures I understand and remember it.

Stay tuned for the Dark Reactions - I suspect they may be sexier.

I am no longer afraid of moles! No, not the little furry buggers that make a mess of your lawn. The once-frightening, but now benign, number used in chemistry so that your head doesn't explode due to excess zeros.

A mole - also known as Avogadro's number - is 6.02 x 10²³ "things". So, one mole of oxygen atoms contains 6.02 x 10²³ atoms. That's quite a large number. So large, that most people can't get their heads around it.

Here's an analogy: one mole of marshmallows would cover the United States of America to a depth of around 6,500 miles*. That is a LOT of marshmallows.

One mole of moles (the little furry buggers this time) would, if placed end-to-end, stretch 11 million light years, and weigh almost as much as the moon.*

Water flows over Niagara Falls at about 650,000 kL (172,500,000 gallons) per minute. At this rate it would take 134,000 years for one mole of water drops (6.02 x 10²³ drops) to flow over Niagara Falls.*

Anyway, enough analogies. Suffice it to say, it's a remarkably large number. Far too large to do anything practical with. So, chemists use the mole as a form of shorthand. At school, I hated chemistry specifically because of moles; I just couldn't get my head around it.

So it was with a sense of trepidation that I approached Book 4: The Right Chemistry.

My fears, however, were unfounded. I'm really, really, enjoying this book! The maths tackled so far has really helped to beat back the terrors of Very Large Numbers, and the book is great at explaining difficult concepts in simple terms.

I do think it helps that I am reading We Need to Talk About Kelvin when I'm not studying. This, too, is a cracking book that manages to explain extremely complicated ideas in layman's terms. Doing a bit of reading around the subject definitely helps to seal ideas into your mind, and allows them to take hold.

Anyway - I digress. I was talking about the mole, and its eternal usefulness.

One mole of any substance contains 6.02 x 10²³ atoms, molecules or ions (whichever is most appropriate) of that substance. So, one mole of marshmallows contains 6.02 x 10²³ marshmallows; one mole of water contains 6.02 x 10²³ water molecules; one mole of mercury contains 6.02 x 10²³ mercury atoms.

And, one mole of any substance has a mass equal to the relative mass of that substance, expressed in grams. So one mole of oxygen atoms has a mass of 16.0 g; one mole of oxygen molecules (it's a diatomic molecule, see) has a mass of 32.0 g. With me?

The Avogadro hypothesis (named after Amadeo Avogadro, an Italian physicist who died in 1856) asserts that this is true. Actually, it asserts that equal volumes of different gases, at the same temperature and pressure, contain equal numbers of molecules. Which is beautifully simple, and has the far-reaching consequences I mentioned above.

It enables the mass of any given substance to be translated directly into numbers of molecules (or atoms) using the Avogadro constant: the mole.

Thus: the number of moles of a substance is equal to the mass of that substance divided by the molar mass of the substance.

E.g. How many moles are in 52 g of water? Well, the molar mass of water is (2 x 1.01) + 16.0 = 18.02 g mol‾¹

So the number of moles in the water = 52 g divided by 18.02 g mol‾¹ = 2.89 mol (3 significant figures). There are 2.89 moles of water molecules in 52 g of water.

Simples!

And the scariest thing? I'm quite enjoying it all! Next, I shall enthuse about covalent bonds. They are this: aces.

*I can't claim the credit for these analogies. They came from a rather cool chemistry site.