• scissors
    May 15th, 2011ImogenUncategorized

    Things I think I don’t have time for when it’s exam time

    • Exercise (beyond walking to places I can’t avoid going to)
    • Interesting Cooking
    • Food Shopping (unless I’ve run out of revision food) (for “revision food” read doritos, apples and custard creams)
    • Going shopping to replace my ripped jeans
    • Writing proper blog posts

    Things I apparently DO have time for at exam time

    • Checking facebook  just incase I’ve missed something interesting/diverting/banal even though only 10 minutes have elapsed
    • Refreshing twitter and investigating mildly interesting-looking links which I usually can’t apply myself to enough to read in their entirity
    • Window shopping online, fully aware that I’m not going to buy anything because then I would have material proof I had been shopping when I should have been working.
    • Reading very long articles about the Science of Itching (see tweet)
    • Keeping up with current affairs (but only celebrity gossip, since interesting thought provoking stories cannot constitute a break from learning)
    • In depth google research on any interesting question that pops into my head and is unrelated to what I am supposed to be doing, i.e., learning things about physics.
    • Staring out of the window (“relaxing my eyes”)
    • Tidying my room. I feel I should let it get into an utter state to prove my commitment to my studies, but I just can’t stop myself putting things away. I’m a disgrace to my siblings, I know.
    • Washing up (ditto)
    • Arranging the app shortcuts on my homescreen into the most efficient and logical configuration
    • Thinking about numerous interesting things to write blog posts about but forgetting them before I have a chance to put something off by writing them.
    • Seeing my boyf. Speaking of which…!

    p.s. Bear with me. I’ll write about something interesting soon. Thanks for understanding. Goodbye.

  • scissors
    March 29th, 2011ImogenUncategorized

    Tea Vortex

    Sometimes it is easy to find anything more interesting than the work you should be getting on with. This morning I took a break from revision to make some tea. I had to use powdered milk but sadly it 1) refused to dissolve properly, and 2) tastes weird, so I didn’t drink the resulting brew and it remains on my desk. As my mind wandered from the mysteries of dielectric materials in capacitors I developed a fascination with stirring my now-cold tea.

    By stirring the tea and then placing the spoon perpendicular to the edge of the cup I can create a mini vortex. Milk particles orbiting in the vortex have more speed than those which continue to do a full circuit of the mug. This is because they seek to conserve their angular momentum. Angular momentum is equal to the product of the radius of the circle, the mass of the particle and its velocity. The mass does not change so as the radius decreases, the velocity must increase in order to keep the angular momentum the same.

    What is concerning is that this is only my second day of revision and my exams are still 6 weeks away. I dread to think what will be entertaining me in the weeks to come. My reflection in a spoon perhaps? Perfecting my “r” rolling? Actually between sentences I am already experimenting with rotating on my swivel chair by waving my arms around like an over-intent cheerleader.

    Whatever keeps us sane, eh? I suppose I’d better get back to work.

    Oh look it’s almost lunchtime!

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  • scissors
    March 24th, 2011ImogenUncategorized

    They say that there is no such thing as bad weather, only inappropriate clothing. However, as a carefree young girl-about-town (read: impoverished student with small handbag) I happened to be tragically ill-prepared one day when the weather took a turn for the worse. As luck would have it on this drizzly day I had cycled into university. In order to retain my right to scoff at fair-weather-cyclists I felt obliged to brave the precipitation, mac or no mac and so I set off on my merry way. At least, it might have been merry if I had worn my gloves.

    For some time I was perplexed as to why my hands were getting so nippy. They were disproportionately chilly compared to the rest of my extremities but I couldn’t work out why. It was only when I got back to my house and was fumbling with the bike lock I realised that there was a very simple reason: it all comes down to evaporation.


    Mastering evaporation. (safely)

    There are two main reasons for this chilling effect (chilling where things get colder, that is. Physics is nothing scary). These are firstly, the varying energies of different molecular states and secondly, the law of diffusion. Here’s how they work.

    Molecules (with a few exceptions) are found bound in one of three states: solids, liquids and gases. A gas molecule has more energy than a liquid molecule, which in turn has more energy than a solid. This energy takes the form of tiny molecular vibrations – generally measured as heat. As temperature increases the individual molecules gain more energy and so start to vibrate more vivaciously. As vibrations grow the molecules will gradually break bonds to their neighbours. This is why as you go from solid to liquid to gas the substance becomes less rigid and more free-flowing.

    When I was learning about molecular states at school we did a practical in the playground, swinging about hanging onto each others’ elbows. As our class’s “heat” increased we were ordered to progressively let go of each other and observed how much further we could rampage as a result. If you feel a desire to experience this yourself I suggest experimenting by grasping on to a friend while you are a) standing on plastic bags, b) standing on skateboards or c) at the mercy of a small footloose child. The less random movement occurring, the greater your chances of remaining bound to your fellow molecule.

    Particles always diffuse from an area of high concentration to low concentration. This is a fundamental rule in physics, and explains why the smell of burnt toast manages to permeate every room in the house. Water on a surface is of a higher concentration than water vapour suspended in the air, so eventually the surface will “dry out” as all the water evaporates in an attempt to even out the concentrations. The surface will also be left cooler, as we have seen before. Finally, moving air increases the rate of evaporation because the concentration in the air is kept much lower than at the surface as evaporated molecules are consistently removed.

    In order to escape from a liquid and become an unconstrained gas particle, a water molecule needs to gain some energy from the liquid first. So how does this relate to my cold hands? As the tiny water droplets left my skin they took some energy with them, making my skin feel cool (because it’s just lost some heat energy). My skin then had to burn stored energy (from food) to generate more heat to bring it back up to temperature – I wouldn’t recommend hypothermia as a great weight-loss method though.

    Instinctively, we already know all this, that’s why everyone blows on soup. By huffing and puffing you increase the rate of evaporation. The greater number of particles escaping the surface means the liquid loses heat energy. This makes your food (/drink, I’m never quite sure with soup) less likely to burn your tongue.

    So what’s a similar effect? A fan in a closed room will not actually cool the room since it’s only moving air around (if anything, it’s heating the room up by creating heat via friction in its moving parts). However, if it’s blowing air at you, you will feel less hot as the moisture on your fevered brow evaporates.

    And this is why my hands were so very chilly in the wind and rain. What I really needed was a good pair of waterproof gloves to keep me warm. In fact, I have some such gloves at my disposal, but I forgot them that fateful day. Maybe what I really need is a better memory, but unfortunately neurology isn’t my speciality. In fact, if anyone would like to break down the science of remembering things for me, I would always love to learn more.

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  • scissors
    March 19th, 2011ImogenUncategorized

    Once upon a time 8 years ago my fellow year 7s and I had to make a powerpoint presentation. Oh the fun we had with the animations, making pages of text fly in letter by letter, and bringing warped photos swooshing in from the sidelines. However, times have (thankfully) moved on and today’s trendy swooshing is coming from the viewpoint and not the subject matter. This is down to Prezi.

    The main idea behind this web-based tool is to create a non-linear presentation. You arrange your text, pictures diagrams et al on an infinite canvas and map a route between them, rotating and zooming as you go. To see what I mean watch any one of the public examples on the Prezi site. Click the “next” button and get transported on a visual journey.

    I have my dad to thank for showing me the future of presentations. He was searching for a new Google programme for making slides (possibly a subset of Google Documents), but instead happened upon Prezi. He introduced me to it but I have never heard about it anywhere else. According to the website they are now turning over a profit, so Prezi must be selling enough subscriptions to survive through word of mouth alone. I actually use it with a free student license, so I feel obliged to express my gratitude via some mild plugging.

    These are my 4 fave things about prezi:

    1. The unpredictable path makes it a bit more interesting.

    2. You can hide things by making them really small and then zooming in

    3. The audience gets a sneaky glimpse of slides to come as you move between images. Alternatively, this could spoil the surprise, but that’s where no. 2 comes in.

    4. None of my audience so far had ever seen it before, so they all thought I was some kind of technical whiz. Once you get the hang of the unfamiliar control pad, Prezis are actually quite easy to make. Just don’t tell my audience that.

    So yes, I am pro-Prezi. I find it such a great tool that I can’t keep it to myself. I just wish there was a way to spread the word among all of the Presenters of the world and none of their Presentees. Oh well, I suppose the mystery couldn’t last forever.

    A Prezi I made recently for a presentation on a Letter to the journal Nature about a new nano-scale imaging technique

    Go forth and present!

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  • scissors
    March 13th, 2011ImogenUncategorized

    MSG in a bowl, in a packet.

    What does MSG stand for? Makes Stuff Great? Or perhaps, Morbid Sauce Generator. I know which is snappier, but what’s the true story about this food additive? I want to find out how it is supposed to be bad for us and more importantly, whether it actually is.

    I mainly became aware of the controversy over glutamate due to the smug messages of “No MSG” on the front of a growing number of processed foods. I feel I am missing some vital information on why manufacturers think that people don’t want to be eating extra glutamate. Glutamate is a naturally occurring version of the synthesised MSG, which is glutamate stabilised by the addition of salt.

    Some of the various alleged side effects of consumption of MSG are numbness, tingling, headaches, nausea, rapid heartbeat, and for asthmatics, difficulty breathing. This website written by an American takes the form of a chain email, sent out to “inform” friends and encourage them to “blow the whistle on MSG”. The main point against seems to be that scientists inject infant rats with MSG to cause them to become obese so they can be used in studies on diabetes et cetera. However, the author of this article has not mentioned the relative levels found in food and that which the rats are given.

    After checking the cupboards of my student kitchen I was surprised by the lack of monosodium glutamate on ingredient lists. In fact the only place it was freely stated was as the second greatest component of Bouillon Stock Powder. This surprised me, since the product is organic and boasts “all-natural ingredients”. However, like most awkward topics, many other names for glutamate are now in use. These include hydrolysed vegetable protein (in pringles) glutamate (a natural result of the formation of soy sauce and cheese) and main constituent of marmite, yeast extract. Lots of lists also included the cover-all terms of “spices” or “natural flavourings”. Even the soy sauce boasted “no added MSG”, which is a bit misleading since glutamate develops naturally during the fermentation of the soy beans. If you are on a serious MSG-hunting mission then check out this page.

    So basically, MSG is in a lot of things we eat but we might not realise it. This means that if it is actually bad for us then this could be worrying. I contemplated catching some rats from Euston underground and conducting my own experiment by feeding them up with all the stock cubes they could eat. However, my student bedroom is cramped enough already and I signed something for the landlord saying I wouldn’t keep any pets, so I decided it was best to leave it to the professionals. So I looked through some studies to find out whether scientists have found any concrete proof that MSG is harmful.

    The first one I came across is titled “Monosodium Glutamate: Lack of Effects on Brain and Reproductive Function in Rats”. The title betrays the non-result. The abstract tells us that they injected infant rats with monosodium glutamate and then basically  tested whether it had an effect when they had grown into adults. In their words: “treated animals showed no adverse monosodium glutamate effects on the reproductive system and neural morphology”, that is, the cells of their brain and nervous system didn’t seem worse off for the dose of glutamate when they were young.

    Another article seems to think it has found a correlation between MSG and the release of growth hormone in rats. However, the injection of MSG these rats were given happened a few weeks after birth and was dosed at 4mg/g bodyweight. This might not sound like much, but for a 60kg human this is the equivalent to 240g of MSG. That’s like if I ate 20kg of parmesan in one sitting. Disregarding whether that is actually humanly possible, anyone would tell you that eating so much of anything is not going to be a good idea. Which is why although the consequences for the rats in this study were not good, I am dubious of whether this is relevant to our everyday eating habits. For example, you can die from drinking too much water but “normal” volumes of it are essential to our bodily functions.

    As they have been saying for centuries; “everything in moderation”. This also applies to glutamate. So basically, don’t eat more than a significant fraction of your bodyweight in marmite at once and you should be fine. I’m off to enhance my food.

    For more info check out this great article at the Guardian by Alex Renton, entitled If MSG is so bad for you, why doesn’t everyone in Asia have a headache?”

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  • scissors
    February 12th, 2011ImogenUncategorized

    This Study of Arms by Leonardo da Vinci shows the muscles in wonderful detail. You can see how far up the arm the tendons for the fingers go.

    I recently had the pleasure of going with my Dad to see Richard Thompson and band performing at the Royal Festival Hall. The concert was amazing, and from our meticulously booked seats I had a great view of RT’s playing. I was fascinated by the muscles apparent in his right forearm as he plucked and strummed. My dad tells me that Mr Thompson practices for two hours a day (even on tour!) and although his arms are not “hench” (as some of my friends back home may say) and hugely bulky, the muscles for his fingers are certainly well-honed.   As you can see in Leonardo da Vinci’s sketch, there are very few muscles actually in the hand. Fingers are controlled by muscles in the arm and the two are connected by tendons.

    Muscles make us move, but like everything else in the body they can go wrong. What I would like to know today is: what are muscle knots? After looking into the answer I find that it is actually relatively simple, they are parts of a muscle that have contracted, but not relaxed along with the rest of the muscle. Muscles can only pull (never push) so a muscle is either contracted or relaxed. A muscle fibre is made up of lots of filaments that slide over each other to create a pulling force. As the filaments overlap more the muscle becomes shorter and more compact. You can see this in action by looking at your inner forearm as you make a fist. Place another hand on your forearm as you do so and you will feel the active muscle changing shape as it contracts. When I do it my hand is also involuntarily lifted up slightly as the muscle shortens.

    So apparently, these knots are actually known as myofascial trigger points. The most common way to remove them is with massage or using hot or cold packs which will encourage the muscle to relax. You can also use electrostimulation or pulsed ultrasound (woo ultrasound!). I actually had electrostimulation while I was seeing a physiotherapist to correct my spinal scoliosis. I can inform you that it is very relaxing and feels like pins and needles.

    I can’t find much information on why these “trigger points” are painful but I make the educated guess that the pain is due to lactic acid build up as the muscle respires faster than the blood can deliver oxygen to it. This is the same source of pain as when you work a muscle very hard, for instance, when running up stairs. From my own experience, massaging a muscle knot is painful too. Does anyone know why this is?

     

    If you’d like to know more about how a muscle contractions then here is a great animation I heard about from my physiology course. Even if you’re not interested in all the fancy names (let’s face it, you’re not going to want to learn them all if you don’t have an exam on it) you might find it interesting to see how the components move past each other.

    Happy muscling!

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  • scissors
    February 8th, 2011ImogenUncategorized

    In My Humble Opinion, Ultrasound is very cool. It is not as amazing to look at as MRI, nor as potentially lethal as X-Rays, but it can be used for a lot of diagnostic purposes. Many of us may remember ultrasound imaging from that grainy black and white image someone showed you excitedly as you tried to work out what it was. Or if you are like me and have not had any pregnant friends, remember that scene in Friends? This is because pregnant women on the NHS are currently offered at least 2 sonograms during their pregnancy in order to calculate the age of the foetus and to check it is growing healthily. Therefore this is the way in which we are most aware the way of using high-frequency sound to image inside the body.

    However, the applications are much broader. The first ultrasound machines were basically modified flaw detectors. Flaw detectors were used by ship builders to detect faults in the metal hulls of boats. The sound waves travel through the metal and are reflected by the air which fills cracks and imperfections. The connection was made by Ian Donald, Regius Professor of Midwifery at the University of Glasgow (Regius means that the post was originally created by a monarch and each appointment must be approved by the crown. This position was founded in 1815 by King George III). He was a keen sailor and became familiar with Sonar and Radar while serving in the RAF in the Second World War. Sonar was developed after the sinking if the Titanic and used sound waves to probe several miles of ocean. Any reflected sound indicated the presence of a possible ship-sinking object. Radar works in a similar way but using radio waves. It was Douglas who first brought ultrasound into the hospital to peek at babies in utero. Many developments then followed to develop the machines we use today, which have a mobile computing and display unit and a small probe on a flexible arm. The first machines required the examinee to sit in water bath so that the probe could achieve a good contact. This is because however hard you press a plain old probe against the skin; some air will still exist where the two meet. The air will reflect the ultrasound waves before they even get into the patient so that you will just get a useless fuzzy image. The modern ultrasound gel is water based (easier to remove than oil-based formulations) and forms a perfect air-free join for the sound waves to pass through before and after the body. It’s true what everyone says though, it does feel very cold when they put it on.

    Unlike X-rays, ultrasound does not fall under the classification of “Ionising Radiation”. That means that when the waves pass through your body they will not cause damage and so their use as a diagnostic tool does not need to be restricted in the same way. In light of this, ultrasound is frequently used to view active functions inside the body, in particular the function of the heart. A physician may employ ultrasound to view the action of particular heart valves if he suspects that the heart is not pumping correctly. By examining arteries to the brain and lower body it is possible to assess the risk of getting a stroke or blood clot by looking for plaque in these important vessels. During the first three months of a foetus’s life, the cells are dividing more rapidly than at any other point in its existence. More cell divisions mean more opportunities for things to go wrong, so to X-ray a baby at this point would be very hazardous. Therefore, non-ionising radiation such as Ultrasound is invaluable to check up on the baby without harming it. Recently, scientists have developed a pre-natal test for Down Syndrome which does not require an extraction of cells from the uterus. This is good because tests such as amniocentesis or chronic villus sampling (both of which use a needle to take cells from the amniotic fluid or placenta respectively) carry a risk of miscarriage. In the new technique, a ultrasonographer examines the nasal bone since babies with Down Syndrome tend to have a flatter bridge of the nose and almost nonexistent nasal bone. A test for “nuchal translucency” can also estimate the thickness of the skin at the back of the neck using a high-frequency ultrasound. A higher than normal thickness can indicate a genetic abnormality.

    However, ultrasound can be used for quite different purposes. Some anti-abortion politicians in certain states in America (such as Montana) think that women seeking a termination should have to have an ultrasound scan and listen to the foetus’s heartbeat for up to one hour before making a final decision. Abortion is a highly controversial issue and if this scan was compulsory then it would not fail to emotionally affect both the woman faced with this decision and the doctor forced by law to carry out the procedure. Some very interesting moral questions are raised, but this is not a political blog, so I won’t say more on the matter.

    AND SO to haul this post back from grim opinion-ism , I would like to draw your attention to this lovely little story I read the other day about the amusing pictures ultrasound can capture. Aaaaaah.

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  • scissors
    January 22nd, 2011ImogenUncategorized

    Myself as a nipper. That hair is in need of some silicone!

    My family loves potato omelette. Recently, leftovers of said omelette were left in the dish it was cooked in for several days and the baked-on grease became very difficult to remove. After it had been soaking for a day with no improvements and we were driving home with Brillo pads I had a brainwave! It went thus: Washing up liquid cleans (in part) by breaking down fats, but the problem here seemed to be the stubborn bits of egg, which are protein. Therefore surely we needed an enzyme which could digest the protein, such as biological washing powder! Unfortunately, it appeared the protein was not the problem so my genius idea was not as useful as I had hoped.

    However, it got me thinking about how we clean other things. In particular; 2-in-1 hair products. I don’t use them a lot, personally, because I don’t want to get shampoo on the long bits of my hair (which are dry already) nor conditioner on my roots (not that dry). But am I being naïve in assuming this will happen? Are 2-in-1s, as I had assumed, just the two individual concoctions mixed together? Well, as I discovered from this very interesting article on the Royal Society of Chemistry’s site, the 2-in-1 is a carefully engineered product in its own right.

    The purpose of shampoo is primarily to remove grease and dirt from hair. However, conditioner adds oils to the hair in order to leave it glossy and smooth. So the question is, how can these two co-exist in the same bottle? One solution that scientists have come up with is to use shampoo and conditioner molecules which repel each other. As the product is rinsed out and mixes with water, the conditioner molecules (which have been coated in a “crystalline matrix” and suspended in the shampoo) are precipitated out since they are not water-soluble. Think of this as like the evaporation of sea water. Salt is soluble in water but not in air, so when the water becomes water vapour suspended in the air, the salt is left behind as little crystals. So the shampoo is washed away, leaving the conditioner to do its work.

    This is all news to me. I thought you were meant to leave conditioner on for a few minutes to get the full effect but this obviously doesn’t translate to 2-in-1s. As to my conditioner-on-hair-roots no-no, this should not be a problem with the combined products, since the conditioner targets dry or damaged regions of your hair. Another interesting point in the article is the balance between mildness and lather-osity. The more lather produced, the more grease the shampoo is taking from your hair. The dirt is then suspended in the lather to prevent it being re-deposited in the hair. However, some shampoos such as those formulated for babies, need to be milder and so produce less lather.

    On an interesting final note, an article in a similar vein on the Beauty Brains blog (“Real Scientists Answer Your Beauty Questions”) tells us that since dimethicone (the silicone bit) is nearly always present in products which condition your hair, even if you don’t realise it. This means that if you only want your shampoo to remove oils from your hair, check the ingredients first! It’s more common to find it in shampoo than you think. Now before you head off to check the ingredients of everything in your bathroom, check out the Electron Microscope photos of damaged hair on Procter and Gamble’s site. The most striking piece of information comes from their assurance that “backcombing is one of the most damaging physical treatments that can be inflicted on hair.” This, along with photographic evidence is definitely going to make me respect my tresses a bit more. Silicone is my saviour!

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