Archive for March, 2011
In Part 1 we tried to imagine just how huge our galaxy is, to show where we live in this universe of ours. To accurately describe the universe beyond our galaxy we’re going to have to shrink the scale we used last time a hell of a lot more. Let’s take our already shrunk 6 million kilometre wide Milky way and pull it all the way down to 1 metre across. At this scale the Sun is 1.5 billionths of a metre across (half the width of DNA) and the Earth is 13.5 trillionths of a metre across (half the size of the smallest atom!). The entire galaxy now comfortably fits between your outstretched hands; hundreds of billions of stars, perhaps trillions of planets all between your fingertips.
But our galaxy doesn’t sail through the universe alone, dotted around us are a number of satellite galaxies, there are around 25 smaller galaxies clustered around our own! The largest is called the Large Magellanic Cloud, on our scale it is a metre and a half from our galaxy (off to the side and slightly below). Home to billions of stars this 14 thousand lightyear wide galaxy would be the size of a pineapple on our little scale. The other galaxies surround ours in all directions with the closest 1 foot from our model and the furthest over 13 metres away, a real-world distance of over 1 million light years!
Even the Milky Way and her satellites are not alone, they are part of what we call the Local Group. Comprised of three major galaxies and dozens of satellites on our scale the local group is the size of a football pitch. Within these 10 millions lightyears lie trillions of stars, the largest galaxy is our nearest neighbour called Andromeda which itself contains well over 1 trillion stars. I always think fondly of Andromeda, as a child I had a book about the universe and I remember becoming upset because it told me that in 4 to 5 billion years the Milky Way and Andromeda are going to crash. Count to five……I’ll give you time to do it……we are now 600 kilometres closer! We are on a collision course with each other, on our scale Andromeda is 25 metres from us (2 and a bit buses) and its racing towards us at a rate of 5 billionths of a metre every year. Granted that doesnt scare me any more, but it’s going to be a titanic display!
Our Local Group may seem huge but it is tiny compared to some of the other groups nearby. 65 million light years away the Virgo Cluster is home to over 1 thousand galaxies! When we look at the Virgo Cluster now we’re seeing it as it was when the dinosaurs were walking the Earth, from the entirety of that point until now those photons have been serenely flying through space until one day after aeons of travel they land in our telescopes to tell us a tale from the deep past. The Virgo Cluster is so huge that we use it to name our local supercluster. Yes our Local Group is just a small part of a bigger group. The Virgo Supercluster contains at least 100 galaxy clusters and on our scale where the Milky way is a metre across and the Earth just half an atom wide it is over a kilometre wide. That’s about the same scale as an ant standing next to a car
Now I know this is beginning to sound repetitive but even our supercluster is just a tiny dot. When we look out beyond our supercluster we see that there are many, many more. Superclusters litter our universe forming truly colossal structures. They bunch together forming filaments (chains billions of lightyears long) and Great Walls formed from giant webs. This is our home. This is our universe. At this size our scale collapses again, with the Milky Way 1 metre wide some of these filaments would be tens of kilometres long!
This is the observable universe, countless stars in hundreds of billions of galaxies. We are but a tiny part of this but it’s all out there! The numbers are horrible and the distances incomprehensible but I hope my analogy has helped. I was planning on taking this further and explaining just how small things in our universe can be but I found this brilliant animation that paints a picture worth a thousand blog posts. Its awesome, its unimaginably big, and its where we live.
At the moment I find myself caught in that horrible time where all my days are spent locked in a room (windows optional) pouring over old notes trying to revise for an exam. This isn’t a new feeling for me, like most people in my generation who continued with higher education our whole experience of learning has involved study for a set period of months followed by a test that your life itself depends on. Traditionally when faced with such tests we revise, a process that is meant to refresh us of all those things we have learnt throughout our time….yeah….about that.
In my experience revision is never a comfortable stroll down memory lane. Its a backbreaking experience whereby 1/3rd of it is refreshing my memory, 1/3rd learning things I have forgot and 1/3rd learning the things I never understood in the first place. I don’t remember much of how I revised for my early life exams but I do distinctly remember Sixth Form being the place where I learnt to loathe revision. It’s not that I don’t like learning, I wouldn’t have chosen to be a scientist if that was the case, I just get sick of spending hour after hour, day after day reading endless notes! Especially when this reading is accompanied by the dread thought that at the end of it I am going to have to sit in a dark room and suffer a Gestapo-like interrogation with a light in my face and bamboo under my finger nails! Not really, but that’s how it feels sometimes.
In actuality what I find annoying is how hard it is to convince the brain to remember something. In Sixth Form I had a tutor who would run revision sessions wherein the whole class would contribute to make a colour coded mindmap using the class’s digital white board (space age or what?). The tutor in question told us that specific colours help remember things when placed in order, I tried this out in other subjects but to be honest it never really worked. Perhaps I wasn’t associating Kant strongly enough with red, or was using the wrong shade of blue to recall how many people died in the Kobe earthquake. Another tutor once told me (with slightly more science behind her assertion) that the area of the brain associated with the sense of smell is next door to the area responsible for laying down long term memories. You may notice that walking into a room with a particular scent sends you flying into the deepest recesses of your mind to re-enact a summer picnic when you were nine. The idea being that if you were to revise with a scented candle for each subject and then take a hanky with a drop of that scent into the exam you could shove it up your nose when you forgot something. Needless to say, this didn’t work.
So I find myself once again wondering what exactly is the best way to revise? I’ve used many different methods in my life and have yet to find a winning combination. I’ve tried remembering things by rote, just repeating them either out loud or in my head, sometimes by writing them down over and over (like some semi-sadistic detention from middle school). This is OK to an extent but it’s hard to remember a thousand pages of work this way. Often I imagine all the elements of what I’m revising dancing around my room, trying to force my brain into remembering it visually. Sometimes I’ll even use my hands to move around these imaginary objects in an attempt to learn kinesthetically. A good trick I’ve picked up recently is creating a story to use as an aide mémoire for instance; “Dr Jell was telling me the other day how he used to be into horse racing. That was until in the 2003 derby he fell from his horse and had to have a hip replacement. He said it’s good but a bit flaky”. This is to jog my memory that Jell et al 2003 is a paper discussing the effects of wear debris from orthopaedic hip replacements.
When faced with many things to learn at once (like the dozen or so ideal properties of a tissue scaffold) I find doodling pictures around my notes helps. Especially if I can give these doodles a little story in my head; “cyborg stickman is a body builder, recently he broke his leg lifting weights and had to get a new bone implant”. This is to remind me that load bearing implants should provide mechanical support. It is very silly (and quite geeky) but because of that I’m definitely going to remember it. In my last exam I was struggling to remember who wrote all the papers I had to learn, when they wrote them and what they said. I ended up making a story about a Chinese takeaway with a trance night club in the basement and an Indian restaurant on top. There’s more to the story than that but I still remember Wu 2001 (cantilever biosensors), Chang 2005 (Quantum dot fluorescent imaging) and Rajnicek 1997 (neurite growth on nanopattern surfaces).
In no way have I found a suite of methods that turn revision from a slow slog through treacle into a laid-back holiday. All the tricks I’ve assembled over the years have helped but it’s still a bit of a chore. I always thought that Neo didn’t realise how good he had it; if I had a chair that could teach me kung-fu in minutes I wouldn’t have to write this blog post complaining about revising. Indeed you would have to drag me kicking and screaming from the chair (which would be hard as I now know kung-fu) to go to the exam because I would be too busy downloading the British library, facebook, Pubmed, facebook, wikipedia and facebook straight into my skull. In the spirit of attempting to assemble a toolkit of revision tricks (whilst we wait for the chair) I’d be interested to know how you revise? What’s your best tricks, do you like working in groups or solo, is there anything that you avoid like the plague? Feel free to leave a message in the comments.
Right, I’ve now spent half an hour bashing this out and it’s got my brain nice and warmed up for what you all know I should be doing. Back to the books!
The answer to that question quite obviously relies on the reader, I’m in London for example. You could be in a town nearby, or across the country or for all I know thousands of miles away. But we can group together where we live, if you are reading this in Brighton or Dunstable then we could say we both live in the south of England. If you’re reading this in York or Leicester we could stretch it and say we both live in England. We can play this game for a little while before we inevitably come to the conclusion “we all live on Earth”, but where exactly is that?
Our pale blue dot is flinging itself around the campfire we call the Sun at around 30km per second (London to New York in 3 minutes). We share this Sun with seven other planets; Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune along with five dwarf planets; Ceres, Pluto, Haumea, Makemake, and Eris. Along with a few score moons, a couple of asteroid belts and a sprinkling of comets we all make up the solar system together. It’s hard to get round just how big the solar system is, there isn’t even a definitive boundary with clouds of asteroids extending for trillions of kilometres around our Sun. But that number “trillions of kilometres” is meaningless, let’s face it, I could have said billions or zillions for all the connection it has with our lives. In light of this I’d like to share an analogy I often use…
Imagine the distance between the Earth and the Sun (some 150 million kilometres) and shrink it right down to just one metre. At this scale the Earth is just 80 millionths of a metre wide (about the size of ten red blood cells side by side). The Sun is little bigger than a marble at 9 thousandths of a metre. 40cm from the Sun we find Mercury and just 30cm beyond that we have Venus. Within our metre sized orbit the Moon is nearly 2mm from our bacteria sized Earth, about the size of two grains of sand. This is the furthest mankind has ever gone in our universe. It took years for thousands of geniuses and billions of dollars to take us just 2mm on our scale. With the solar system shrunk down like this Neptune, the furthest planet, is just 30 metres away from our marble sized Sun. Eris, the furthest dwarf planet doubles that distance at 62 metres. Taking this orbit as the boundary of our system on our scale a football pitch would fit within our entire solar system with a few metres either side to spare. This is our solar system, over 120 metres wide and the furthest we have travelled is just two measly millimetres. But our home doesn’t stop there.
Our solar system is just one of hundreds of billions inside the galaxy we call the Milky Way. If you live in a place with low light pollution you can look up at night and see the disk of our galaxy cutting straight across the dark. Our spiral galaxy is so large that we have to measure it in lightyears, that’s the distance that light (the fastest possible thing, it travels at 299,792.4 kilometres every second) travels in an entire year! In kilometres that’s 9,450,000,000,000,000! In our scale one lightyear is 61km, nearly twice the length of the English channel at it’s smallest width. The nearest star system to us is four times that again! On our little scale where the Sun is a marble and the Earth just a collection of cells wide the Milky Way is 6 million kilometres wide. Even with our horrendously shrunk down scale the length of the Milky Way is equivalent to circling the equator 200 times. This is our home; our town, our country, Earth, every planet we’ve ever seen all of them are there in this galaxy. But if we are being honest, it’s not really our home. Oh no, we’ve barely begun to talk about that…to be continued.
Over the past month or so the BBC has been running a primetime show called “Outcasts”. I heard about this some time ago becuse it was being billed as a great new BBC drama; that’s right, drama. In spite of the fact that the show is about colonists on a distant planet in the future who escaped the end of the Earth the BBC refused to call it Sci-Fi at first. Indeed the series designer is reported to have said:
the BBC doesn’t want to give the impression it’s putting out a sci-fi show on prime-time BBC1. This is a futuristic drama with the focus on pioneering humans who, out of necessity, just happen to be living on a planet that is not Earth.
I think it’s a bit of a stretch to set something in such a science-fictional setting but deny that it is one purely so that you can avoid being viewed as as a channel that puts out trivial TV. In actuality Outcasts manages to be trivial all by itself. If you haven’t seen it (don’t bother to now) the basic plot is that after some apocalypse a ragtag group of characters fly off into space and try to settle another planet. This is an interesting setup and it’s what got me to watch the show, however in spite of all the potential stories that could be told about the difficulties of such a task the BBC fills the show with ghost aliens, mysterious ten thousand year old human remains, evil genetically engineered rebels and horrifically clichéd characters. Now I’m not writing this post with the intent of writing a comprehensive review of Outcasts as it has been done elsewhere many times, instead I’d like to ask a question; why the hell do TV shows feel the need to make science fiction by dropping outdated clichés into a blender with awful actors before forcibly pouring it into our eyes with all the grace and subtly of a wet fart at a funeral? Outcasts is by no means alone in this, most visual media of this nature, be it film or TV, take a story that they want to tell (i.e. a unifying republic devoted to democracy being slowly corrupted into a totalitarian empire) and bolt on lasers, spaceships and aliens (can you spot where the example was from?).
If you wanted to write about colonising another planet then why not address the real issues of such a feat? Issues like how to grow terrestrial crops on an alien world, how to avoid alien antigens and the logistics of transporting a fully capable industrial society (with all the support infrastructure and technology needed) to another star, not to mention how the society would survive if the planet didn’t have the right atmosphere mix, pressure and temperature. I’m not calling for totally realistic stories but surely I’m not the only one who thinks that taking a story that could work perfectly well in the present day real-world and slapping on spaceships and aliens is a lazy means of story telling? Should’t the aim of any speculative fiction be to explore the human condition in situations radically different to those ever encountered before rather than vomiting canned plots onto the surface of an alien planet?