Tuesday, 14 December 2010

Uni essay: Bacon

Yaaaay, I wroted an essay for the 'History of the Philosophy of Science' module at uni.  2,000 words, on a given topic.  The lecturer seemed to like it!

Why is Sir Francis Bacon a candidate for the title “Founder of Modern Science"?
Sir Francis Bacon, lawyer, essayist, politician and philosopher, produced a number of philosophical works promoting science and laying out a logical system for its pursuit. His rhetorical voice and reforming zeal helped precipitate modern science from the technological advances of the time. He wished to reform systems of thought such that readers might see beyond the received wisdom of scripture and Aristotelian teachings and so bring practical benefits to humanity.
Born in 1561 to Sir Nicholas Bacon (Keeper of the Seal) and Lady Anne Coke Bacon (the learned daughter of a leading humanist), Francis Bacon was educated after the fashion of the time, in the scholastic tradition. Through Latin he was taught logic, natural philosophy, medicine, law and theology. The uniting theme in all these areas was the systems and traditions of Aristotelian thought.
Aristotle (384-322 BC) wrote on an incredibly broad range of topics, from logic to poetry, rhetoric to zoology, music to ethics. Of particular interest to this discussion are his methods of constructing systems of knowledge.
Fundamental to Aristotelian thought is the idea that our minds are blank slates, and that impressions derived from the evidence of our senses are a true representation of the world. From observations general rules are drawn, then by deduction working back from these general rules, axioms are created. The test of their truth is whether they can be supported in debate, and whether they satisfy someone's imaginative preconceptions, rather than if they are able, as Bacon put it, to "direct him and give him light to new experiences and inventions" [Bacon,1887:232]. Crowley [1668] describes how these "...pleasant Labyrinths of ever-fresh Discourse" created a system of beautiful idealisations, perfect circles and straight lines, "Pageants of the Brain".
The methods of deduction propounded by Aristotle did not include an external method of refutation, but are defended by "refutation of refutations" [Russell, 1946:195]. Instances which do not fit the axioms drawn from the general rules are classed as aberrations or 'monsters'. Aristotle's position near the end of the golden period of early Greek philosophy left him a largely unchallenged position, and Russell [1946:157] asserts that "after his death, it was two thousand years before the world produced any philosopher who could be regarded as approximately his equal".
At the time of Bacon, Aristotelian thought still dominated the structure of scientific and philosophical endeavour, with the ancient Greek's authority almost as unquestioned as that of the church, which itself exercised considerable control over the circulation of ideas. Bacon saw this uncritical acceptance as a huge obstacle to progress, and much of his writing directly criticises Aristotle's ideas. Huge strides in technology and instrumentation were sadly unmatched in philosophy, which could be said to be stultifyingly dogmatic. Publications were subject to inquisition and authors faced censure if considered heretical.
In spite of this oppressive atmosphere, developments such as the compound microscope and telescope enabled unprecedented examination of the natural world, and provided an increasing accumulation of 'monsters' which weighed heavily against received doctrines and centuries of inertia.
A profound example of the assault on Aristotelian and scriptural ideas, as well as a critical turning point in our perceptions of the universe can be seen in the notion of a heliocentric universe.
A mathematician and clergyman, Copernicus (1473-1543) formulated the theory that the Earth both rotated and revolved relatively early in his life, but was not able to give any conclusive evidence. Being a profoundly pious man, he delayed publication of his theory until the year of his death for fear of censure. [Russell, 1946:485] Kepler (1571-1630) made close observation of the planets and identified their orbits as elliptical - anathema to traditional notions of heavenly bodies describing perfect circles.
Along with Kepler, Galileo (1564-1642) ardently championed Copernicus' theory. His developments in telescope manufacture allowed him to make corroborating observations, such as identifying moons in orbit about Jupiter, and the phases of Venus. However, we must recall that these observers themselves cannot be considered free of misconceptions and cognitive bias. Galileo struggled to reconcile the hypothesis of the revolution and rotation of the Earth with the absence of its of observable, mechanical effects. He attempted to wring an explanation of the tides from his incomplete picture of mechanics, invoking fascinating arguments which he himself would not have accepted had they come from an outside source. [Einstein, 1967]
He was famously condemned by the Inquisition for heresy, though Gerard [1913] presents a different slant on the story, asserting that the Catholic Church's condemnation of Galileo was not due to his profession of heliocentrism, but rather to his promotion of it in opposition to scripture. He states that that they were "convinced... that the new teaching was radically false and unscientific... Galileo himself had no sufficient proof of what he so vehemently advocated", providing an example of the Church as arbiters of knowledge at the time.
While his contemporaries attempted to throw off the restrictions of classical thought by presenting hypotheses supported by evidence, Bacon sought to change the world by proposing a new philosophy.
His prolific essay-writing dealt with the subject throughout his life, and from a young age he expressed his dissatisfaction with traditional modes of thought and laid out a grand plan of reform.
Following his education at Cambridge and Gray's Inn, Bacon travelled around Europe and returned inspired by the state of scientific investigation. However, financial circumstances drove him to practice law and seek political office. A member of parliament for 37 years, he shrewdly managed to survive a change of monarch and thrived, becoming Lord Chancellor and having the ear of the King. Eventually driven out of political life by scandal and plot, Bacon devoted the last 5 years of his life to writing. While during his lifetime he was known as a legal theorist, rationalist and systematiser, it is this work on the philosophy of science that he is now remembered for most. Although when he died he had completed only a fraction of his hugely ambitious plans, the completed volumes on his research strategy have had considerable impact.
Bacon proposed the creation of a general theory of science, that could be applied over all branches of knowledge and would allow practitioners to progress beyond what was possible using traditional methods.
Fundamental to his approach is the idea that the human mind, rather than a blank slate receiving the evidence of our senses, is an imperfect mirror that reflects an imperfect image of reality. He identifies sources of misconception, 'idols' of the mind: innate human failings, closely-held doctrines, imperfect language and received philosophical systems [Klein, 2009]. Critically, this final idol highlights that what has gone before not only can but must be challenged before useful work can be done. Bacon entitled his work on research methodology Novum Organum, setting it up in direct opposition to Aristotle's Organum, or 'system of knowing'. This conceptual shift towards identifying and battling subjectivity is central to the pursuit of modern science.
Bacon proposes that once influences on the mind have been isolated, the natural philosopher should approach observation with an open mind, in an empirical fashion: gathering knowledge on the topic of interest without any prejudicial notions of what the outcome might be. From these data axioms are constructed by induction, each one thoroughly tested by observation, which gradually build upon each other in a pyramid of knowledge culminating in general laws.
We see Bacon's rhetorical style in his comparison between traditional philosophers as spiders, spinning webs of thought from their own bodies, and empirical investigators as bees, gathering information and building it up via their methods of reasoning into nutritive knowledge.
Bacon directs that tables of instances of the phenomenon under investigation should be drawn up, that agreements, differences and variations be identified, which will direct the investigator toward axiomatic truths. This is a hugely impractical and labour-intensive operation, and in fact modern scientific methods rely more on the hypothetico-deductive method, where the power of intuition and creativity is utilised in proposing a solution, which is formalised, and then investigated with the aim of corroborate or falsifying the theory. While few if any researchers have directly used the purely inductive method (Pomphrey, 2009), the beauty of these notions is that they can be challenged, that they set up a different starting point from which better methods can be developed.
While a man of faith, Bacon developed upon St. Tomas Aquina's 13th Century ideas separating articles of faith from knowledge gleaned by reason. He proposed a collective institution for the investigation of the natural world, funded by the state and completely independent of the Church. Named "Solomon's House", or alternatively the "College of the Six Days Works", it sought "the knowledge of causes, and secret motions of things; and the enlarging of the bounds of human empire, to the effecting of all things possible". [Bacon, 1623] With a hierarchical structure divided into teams for particular spheres of investigation, it has its echoes in the modern conception of a research university. While Hegel criticises Bacon as a low-minded philosopher for civil servants and shopkeepers [Simpson, 2005], his emphasis on worldly and practical outcomes of science seems to to be a key part of what made his ideas so successful.
Bacon's familiarity with techniques of rhetoric, debate, persuasion and law are evident in his writing. While it bears testament to his flair that some of Shakespeare's works have been arguably attributed to him, his focus was not on literary merit. Pitching his writing at political decision-makers of the time, Bacon aimed to mould their agendas and guide their policies. [Simpson, 2005] He appealed directly to their patronage, painting pictures of the benefits his new philosophy could offer. His rhetorical prowess also meant that his ideas could be transmitted directly, without need for generations of scholars to digest his work and distil its merit.
Shortly after his death, we can see Bacon's ideal of Solomon's House being attempted in earnest. A circle of eminent thinkers (John Wilkins, Jonathan Goddard, Robert Hooke, Christopher Wren, William Petty, Robert Boyle et al.) formed the "Invisible College" out-with the existing university structure, meeting weekly to perform and discuss experiments investigating the natural world. After the reformation, the college was reformed and obtained a royal charter, becoming the Royal Society of London in 1660. Later chaired by Newton, the Society lauded Bacon as its inspiration.
Members of the Royal Society considered him a "daring originator of a new intellectual era" [Simpson, 2005], and their attitude is succinctly expressed by Adrian Cowley in his poem To the Royal Society [1668]:

"Bacon at last, a mighty Man, arose
Whom a wise King and Nature chose
Lord Chancellor of both their Lawes...
"The barren Wilderness he past,
Did on the very Border stand
Of the great promis’d Land,
And from the Mountains Top of his Exalted Wit,
Saw it himself and shew’d us it... "

Cowley paints Bacon as a visionary reformer, transmitting to contemporaries and followers the future of natural enquiry, the “promis'd Land" that only he had the capacity to see. Perhaps he might be considered more as a vocaliser and systematiser of what was happening in the world in his time, but either way his ideas were influential, despite their incompleteness. While his methods might have been imperfect (such as the exclusion of hypothesis from his inductive method), his separation of philosophy from theology and emphasis on observation with an open, unencumbered mind form the basis of the ideals of science as it is practised today.

Bacon, F., The Works, Volume III, Spedding, J. et al. (ed), (London, 1887)
Bacon, F., New Atlantis, (London, Rowley, 1623) E-book: (US, Project Gutenberg, 2001), Accessed 1 November 2010, URL: http://www.gutenberg.org/files/2434/2434-h/2434-h.htm
Cowley, A, “To the Royal Society", Works, (London, 1668)
Einstein, A., “Foreword", Dialogue Concerning the Two Chief World Systems—Ptolemaic & Copernican, Galilei, G., (USA, University of California Press, 2nd ed., 1967)
Gerard, J., “Galileo Galilei", Catholic Encyclopedia, Herbermann, C.G. (ed), (USA, Robert Appleton Company, 1913)
Klein, J., “Francis Bacon", The Stanford Encyclopedia of Philosophy (Spring 2009 Edition), Zalta, E.N. (ed.), URL = http://plato.stanford.edu/archives/spr2009/entries/francis-bacon
Pumfrey, S., (contributor), “Sir Francis Bacon", In Our Time, BBC Radio 4, 2 April 2009
Russell, B., History of Western Philosophy, (London: George Allen & Unwin Ltd, 1946)
Simpson, D., “Francis Bacon", Internet Encyclopedia of Philosophy, Fieser, J. and Dowden, B., (http://www.iep.utm.edu, 2005), Accessed 5 November 2010, URL: http://www.iep.utm.edu/bacon/

Wednesday, 8 September 2010

If I had eyes that could see...

I was just sent this beautiful image, used to illustrate a piece on BBC News on spiral galaxies.  I had a look on the source website, and they have the original image in all its hugeness (and convenient wallpaper sizes) available to download.

I don't think I really need to say anything more about it than please, go and look.  Our galaxy is a beautiful place.

The Milky Way (seen here from the Paranal observatory in Chile) courtesy of ESO

Tuesday, 7 September 2010

A quasi-political Explanation of the Higgs Boson

This explanation of the Higgs mechanism and boson theories was written by David J Miller (then of UCL) to enlighten the UK science minister Mr Waldegrave in 1993.  This has been something that's bugged me I've not got around to finding out about, and I find the analogy very elegant...
1. The Higgs Mechanism
Imagine a cocktail party of political party workers who are uniformly distributed across the floor, all talking to their nearest neighbours. The ex-Prime- Minister enters and crosses the room. All of the workers in her neighbourhood are strongly attracted to her and cluster round her. As she moves she attracts the people she comes close to, while the ones she has left return to their even spacing. Because of the knot of people always clustered around her she acquires a greater mass than normal, that is, she has more momentum for the same speed of movement across the room. Once moving she is harder to stop, and once stopped she is harder to get moving again because the clustering process has to be restarted.
In three dimensions, and with the complications of relativity, this is the Higgs mechanism. In order to give particles mass, a background field is invented which becomes locally distorted whenever a particle moves through it. The distortion - the clustering of the field around the particle - generates the particle's mass. The idea comes directly from the Physics of Solids. Instead of a field spread throughout all space a solid contains a lattice of positively charged crystal atoms. When an electron moves through the lattice the atoms are attracted to it, causing the electron's effective mass to be as much as 40 times bigger than the mass of a free electron. The postulated Higgs field in the vacuum is a sort of hypothetical lattice which fills our Universe. We need it because otherwise we cannot explain why the Z and W particles which carry the Weak Interactions are so heavy while the photon which carries Electromagnetic forces is massless.
2. The Higgs Boson.
Now consider a rumour passing through our room full of uniformly spread political workers. Those near the door hear of it first and cluster together to get the details, then they turn and move closer to their next neighbours who want to know about it too.  A wave of clustering passes through the room. It may spread out to all the corners, or it may form a compact bunch which carries the news along a line of workers from the door to some dignitary at the other side of the room.
Since the information is carried by clusters of people, and since it was clustering which gave extra mass to the ex-Prime Minister, then the rumour-carrying clusters also have mass. The Higgs boson is predicted to be just such a clustering in the Higgs field. We will find it much easier to believe that the field exists, and that the mechanism for giving other particles mass is true, if we actually see the Higgs particle itself. Again, there are analogies in the Physics of Solids. A crystal lattice can carry waves of clustering without needing an electron to move and attract the atoms. These waves can behave as if they are particles. They are called phonons, and they too are bosons. There could be a Higgs mechanism, and a Higgs field throughout our Universe, without there being a Higgs boson. The next generation of colliders will sort this out.

from David J. Miller, Physics and Astronomy, University College London.
(cartoons courtesy of CERN).

Tuesday, 30 March 2010

LHC cam

Just one more post.  Then I go nurse my head:


LHC Hooray

The beams are up to power, they're aligned together, waiting for them to become stable...

It's astonishing that the two beams of protons were separated by only 3mm around the 27km ring, before they reached 3.5TeV each and were brought together in grand 7TeV collisions.

Now there are collisions but the experiments aren't switched on and the beams aren't stable.  They're waiting until everything's perfectly aligned and stable before they insert protective collimators (in case something goes astray) and open the delicate detectors.

Collimators in, beams tidied, and now they're happy with the beam conditions they're going to declare it 'stable' and not touch any of the beam controls for as long as they can - they estimate 2 hours

Collisions!  Data!  Jubilation! 

The data already being recieved are being described as 'beautiful' - I can't wait to see more, and perhaps to learn how to 'read' the image records.  The webcast has included live collision record images from the ATLAS experiment, which I'll admit are pretty snazzy looking. 

It's wonderful to see and hear the celebration and enthusiasm of such an incredible communal endeavour coming together. 

Unfortunately my head hurts too much now so I'm going to have to stop writing and just listen to the 'cast.  More later!

LHC Restart - live webcast

I wonder just how many people across the world are watching this feed with me:

There have been a couple of glitches in the cooling and monitoring systems, but nothing catastrophic so far, and the system is now being brought up to speed again.  While everyone is waiting for the beams to reach the required energies again, some talking heads are discussing what the LHC is looking for and how.  It's fun spotting people I've dealt with through my work:  Ooh, they're on the editorial board, ooh, that was that nice guy who published with us last year!

It's so exciting.  I just wish I wasn't the only physics-educated geek in a building full of biologists and medics...  Oh, and that I had some popcorn.

Edit:  Great, now I have my second only ever migrane precursor sparkly vision artifacts.  They're very pretty, but they're interfering with my webcast watching, damnit!

Monday, 15 March 2010

Be still my nerdy heart: LHC pop-up book

 Atlas detector - complete it yourself, but try and take less than 25 years...

As a massive physics and papercraft geek, this announcement had me swooning: an LHC pop-up book.  Entitled Voyage to the Heart of Matter: The ATLAS Experiment at CERN, it explores through paper engineering the motivation, construction and operation of part of the world's biggest experiment.

Not just mega-science, but mega-engineering

To quote the press release,
"In this unique collaboration between ATLAS and renowned paper engineer Anton Radevsky, 7000 tonnes of metal, glass, plastic, cables and computer chips leap from the page in miniature pop-up, to tell the story of CERN’s quest to understand the birth of the universe."
I'm really excited by the immediacy and spatial understanding that comes from the use of physical models to represent concepts, and a pop-up book is a fantastically portable way of bringing to the grubby paws of the masses.
 The book goes back to the big bang to explain the experiment's motivations
I've always adored pop-up books.  Needless to say, I'm drooling over this one.

Sold out at the publisher here, but in stock with Amazon here.

Exploring digital worlds

I just read another interesting post over on Cocktail Party Physics, this time talking about MMORPGs (Massive Multiplayer Online Role-Playing Games) such as World of Warcraft as models for human behaviour in the face of epidemic or economic crises.  Knowing several WoW-heads myself, I find the headspace it occupies interesting, including its carefully engineered addictiveness. 

However, what buzzed me was the mention of educational games.  I recall playing a few when I was younger, including the non-taxing (piloting a dolphin around an underwater reef, solving simple sums before it ran out of air), the entertaining but limited (completing equations to zap alien rubbish, avoid asteroids and navigate space stations), and the wickedly catchy (a kiddie's colour, number, and shape recognition complete with insidous earworms, with my little brother you understand).  I even wrote a tiny  times-table practice tool in True Basic.

Though not really targeted as a game, I can't recommend highly enough the magnificent Mavis Beacon Teaches Typing.  Perhaps you've got to be a special kind of nerd to enjoy racing cars by typing quickly and accurately, but it was better than school typing lessons.  Accuracy at over >70wpm is an indispensable skill - I can actually type faster than write, with the added advantage of legibility!  I just wish my brother had played it too, perhaps I'd be able to talk to him online without wincing.

The increasing use of physics simulations (crayon physics, little big planet and the rest) is fantastically exciting, especially when experiments are increasingly restricted in schools, but as mentioned in the Cocktail Physics article the use of online community-building techniques and mobile technology could lead to a new generation of engaging science games.  As a case in point, Whyville looks very cool - I love the sound of kids actually investigating an infection of "Whypox" themselves. 

One of our journals recently published a piece on the use of Second Life as a visualisation, research and educational tool.  According to the reviewer reports its contribution to science was slightly debatable, but it's certainly an interesting conceit.  Alas, not having played with any such online worlds I can't really conjecture on its effectiveness or how it might be improved. 

Still, I really hope a game developer mashes all these ideas together and runs with them, creating a freely roamable world complete with intriguing tableau, enlightening encounters and a culture of exploration and learning. With an element of user-contributed content and community building, just think of what would be available to someone with an internet connection - a world of information not just presented in bite-sized chunks, but integrated into an engaging framework that rewards curiosity and reinforces enquiring habits.  It's so much more satisfying to find things out for yourself!

Tuesday, 16 February 2010

Twice crowned in fire

 Gorgeous visible and ultraviolet composite of Saturn and its aurora from Spacetelescope.org
I've just been admiring the luscious production values of NASA's Hubblecast, as superbly displayed by their most recent video which looks at the aurorae of Saturn.  Formed in the same way as Earth's Northern and Southern lights, the aurorae of Saturn circle both poles of the planet and rise more than a thousand miles above the cloud tops. 

Hubble image of Saturn showing both poles with aurorae, and the planet's rings edge-on, from Spacetelescope.org

The gas giant recently moved into a position where the light shows of both poles are visible simultaneously.  Fortuitously, this coincides with the planet's equinox, allowing scientists to make a direct comparison between the two displays, as the two poles are recieving an equal influx of charged particles from the sun.  Interestingly this has shown up a subtle difference in activity, which implies that the magnetic field of the planet is not evenly distributed.  I'm intrigued to find out where this goes with further observation. 

In the meantime, the beautiful video of fluttering, coruscating curtains of light encircling the planet's poles has really inspired me to create some jewellery - I'll share if it works!

Monday, 8 February 2010

Submarines to sprogs

Dr Mark Lythgoe gave me another generous helping of food for thought the other morning, with episode three of his Images That Changed the World series, considering the foetal ultrasound scan.


Ultrasound imaging (also known as sonography) is an incredible tool for safe and non-invasive investigation of the soft tissues of the body. It can reveal the presence of an embryo at a very early stage in development, as well as show the foetus in sufficient detail not only to let its digits be counted, but to look further inside and resolve abnormalities in the internal organs.  Dr Joseph Woo has put together a fantastic site on the usage and history of ultrasound in obstetrics, including an amazing gallery of images.

Twin pregnancy at 10 weeks from Obstetric Ultrasound - A Comprehensive guide
Ultrasound images are such a routine part of obstetrics now that it's hard to imagine a time without them. Historically, however, the 9 month journey from bundle of cells to wriggling sprog was shrouded in mystery, punctuated by unseen movement and illustrated only by the unsettling sight of cold, grotesque pickled embryos and foetuses in jars. The programme explored the impact on parents of having even a scruffy little black and white outline of their offspring-in-progress, but what caught my ear was the history of the development of ultrasound imaging technology.

Towards the end of the 18th Century, Italian experimental biologist Lazzaro Spallanzani concluded that the uncanny ability of bats to orient themselves without the use of sight is related to their hearing. 140 years later Donald Griffin recorded their inaudible cries using the first ultrasound microphone and completed the picture. Bats emit sharp sounds above the range of human hearing ('ultrasound' begins just beyond what we can hear, about 20 kilohertz), and listen for the echoes, using the timing and volume of the echo to guage the distance and nature of obstacles and prey. The resolution of echolocation is dependent on the frequency of the sound used, so the extremely high-pitched squeaks of bats allows them to detect tiny prey insects on the wing. I found a great page from the Western Ecological Research Center, with modified recordings of the sounds various species of bat use to investigate their surroundings – there's even one which is low enough for humans to hear without modification.

Bat in flight by Arnold Song at Brown University, who was researching the aerodynamics of their flight

Other species also use echolocation, from cave-dwelling swiftlets to the tiny shrew, but perhaps the most well-known are the toothed whales, including dolphins. Greater sound transmission in the liquid medium apparently allows a dolphin to resolve a golfball a football field away, but that's far too sporting a measure for me. Let's just say that it beats a bat's ~17 meter range.

It wasn't until the Titanic was rusting on the sea bed, however, that humans really took up the act.  In 1913 Alexander Behm patented the echo sounder, a device intended to prevent future disasters by detecing icebergs.  It proved much more effective at locating the sea-bed though, and has been a huge aid to shipping since.

During WWI the threat of enemy submarines drove further research into the potential of echoes, culminating in the invention of ASDIC (later renamed 'SONAR' by the Americans), the piercing 'ping' of which is a familiar staple of tense, dank aquatic thrillers. Reflected sound was also used to detect far smaller dangers, when engineers used ultrasound to examine the internal structures of aircraft wings for stress-induced cracks.

Submarine Sonar Operator's Manual - a fantastic piece of online archive material, training operators of the US's state-of-the-art sonar equiment at the end of WWII - from the Maritime Park Association

In the wake of WWII, obstetrician Professor Ian Donald returned home and began to wonder about the application of this technology to his own profession.  Armed with an ultrasound transducer, he began experimenting on tumours and cysts removed from patients, to see whether they could be differentiated from other tissues, such as muscles (represented by slices of beef). In 1958 he published his work, and so began the application of ultrasound imaging to medicine.

While it has used the same basic principle of reflected sound waves for the past 50-odd years, sonography has evolved into a vital medical tool.  Imaging resolution has improved hugely, structures can be viewed in realtime (cue videos of waving foetal hands and wrinkling noses) and shown 3D rather than cross-section.  Ultrasound can even reveal blood flow in the arteries by analysing the doppler shift of the echoes.  It can also be used in more active ways, such as in controlled powerful bursts to break up kidney stones into easily passed fragments. 

From submarines in the watery deeps to foetuses immersed in amniotic fluid - not a bad bit of lateral thinking, and one that has had a huge impact on medicine and pregnancy.

Monday, 1 February 2010

The Death Inside

This morning I've been listening to yet another fascinating piece of radio from the BBC.  Images That Changed The World is a series of 15 minute programmes presented by Dr Mark Lythgoe examining the history of medical imaging, and how five leaps in imaging technology impacted popular culture at the time.

The first X-ray image of the hand of Röntgen's wife (who exclaimed something along the lines of "It's like seeing the death inside me"), taken from the mesmerising Dream Anatomy gallery at the NIH's NLM

When in 1896 Wilhelm Conrad Röntgen presented his discovery of X-rays, the ghostly depiction of his wife's hand which illustrated the work took only days to reach newspaper and magazine covers around the world.  Never before had the deep, delicate structures within the body been seen in their living context, and the new technology went straight to the public's imagination. X-ray machines were installed in big department stores and fairgrounds, and the public flocked to have their pictures taken.  There were even fads for X-ray family portraits, and the possibility of buying lead-lined underwear to protect a lady's modesty.

Coin operated X-ray machine c1900, taken from A Short History of Amusement Arcades

An anecdotal tale of a woman's diamond engagement ring being revealed as a fake or 'paste' gem led me off at slight tangent.  I've heard the term before many times in venerable works of detective fiction, but the word 'paste' did not call to mind anything you could mistake for the sparkle of finest emeralds.  It turns out that 'paste' gems are a form of heavy glass with a high refractive index, which when cut well can imitate gemstones.  'Paste' refers to the method of manufacture: powdered silica, soda and lead or other metal oxides are combined with water to ensure even mixing, before being heated in a kiln until fused.  [This page on gem creation is a good read if you have any interest in jewellery and gemology.] A more common name for a paste gem which you might recognise is 'rhinestone', widely used in costume jewellery.

 Radiograph of a diamond ring from Myth busting – in the world of x-rays

Being amorphous, fused glasses rather than single, grown crystals of gemstone, paste gems have subtly different optical properties, meaning that the expert can distinguish them just by looking (an important plot point!).  Even an untrained eye, however, can spot when the diamond they expect to appear as a faint smudge appears completely opaque in an X-Ray image - hence the woman's outrage at the X-ray image's revelation. 


Within a year of the announcement of Röntgen's announcement reaching Britain, school student Russell Reynolds completed the building of his own X-ray apparatus.  Home machines like these became widespread, with enthusiastic amateurs able to bring cutting-edge scientific equipment to their parlours.  Experiencing the glee of examining everything within reach with a microscope makes it easy to imagine excited Victorians X-raying hands, feet, cats, frogs, and indeed anything that they could get their hands on.

Unfortunately however this orgy of discovery came at a price - the following years revealed the dangers of overexposure to the ionising radiation - burns, ulcers, cancers and amputations.  The grisly vignette of a conference of radiologists unable to cut up their food due to the loss of one or both hands puts a chilling dampener on the joy of discovery.

X-ray images revolutionised medicine by enabling the harder structures within the body to be viewed non-intrusively for the first time, revealing everything from broken bones to tuberculosis.  Understandably, the X-ray machine above has been selected by curators at the Science Museum in London as the item in its collection that had made the biggest impact on human history. 

Nowadays X-ray images of the human body are familiar, but along with less familiar portraits of plants, animals and everyday objects the can be fascinating and beautiful, as well as instructive.  I highly recommend you check out the incredible work of Albert Koetsier and Nick Veasey, but be warned you may be there some time.

Tuesday, 12 January 2010

Let's have a little atmosphere

A friend linked me to a visually interesting news snippet on the BBC, featuring striking images of drifting and persisting aircraft contrails, adding to cloud cover eastward of the coast of the UK:

Unfortunately, one of the things about the BBC news website is that really bugs me is the complete absence of onwards links or information.  In this case it wasn't too hard to find the right paper, but I'm more used to reading articles which anchor a web of information leading to as much detail as you could wish for, and again and again with the BBC news site I find myself rather uncomfortably brought short.

Getting back to the research, 
"A single aircraft operating in conditions favorable for persistent contrail formation appears to exert a contrail-induced radiative forcing some 5000 times greater (in W m−2 km−1) than recent estimates of the average persistent contrail radiative forcing from the entire civil aviation fleet." Abstract of paper

While I don't particularly feel like dissecting this and other effects of high-altitude flights right now, the piece put me in mind of an interesting article I read the other day over on Cocktail Party Physics, on the effects of space shuttle exhaust on ionisation of the atmosphere, an in turn on radio communications.

It's another example of the fine work done by the blog's contributors, starting from an anecdote, exploring around the topic, explaining the science clearly and bringing it all together in a memorable way, without skimping on detail.  I love their work, which always offers you an entertaining read while casually filling your brain the kind of quirky knowledge that might come in handy at cocktail parties. 

I highly recommend you go and explore the archives (who doesn't love a science blog that has a 'zombies' category?) where you'll certainly find something interesting to while your time away, or subscribe to it and just wait for the posts to roll in.

Friday, 8 January 2010

A Wondering Manifesto

I have a tendency to wonder.  Having taken a degree in Physics in the hopes that this would somehow help, I have a certain way of thinking about things and a brain-sponge full of abstract knowledge.  When I wonder, I can often form a reasonable explanation from knowledge I already have, but don't have sufficient detail to make it rock-solid and fully sate my curiosity.  I'm embarking on this blog as an organised way of discovering and conveying interesting facts, and hopefully honing my communication skills and writing confidence along the way. 

I hope to explore things both from the research edge and from the everyday, hoovering up knowledge and spinning it into interesting, digestible, pleasing prose, perhaps with a few diagrams in there for flavour.  As a creative nut I've adopted "Get excited and make things" as a personal motto, but perhaps in this endeavour I should aim to "Get excited and discover things".  I hope I can bring you along with me.