Friday, 31 May 2013

Petri's 161st Birthday!

Today is the 161st birthday of Julius Richard Petri, the German microbiologist who invented the Petri dish. As part of my History GCSE I am studying the History of Medicine, so I thought it appropriate to do a short blog post on him.

Petri,(May 31, 1852 – December 20, 1921) was a German microbiologist who is generally credited with inventing the Petri dish while working as an assistant to pioneering bacteriologist Robert Koch.

Petri studied medicine at the Kaiser Wilhelm Academy for Military Physicians and received his medical degree in 1876. He then worked and studied as a military physician until 1882, until he began working as an assistant to Robert Koch, the great microbiologist who first discovered the bacteria for anthrax in 1875, and many other bacteria in the following years.

Koch began to culture bacteria on agar plates on the advice on Angelina Hesse, which led to Petri then inventing the standard Petri dish, and improving the technique of agar culture to purify or clone bacteria. This invention made it possible, for the first time, to study colonies and identify the bacteria responsible for individual diseases.

Petri's contribution to science is undoubtedly incredibly significant and whilst the culture dish is named after him, Petri's work is often forgotten as people tend to focus on Koch. So, happy birthday Julius Richard Petri!

Tuesday, 28 May 2013

So why does the school year start in September?

As I near the end of my final year in senior school and prepare to enter sixth form, I have been thinking a lot about the school year and its layout. I began to research questions which I have always had but never had the chance to pursue, and this is what I found;

The school year in the United Kingdom is generally divided into three terms running from autumn to summer. For state schools, the school year consists of 195 days of which there are 190 teaching days and 5 inset (teacher training) days. For independent schools, the school year can be as short as 175 days. The structure of the school year varies between different areas of the UK and school holiday dates vary between different local education authorities.

The reason for the long summer holiday arose in the 19th century, before the mechanization of agriculture, and when most of the population were dependent on the land and lived in rural areas. Children were needed at home through the haymaking and wheat harvest season, around the start to the end of August, when every pair of hands counted. The education authorities finally gave up the losing battle to try and keep children in school during this time.

The academic year, centred around the long holiday in July and August (designed for pre-industrialised England) also has a Christmas and Easter break, for obvious religious reasons. The school year is made up of three terms which all have a half-term break in the middle of them to allow pupils and teachers a break.

The long summer holiday has often been criticised by educationalists who say that the long breaks delay academic progress. In 1999 the House of Commons Education Select Committee recommended that schools switch to a five-term academic year, abolishing the long summer holidays. Each term would be eight weeks long with a two-week break in between terms, and a minimum four-week summer holiday, with no half terms—the idea being that children can keep up momentum for eight weeks without a break. The proposals were introduced at a small number of schools nationally.

In 1999, the Local Government Association set up a commission to look at alternative proposals for a more balanced school year. In partnership with Local Authorities and teachers unions, they were unable to agree to a suitable alternative arrangement for terms, but by 2004 came to an agreement with the National Association of Schoolmasters Union of Women Teachers for a standardised arrangement of school terms. Since 2004, around one third of English local authorities have signed up to the proposals which see a standard academic year agreed between the authorities.

Sunday, 26 May 2013

The Baghdad Batteries

The Baghdad Batteries are a series of artefacts found in the area of Mesopotamia dating from the early centuries AD. When archaeologists stumbled upon the batteries, they assumed they were just regular clay pots for storage, but soon realised that was incorrect as each pot contained a copper rod that shows evidence of acid corrosion. This, theoretically means that these pots contained a liquid that interacted with the copper, produced an electrical charge, and therefore makes these the first batteries known to man. 
The problem is, what were the batteries used for? Some believe the batteries were used to power the "Dendera Light", an electrical arc of light. Others believe that they were used to electroplate items with gold, and some even say they were used medically to shock people. It remains a mystery; despite decades of experiments and discussion, no one is really sure what these pots were used for. 
I have found a great article if you are interested in reading into this some more: http://news.bbc.co.uk/1/hi/sci/tech/2804257.stm

Friday, 24 May 2013

The Turk

Whilst watching a recent episode of Doctor Who I was reminded of The Turk. The Turk (or Mechanical Turk) was a fake chess-playing machine first constructed in Vienna in 1770, to impress the Empress Maria Theresa of Austria.

The presenter, Wolfgang von Kempelen, and later Johann Maelzel when he purchased the machine in 1804, would assemble a paying audience, open the doors of the lower cabinet and show an impressively whirring clockwork mechanism that filled the inner compartments beneath the seated figure. Then he would close the cabinet, and invite a challenger to play chess.

The thing was a sensation.

Before it was destroyed by fire in New York in the 1850s, it played games with everyone from Benjamin Franklin to Napoleon Bonaparte. In the 84 years the Turk was in use, it was almost unbeatable. The operator during Kemplen's original tour remains a mystery, but when exhibited by Malzel, the machine was operated by ordinary chess players.

The public at the time truly believed artificial intelligence had arrived on earth. The Turk was, of course, a fraud. It was a clever magician's illusion, with a sliding sled that fitted inside the lower cabinet and allowed the hidden chess player to slide easily, and most importantly, silently into the machine's lower compartments. The cabinet actually had a lot more free space then the clockwork machinery suggested.

The interior of the machine was very complicated and designed to mislead those who observed it. The design allowed the presenter of the machine to open every available door to the public, to maintain the illusion. The operator actually sat on a sliding seat and moved through the machine as the operator opened and closed each door, thus evading observation.

The chessboard on the top of the cabinet was thin enough to allow for a magnetic linkage. Each piece in the chess set had a small, strong magnet attached to its base, and when they were placed on the board the pieces would attract a magnet attached to a string under their specific places on the board. This allowed the director inside the machine to see which pieces moved where on the chess board. The internal magnets were positioned in a way that outside magnetic forces did not influence them, and Kempelen would often allow a large magnet to sit at the side of the board in an attempt to show that the machine was not influenced by magnetism.

An operator inside the machine also had tools to assist in communicating with the presenter outside. Two brass discs equipped with numbers were positioned opposite each other on the inside and outside of the cabinet. A rod could rotate the discs to the desired number, which acted as a code between the two.

Another part of the machine's exhibition was the completion of the knight's tour, a famed chess puzzle. The puzzle requires the player to move a knight around a chessboard, touching each square once along the way. While most experienced chess players of the time still struggled with the puzzle, the Turk was capable of completing the tour without any difficulty from any starting point on the chessboard.

I find the Turk fascinating for several reasons. Firstly, it displays an odd, haunting hole in human reasoning. Common sense should have told the people who watched and challenged it that for the Turk to have really been a chess-playing machine, it would have had to have been the latest in a long sequence of such machines. For there to be a mechanical Turk who played chess, there should have been several generations of more basic chess-playing machines.

It's true that the late 18th Century was a great age of robots, machines that could make programmed tapestries and mechanical birds that could sing. In large part, I think people were fooled because they were looking, as we always seem to do, for the beautiful and elegant solution to a problem, even when the cynical and ugly one is right.

What also interests me is that it turns out that the chess players who operated the Turk from inside were just chess players, an ever-changing sequence of strong but not star players, who needed the work badly enough to be willing to spend a week or a month inside its smoky innards. Maelzel picked up chess players on the run, wherever he happened to be.

The Turk is a fantastic piece of machinery that fooled thousands during the 1800s, and whilst nowadays we have computer chess players and robots who can play chess, I think the Turk stands out for its ingenious design at the time.

Saturday, 4 May 2013

May Day (Happy May!)

True to History Girl style, as it is now May I thought I ought to do a May related blog, and what better May related blog could there be then a post about the history of May Day?!

In medieval times May Day was celebrated by an annual dance around the maypole - a specially decorated tree. The branches of the tree were cut off and coloured ribbons tied to the top, which the villagers would hold on to as they danced around the tree. The tradition is still very much alive today in many villages across Britain. May Day also included a procession led by the May Queen, often a young girl who was voted into the position alongside a boy for May King. They would dress in green to symbolise springtime and fertility.

In Germany, tradition has it that young bachelors would cut down a fir tree on the eve of May Day, remove the branches, decorate it and then set it up in the village square. The tree had to be guarded all night to prevent it being stolen by neighbouring villages, however trees were often stolen and sold for a meal and a barrel of beer. 

May Day may have possibly originated from Floralia, an end-of-April festival in ancient Rome, where offerings were given to the flower goddess Flora, which followed by more offerings on the 1st May, instead to the goddess Maia, after whom the month May is named. Pagan groups used to call the festival of fertility by it's Celtic name, Beltane.

The Protestant Reformation in the 1600s put an end to all May Day celebrations. The Puritans were horrified at the drinking and dancing that took place, and in 1644 maypoles were banned by Parliament. However, when Charles II was restored to the throne years later, people all over the country celebrated by putting up maypoles as a symbol of loyalty to the crown. In the 19th century the Victorians turned May Day into a children's game of dancing around the maypole, and the pagan aspects of the day were forgotten.

Nowadays people often 'bring in May' by getting up early, gathering flowers, making them into garlands and giving them to their friends. Often people create 'May baskets' for people in need of cheering up.

I hope you all have a lovely weekend and enjoy the warm weather!