"About 2,200 years ago an unknown genius in ancient Greece built a mechanical computer" - Guest Blog by John Faulkner

 About 2,200 years ago an unknown genius in ancient Greece built a mechanical computer. It calculated and displayed astronomical events. The device had a level of engineering skill 1,500 years ahead of its time.

In 1900 Greek sponge divers, blown off course by a storm, took their chances in deep water. They were off the island of Antekythera and instead found a Roman shipwreck from 85BC, loaded with Greek artefacts. The haul contained curious wood and bronze fragments. About the size of a roof tile, the largest piece had gear wheels visible. Archaeologists were baffled but with modern scanning techniques and rigorous science, over a period of about 60 years of painstaking work, the puzzle has been solved.

The Antekythera Mechanism Research Project, set up by Cardiff University in 2000, used CT scans (microfocus X Ray Computer Tomography) to produce 3D structural images and advanced photography (polynomial texture mapping) to search for markings. This  revealed hidden gears, lines, text and markings on the fragments. They confirmed the ancient Greeks had arranged precision gears so accurately the device could model the motion of astronomical objects far into the future. It was operated by handle and individual pointers on the front face, driven by 30 intermeshed gears, indicated the astronomical position of the sun, moon and planets. On the rear face is the ancient Greek calendar with pointers to predict lunar eclipses, solar eclipses and the Olympic games dates between their four games venues.

To predict lunar position and phase is very complicated.  The moon shifts position, speed and angle on it's elliptical orbit of the earth. Also a year is 365.25 days so to make any daily calendar work regular corrections are needed. This complexity means a complete lunar cycle, where the moon ends up at the same phase and position in the sky, takes about 19 years. This is called the Metatonic cycle. However an even more accurate 76 year cycle, discovered and used by the Greeks, called the Callipic cycle confirms an astonishing level of technical and scientific skill. 

Thought to be invented in the middle ages the mechanism had differential (variable speed) gears yet the calendar start date was 205BC.

The first scientist to reconstruct a machine  is Dr Michael Wright previously of the Science Museum  here are the workings of his model: https://m.youtube.com/watch?v=MqhuAnySPZ0

The maker is unknown but are there clues? There are several philosophers possibly involved and such a complex device would have evolved over time. Archimedes (287 - 212BC) as an engineer used gears and the astronomy is based on theories of Hipparchus(190 - 120BC). An intriguing clue about a mechanism can be found in a surviving letter. Hipparchus is thought to have founded a school on Rhodes. One of his students Posidonius, who knew the Roman diarist Cicaro, later ran the school. In 79BC, Cicero mentions, in one of his letters a device “recently constructed by our friend Posidonius, which at each revolution reproduces the same motions of the sun, the moon, and the five planets that take place in the heavens every day and night.”

The Antekythera Mechanism was lost for 2000 years. Bronze was very valuable to the Roman military and melted much down, so other devices may have been destroyed. However, the technology was not lost and appeared later in the Arabian geared Islamic Astrolabe and then in Europe in the first clocks, leading to our modern geared machines. Yes, the ancestor of the gearbox in your car could well be a 2200 year old computer!

and here is a Lego version!.....

https://m.youtube.com/watch?v=RLPVCJjTNgk

                                                                                                                                   - John Faulkner

Richard Feynman by guest blogger John Faulkner

Born in New York in 1918, Richard Feynman grew up to become one the great 20th century scientists. He shared the 1965 Nobel Prize in Physics for the theory of Quantum Electrodynamics (QED), the explanation of how light and matter interact. To simplify the physics and mathematics involved in QED he invented Feynman Diagrams - the visualisation of complex interactions.

 

To other scientists he was known as the Great Explainer, excelling as a communicator with his lectures, books and interviews. See the clip below:

 

https://m.youtube.com/watch?v=cRmbwczTC6E

 

In the clip he is saying that to be a scientist you need to:

 

- Be driven by your natural curiosity - follow wherever it takes you.

 

- Don't be afraid of the unknown or doubt - some of the great discoveries have been made this way.

 

- Approach problems in your own way - challenge orthodox thinking.

 

In one lecture he states a new law in science starts with a guess, then the consequences are computed and compared with experience or experiment...

 

"If it disagrees with experiment it's wrong. That simple statement is the key to science. It doesn't matter how beautiful your guess is, how smart you are, who made the guess or what his name is... if it disagrees with experiment it's wrong. That's all there is to it."

 

Here is part of that lecture (10 minutes):

 

https://m.youtube.com/watch?v=EYPapE-3FRw

 

As a practical joker he convinced Italians, where he lived, he was fluent and even made himself understood. He did not know a word - they thought he had an unusual dialect!  He questioned the value of awards and prizes and when pressured into accepting his Nobel Prize he later said "prizes bother me, I don't need prizes, I already have the prize, the pleasure of finding something out new to the world'.

 

Shortly before he died he was invited to join investigators on the 1986 NASA Challenger Shuttle disaster. Following launch on a very cold day, the main rocket exploded killing all 7 astronauts. At the opening press conference he famously conducted an impromptu experiment to suggest a cause. By placing O ring material, used to seal rocket segments, in a glass of ice water he showed it lost elasticity. This was correct and failure of this seal turned out to be the cause. He found NASA management believed their own unrealistic loss of 1 in 100,000 launches and not listening to engineering concerns. His appendix to the investigation report concludes:

 

'NASA owes it to the citizens from whom it asks for support to be frank, honest and informative, so that these citizens can make the wisest decisions for the use of the limited resources.

 

For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.

 

To find out more about Richard Feynman's life some of his books are:

 

Surely you're Joking Mr Feynman: Adventures of a Curious Character What do you care What Other People Think: Further Adventures of a Curious Character The Pleasure of Finding Things Out.

- John Faulkner

James Lovelock by guest blogger John Faulkner

Hiking with his father on Leith Hill, young James Lovelock would admire the view across to the South Downs. Years later, in the 1960s, the view did not seem as clear. There was a haze. Was it man made? Where did it come from? The answer would introduce a precision instrument for measuring air pollution, both help to start the environmental movement and avert a catastrophe.

Inspired by visits to the Science Museum, impoverished James Lovelock self funded his ambition to become a scientist. Frustrated with university authority he did his science independently as a 'maverick'. Among his discoveries and inventions is the Electron Capture Detector (ECD).  This is an instrument so sensitive it can detect airborne particles in parts per trillion (1 in 1000,000,000,000). The ECD works by ionising a gas then passing an electrical current through it. Specific atoms or molecules introduced to the gas can be identified by changes in the current.

He used his ECD on the North Downs air. Testing for man made chlorofluorocarbons (CFC), used for aerosols and refrigerants, he discovered them in the wind from London. Was CFC dispersal wider? He part funded joining British research ship Shackleton on it's 1972 Antarctic voyage. His resulting paper and lectures on global dispersal alerted other scientists. Alarmingly they found CFC action was destroying the earth's ozone layer. Ozone protects life from the harmful effects of the sun's Ultra Violet radiation. In 1987 the Montreal Protocol, to control CFCs, was agreed by 197 UN countries and is the first worldwide agreement to protect the Earth's environment.

After a distinguished science career, at 96, James Lovelock now writes on the environment. He is most famous for the Gaia hypothesis developed while consulting NASA on how landers might test for the presence of life on Mars. Gaia proposes the Earth's environment is self regulating, where life maintains the balance of nature. Living processes, for example, coordinate to maintain the air's oxygen level at 21%, the exact proportion in air needed by our biosphere to survive.

Recognising Science Museum influences, in 2015, he donated his fascinating and important archive to it. It includes the ECD, built in his garden shed laboratory! See the link below...

http://www.sciencemuseum.org.uk/visitmuseum/Plan_your_visit/exhibitions/lovelock.aspx

There are many anecdotes from him and one that impresses me is his response during the war to using shaved rabbits to categorise degrees of skin burn. He refused to harm innocent animals and successfully conducted the tests on himself which he described as 'exquisitely painful'!

- John Faulkner, SATRO Volunteer

Mathematician, Sir William Oughtred by Guest Blogger John Faulkner

In mathematics when "x" is used as shorthand for "multiply" thank Sir William Oughtred. He was rector of the Surrey village of Albury from 1603 to his death in 1660. A Fellow of Kings College Cambridge he taught mathematics free to anyone interested in the subject. One of his many students was Christopher Wren, the acclaimed architect of St Paul's Cathedral. He authored mathematics text books and these had other familiar terms such as Sin and Cos for the first time. His books were used by scientists such as Isaac Newton and Robert Boyle.

Sir William Oughtred's greatest contribution to STEM however, was to invent the Slide Rule. Four hundred years ago this year John Napier invented Logarithms making mathematical problems easier to solve. Using this, Oughtred inscribed logarithmic scales on two sliding wooden strips creating a powerful and simple calculating device. A slide rule is about the size of a ruler. By sliding the scales and aligning your numbers quick calculations can be made. Until the introduction of computers the slide rule was a fundamental science and engineering instrument. A slide rule needs no electricity or software and because of their simplicity were used by NASA as computer backup for the Apollo moon programme. Lunar Module pilot Buzz Aldrin took his slide rule with him to the moon and in 2007 it famously auctioned for $77,675.

So if you visit Albury remember that it was here, four hundred years ago, some of our common mathematical symbols were defined and a device invented that flew to the moon!

- John Faulkner

ON THIS DAY IN SCIENCE HISTORY - 6TH AUGUST

On this day in 1996, NASA announced the discovery of potential evidence of an early life form on Mars. It came in the form of an alleged tiny fossil found on a meteorite in Antarctica, which was believed to have come from Mars. The fossil could only been seen as a highly magnified image, as a microscopic tube-like form, less than 1% of the width of a human hair. Some believed that it could perhaps represent a simple Martian organism that lived over 3.6 million years ago. A huge impact 16 million years ago could have blasted the rock into space, and it landed in Earth’s Antarctica only 13,000 years ago. The meteorite ‘ALH 84001’ also carried organic molecules and mineral features which are characteristics of biological activity. At best, the evidence is inconclusive, and other scientists often entirely dispute the interpretation.  

NEIL ARMSTRONG'S BIRTHDAY

On this day in 1930, Neil Armstrong was born. He was an American astronaut, and the first person to ever walk on the Moon. He was also an aerospace engineer, naval aviator, test pilot and a University Professor. Before becoming an astronaut, Neil Armstrong was an officer in the U.S. Navy and served in the Korean War during the 1950’s. When the war had ended, he earned his bachelor’s degree and became a test pilot at the National Advisory Committee for Aeronautics (which then became NASA), where he logged over 900 flights. Armstrong joined the NASA Astronaut Corps in 1962, and made his first space flight, as command pilot of Gemini 8, becoming NASA’s first civilian astronaut to fly in space. His second and last space flight was as mission commander of the Apollo 11 Moon Landing in July 1969. During this mission, Armstrong and Buzz Aldrin descended to the lunar surface and spent two and a half hours exploring.