Remembering Ernest Walton: Splitting the Atom

Public domain image via Wikimedia Commons

On 25th June, 1995, Ernest Walton, our only Nobel laureate for physics died in Belfast at the age of 91. Together with his colleague John Cockcroft, they built one of the first particle accelerators at the Cavendish Laboratory in Cambridge in the 1930s. This ultimately led to what's generally known as "splitting the atom". For this work, he was awarded along with Cockcroft a Nobel Prize in 1951.

Walton came to visit us in DIT, Kevin Street in Dublin when I was a student there in the mid 80s, and gave a lecture during which he spoke about his work in Cambridge. He appeared to be a mild mannered and unassuming man. I'm ashamed to say I didn't know who he was at the time. It was in an era before the Internet and our education system was hardly informative either. History books told us about the figures involved in revolution and the struggle for independence, but shamefully left out Walton, Hamilton and others involved in scientific discovery. I wish I could remember the content of Walton's lecture. I vaguely remember him talking about Ernest Rutherford, the New Zealand scientist who was also a pioneering researcher in the field of nuclear physics and radioactivity from the end of the 19th century onwards. Rutherford apparently had a larger than life personality and Cockcroft and Walton, his research students, used to wind him up.

Cockcroft and Walton's particle accelerator was one of the first machines for accelerating sub-atomic particles to high velocities so they would smash into atoms, breaking them apart. By studying what happened, scientists learned about the fundamental nature of matter. That work continues to this day, the 8.6 km diameter Large Hadron Collider located near Geneva, operated by CERN (European Organization for Nuclear Research) being immensely more powerful and capable of accelerating matter to almost the speed of light.

Bike Ride to Investigate the Barrow Way and New Barrow Bridge

© Eugene Brennan

I did a 77 km cycle yesterday following a loop taking in the greenway from Athy to Vicarstown, having previously done the Monasterevin to Vicarstown section. I hadn't been on the new distributor road in Athy before, which has a nice cycle path that runs over the old railway bridge crossing the River Barrow (Bleach Bridge). This was one of the first concrete bridges in Ireland, the branch line crossing it coming off the GSWR mainline near Athy station. The branch served the two collieries south of Athy at Gracefield and Modubeagh and laterally the Tegral factory. The distributor road is carried over a new single-span steel composite bridge. According to Roughan & O’Donovan-AECOM who were appointed to provide technical consultancy services for the Athy Distributor Road project, the bridge consists of two, 80 m steel plate girders, made from weathering steel to reduce future maintenance costs. Weathering steel, also known by the trademark COR-TEN or corten steel is an alloy made by adding copper and other elements to resist corrosion. (Similar to the way stainless steel has chrome added). However weathering steel builds up a patina or weathered coating that resists further corrosion, unlike "normal" steel. Corten steel is used for the Fionn MacCumhaill and his hounds sculpture at junction 12 on the M7 at Ballymany.

© Eugene Brennan

 

Methanol as a Fuel Source

Public domain image by Benjah-bmm27 via Wikimedia Commons

Some interesting reading here on methanol as a fuel in engines, what changes have to be made to engine technology to use it and its consequences. The alcohol content of petrol in Ireland (ethanol, not methanol) was, or was supposed to have been increased from 5% to 10% in July of last year, but there wasn't much coverage of the fact in the media. In other countries the ethanol content is higher in some regions. The consequences for small engines are absorption of water by fuel over time as alcohol is hygroscopic (like the way table salt gets damp if exposed to air). The water doesn't separate out, which normally occurs when two immiscible liquids such as oil and water are mixed, but mixes with petrol to form an emulsion (like homogenised milk or mayonnaise). This water causes corrosion of parts, and alcohol can also damage polymers used in gaskets. I haven't found any issue with my garden equipment so far, but I ran the engine of my mower until it cut out from lack of fuel at the end of the season and drained the carburetor float bowl. This year, I burned off old fuel by adding a small amount at a time to new fuel over the last few months. In any case, fuel shouldn't be left in tanks for long periods to prevent water buildup.