All posts by Glyn Davies

Much Ado About Mothing — Ben Keywood — 26Th March 2018

Moths have a bad repu­ta­tion because most people think that they eat clothes.  In fact they do not.  It is the larvae of a very few moth spe­cies that eat clothes.  These larvae prob­ably fed on the lin­ings in birds’ nests before humans wore clothes made of nat­ural fibers.  Generally moths do not lay eggs on clothes made of man-made fibers or on  laundered clothes, but, if you have an item at the back of the ward­robe  that you haven’t worn for years, it might become infes­ted with moth larvae about 3mm. long.  Sometimes people think that their car­pets have been eaten by moth larvae but it was prob­ably varied carpet beetle larvae that were to blame.

There are 2,400  moth spe­cies in the U.K. but only about 60 but­ter­fly spe­cies.  There are two groups of moths: Micro and Macro.  These are not based on size but on fam­il­ies.  About 800 spe­cies are Macro, arranged in 56 fam­il­ies.  Both moths and but­ter­flies are Lepidoptera so they are closely related.  Most moths are noc­turnal (active at night) but some are diurnal (active in day­time) and some are both.

Ben explained that moths are con­sidered to be sci­en­tific­ally import­ant because:

  • They are highly sens­it­ive to very small envir­on­mental changes so they are a good indic­ator spe­cies.
  • They are pol­lin­at­ors.
  • They are at the bottom of the food chain and, as such, are a major source of food for birds and other anim­als.

The peppered moth is a good example of how changes in the envir­on­ment can affect the spe­cies.  It nor­mally has white wings peppered with tiny black spots.  In the past, when the atmo­sphere in Sheffield was full of indus­trial pol­lu­tion and build­ings and trees were covered in soot, an all-black form of the peppered moth was common.  It was thought that the black form dom­in­ated because the white form was easily picked off by birds, but  black form moths were cam­ou­flaged and sur­vived to breed more black form moths, an example of evol­u­tion.

Moths have amaz­ing cam­ou­flage.  Many moths mimic dead leaves when they close their wings.  Some look like bird drop­pings or sticks when their wings are closed. They are also good at pre­tend­ing to be dan­ger­ous to pred­at­ors.  Some moths have large ‘eyes’ on their wings which make them look dan­ger­ous.  Some have col­oured bodies that make them look like hor­nets.  One large moth flut­ters its wings rap­idly so that it looks like a hum­ming bird.  Another has a yellow head and upper body and a ‘beak’ so it looks like a canary.

People think that moths are brown and have furry bodies, but many spe­cies are beau­ti­fully bright col­oured with very com­plex pat­terns on their wings.  Many moths are just like but­ter­flies to look at.  The green carpet moth’s wings are emer­ald green with a pat­tern like a carpet.  It feeds on bil­ber­ries on the moors around Sheffield.

Some moths have cater­pil­lars that look like sticks or pieces of wood.  The ele­phant hawk moth’s cater­pil­lar is about 10 cm. long (and looks like an elephant’s trunk) but is col­oured with pat­terns and ‘eyes’ so it looks like a small snake.  The syca­more moth’s cater­pil­lar is about 5 cm. long and has bright yellow hairs stick­ing out all round.  This seems to put off pred­at­ors.  Some cater­pil­lars are tiny — the horse chest­nut leaf miner bur­rows between two sur­faces of a leaf, eating away in safety until it is large enough to pupate.  Another cater­pil­lar, only 2 mm. long, rolls up a leaf into a tube and eats away inside it.

Ben showed a photo of his moth trap (a bright light over a funneled box) which he used to catch moths in an area of well-mowed lawns near a University Hall of Residence.  He caught many moths but they were all of one type.  He said that this was because the avail­able food suited only this moth type.  He sug­ges­ted to the Hall res­id­ents that they let the grass grow and allow other plants like but­ter­cups, dais­ies and plantains to grow in the grass.  When he set up his trap some­time later he caught sev­eral dif­fer­ent types of moths.  He said that if we want a wide vari­ety of insects (he meant moths!) in our gar­dens then we need a wide vari­ety of plants and not to spray chem­ic­als at all.

At the end Ben was asked what is the dif­fer­ence between moths and but­ter­flies.  He admit­ted that, in fact, there is no real dif­fer­ence.           This was a fas­cin­at­ing talk with so much new inform­a­tion that I’ve only scraped the sur­face.

Railways in the Cornish Landscape — part 2. — Stephen Gay — 12/02/2018

After telling us how he found a grave­stone with his name on it in St. Keys grave­yard, Stephen began his story of the Redruth and Chasewater Railway begin­ning near Truro.

His talk was accom­pan­ied by won­der­ful pho­to­graphs that he has taken on his travels.

He showed us Devoran Village Hall, which was once an engine shed.  The road along­side the hall was where the rail­way ran ori­gin­ally. A branch line, which car­ried min­er­als, once ran from the main line down to the River Fal where the min­eral boats were moored.

We were taken on a cruise down the river to Falmouth, which was the deep­est nat­ural port in England.  Stephen stayed in Falmouth at the Green Bank Hotel.  He found that Florence Nightingale and, later, Kenneth Graham, of ‘Wind in the Willows’ fame, stayed at the hotel.

He vis­ited Pendennis shipyard, where naval ves­sels were main­tained, because he knew that steam trains were still used there until 1986. The main line con­tin­ues across a via­duct where the stone pil­lars of Brunel’s ori­ginal timber via­duct can be seen along­side.  The ori­ginal via­duct was replaced in 1933.  Brunel’s lines were seven and a quarter foot gauge, much wider than modern track.

His next sta­tion was at Perranwell, a request stop, where Stephen and Wrawby, his Germen Shepherd dog, went for a walk.  They dis­covered an ancient fin­ger­post, which dir­ec­ted them to King Harry’s Ferry, which was a chain-link ferry across the river.

The line con­tin­ues through Penryn and is single track.  It is very busy with tour­ists and stu­dents, but at Penryn sta­tion there is a side loop where trains trav­el­ling up and down the line can pass each other.  The plat­form is extra long to accom­mod­ate trains in both dir­ec­tions. The next via­duct was the last of Brunel’s timber via­ducts to be replaced.

On to Falmouth Dock sta­tion, which could become very much busier.  There are rumours that cruise liners from crowded Southampton port are to be diver­ted to Falmouth.

Then to Chasewater sta­tion which closed in 1963 when Beeching closed the branch line to Perranporth.

Stephen diver­ted to Perranporth sta­tion where there was a Millenium Project to make a Railway Walk along the dis­used line. He went by bus down to the beach where an artist called Kenneth Steel was once employed by British Railways to paint coastal views for BR posters.  Stephen told us that there is a Steel poster on Dronfield sta­tion and a paint­ing by Steel on the first floor of Atkinsons store near the toi­lets.

Redruth Station is approached by a short tunnel and in the sta­tion café is a plaque that says “Jenny Agutter stayed here.”

Camborne, next on the line, is the birth­place of Richard Trevithick, a rail­way pion­eer.  There is a statue of him in the town.  (Stephen read his poem about Trevithic.) He dis­covered another old finger post that still dir­ec­ted him to a sta­tion that closed in 1963!

Stephen stood on the dis­used (dan­ger­ous) Helston via­duct to take a pho­to­graph, then on to Helston sta­tion, which is the south­ern­most sta­tion in England.  GWR ran out of money so they opened a bus link to the Lizard where they built a narrow gauge (funicu­lar) rail­way down to the life­boat sta­tion.

Further on he passed Lelant Saltings sta­tion, which was one of the first ‘Park and Ride’ sta­tions.  When it opened in 1978 the cost for park­ing a car and a return to St. Ives for 4 people was 60p.

The line runs along the coast towards St. Ives where the sta­tion is next to the beach at the end of the line.  Stephen took a pho­to­graph of St. Ives sta­tion from the inside of a tele­phone box after he had cleaned evid­ence of the pres­ence of many seagulls from the win­dows. (He read his poem about how mobile phones are threat­en­ing the phone boxes.)

The whole ‘trip’ was an enorm­ous pleas­ure, through the present and past of Cornwall, illus­trated by splen­did pho­to­graphs and Stephen’s poems.

 

A Celebration of Entertainment and Entertainers of Days Gone By — By Dave Moylan. — 18th December 2017.

Dave began with the ‘magic’ cup-and-ball trick, which he said was known to the Romans and Ancient Greeks.   Even though I knew (or sus­pec­ted) how it was done I could not see how he moved the balls- he was too pro­fi­cient.  He fol­lowed this with a 5-card trick too fast for us to really spot the method — his patter and dis­trac­tions worked too well.

He explained the dif­fer­ence between magic and illu­sion.                             “In 1966 an England team won the World Cup — that was magic.   Illusion is that people think that will happen again!”

Dave then played the guitar and sang a comic song.  He sang ‘I want a proper cup of coffee made in a proper copper coffee pot.’ and we joined in the chorus, shout­ing “Oy”.

He switched back to magic, doing his ‘rope trick’, using Stan as his assist­ant.  In this trick he cut a piece of cord in half sev­eral times in dif­fer­ent ways, but it always remained in one piece.  It was beau­ti­fully done, and Stan played his part admir­ably!

Then Dave returned to jokes:                                                                                         “Bill had to have an ear trans­plant.  The sur­geon gave him a pig’s ear that worked fine except for a bit of crack­ling.”                                                    “Fred, for a dare, ate 18 kg of curry powder.  It didn’t kill him but he is now in a korma.”

Next Dave said that he admired the old radio comedi­ans, like Al Read, because he told jokes about the sort of people that you knew.   These comedi­ans thought that the way to deal with unpleas­ant sub­jects, like death, was to laugh at them.                                                              “A hus­band said to his wife, “When I die will you sell the house?”           “No,” she said.  “I like living here.”                                                                                 “Will you get mar­ried again?” he asked.                                                                   She said, “I might do, because I won’t want to spend my life alone.”       “You won’t let him use my golf clubs, will you? he said.                                  “Oh, no. They won’t be any use to him because he’s left-handed.”

Dave asked if we remembered Max Wall.  He said he’d asked many teen­aged girls the same ques­tion.  They all said they didn’t.  So why do they dress like him?

He took up a ukulele and played and sang a George Formby song          “If women like them like men like those why don’t women like me?”    Then more jokes, too fast for me to note them, and a song of ‘The Old Bazaar in Cairo’.

He then told us that Liverpool has pro­duced many, many comedi­ans and he told  jokes using dif­fer­ent accents: Welsh, Brummie, Scouse.   A man asked a lady at the big house if she had any odd jobs he could do.      “Take this can of black paint and paint the porch at the back of the house,” she said.                                                                                                                     Some hours later he came back covered in splashes of black paint to say that he had fin­ished.                                                                                                    “But,” he said, “It isn’t a Porshe, it’s a Ferrari.” 

A splen­did talk that was thor­oughly enjoyed by all. Thank you, Dave.

 

Particle Physics — Understanding the Universe’s ‘LEGO Bricks’. — Professor Lee Thompson — 25th September 2017.

One of the reas­ons for research­ing the make-up of atoms is that look­ing closely at the smal­lest things can tell us much about the largest things, such as suns, stars and galax­ies.

Only 5 or 6 types of ‘bricks’ can make lots of dif­fer­ent things.

A clearer under­stand­ing of the atom was made by Thomson in 1897 when he dis­covered that cath­ode rays are elec­trons, and that elec­trons exist at the ‘edge’ of atoms and are not tightly bound to the atom.

In 1909 Rutherford, Geiger and Marsden, made an appar­atus that would fit on a desk top.

It was a cyl­in­der, sur­roun­ded by pho­to­graphic film, with a small gold foil taget in the middle.  They dir­ec­ted a beam of alpha particles at the thin sheet of gold and the photo film would detect the alpha particles.  As it was thought that the interior of atoms was mainly empty space they expec­ted that the beam would pass through the foil without devi­ation.  However some of the particles were scattered and some even appeared to bounce back.

In 1911 Rutherford con­cluded that there was a very tiny, very dense centre to the atom.  He called this the nuc­leus.

Nowadays we want to look inside the nuc­leus and to do this we need a lot more energy so we use particle accel­er­at­ors.

The largest accel­er­ator is at CERN on the Swiss/French border.

This is housed in a large cir­cu­lar tunnel that is 27 km in cir­cum­fer­ence and is 150 metres under­ground.  In it particles are accel­er­ated to near light speeds and are smashed into each other to find out what comes off so soph­ist­ic­ated particle detect­ors are required.

Four dif­fer­ent types of detector are used made up of gas, liquid and plastics.

The ATLAS detector is enorm­ous and weighs over 70,000 tons and is 44 metres wide.

Phenomenal com­put­ing power is needed to ana­lyse the particles given off after col­li­sion.

At school I was taught that atoms were made up of elec­trons orbit­ing the nuc­leus, which con­tained pro­tons and neut­rons.  If elec­trons were stripped of the atoms they were called beta particles.  A helium nuc­leus, con­sist­ing of 2 pro­tons and 2 neut­rons, was an alpha particle.

Now we have:

  • Electrons
  • Muons — heav­ier elec­trons
  • Tau — even heav­ier elec­trons

Inside Protons and Neutrons we have Quarks, iden­ti­fied as Up Quarks and Down Quarks. Quarks come in pairs or threes — Protons have 1 Up Quark and 1 Down Quark, Neutrons have 1 Up Quark and 2 Down Quarks.

Other particles, called nutri­nos, have been detec­ted and  there are sev­eral sources of these particles — the Sun, nuc­lear power sta­tions and CERN.  Earth is con­tinu­ally bom­barded by showers of nutri­nos, but they pass through us and pen­et­rate the Earth without appar­ently caus­ing us any harm.

The Japanese are research­ing nutri­nos.  They aim a beam of nutri­nos at a research centre 293 km away, which has a detector con­sist­ing of  a huge spher­ical tank con­tain­ing 50,00 tons of water.  The tank roof is lined with a huge number of light detect­ors cost­ing mil­lions of dol­lars.  If a nutrino hits and reacts with atom in the water a tiny flash of light is emit­ted and detec­ted.  This is a very rare event.

The point of all this research at CERN and Japan is that it has brought many advances to the man in the street.

The World Wide Web was devised at CERN to allow inter­na­tional com­mu­nic­a­tion for phys­i­cists. High per­form­ance com­put­ing hand­ling large data volumes. Medical phys­ics has developed dia­gnostic tools for NMR and PET treat­ments and Hadron ther­apy and the pro­duc­tion of iso­topes.

Cosmic rays inter­act in the atmo­sphere to gen­er­ate muons, which can be used to detect illegal imports of terrorist-owned nuc­lear mater­i­als in con­tain­ers at our ports. Also muons  tomo­graphy can be used to exam­ine the interi­ors of pyr­am­ids and magma cham­bers and vol­ca­noes.

It was an inter­est­ing talk, con­tain­ing masses of mater­ial, that Prof. Thompson made as straight­for­ward as he could for the non-physicists!

Fix-My-PC — Jonathan Frost — 17th July 2017.

Jonathan began by warn­ing us not to trust anyone who rang up claim­ing to be from Microsoft who said that they have detec­ted a fault on our com­puter.  They offer to cure the fault if we allow them access to the com­puter.

It is a scam.  Microsoft, our banks, HMRC etc. will not con­tact us by ‘phone if they need to deal with prob­lems affect­ing our equip­ment or accounts so say, “Thank you for call­ing.” then hang up the ‘phone.

He asked how many of us back up our com­puter using an external hard drive.  If we have sev­eral hun­dred photos stored in the com­puter memory and it crashes we could lose all those memor­ies if they could not be retrieved.  In fact, he sug­ges­ted, it is better to back up onto two external hard drives because they are easily dam­aged by a knock or being dropped.

USB memory sticks should be used for trans­fer­ring files or photos, but not for stor­ing them, because memory sticks or flash drives can also be easily dam­aged.

Someone said he backed up his com­puter using the Cloud.  That is a slow pro­cess if you try to put in a lot of photos at once but is O.K. if you are adding  a few at a time over a longer period.

Modern tech­no­logy is advan­cing so rap­idly that com­mu­nic­a­tion and stor­age meth­ods are fast becom­ing out of date.  Audio tapes and VHS and even CDs are becom­ing use­less because you soon will not be able to buy a machine to play them.  Writing on paper or prin­ted photos is often the best way to keep inform­a­tion for any length of time — they don’t need machines to inter­pret them!

Passwords are often easier to guess than we might think.  Criminals may be able to log in to your com­puter and get a super com­puter to guess yours.  Because these com­puters can per­form mil­lions of actions in a short time, they may be able to try enough com­bin­a­tions to determ­ine you pass­word in as little as three days!

Jonathan sug­ges­ted that a more com­plex pass­word of the type   ‘cor­rect   horse   bat­tery  staple’  would take even a super com­puter about 550 years to guess!   Obviously you would have to choose a sequence of words that you could remem­ber.

He asked if anyone had com­puter ques­tions that he could help with.  Antivirus soft­ware?  None would be good for a long time because more and more vir­uses occurred.  He recom­men­ded Avast free.    Avoiding  hack­ers and vir­uses?
1.Too many free apps on your phone may make you vul­ner­able  to both.
2. Never click on a link in an e-mail unless you trust the source.
3.If you still use XP don’t use it on the Internet — it is not safe.

He said that he and his son con­duct a free com­puter clinic each Wednesday from 10am to 12pm at Broomhill lib­rary.

Finally he asked how many of us look at our web­site and did we have com­ments?   Most looked at blogs or future speak­ers, not many used the Forum.  Some blogs (like this one?) were too long.

A very good present­a­tion that was help­ful, but I think I need to attend  free clinic to get the full bene­fit!

 

So you think you are British, do you? by John B Taylor. 10th April 2017

John’s aim was to show that being British means that we are des­cend­ants of immig­rants even if we do not like the present form of immig­ra­tion.

What do we think are sym­bols of Britishness?

He showed a series of ‘British’ sym­bols:  Winston Churchill, The Union Flag, The Coat of Arms, Buckingham Palace, Tower Bridge, The Tower of London (where many exe­cu­tions were car­ried out), Shakespear, Edinburgh Castle, Snowdonia and the Giant’s Causeway.

He asked if these are what we think of as ‘British’.  He told us that bills that are passed from the Commons to the Lords and back are writ­ten in Norman French even today.  The statue of Richard the Lionheart (another ‘British’ symbol) was sculp­ted by a man from Turin, who also made the Trafalgar Square lions.  (Richard the Lionheart was King of England for 10 years but spent only six months in England).

Who are the British?

Migrants had been coming to Britain for thou­sands of years, before the islands became sep­ar­ated from main­land Europe.  Tribes came from all over Europe from as far away as Iberia and the bor­ders of Russia.  After the islands formed there were as many as 45 dif­fer­ent tribes living on the main island of Britain.  (This may account for the many dif­fer­ent dia­lects we have today).

The Romans invaded in around 55BC with 20000 legion­naires and another 20000 retain­ers.  They brought the seeds of their civil­isa­tion with them: run­ning water, toi­lets, bath­houses, lib­rar­ies, taxes and roads.  Towns were developed with linear roads.  The Romans stayed for 350 years and when they left many stayed on, per­haps they were mar­ried and had fam­il­ies in Britain.

Many other inva­sions of these islands happened.  The Jutes, Angles, Saxons, and in 793AD the Vikings, invaded and in 1066AD the Normans came.

The English lan­guage.

The lan­guage was prob­ably Celtic but Germanic dia­lects were intro­duced by the Angles, Jutes and Saxons.  The Romans intro­duced Latin and later the Vikings brought new words: the days of the week, skull, scarf, murder are thought to be Viking.  Later still, after the Norman Conquest, the mother tongue of the kings and queens Norman French was used in the Royal Court and in many parts of Britain.  In fact, English was not adop­ted in the Royal Court until 1362AD by Edward III.  Even today we still have echoes of other lan­guages in our system — the law­yers use “habeas corpus” and sim­ilar expres­sions in their legal doc­u­ments.

After 1066AD all the Royals, from William I, William II, Stephen etc. up to Prince Albert, were for­eign born.  Even St. George, the patron saint of England, was based on a Roman cen­tur­ion who was born in Palestine.

We have a his­tory of wel­com­ing for­eign­ers to Britain.  When the king of France made it illegal to be Protestant in Catholic France many Protestants were exiled to Britain.  William of Orange brought hun­dreds of retain­ers with him to Britain.  The slave trade intro­duced black African ser­vants and, in the Fifties, West Indians were invited to Britain to work here.

John fin­ished with a poster:

BEING BRITISH means: driv­ing a GERMAN car to an IRISH pub to drink BELGIAN beer and, on the way home pick­ing up an INDIAN curry, and, at home, sit­ting on SWEDISH fur­niture watch­ing an AMERICAN cop show on a JAPANESE tele­vi­sion.