Ernest Rutherford...
                                   1871 - 1937







 Sir Ernest Rutherford.  
  Date of Birth …..30th August.

 A second Newton’, the man who tunneled into the very material of God”........ Einstein,

    The farm boy that Sweden recognised as a Nobel Laureate, and Britain honoured with the title Baron Rutherford of Nelson’, still runs from hand to hand in the hundred dollar bill in New Zealand.

 Based on the observations made by his two students,  Hans Geiger and Ernest Marsden, He correctly inferred that there is a collection of massive, charged sub atomic particles at the centre of atoms.

    He studied the nature and  named the alpha , beta and gamma rays.

     1871     Birth:-              dThe boy was the fourth child born to James Rutherford and Martha Thompson who had immigrated to New Zealand from UK.

   Ernest was born in Spring grove, (Brightwater), near Nelson, in the South Island of New Zealand.           He had an adventurous childhood, along with 11 siblings in the rugged virgin land.                               His father was a versatile farmer, wheelwright and a flax miller. , “My father  produced more children than flax”:

   We didn’t have the money, so we had to think”.Rutherford  quoted later in life,                                

 1876  Age 5 yrs.

  Ernest attended the Fox Hill school from the age of 5 for 5 years, where his mother had been a teacher. The head master Mr. Harry Ladley recognised the boy’s talent and gave him extra home work. He gifted him a science book which sparked the interest in science. His mother who had assisted the children to learn with the dictum “Knowledge is power”. 

 Father got them involved in making cart wheels, repairing water pumps and other skilled work in the farm and the mill. When his father started a flax mill in Havelock, operating by the water from Ruapaka stream, the family moved there.

 1882 Age 11 yrs.

 The children were admitted to Havelock school in Marlborough Sounds.  Ernest and his brother Jim were among gifted children that were given special lessons in Latin and Maths by Mr Jacob Reynolds.

 The structure of the atom could have been still hidden to us if James, on a particular day, did not compel Ernest to do an errand. The children had planned a fishing expedition. Two younger brothers of Ernest that joined, Charles 10 and Herbert 12 never returned. Martha heard the heart-breaking news of drowning while playing the piano. It had been their custom to gather round the piano in the evenings and sing. Martha never touched the piano since the tragedy.

1887 Age 16 yrs. 

  Rutherford won a scholarship and entered Nelson College as a boarder.­ He came home during the holidays and attended to the work in the farm and the mill. Once James noticed his son standing all alone, and counting. When queried Ernest said, “If you count the seconds between the flash and the thunder and multiply by 1200, you can tell the distance to storm in feet."   

 Another occasion James found cog wheels, springs etc. strewn right round the place from a dismantled clock. He got mad, but controlled himself. When he came back he found the clock on the wall showing the correct time.

 Ernest became such a good handyman that he made complex toys with odds and ends including a real bicycle in wood.

 Ernest had a fruitful school life at Nelson College, gaining an excellent education both in academics and extracurricular work that culminated in becoming the head boy, achieving dux, and being a forward in the rugby First XV.

1888 Age 17 yrs.

  James fractured a few of his ribs due to an accident. He had a saw mill and was supplying sleepers for the Railway. While he was convalescing the contract got cancelled, due to the long depression. James sold his farm and the mill and migrated North. He built a wooden villa in Pangarehu, South of New Plymouth, and a steam driven mill with a huge pond to soak the flax.

1890  Age 18 yrs.

 Ernest entered the University of Canterbury on a scholarship. After a noteworthy undergraduate career of three years, he obtained a BA majoring in Mathematics. He followed it up with an MA in Mathematics and Physics gaining First class Honours next year. He has paid a special tribute to Professor Alexander Bickerton as, “His genuine enthusiasm for science gave a stimulus to me to start investigations of my own”. Based on his brilliant performance the University offered him a research scholarship.

 He rented out a room at Christ church from Mrs. Marie Newton. His one and only romance was the relationship with her pretty, eldest daughter Mary.

1894 Age 22 yrs.

 After a short period of meticulous research on electromagnetic effects he invented a special radio receiver. This brought him fame in the local science community.

 In spite of the bright academic career all his attempts to get a permanent job failed. Then he applied for a British scholarship. It was awarded to one James from the Auckland University. Rutherford started assisting his father in the farm. 

 One day when he was digging potatoes, he received a telegram. He read it with nervous fingers; lady luck had smiled. James had not accepted the scholarship and it came over to him. He dropped the potato in his hand saying, “I shall never dig a single potato again”.

 Before sailing to England he got engaged to Miss. Mary Georgina Newton.

Life in England

1895  Age 23 yrs.

 Rutherford landed in England  with 3 Canterbury degrees in his pocket.                                                         He also had a reputation as a researcher.                                                                                                               He was the first non-Cambridge graduate allowed to do research at the Cavendish Laboratory.               There was some criticism and jealousy from certain quarters. One fellow student called him “A rabbit from the antipodes who borrows mighty deep” Probably to silence them he completed a Cambridge BSc, offering Geology and Chemistry.

 Ernest and Mary continuously exchanged letters. In one letter he wrote, “I must do something somehow,…………. it will be for thee since my fortunes are thy fortunes”

 Professor J.J. Thomson, who had discovered the ‘electron’ and proposed the ‘plum pudding model’ of the atom recognised him as an outstanding research worker and selected him to assist in his own research. They investigated the conduction of electricity in gases.

Rutherford had devised an apparatus to detect electromagnetic waves. He took his transmitter about 500 yards away from his receiver. Along with 2 friends, trying till 1 a.m, it failed to detect a signal. Rutherford got a chance to do more trials in the observatory. Ultimately he succeeded in transmitting a signal from a mile away.

 At the request of an adviser for maintaining light hoses, he increased the sensitivity of this system enabling the ships to detect a lighthouse in a fog.

 This was the year Rontgen discovered some rays and called them X’ rays as they were unknown.

1896 Age 24 yrs.

  Henry Becquerel discovered some rays, slightly different from X rays, emanating from fluorescent chemicals. While X’ rays were unaffected in a magnetic field ‘Becquerel rays’ got deflected. This discovery triggered the investigations of two great scientists Madam Curie in France and Ernest Rutherford in England.



Fig, 2 Ernest Rutherford adopting Becquerel’s experiment.

Rutherford repeated Becquerel’s experiment of analysing ‘Uranium rays’ (as Becquerel called them). Instead of using photographic films to detect the rays he adopted a discovery made by his teacher. Professor Thomson had discovered that gases can be made to conduct electricity when bombarded with certain rays.    

In the circuit shown there is a gap between the positive and negative plates preventing a current passing through. When the alpha rays pass through the meter showed a current. Rutherford placed various materials to block rays and tested the penetrating power.

He found what Becquerel had suspected to be correct. While some rays could not pass through even a tissue paper others could even pierce a sheet of Aluminium. He named the rays stopped by paper as Alpha and the rays with a high penetrating power as Beta. 

 1898 Age 26 yrs.

Rutherford changed the mode of detecting these rays from the ionization method to a fluoroscope method. He applied Zinc sulphide on aglass plate to detect alpha collisions.


Fig.2 Rays deviating due to an electric field.

He also discovered that the rays could be separated by using two electrically charged plates or by a magnetic field. Alpha rays got slightly attracted to the negative plate while the Beta rays deviated a lot by the positive charge. He found that the Beta rays to be similar to a stream of electrons concluded that alpha particles ought to be much heavier than the electrons.

With this discovery he became world famous. On a request made by the McGill University in Canada, Professor J.J. Thomson wrote, “I have never had a student with more enthusiasm or ability for original research than Mr Rutherford and I am sure that if elected he would establish a distinguished school of Physics at Montreal.”

Rutherford was not very eager to leave Cambridge and go to  Canada. But for the 26 year old lad to get a Research Professorship to work in a highly sophisticated lab, with an annual salary of $ 2,500 p.a., was not an offer to be refused.

1900 Age 28 yrs.

 Paul Villard in Paris recognised the highly penetrating rays which were similar to X’ rays. They are named as Gamma rays.

 For the first time in his life, Rutherford got a permanent employment. It was time for him to think of his fiancée. The same year he returned to New Zealand to meet Miss. Mary Newton. Mary and her mother were well known social workers. Soon the wedding bells pealed at Christchurch for Ernest and Mary.

1901 Age 29 yrs.

 Mary gave birth to a daughter and named her as Eileen Rutherford.

 Leaving childcare and the household chores to his wife Rutherford worked zealously, along with a few dedicated students, to solve the mystery Marie Curie had named as ‘Radioactivity’. The work he did with a demonstrator Frederick Soddy (1921 Noble laureate) was extremely crucial. They discovered that heavy atoms break down into lighter atoms, contrary to the belief at the time that “atoms are indivisible”. In the meantime he also discovered a new element. This was a radioactive gas which he named as Radon.

1907 Age 35 yrs.

 Rutherford returned to England and joined Manchester University as a Professor. He started research with a German scientist Dr. Hans Geiger. They passed alpha rays through extremely thin sheets of mica and various other metals using a radioactive gas radon-222 as the source. The rays had to pass inside a partially evacuated tube. It was necessary for them to stay in a dark room for quite some time for the eyes to get adapted to feeble light. They also used an electronic device to count. A remark by Rutherford  shows how tedious the job was, “Geiger is a good man and worked like a slave. Our tube worked like a charm… Geiger could count at intervals the whole night.”

The deviations they found were extremely small.They thought an alpha particle to get deflected very slightly be each charged particle and the resulting deviation to be the cumulative effect of a large number of such particles.

Fig.3 The apparatus they used to observe the scattering of alpha rays.


1908 Age 36 yrs. 

 The Royal Swedish Academy of Sciences awarded him the Nobel Prize for Physics.

Rutherford along with Thomas Royds identified alpha particles as Helium atoms devoid of electrons. Alpha particle had an atomic mass of 4 and a positive charge of 2.

1909 Age 37 yrs.

 Geiger announced that a 20 year old undergraduate, Ernest Marsden was looking for a research project. Important investigations Rutherford assigned to final year students.   Here he made an exception. He wished Marsden to measure the deviations of alpha rays scattering through metal foils of various nature.

The assignment included, finding the relationships between the number of particles deflecting at a certain angle and the following:-

  •         The diameter of the scattering foil.
  •          Atomic mass of the metal used for scattering.
  •           The nuclear charge of the alpha source.
  •           Velocity of alpha particles.

They found gold to be ideal for this as it could be beaten into very thin sheets. The trio devised a zinc sulphide as fluorescent material, a rotating microscope to observe the individual flashes and   a counting tube which developed into the Geiger Muller tube later on. They used Radium as the nuclear material instead of Radon gas.

Physicist were unable to explain how the atoms remain electrically neutral with the negatively charged electrons. One explanation given by JJ., was that the two kinds of particles, positives and negatives are scattered just as plums in a pudding. Nobody knew about a positive particles except alpha.

Marsden after getting adjusted to darkness stared at the screen to observe any particles getting   reflected. He was such an obedient student, knowing nothing would come, stared at the fluorescent screen from the incident side. To his utter amazement he saw a tiny flash about once in every second. Geiger and Marsden checked the results over and over again only to find that the unbelievable was right.  One in a few thousand particles deviated over 90 degrees.

They hesitantly reported to Rutherford “A few alpha particles not only deviated by large angles but about one in a thousand bounced back”.

He couldn’t believe his ears.. Later he has said that, “It was the most incredible event of his life, as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you"

Rutherford knew that these observations of Geiger and Marsden would be an important landmark in the history of understanding matter. He permitted them to publish the paper on their own names enabling them to get the entire credit. Philosophy Magazine published it.

1910

Rutherford experimenting with Thomas Royds had discovered the nature of the alpha particle. It was 4 times as heavy as the Hydrogen atom and required 2 electrons to neutralize it.

Simple calculations based on statistics of Geiger and marsden showed that the atom was mostly empty space. The core or the central part, (at the time the word ‘nucleus’ had not been adopted.) amounted to only 1/100,000 the size of the atom.

‘Plum pudding model’ could not withstand the latest findings. He went back to history. In 1903 Hantaro Nagaoka had proposed a model with a heavy positive centre and orbiting electron in rings as in the planet Saturn. It was abandoned by the creator in 1908.

1911

Rutherford could not say whether the atom was a disc or a sphere. He did not know whether the core was positive or negative. ( Protons had not been discovered at the time) He could only say mass or the matter was mainly at the centre and the electrons are orbiting as the planets revolve round the sun. This was the ‘Solar model.’

1912

There was strong opposition for this model. They had to explain why the similar charges, clustered at the core do not repel each other and why the orbiting electrons do not lose energy and fall back to the centre. Although he predicted a strong force (now named Nuclear force) holding the similar charges together at the core of the atom electron problem remained unsolved.

The person who came to the rescue was the Danish scientist Niels Bohr. He showed mathematically that electrons can orbit at certain levels in a stable manner.

1916

He had foreseen the nuclear threat to mankind and stated , “I personally hope method of extracting atomic energy will not be discovered until man discovers friendly co-existence” 

1930

Rutherford’s daughter Eileen passed away.

1932

The proton–neutron model of the nucleus was proposed by the Russian scientist Dmitry Ivanenko


 Fig.4  Rutherford Bohr model of the atom

1937

Ernest Rutherford passed away due to a negligence of his illness. The ashes were buried in Westminster Abbey, in London

1991

‘The Rutherford Origin’, with information displays about Rutherford in a garden setting, was opened on December 6, his birthplace.

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