Lord Ernest Rutherford

Various people have been posting about Rutherford's contribution to physics.

I believe that Geiger, he of the counters, was a student of Rutherford, and was given the idea by him.

Here's a personal Rutherford story.

In 1961, when I was transport officer at the Canadian army depot at Longue Pointe (east end Montreal), I was ordered to deliver a vehicle to the base workshop, where it would be modified to carry radioactive material and then turned over to a nuclear decontamination team for as long as they needed it.

A graduate student had been carrying a Geiger counter through a back corridor in the old Physics Building at McGill University. When he idly flicked the switch on the counter, it went off. Subsequent investigation showed that a stretch of one wall of the corridor was hot. Behind that stretch of wall was a long-unused small room in which Rutherford had worked sometime around the turn of the century. The military recon team took apart the wall, and cleaned up the corridor.

Later on in life I acquired a Kiwi mother-in-law (now ex-mother-in-law) who was a South Island Rutherford, and related to the great man himself.

Art Schwartz

O.K. At the time there was no independent New Zealand citizenship - colonials such as Rutherford were British subjects and British citizens. Rutherford was made Baron specifically of a place in New Zealand, but at that time he would still have been a member of the peerage of the United Kingdom not of some New Zealand peerage. Because New Zealand was a colony of the U.K., his title was as valid here as it was there.

Although it didn't affect Rutherford, there does exist a much-ignored law, which we inherited from England, against using foreign titles in New Zealand. To lawfully use a title here, it must be a title granted by the Sovereign of New Zealand, or the Sovereign must have given permission for its use. This piece of common law is often broken out of sheer ignorance of its existence - for example by various Pacific Islands title-holders who continue to be known by their titles in New Zealand.

The position of British peers, knights etc is not clear to me - it could be argued that they may use their titles here because they depend from the same Sovereign, but I think that there is the stronger counter- argument that their titles do not depend from the same *crown* which is what is important, not the trivial fact the same person happens (at the moment) to wear both the British crown and the New Zealand crown. No one's very worried about it!

Lyndon Watson

Rutherford did both experimental and theoretical work. He is most famous for an experiment he did not do [Geiger and Marsden scattered the alphas from gold: Proc. Roy. Soc. 82 (1909) 495]. Rutherford explained it in [Philos. Mag. (6th Ser) 21 (1911) 669]. Actually, he deserves a lot of this credit because he was the intellectual stimulus behind what happened at the lab he operated. He made many specific contributions at many stages of the process that led to an understanding that there is a nucleus in the atom that defines the kind of chemical element and that it can be changed by a 'nuclear reaction' as well as natural radioactivity.

This is not really the forum to digress into why Geiger invented a device so he no longer had to stare into the optical predecessor of a modern solid-state particle 'telescope' and identify the protons from the N-14 + alpha --> O-17 + proton reaction via the brightness of their scintillations on a screen viewed with a microscope, or tell the first-hand stories I have heard about how those experiments were done. Much of that history is covered nicely in the first part of "The Making of the Atomic Bomb", "The Second Creation", and similar histories of the era.

What I do *not* know is why the Brits made a Kiwi a Baron. He is called 'Lord' as the normal honorific applied to a Lord. I had always assumed this was subsequent to his many discoveries and awards, but the citation above suggests it was prior to this. Is the citation wrong? Or was he a Baron in NZ?

James A. Carr

(1) Rutherford did not discover nuclear fission. Many people saw the phenomenon but it was understood by Hahn and Meitner, with some input from her nephew Frisch.
(2) The discovery of nuclear fission happened decades later.
(3) The size and nature of the nucleus as well as the existence of the neutron was well understood by the time fission was discovered.
(4) The Thomson 'plum pudding model' [Proc. Cambridge Philos. Soc. 15, (1910) 465] was a contemporary of this other work (note that it appeared after the Geiger and Marsden experiment!) and was only 'popular' in that it was an articulation of what many people visualized when they tried to construct a model of an atom that had constituents. Atoms were just 'atoms' before this point, and even after Rutherford's model, but prior to Chadwick and the neutron, there had to be electrons in the nucleus to explain the charge, mass, and beta decay one observed.

As I pointed out elsewhere, Rutherford did not do this experiment. It was done by Geiger and Marsden at his suggestion. His explanation was published 2 years later. The original papers make interesting reading, much more interesting than the usual description in textbooks.

James A. Carr

Rutherford's scattering experiments both proved that atoms had small, dense nuclei and proved that the nuclei consisted of relatively massive electrically neutral and positively charged particles. He discovered that radioactivity, reported earlier by the Curies, consisted of electrically positive, negative and neutral kinds, and I think it was Rutherford who gave them the names of alpha, beta and gamma rays before he worked out just what they were. Rutherford, the great deviser of experiments, and his close friend Nils Bohr, the theoretician, were together responsible for the image of the atom that we still have - the cluster of protons and neutrons forming the nucleus, and the surrounding cloud of electrons.

One of the oddities of Rutherford's Nobel Prize was that it was granted for achievements in chemistry. That apparently greatly amused Rutherford who claimed to be quite ignorant of chemistry. The Nobel committee apparently considered that the discovery of the formation of new elements early in Rutherford's career was a chemical rather than a physical matter.

As for the lord business, yes, Rutherford was made Baron Rutherford of Nelson. One of the handful of New Zealanders who have been elevated to the peerage (the only other one that I can think of at the moment is the much more recent Lord Elworthy).

Lyndon Watson

What???? Nuclear fission was discovered after Rutherford was dead.

Rutherford major discoveries (some of these were in collaboration):
1) The natural "transformation" of atoms. (Soddy: "Rutherford, this is transmutation!" R.: "For Mike's sake, Soddy, don't call it transmutation, or they will have our heads off as alchemists!")
2) The discovery of half-lives, and the exponential decline of radioactivity.
3) The discovery of radon.
4) The identification of numerous isotopes and the tracing of many radioactive decay chains.
5) The proof that alpha particles were ionized helium (which instantly gave a much more accurate experimental value of the charge of the electron, although Planck's blackbody work had anticipated it).
6) The discovery of the atomic nucleus.
6.5) Niels Bohr :-)
7) The discovery of the nuclear force.
8) The first artificial transmutation (N + He -> O + H).

All of this is from memory; I may have forgotten something. I second the recommendation to read Pais's ‘Inward Bound’.

(I will _not_ try and figure out the nomenclature of the British nobility!)

Courtenay Footman

According to Rutherford Simple Genius (David Wilson) MIT Press 1982 Rutherford was knighted in 1914 and became Lord Rutherford of Nelson in 1931 - most likely for his services to science (e.g. President of the Royal Society) than for his research (great though it was). And yes, he is attributed with that nasty little pro-physics saying.

Rutherford accomplished a hell of a lot. He is often referred to as the "Father" of nuclear physics. His work with Soddy took place at McGill University in Canada. It was because of his remarkable accomplishments there that he got his next job at Manchester where he did his work on the atomic nucleus. After that he became head of the Cavendish Lab where he had earlier been a student with JJ Thomson (very famous physicist for those who don't know).

It was his work at McGill on radioactivity that eventually won him the Nobel Prize (in Chemistry!) in 1908. His alpha particle scattering experiments (i.e. those conducted by Geiger and Marsden under his direction) and his conclusions about the structure of the atom didn't come until 1911. His "splitting of the atom", for which he was best remembered by the general NZ public came in 1919.

In addition he had, as early as 1897, discovered that natural radioactivity consisted of the emission of more than one type of "ray" (alpha and beta) and he contributed much to the understanding of those emissions and techniques for studying them. In 1909 he (and Royds) identified the alpha particles as Helium nuclei. Rutherford also postulated the existence of the neutron circa 1924 --- several years before its discovery by Chadwick in 1932.

As for the "lord" business, well, believe it or not, scientists were regarded with esteem in those days and the British government created the title for him. Rutherford chose this title to be designated as Lord Rutherford of Nelson, after his birthplace in NZ.

Paul Bickerstaff

>My question concerned the attribution of the quote:

>Was Rutherford a Baron in 1902, before his discoveries, or was that title given to him later as an honor for those discoveries?

>Do any Kiwis know?

Rutherford was ennobled for his discoveries but I don't know the date. Incidentally he won his initial scholarship, which enabled him to work overseas, for advances in radio receivers. He perfected an improved coherer (long obsolete type of detector - even preceded the crystal set).

I was at school at Nelson College (his old school) and there was quite a lot of stuff (papers, personal articles) in the school museum. His parents were farmers.

Martin

The fact that radioactivity changed one element into another was *extremely* fundamental. The Geiger + Marsden experiment only set limits on the size of the nucleus and full understanding of it came much later after the experiments of Hofstadter in 1955 actually resolved the nucleus. You needed the wave theory (Nobel for deBroglie) and all of quantum mechanics to reach those conclusions.

The small size was important for the advances in atomic physics (it gave the 'centre' for the Bohr-Sommerfeld model and later work with the coulomb potential in wave mechanics), but our view of it from the nuclear physics side reflects later developments.

Anyway, most of the fundamental discoveries were given prizes. Many other people made multiple discoveries worthy of the Nobel and got only one or zero.

>Also the fission experiment could also warranted a Noble as well and there.

No. Rutherford did not do that experiment. It warranted a Nobel (in Chemistry again) and got it -- for Hahn and Meitner.

>Ironically last year an important and famous physicist called Weizmann wrote an article that appeared in the CERN Courier giving a brief history from his view of nuclear physics. No mention of Rutherford. The list of hundreds of other important contributors (some only supplying details) starts with the Bohr of Bohr model fame. Rutherford made the unfortunate statement that the electrons where orbiting about the nucleus rather then wandering about the nucleus. This seems to have rendered his contribution as somewhat of an aside. I plan to write to this Weizmann guy and point this small anomaly in his article.

You might get his name right first. Then you might reread the articleand compare it to other histories (Second Creation, Making of the Atomic Bomb) before formulating your criticism. The three articles do, after all, only represent Weisskopf's opinion on the important developments, and Weisskopf is a theorist. Thus, in writing a 3-page summary of the developments in physics (*all* of physics, not just nuclear physics, but he does emphasize atomic, nuclear and particle physics as one might expect based on his work) from 1900 to WWII, he emphasizes theory.

However, I am not alone in agreeing with him that the discovery of the neutron in 1932 was the key that opened up the study of the atomic nucleus as a separate field of physics. There is little question of that. Until then, one did not know the primary constituents of the system, and you cannot do physics until you know that little detail.

James A. Carr

Rutherford took up a physics professorship at McGill in 1898, worked with Soddy and in 1902-3 identified radioactive half-life, moved to Manchester in 1907 and was awarded the Nobel Prize in chemistry in 1908 for his work on radioactivity. He worked with Geiger in 1908 and in 1909 used alpha particle bombardment of thin foils to lead to his 1911 description of atomic structure.

He was knighted in 1914, then succeeded Thomson at the Cavendish Laboratory in 1919. He was elevated to the peerage in 1931. His other awards included an Order of Merit in 1921, the Copley Medal of the Royal Society in 1922, and he was President of the Royal Society from 1925 until 1930.

Gary

You might also care to mention that he was registered at birth as Earnest but dropped the "a" on his marriage certificate. Not many people know that.

Brian Dooley