Why do photons and protons exhibit such anomalous behavior?
As Bruce Hayes (UCLA) puts it,
Word-medial voiceless stops are aspirated provided they are in the onset of a stressed syllable and are not preceded by a strident (Hayes 1995: 13).
Thus,
proton [ˈpʰɹouˌtʰɑn] in AmE.
There's no secondary stress in "voting" in AmE.
See a note on aspiration in the Longman Pronunciation Dictionary (3rd ed., Wells 2008: 45) - those rules are rather comprehensive; at least, that should be enough for someone who's not a professional phonetician.
The most important thing to remember is that aspiration is not binary, aspirated or unaspirated, but rather gradual. See fig. 6.6 in Ladefoged 2006, A Course in English Phonetics.
Actually, it is the suffix -on that causes the secondary stress to happen in most situations, like when it is added after a consonant.
This phenomenon is very common in AmE. But not the case in BrE: OBED and many other British dictionaries show otherwise (no secondary stress). [ Though many British physicists still stress the word in a way that gives secondary stress on the second syllable.]
OE suggests that "on" made its first appearance in the early 19th century in atomic physics:
ion (n.) 1834 [interestedly I've heard people pronounce it two ways: ˈaɪən and ˈaɪˌɑn]
introduced by English physicist and chemist Michael Faraday (suggested by the Rev. William Whewell, English polymath), coined from Greek ion, neuter prp. of ienai "go," from PIE root *ei- "to go, to walk".
So called because ions move toward the electrode of opposite charge.
It was not until the late 19th century that it is used as a suffix.
In 1894, Stoney coined the term electron to describe these elementary charges, saying, "... an estimate was made of the actual amount of this most remarkable fundamental unit of electricity, for which I have since ventured to suggest the name electron". The word electron is a combination of the word electric(icity) and the Greek suffix "tron", meaning roughly 'the means by which it is done'. The suffix -on which is now used to designate other subatomic particles, such as a proton or neutron, is in turn derived from electron.
In the 20th century, it becomes a fashion to use it for coining new terms not only in physics:
proton is coined in 1920 {it was used earlier in embryology (1893) at a translation of German anlage},
neutron [ˈn(j)uˌtrɑn] is coined in 1921,
photon (a particle-like package of light) is coined in 1926,
positron [ˈpɑzəˌtrɑn] (the antiparticle of electron) is coined in 1933,
negatron [ˈnɛɡəˌtrɑn] (the antiparticle of proton) is coined around 1933,
fermion [ˈfɜrmiˌɑn] (any particle that follows the Pauli exclusion principle) and
boson [ˈboʊsˌɑn] (any particles that don't follow the exclusion principle) are coined in the mid 20th century
[A famous example of boson would be the higgs boson which may help us to gain a
deeper insight into dark matter and dark energy, recently discovered by CERN (though it is not exactly the higgs boson predicted by the Standard Model)]lepton (any particle that does not undergo strong interactions but follows the exclusion principle E.g. electron) is coined in 1948
muon [ˈmjuˌɑn] (an unstable, negatively charged lepton) is coined in the mid 20th century
gluon [ˈgluˌɑn'] (an exchange particle responsible for strong interaction) is coined in the mid 20th century
but also in other branches of science:
interferon [ˌɪntərˈfirˌɑn] Biochemistry
a protein released by animal cells, usually in response to the entry of a virus, that has >the property of inhibiting virus replication.
1957, coined in English, so called because it "interferes" with the reduplication of viruses. From interfere + subatomic particle suffix -on.
codon [ˈkoʊˌdɑn] Biochemistry
a sequence of three nucleotides that together form a unit of genetic code in a DNA or RNA >molecule.
1962, from code (n.) + -on.
operon [ˈɑpəˌrɑn] Biology
a unit made up of linked genes that is thought to regulate other genes responsible for >protein synthesis.
1960s: from French opérer ‘to effect, work’ + -on.
radon [ˈreɪˌdɑn] Chemistry
the chemical element of atomic number 86, a rare radioactive gas belonging to the noble gas series.
*1918, from radium (q.v.) + -on suffix of inert gases. *
A very famous physicist, Richard Feynman, even used the prefix -on to make up his own word, "parton" when he explained a seemingly-complex concept. And thus you can tell at that time the prefix -on was pretty well-used in the science community.
Notes: Not all 19th & 20th century scientific terms ending with "on" make use of the prefix "-on". One example would be ion as mentioned above, and here is another example
neuron [ˈn(j)ʊˌrɑn]
"a nerve cell with appendages," 1891, from German Neuron, from Greek neuron (see neuro-). Used earlier (1884) for "the spinal cord and brain."
Both the suffix -on and terms that exhibit secondary stress, such as neuron, ion, come from Greeks words.
So you are right, the Greeks are behind this.
You are correct in your guess about Greek. The first "-ton" (in relation to particle physics) was the proton. Ernest Rutherford named the proton from the Greek πρῶτον, meaning "first".
Incidentally, Rutherford also had William Prout in mind when he named the proton and even suggested that one of two names be used: protons or proutons. Prout was the first person to theorize a fundamental particle of matter, which he referred to as a protyle.
As particle physics evolved, further discovered particles were named in a similar fashion. Photons are the elementary particles of light, and were named "φῶς + ton". Most other elementary particles are named either for Greek words + "on" or "ton", or else after various physicists who had a hand in their discovery/description with "on" tacked on the end to indicate that it is a subatomic particle.
I also think your speculation about them being new words likely has something to do with their pronunciation. Proton began appearing in science literature in the 1920's. Every other subatomic particle name has been coined since then - these words are all less than 100 years old. They all originated after the invention of audio recordings, and none are used commonly enough to be changed by regional dialects.
The OED acknowledges that the pronunciations differ between US and British usage:
- Brit.
/ˈprəʊtɒn/ - U.S.
/ˈproʊˌtɑn/
I will now speculate generously, but precisely ~~~
Words like proton rose in prevalence within the US populace during the race into the 'Atomic Age'. Texas, due to the wealth of oil tycoons and the geological coincidence of petroleum and heavy metals, was the hotbed of nuclear developments in the US.
Texas are known for their particular drawl. The drawl is of French origin, and in the US became know as Cajun. This French-speaking influence is the basis for much of what is known as the "Southern Dialect". Particularly, this dialect is known for emphasizing the second syllable:
"Cajuns are quite distinct. They tend to place emphasis on the second syllable of a word, when possible. They use French words and phrases frequently in everyday speech. The names of Cajun cities and people often end in the very French suffixes '-ieux' and '-eaux', pronounced like a short 'o' sound"
Those familiar with the French style of speaking know that such words mentioned above, though 'short' in the Cajun dialect, are often emphasized.
Emphasis is often used for words of increased value or meaning.
As such, it is no stretch to conclude that the word "proton" would have garnered this attention by Southern speakers in the region, many of whom were staking business interest in booming nuclear operations - whose core science was based around the activities of Protons and other subatomic particles.