[NOTE: I HAVE NOW EDITED THE WIKIPEDIA PAGES ON 'VOWEL LENGTH', 'ENGLISH PHONOLOGY' AND 'RECEIVED PRONUNCIATION' TO CORRECT THE VOWEL LENGTHENING/VOWEL SHORTENING PROBLEM DESCRIBED BELOW]
I have noticed that an old fallacy survives in a couple of Wikipedia articles. In Vowel length and in English phonology you find the statement (made without any citation to support it) that English vowels are lengthened when followed by voiced (lenis) consonants or in an open syllable. The correct statement is that vowels are shortened when they are followed by a voiceless (fortis) consonant. You can see this in the descriptions in Cruttenden’s Gimson, section 8.4.1. The basic scientific work was published in 1970 by Matthew Chen in an interesting article entitled ‘Vowel length variation as a function of the consonant environment’ (Phonetica, 22, 129-59). I have written about this issue very briefly in ‘English Phonetics and Phonology’ (page 29 in the latest edition, in “problems and further reading”, 4.4.) A simple “do-it-yourself” test is to measure your pronunciation of ‘ride’, ‘rye’ and ‘right’. The duration of the diphthong in ‘rye’, being in a zero-coda syllable, may be taken as the baseline duration. ‘Ride’ will show a very similar duration, but ‘right’ will have a markedly shorter duration. I will edit the two articles (and any others I find with the same error) and also remove the “generative rule” included in the Vowel length article (which is not only ad hoc and unnecessary, but also wrong).