Is "gravity" pronounced /'græ.vɪ.ti/ or /'græv.ɪ.ti/? I had always assumed that it was the former, but the latter is shown in most dictionaries. Is there variation between accents?
The Maximal Onset Principle states that where there is a choice over the syllable in which a consonant, in this case /v/, is to be placed, it goes into the onset rather than the coda, that is to say, at the beginning of the following syllable, rather than the end of the preceding syllable, but this applies only within certain phonotactic constraints. One such constraint is that a syllable may not end with a vowel such as /æ/, and this will almost certainly explain why you have seen it as /'græv.ɪ.ti/ in most dictionaries.
Syllable boundaries are of interest to the phonetician, but they don’t normally have as much bearing on actual pronunciation as the stress, which in this case is correctly shown as being on the first syllable.