Can anybody give me a brief summary/explanation of all this laryangeal/schwa stuff? It's obviosuly a major part of PIE philology but it seems very confusing to me. I understand that they were consonants, but why are they listed (in Sihler) in conjunction with vowels (such as eH1) and what effect do they have on subsequent languages (i.e. reflexes)?
Or is it not possible to summarise this issue? It certainly seems complicated and contraversial.