To me, Otto's post sounds perfectly correct. The sentence he used is an example of a contracted sentence, where parts of a clause which would normally be included are omitted, and the reader is supposed to "fill in" the missing words for himself or herself.
It works like this: "
Bored with his life, he took up gambling" is a shortened form of "
Since he was bored with his life, he took up gambling".
Being a Swede, I have had to pay special attention to such contracted sentences in English, since they don't exist in Swedish.
Otto's post is a somewhat more complicated example of a contracted sentence. Otto wrote:
Known as aurora australis or southern lights, the shifting, luminous bands are commonly seen at high northern latitudes as well, there known as the aurora borealis or northern lights.
Otto's sentence may be "lengthened" like this:
Known as aurora australis or southern lights, the shifting, luminous bands are commonly seen at high northern latitudes as well, and there they are known as the aurora borealis or northern lights.
Another way of lengthening Otto's sentence forces you to replace "there" with "where":
Known as aurora australis or southern lights, the shifting, luminous bands are commonly seen at high northern latitudes as well, where they are known as the aurora borealis or northern lights..
<stepping down from the pulpit>
Ann