Lighter than air is the name given to gasses like hydrogen and helium. They have been used to give buoyancy to balloons and airships for over a hundred years.

In my book, Lighter Than Air, the term is also used in its romantic sense.

The love a man and a woman have for each other that never dies. Their love
transcends human mortality and moves through time barriers, to continue
a love story that is everlasting.  

Lighter Than Air will take you flying in modern RAF Tornados and floating
in the 1930’s Zeppelin, Hindenburg. You will follow the fortunes of a
modern war hero and a lowly airship mechanic and discover how their lives
and their loves are bound together.  

I hope readers will gain as much pleasure from reading Lighter than Air
as I have from writing this story.