Hargrave's aeronautical journals and drawings illustrate his lifelong project to develop a practical flying machine and power plant in Australia.

UNESCO: Communication et information

The Death Star project concept falls in a practical sense at the first hurdle as nobody knows how to build a near light speed propulsion engine for it.

FORBES: White House Denies Petition Request To Build A Death Star

The UNESCO Global Microscience Experiments Project aims to provide a practical approach to experiencing science for elementary and secondary school students (and in some countries, students in their first academic year), using kits designed especially with a textbook illustrating the various experiments.

UNESCO: Strenthening Scientific Education in Niger

David Kesterton, parenthood and community project manager at the Family Planning Association, says there are a variety of sensible and practical reasons why men are having children later in life.

BBC: Older fathers: what's behind the trend?