Today's trains are sleeker, greener and faster than ever before. Tomorrow's trains could travel through space at 23 times the speed of sound -- nearly 30 000 km/h (19 000 m.p.h.)! But did you know that train technology goes back 5 000 years? All aboard Ultimate Trains, which takes readers on a trip through the evolution of train technology, bringing to life the trains of yesterday, today and tomorrow. Five "Build It Yourself" experiments -- simple enough to create at home -- put train technology into action. Readers can learn how to build a steam engine from a soda pop can, test an electromagnetic track and go online to construct their own magnetic levitation train.