The technological revolutions of the 20th century have brought both great benefits and great environmental and other problems. Humanity is riding a wild stallion called technology and if we do not control it then it will throw and destroy us. However, we can use new forms of technology to rein in the wild stallion and ride safely into the 2lst century and beyond. This book reviews the great technological revolutions of the 20th century and points out the problems they created and some possible solutions. It also attempts to differentiate the real problems from those that up to date have no proven basis. This is vital if we want to keep the benefits without destroying the technology. The scientists and engineers who shaped the great technological revolutions of the 20th century were a reflection of humanity as a whole.