Unit 3 Understanding Science
Part I Journey on the Paper
Now let’s go on a journey through the most spectacular 100 years in the history of science and technology to have an overview of how our understanding of the world has grown from 1900 to today.
MATTERS OF LIFE AND DEATH -- Medicine and Health 1900:
Patients battle illness, while doctors can do little more than counsel（劝告）and comfort them and keep them clean. Today:
Doctors treat and often cure patients with a vast array (一大批) of medicines and medical technologies, but some diseases are still incurable.
MYSTERIES OF THE UNIVERSE -- Physics and Astronomy
The Milky Way galaxy（星系）(including some unexplained nebular clouds（星云）) is the known universe. Newton’s laws explain the physical world. Matter is composed of atoms. Today:
The Milky Way is just one galaxy among countless millions we have observed in the universe. There is no set of laws that explains all phenomena in the