北师大版模块7 Unit 20 Lesson 3

E=mc2 showed how a small piece of mass could produce unbelievable amount of energy.
Einstein then showed in his “theory of relativity” that not even time, mass or length are constant — they change according to our experience of them.
He discovered small areas of mist which were in fact galaxies like our own, millions of light years away from us, which proved that the universe was vastly larger than had previously been thought.
One of the 20th century's premier scientists was Albert Einstein. In the summer of 1905, this outspoken young man was rocking his one-year-old baby when he was suddenly inspired. “E=mc2” was born.
In 1929, another far-reaching finding was made by the son of a Scottish shepherd.
Before he went on holiday, biologist Alexander Fleming left a dish with bacteria in it in his laboratory. When he came back, he noticed something strange.
Communications changed with the introduction of mobile phones and the way we correspond went from writing letters to emailing.
We started flying around the world and meanwhile, scientists figured out how to split the atom, previously thought to be the smallest particle of matter in the universe.
It measured 100 feet long by over 10 feet high and weighed over 30 tonnes. With 18,000 tubes, thousands of circuits and 6,000 switches, it used so much energy that when it was turned on, the lights in the local town went out!
“Nature made penicillin,” he said, “I just found it.” During the Second World War, when Fleming's discovery was first helping to cure people, the US Navy was looking for ways of improving the accuracy of their missiles.
The navy turned to Eckert, an engineer, and Mauchly, a physicist, to wrestle with the problem and produce a machine to do the job.
Although they only finished after the war in 1946, it did not matter. This huge machine was the world's first computer, but it was nothing like our computers today.
Medical advances ranged from discovering the causes of diseases under microscopes to surgical procedures replacing diseased organs with donated ones.
There is no doubt about it. Without the breakthroughs of these pioneers in science and technology, whether lucky or planned, the world as we know it today would have been a completely different place.
For example, we are all grateful for the handy microwave oven that allows us to prepare meals in minutes and we have Percy Spencer to thank.
This inventor, with 120 patents to his name, discovered microwaves when he was experimenting with radars and noticed a chocolate melting in his pocket.
Einstein had already become world-famous when a young ex-lawyer, returning from the First World War, started work in California.
Using the most high-powered telescope of the time, he began the long, slow process of exploring our galaxy. Edwin Hubble was about to make astronomy's greatest breakthrough of the century.
A few years later, penicillin was being mass-produced and helping to save the lives of millions. Fleming remained modest about the amazing outcome of his discovery.
These pioneers of the 20th century were all dedicated to improving the quality of human life on earth, but sometimes breakthrough discoveries that have affected our lives today happened by mistake!
If you had to choose the single most important discovery of the 20th century, you would have a real dilemma on your hands.
In just 100 years, the world changed completely. Amazing discoveries were made in medicine, communications and transport, not to mention our knowledge of the world and space.
He double-checked and saw a blue mould in the dish around which t. This blue mould was in fact the natural form of penicillin, which Fleming realised could be used to kill bacteria.
Although it is impossible to choose the most important discovery, it is possible to single out a few pioneers of the 20th century. Here are five of them.