Learning About Science PDF

### Learning about science #### 1.1 Learning about science **Let’s begin** Mary and Peter are having a picnic in a park. - Why is the sky blue in color? - What are these green dots growing on the bread? Mary's and Peter's questions are related to science. What is science? **A What is science?*...

### Learning about science #### 1.1 Learning about science **Let’s begin** Mary and Peter are having a picnic in a park. - Why is the sky blue in color? - What are these green dots growing on the bread? Mary's and Peter's questions are related to science. What is science? **A What is science?** People are curious about things happening around them. When we find something we do not understand, we often ask questions about it and try to find out the answers. Science is the study of phenomena and events in Nature. Scientists ask many questions about Nature. The questions in Let’s begin are examples. Below are other examples. - How does hail form? - What causes food spoilage? Scientific knowledge is built through systematic studies, which involve observation, experimentation, and analysis. This will be discussed in detail in the next section. *Key point* - Science is the study of phenomena and events in Nature. - We often apply scientific knowledge to deal with daily life problems. *Go further* **Branches of science** Science can be divided into different branches. Each branch has its own area of study. Fig 1.2 shows some examples. - **Biology** - the study of living things - **Physics** - the study of matter, energy and force - **Chemistry** - the study of properties, structures and reactions of substances - **Astronomy** - the study of the universe - **Geology** - the study of rock and the structure of the Earth - **Medicine **- the study of diseases *Key point* We often apply scientific knowledge to deal with daily life problems. For example, from scientific studies, we know that food spoilage is mainly caused by the action of microorganisms on food, and that microorganisms grow slowly at low temperatures. We can then apply this knowledge to develop ways to preserve food (Fig 1.1). **B Nature of science** **1 Science is based on evidence** Scientists accept an idea only with the support of evidence. Doing experiments is one of the ways of collecting evidence to test an idea. The story below gives an example of this. - **A long time ago, the great thinker Aristotle suggested that heavier objects fell faster than lighter objects. This idea was thought to be true for nearly 2000 years. Is Aristotle’s idea true? ** In the 16th century, Galileo Galilei questioned Aristotle's idea. He decided to do an experiment to test if the idea is true or not. **Galileo dropped two objects of different masses from the top of a tower. Both objects landed at the same time!** Galileo’s experiment provided evidence that Aristotle’s idea of heavier objects falling faster than lighter objects was not true. *Key point* Science is based on evidence. **2 Scientific knowledge is subject to change** Scientific knowledge is based on evidence. Hence, people tend to think that it will never change. Is it really the case? **Activity 1.1 The of gastric ulcers** Read the article below and answer the question. A *gastric ulcer* is a sore of the stomach wall. Through a lot of scientific studies, scientists came to believe that gastric ulcers were caused by too much stomach acid. Hence, doctors usually treated gastric ulcers with drugs to reduce stomach acid. However, the drugs did not work well. **In the 1980s, Barry Marshall found bacteria on the stomach wall of ulcer patients. He wondered if the bacteria were the real cause of gastric ulcers. To collect evidence he treated some ulcer patients with drugs that could kill bacteria. His treatment was successful. This result supported his idea.** From the article, do you think scientific knowledge is definite or it may change over time? From the activity, we can see that scientific knowledge is subject to change. When new evidence is found, scientists will revise the old idea and raise a new idea. In this way, scientific knowledge continually develops. *Key point* Scientific knowledge is subject to change when new evidence is found. **3 Scientific knowledge has limitations** With increasing scientific knowledge, we know more and more about how the natural world works. However, scientific knowledge has limitations. There are still many questions about Nature that cannot be answered using present scientific knowledge. For example: - Is there life on other planets? - How can we cure cancer completely? - How can we predict earthquakes accurately? In addition, we cannot use scientific knowledge to solve problems related to personal values and ethics, e.g. Is nuclear power good or bad?, Should we use animals to test new drugs?, etc. *Key point* Scientific knowledge has limitations. It cannot solve all problems. **Quick check** Write ‘T’ for a true statement and ‘F’ for a false statement in the boxes provided. - Science enables us to better understand how the natural world works. (T) - Scientific knowledge is supported by evidence and hence it is always true. (F) - We can solve all problems using scientific knowledge. (F) **4 Are applications of science always good?** Read the news headline on the right. Do you think that applications of science always bring benefits to us? Science is applied in many ways to bring us technological advances and better ways of living. However, the applications can be harmful if they are misused. For example, the invention of plastic brings us convenience but its overuse produces a lot of waste and leads to pollution. **Activity 1.3 The two sides of science** Below are two examples of the applications of science. What benefits do they bring to us? What possible harms could result if we misuse them? Discuss with your classmates and complete the table. | Benefit to us | Possible harm if misused | |---|---| | **Nuclear technology** : We can use nuclear technology to generate electricity. | If we abuse nuclear technology, it can cause environmental pollution and health problems. | | **Drugs** : We can take drugs to cure diseases. | If we abuse drugs, the drug will harm our health. | *Key point* The applications of science bring benefits to us. However, they can be harmful if we misuse them. **After-class activity** Find out more about possible harm caused by the misuse of science on the Internet. Design a poster to present your findings. **Quick check** Write ‘T’ for a true statement and ‘F’ for a false statement in the boxes provided. - Scientists have discovered many products that have greatly improved our quality of life. (T) - Using scientific knowledge, we can manage natural resources more effectively. (T) - The applications of science can be harmful to us. (T) **Section summary 1.1** **What science is** Science is the study of phenomena and events in Nature. **Nature of science** - Science is based on evidence. - Scientific knowledge is subject to change - Scientific knowledge has limitations. **Application and impact of science** - Scientific discoveries have increased our understanding of the natural world. The discoveries have also led to many inventions that have improved our quality of life. - Using scientific knowledge, we can manage natural resources more effectively. - Scientific knowledge is applied in the development of technology. - When solving daily life problems, we often need to integrate and apply knowledge and skills of science, technology and mathematics. - The applications of science bring benefits to us. However, they can be harmful if we misuse them. **Section exercise 1.1** **Level 1** 1. Which of the following belong to science? - To understand how rainbows form - To explain why we breathe faster when we do exercise - To find out what caused the extinction of dinosaurs *Answer: (1) and (2) only* 2. Which of the following statements about science are correct? - Science is based on evidence. - Scientific knowledge has limitations. - The applications of scientific knowledge always bring benefits to us. *Answer: (1) and (2) only* **Level 2** 3. In ancient times, people suggested that the Sun moved around the Earth. With more observations using powerful telescopes, now scientists find evidence to prove that the Earth moves around the Sun. Which of the following does this show? Put a tick "✓" in the appropriate box(es). - Science can explain everything. - Science is based on evidence. - Scientific knowledge is subject to change. *Answer: Science is based on evidence. ✓, Scientific knowledge is subject to change. ✓ * 4. Smartphones are very popular today. - Are smartphones a scientific discovery or a scientific invention? (1 mark) - Suggest ONE benefit brought about by smartphones. (1 mark) - How may overuse of smartphones cause harm to our health? Suggest ONE. (1 mark) *Answers: - Scientific invention. - A benefit of smartphones is that allows for communication with the internet. - Overuse of smartphones can harm our health by causing eye strain. *