Lesson 3: Making of physics knowledge
Video Lesson
Lesson objective
Dear learners,
At the end of the lesson you will be able to
- Discuss how scientific knowledge (especially physics) is constructed.
- Discuss the roles that the learning of physics plays to the individual intellectual satisfaction.
Brainstorming question
What is the process of gaining knowledge in physics?
Key Terms and Concepts
- Sensory Perception:
- Introspection:
- Memory:
- Testimony:
- Inference:
Knowledge gained through the senses, such as sight, hearing, touch, taste, and smell.
Knowledge obtained by examining one’s own thoughts, feelings, and sensations.
Knowledge recalled from past experiences and stored in the mind
Knowledge acquired from others’ reports, statements, or accounts
Knowledge derived by reasoning and drawing conclusions from evidence and premises.
LESSON Presentation
- One way of understanding the concept of knowledge is to look at the different ways in which we acquire knowledge.
- There are two types of knowledge from two entirely different sources.
- knowledge through experience:- seeing something, hearingaboutsomething,feelingsomethingcalledaposterioriknowledge.
- knowledge that does not come from experience, but perhaps instead is intuitively supplied from reason itself, such as logical and mathematical truths called a priori knowledge.
Experimental knowledge
Experiential (a posteriori) knowledge is of many types.
Four of them are sensory perception, introspection, memory, and testimony: these are the four main ways of acquiring knowledge through experience.
- Sensory perception: is perhaps the dominant source of experiential knowledge, it immediately raises a critical question. We gather knowledge by seeing, touching hearing, etc.
- Introspection: is like a sixth sense that looks into the most intimate parts of our minds, which allows us to inspect how we are feeling and how our thoughts are operating. If I go to a doctor complaining of an aching back, she’ll ask me to describe my pain. Through introspection I then mightreport,“Well,it’sasharppainthatstartsrighthereandstopsrighthere.” The doctor herself cannot directly experience what I do and must rely on my introspective description.
- Memory: is like a recording device that captures events that one can experience more or less in the order that they occur.
- Testimony: Testimonies from written sources are usually more reliable than oral sources, but much depends on the integrity of the author, publisher, and the methods of fact-gathering.
Non-Experiential Knowledge
Non-experiential (a priori) knowledge, this source of information is more difficult to describe. We presumably gain access to this knowledge through rational insight. Usual examples of non-experiential knowledge are mathematics and logic. Take, for example, 2+2=4. Indeed, I might learn from experience that two apples plus two more apples will give me four apples.
Scientific method
The scientific method is an ordered series of steps to acquire knowledge based on experimental evidence
Examples of Scientific Method in Physics
Observation: the water boiled at a lower temperature when I was visiting the mountains than when I was in other cities with low altitudes.
Question: Why does my water boil at different temperatures?
Research: In a chemistry book, you read that the boiling temperature of a substance depends on the strength of the molecular bonds of a substance and the pressure.
Hypothesis: Since the atmospheric pressure changes with altitude, the boiling temperature of water is different at different altitudes.
Experiment: You decide to heat water at different altitudes and record the boiling temperature.
Analysis: Your measurements indicate that as the height increases, the boiling temperature of water decreases
| Altitude(m) | Boiling point of water(Co) |
| 0 | 100 |
| 150 | 99.5 |
| 305 | 99 |
| 610 | 98 |
| 1524 | 95 |
Figure 1.1 Diagram of scientific method
Conclusion: The original hypothesis was correct. The boiling temperature of water decreases approximately by one degree Celsius