Definition
Science is the collective knowledge of natural phenomena, processes and events occurring around us. It is divided into two main groups: biological sciences (the study of living things) and physical sciences (the study of non-living things).
Physics is a fundamental science and the basic part of the physical sciences. It deals with matter, energy, space and time, and their relationship and interaction with one another — from particles smaller than an atom to stars and galaxies.
Definition
Mechanics: motion of objects and the forces acting on them. Heat and thermodynamics: heat, temperature and their relation with work. Acoustics: sound. Optics: light.
Electromagnetism: electric current, magnetic fields and the relationship between them. Quantum mechanics: behaviour of atoms and particles smaller than atoms. Relativistic mechanics: position and time are not absolute but depend on the observer, and are affected by gravity and speed.
Nuclear physics: properties of the nuclei of atoms. Particle physics: particles smaller than atoms and elementary particles. Astronomy: celestial bodies such as planets, stars and galaxies.
Definition
An interdisciplinary field is formed when physics merges and interacts with other disciplines of science.
Examples: biophysics (physics of living systems), astrophysics (physics of stars and the universe), geophysics (the Earth's internal structure, its magnetic and gravitational fields, earthquakes and volcanoes), climate physics (the atmosphere, weather and climate change), computational physics (solving complex physical problems with computational techniques).
Remember
Complex problems — climate change, prevention and treatment of diseases, long-term energy solutions — are too varied for a single field. During the COVID epidemic, experts in biology, chemistry, physics, medical technology and data science had to work together. This is why interdisciplinary research and collaboration are necessary.
Rule
Observation: carefully studying a natural phenomenon and collecting data about it.
Hypothesis: a possible explanation, based on the observations, that can be tested.
Experiment: an organised procedure to check whether the hypothesis is correct or not.
Theory: a hypothesis confirmed by successful experiments — a logical explanation of the causes and effects of a natural phenomenon.
Prediction: what the theory says should happen in situations not yet observed; it is tested by repeated experiments. If the results do not agree, the theory is modified or rejected.
Law: a theory that has been tested again and again and is accepted as a truth.
Example 1 — light travels in a straight line
Apply the steps of the scientific method to the formation of shadows.
- Observation: an opaque object placed in the path of sunlight or lamp light forms a shadow.
- Hypothesis: shadows are formed because light travels in a straight line.
- Experiment: a lit torch is seen through holes in four cardboards only when all the holes are in one straight line.
- Theory and prediction: light travels in a straight line, so the shadow of an object will have a shape similar to the object.
Answer: The shadow of a ball is round and the shadow of a rectangular block is rectangular — the prediction holds, so it is accepted as a law
Remember
Falsifiability: a theory is scientific only if it makes predictions that can be tested and could possibly be proved wrong. This separates scientific theories from vague claims and false beliefs that cannot be tested by experiment. A small amount of data can never prove that a prediction is always correct, but a single contrary result can prove that it is not always correct.
Definition
Science: knowledge gained by studying nature through observation and experiment.
Technology: the application of scientific knowledge for practical purposes. Engineering: using science and technology to design and build machines, structures and systems.
Examples: automobile technology, refrigeration and air conditioning are based on thermodynamics; smartphones use electronic and information technology; lasers are an application of the physics of light.
Quick Recap
- ●Science: collective knowledge of natural phenomena; two groups — biological and physical sciences
- ●Physics: matter, energy, space, time and their interactions; branches include mechanics, heat, optics, acoustics, electromagnetism, quantum, nuclear and particle physics
- ●Interdisciplinary fields: biophysics, astrophysics, geophysics, climate physics, computational physics
- ●Scientific method: observation → hypothesis → experiment → theory → prediction → law
- ●A scientific theory must be falsifiable; technology and engineering apply the knowledge of science
