Section 3: Scientific Models

What is a model?

the representation or description designed to show the workings of an object or system.

Note:

Models have limitations. A model is never exactly like the real thing--- if it were, it would no longer be a model.

Which are the three types of models?

Physical models, mathematical models, and conceptual models.

What is a physical model?

A model that you can touch

What is a mathematical model?

A model made of numbers, equations and other forms of data

What is a conceptual model?

A model that represents a system of ideas

Examples of physical models:

Toy car, plastic skeleton, baby doll

Examples of mathematical models:

A punnet square, weather forecast, charts 📊, graphs 📈

Examples of conceptual models:

the Big Bang theory, atoms

Remember:

Computers are useful for creating and manipulating MATHEMATICAL models.

Remember:

Scientists also use CONCEPTUAL models to classify behaviors of animals.

Benefits of models:

1. Models are used to represent things that are too big or too small in real life.
2. We can use models to represent an object that is too dangerous to visit in real life.
3. Models can be used to represent things that no longer exist (dinosaurs).

A model can be a kind of hypothesis…?

TRUE

What is a theory?

an explanation that ties together many hypotheses and observations

Theories are what type of model?

CONCEPTUAL

Remember:

A theory is a hypothesis with enough evidence to prove it is true, but it cannot be proven completely.

What is a law?

A summary of many experimental results and observations.
A hypothesis that has been proven so many times becomes a law and it is rare for it to change.

Laws are not based on what people may want for it to happen, they are based on…?

what WILL actually happen in a situation.

“All living things are made up of cells” is a THEORY or LAW?

THEORY, because it has evidence but can’t be proven completely.

A leaf falling from a tree to the ground is an example of THEORY or LAW?

LAW, because it follows gravity.
It has been proven that everything that goes up will eventually come down.

New scientific ideas are easily accepted as theories and laws. TRUE or FALSE?

FALSE. Nowadays, it is hard to accept an idea, because the majority of theories and laws are already stated.

Scientists should:
a) Always reject new ideas
b) Be open to new ideas, to prove them using the scientific method, and re-examine evidence

B

A ______ is an explanation that matches many hypotheses but may still change.

THEORY

A ______ tells you exactly what to expect in certain situations.

LAW

A limitation of a model is:
a) they are large enough to see
b) they don’t exactly act like the thing they model
c) they are smaller than the things they model
d) they model unfamiliar things

B