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sciencescientific thinkingJuly 24, 20265 min read

Why Scientists Use Models to Understand the Unseen

By the BrainSnail editorial team. How these articles are written and checked, and how to tell us when one is wrong.

You cannot hold the solar system in your hands or watch an atom with ordinary eyes. Scientists still need ways to test ideas about such things, so they build models - simplified representations that help explain, compare, and predict.

A model makes complexity manageable

A model can be a drawing, a physical object, a set of equations, a computer simulation, or even a carefully chosen analogy. Each type highlights some features and leaves out others. A globe, for example, shows the shape and relative positions of continents, but it cannot include every road, tree, current, and cloud.

This simplification is not a flaw by itself. It is the point. OpenStax explains that models place intangible or extremely complex systems into forms people can visualise, discuss, and test. A useful model is therefore less like a miniature copy and more like a carefully chosen question. It shows the features needed for that question and ignores distractions.

Models help scientists ask what happens next

Once a model matches important observations, scientists can use it to make predictions. A weather model can estimate how air, moisture, and temperature may change. A model of an atom can help predict how matter will interact. A disease model can explore how different conditions might affect spread. Models can also explore situations that would be too slow, costly, rare, or dangerous to repeat directly, provided scientists check the model against real observations.

Predictions give the model a real test. Scientists compare the expected result with new measurements. If the model repeatedly misses, they may adjust its assumptions, add missing information, or replace it with a better one. Scientific models can change when evidence demands it, and that willingness to improve is one of their strengths.

Every model has limits

A model is built for a purpose, so it should be judged by that purpose. A simple classroom model of the lungs may show airflow clearly while ignoring microscopic tissue. A city map may help you find a street while saying nothing about noise, weather, or how steep the walk will feel.

Ask these questions when you meet a model:

  • What part of reality does it represent?
  • Which details does it leave out?
  • What evidence was used to build it?
  • What predictions can it make?
  • When might it stop being reliable?

People sometimes mistake a familiar diagram for the thing itself. An atom is not literally a cluster of coloured balls, and Earth does not have bright border lines painted across it. Those images are useful because they organise ideas, not because they are exact pictures of nature. A strong science learner can use a model while remembering its limits. That balance lets you gain clarity without becoming trapped by an oversimplified picture.

The takeaway

Scientific models help you think about systems that are too large, small, distant, dangerous, or complex to study directly. Use them to explain and predict, but always ask what they include, what they omit, and how evidence could improve them.

Practise this

Questions from What is Science?

Reading about something is not the same as being able to recall it. These are real questions from the What is Science? unit in our Science track, answers and explanations included. The unit has 129 in total across 22 steps.

  • Choose all that applyLevel 2

    1. Which of these can you find out by testing? Pick all that apply.

    • Which paper airplane flies farthestcorrect
    • How many days a bean takes to sproutcorrect
    • Which ice cube melts firstcorrect
    • What the prettiest color is

    You can test and measure real things, but 'prettiest' is just an opinion.

  • Multiple choiceLevel 1

    2. What does a magnifying glass do?

    • Makes small things look biggercorrect
    • Makes things colder
    • Makes loud music
    • Makes things fly

    A magnifying glass makes tiny things look bigger so you can see them.

  • Fact or fibLevel 1

    3. Kids can act like scientists by observing and asking questions.

    Answer: True

    Anyone, even a kid, can be a scientist by looking closely and asking questions.