Motion & position
The idea
Where is the ball? You answer by comparing it to something else: next to the slide, under the bench, behind the tree. That comparing is what position means — where something is, told from a chosen spot. Words like near, far, above, below, left, and right only make sense when you say what they are measured from. Motion means a change of position: something moved if it is now in a different place compared to that chosen spot.
To tell whether something moved, pick a landmark — a thing that stays put, like a bench or a tree — and check the object's position against it twice. If the position changed, there was motion. You can even measure the change by counting steps from the landmark. A common mix-up is saying something is just far away without saying far from what. The school might be far from your house but close to the park. Position is always a comparison, never a fact about the thing all by itself.
Worked example
You sit on a park bench. Your friend stands 3 big steps from the bench, by the water fountain. You close your eyes for one minute, and when you open them, your friend is 10 big steps from the bench, next to the slide. Did your friend move, and how can you be sure?
- Pick a landmark that stays put. The bench does not move, so measure every position from the bench.
- Record the first position: your friend was 3 steps from the bench, beside the fountain.
- Record the second position: now your friend is 10 steps from the bench, beside the slide.
- Compare the two positions: 3 steps and 10 steps are different distances, and the fountain and the slide are different places. The position changed, so your friend moved while your eyes were closed.
- Check your landmark choice: if you had measured from your friend's own shoes, you could never tell anything, because the shoes travel along too. You need a spot that stays still to compare against.
Answer. Yes — your friend moved, because their position changed from 3 big steps to 10 big steps away from the bench.
Check your understanding
- How would you describe where your bed is so a visitor could find it, and which landmarks would you use?
- Why is it not enough to say a playground is far away, and what is missing from that sentence?
- When you ride in a car, the trees seem to slide backward — what landmark is your mind using, and which landmark would make the trees stay still?
- How could counting steps from a rock prove that a snail moved, even though it crawls too slowly to watch?