Why do shadows change during the day?
A shadow forms where something blocks sunlight. As the Sun moves across the sky, shadows change length and point a different way.
Morning
The Sun is climbing higher, so shadows are getting shorter and swinging round.
Shown for a place about 30° north of the equator (like Delhi or Cairo) in March or September. The Sun and its path are drawn close to the garden so you can see them; the real Sun is far away.
Shadows: questions and answers
A shadow is the dark shape where light cannot reach because something is in the way. Shadows always point away from the light. When the Sun is low, shadows are long. When the Sun is high, shadows are short.
What is a shadow?
Light travels in straight lines. When something solid, like you or a tree, blocks the light, the area behind it gets less light. That darker area is a shadow.
Why are shadows long in the morning and evening?
In the morning and evening the Sun is low in the sky. Its light comes from the side, so it skims past you and makes a long, stretched-out shadow.
Why are shadows short at midday?
Around midday the Sun is highest in the sky. Its light comes from above, so your shadow is small and close to your feet.
Why does my shadow change direction?
Your shadow always points away from the Sun. In the morning the Sun is in the east, so your shadow points west. In the evening the Sun is in the west, so your shadow points east.
Does the Sun really move across the sky?
It looks like it does, but really Earth is spinning. As Earth turns, the Sun appears to rise, climb, sink and set. See the day and night lesson to watch Earth spin.
Why are there no sharp shadows before sunrise?
Before sunrise and after sunset, the Sun is below the horizon. The sky still glows, but that soft light comes from every direction, so it does not make sharp shadows.
What the 3D model shows
The model shows a sunny garden with a child, a tree, a blue ball and a short wooden post. Letters on the grass show north, south, east and west. A small Sun moves along a dotted curve across the sky, from the east in the morning, high in the south at midday, to the west in the evening. Each object casts a dark shadow on the opposite side from the Sun. In the early morning the shadows are long and point west. They shrink and swing round until midday, when they are shortest and point north. In the afternoon they grow longer again and point east. The panel shows the time, how high the Sun is, which way shadows point, and how long the child’s shadow is compared with their height.
Common mix-ups
- “Shadows are made of something.” A shadow is not a thing; it is just a place where light is blocked.
- “My shadow is longest at midday.” It is actually shortest around midday, when the Sun is highest.
- “The Sun is directly overhead at noon everywhere.” Only near the equator can the Sun be straight overhead. In most places it is high, but still a little to one side.
- “A shadow always points the same way.” It turns during the day, always pointing away from the Sun.
Remember
Shadows point away from the Sun. A low Sun makes long shadows; a high Sun makes short shadows.
For grown-ups: things to ask
- Before pressing Play, ask: “Where will the shadow be at lunchtime? Will it be longer or shorter?”
- On a sunny day, mark the tip of a stick’s shadow with stones every hour. Look at the pattern together.
- Ask: “Which way is your shadow pointing right now? So where must the Sun be?”
Going deeper (ages 9–11)
Why do shadows point north at midday?
For places north of the tropics, like most of Europe, the USA and northern India, the midday Sun is in the southern part of the sky, so shadows point north. South of the tropics, like in Australia, it is the other way round: the midday Sun is in the north and shadows point south.
How can you work out shadow length?
Shadow length depends on the Sun’s height (its angle above the horizon). When the Sun is 45° high, a shadow is about as long as the object is tall. Lower than 45°, the shadow is longer; higher, it is shorter. The panel shows this as “your shadow is 1.5× your height”.
Are shadows different in summer and winter?
Yes. In summer the midday Sun is higher, so midday shadows are shorter. In winter the Sun stays lower, so even midday shadows are long. This model shows March or September, halfway between.
Why are shadow edges a little blurry?
The Sun is not a single dot; it is a disc in the sky. Light from different parts of the disc makes the edges of a shadow slightly soft, especially for tall objects.
What this model simplifies
- The Sun is drawn small and close so it fits on screen. The real Sun is huge and about 150 million kilometres away, which is why sunlight arrives in almost parallel lines and all the shadows point the same way.
- The time shown is “Sun time”, when noon means the Sun is highest. Clock time can differ by up to an hour or more.
- The model shows one place and one time of year. The Sun’s height and path change with where you live and the season.
- Light scattered by the sky and clouds is simplified.
Sources
- BBC Bitesize: Light and shadows
- NASA Goddard: The sky above us (shadows and the Sun’s path)
- NSTA: Me and my shadow
- NOAA solar calculator (Sun height for any place and date)
Last updated 10 November 2026. Made by Akhil Paul. Interactive lessons are free to use.