Mon Prof Augmenté
Shielded Lamps and Dark Skies
Streetlights without shields send light upward, making the night sky brighter and hiding faint stars. Streetlights with flat tops and shields send light down, so the sky stays darker and more stars appear.
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In the picture
- Bare globe streetlamp: a round glass lamp that sends light in all directions.
- Pale sky with faint stars above the bare lamps: scattered light that hides most stars.
- Flat-topped shielded lamp: a fixture with an opaque cap and side shields.
- Downward light cone on the pavement: a bright pool where the shielded lamp aims its light.
- Dark sky with many stars above the shielded lamps: a sky where faint stars remain visible.
Examples
- A porch light that shines upward into tree branches.
- A parking lot lamp with a top cover that keeps light on the ground.
Key takeaways
- Light aimed upward scatters in the air and brightens the night sky.
- Shields direct light downward and reduce sky glow.
Carry on in the app
Three questions on this lesson. It has left the free week, so its quiz is for subscribers.
At least one new illustrated lesson every weekday for your child’s year, with its quiz and a reminder at 6:15 pm.
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