======Inverse Square Law With Balloon======


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**Alternative titles:** Solar Power and Distance Demonstration
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====Summary====                   
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====Procedure====  
  - Inflate a round balloon to about 10 cm in diameter and imagine the Sun at its center.
  - Draw a 1 cm by 1 cm square near the bottom of the balloon with a marker. This square represents the amount of sunlight collected at a certain distance.
  - Inflate the balloon to about 20 cm diameter, doubling the distance from the center. Measure the square again and record how its area has changed.
  - Inflate the balloon further to about 30 cm diameter, tripling the distance from the center. Measure the square again and record the change.
  - Compare the increase in balloon radius with the change in square area. Discuss how light intensity decreases as distance increases.
  - Relate findings to solar-powered spacecraft and why their panels must grow in size as they travel farther from the Sun.



====Links==== 
📄 Collecting Light: Inverse Square Law Demo - NASA: [[https://www.jpl.nasa.gov/edu/resources/lesson-plan/collecting-light-inverse-square-law-demo/]]\\


====Variations====
  * Compare results to actual missions like Juno, Psyche, or Europa Clipper and their solar array designs.
  * Extend the demo to other forms of energy that follow the inverse square law (sound, gravity, radiation).



====Safety Precautions====
  * Be careful not to over-inflate balloons, which may pop suddenly.
  * Use caution when working with electrical equipment such as lamps or sensors.
  * Keep markers and balloon fragments away from younger children.



====Questions to Consider====
  * What happens to the available sunlight at Jupiter compared to Earth? (It is 1/25th as much, since Jupiter is 5 times farther away.)
  * How does the inverse square law explain the need for very large solar panels on distant spacecraft? (Because the available light decreases rapidly with distance, requiring more collection area.)
  * Does the inverse square law apply only to light? (No, it also applies to sound, gravity, radiation, and other forms of energy that spread out spherically.)
  * How does the amount of sunlight at Saturn compare to that at Jupiter? (Saturn is twice as far as Jupiter, so light there is about 1/4 of that at Jupiter.)