When high energy radiation strikes the Earth from space, it’s called cosmic rays. To be accurate, a cosmic ray is not like a ray of sunshine, but rather is a super-fast particle slinging through space. Think of throwing a grain of sand at a 100 mph… and that’s what we call a ‘cosmic ray’. Build your own electroscope with this video!
[am4show have=’p8;p9;p11;p38;p92;p17;p44;p76;p90;p58;’ guest_error=’Guest error message’ user_error=’User error message’ ]
Materials:
- Clean glass jar with a lid
- Wire coat hanger and sand paper
- Aluminum foil
- Vice grips or a hacksaw
- Scissors
- Balloon or other object to create a static charge
- Hot glue gun (optional)
Download Student Worksheet & Exercises
Troubleshooting: This device is also known as an electroscope, and its job is to detect static charges, whether positive or negative. The easiest way to make sure your electroscope is working is to rub your head with a balloon and bring it near the foil ball on top – the foil “leaves” inside the jar should spread apart into a V-shape.
Exercises
- How does this detector work?
- Do all particles leave the same trail?
- What happens when the magnet is brought close to the jar?
[/am4show]
Please try these items.
1) Instead of sanding the entire coat hanger, only sand the area where the aluminum foil will hang and the top of the coat hanger there you attach the ball of foil. By leaving the thin coating on the long part of the coat hanger, you’ll help prevent electrons from leaking into the lid of the jar.
2) It is best to use really thin aluminum foil. Brand name foils can be too thick, which causes them to be too heavy for the static to push the foil leaves apart. Try getting some really thin foil from a “99 cents” type store.
This isn’t working for me. When I hold to balloon close to the foil ball, I hear a static charge from the balloon to the foil ball but the foil leaf doesn’t move at all. What am I doing wrong?
this is so good