Question: You want to measure the thickness of a mysterious sheet, but how?
Answer: Use radioactive materials, of course!

• Radioactive materials are becoming the cool kids on the block in industries.
• Main Use: Measuring thickness quickly and accurately.
• Fun Fact: The radiation intensity changes (or, in fancy terms, "varies exponentially") as it goes through materials.

• Beta-minus particles (Cool name, right?)
  • Perfect for measuring the thickness of aluminium when it's being rolled into sheets.
  • Imagine you're making a super-thin pizza crust; these are your go-to guys.
• Alpha particles
  • Nope, not so much for aluminium. Most of these particles get absorbed by the metal.
  • It's like throwing water balloons at a sponge wall; they won’t get far.
• Gamma photons
  • They’re like the ninjas of radiation! Aluminium doesn't stop them at all.
  • It's like trying to stop a car with a feather. Not happening!