* Mechanical waves require a medium: Mechanical waves, like sound waves or waves on a string, need a medium (like air, water, or a solid material) to travel through. They transfer energy by the vibration of particles within that medium.
* Gamma rays are electromagnetic radiation: Gamma rays are a form of electromagnetic radiation, which means they are made up of oscillating electric and magnetic fields. They do not need a medium to travel and can move through the vacuum of space.
In summary:
* Mechanical waves: Require a medium, travel through vibrations.
* Electromagnetic waves (like gamma rays): Do not require a medium, travel through oscillating electric and magnetic fields.
