For example, light can travel in waves, creating patterns of color and interference. But when we look closely, we find that light is made of tiny packets of energy called photons, which behave like particles. Experiments such as the famous double-slit experiment show that the same particle can create a wave-like pattern—unless we watch it closely, in which case it acts like a particle!

 

This dual nature means quantum objects don’t fit into the categories we use in everyday life. They’re not just particles or waves—they’re both, depending on how we measure them.