Why do THz waves have short propagation distances?

THz waves can't travel very far because they get stopped by things in their way, just like how a toy car gets stuck in the mud.

Imagine THz waves are little bouncy balls, they zoom through space really fast. But when they hit something, like a wall or even your hand, they bounce around a lot instead of going straight through. The more things they hit, the more they get scattered and lose energy.

If you're hiding and there are lots of people in the room, it's harder to stay hidden because the people keep moving and blocking your view. THz waves are like you, trying to be seen through all that movement and noise. The more things they bump into, the less they can get through.

If THz waves go through something thick or full of stuff, like a wall, they have a hard time getting out on the other side. That’s why they don’t travel far in places with lots of things blocking their path. It's like trying to throw a ball all the way across a room full of kids, it doesn't get very far!