
I do. I tested their object
permanence with a RUBBER duck,
The Big Bang Theory Season 12, Episode 17

The pencil's RUBBER.
The Big Bang Theory Season 4, Episode 18

I've bounced many a RUBBER ball
in my day.
The Big Bang Theory Season 5, Episode 17

And RUBBER gloves, air freshener...
The Big Bang Theory Season 8, Episode 19

It can cut through steel
like it was RUBBER.
The Big Bang Theory Season 2, Episode 12