Finally

There aren't that many more episodes left of The Big Bang Theory. And after about 270 episodes, they just did something I don't recall them ever doing before.

The episode, "The Confirmation Polarization," aired two days ago.  The characters were discussing how experimenters sometimes win Nobel Prizes over the theoreticians behind their work.

The specific example was Penzias and Wilson, who discovered cosmic background radiation.  They didn't even know what they had.  In fact, they thought their equipment was faulty until someone explained to them the significance of the data.

In other words, they won a Nobel Prize in physics for unwittingly helping to establish the Big Bang theory.

I haven't watched every episode ever on the show, and I don't remember everything the characters have ever said, but I think this was the first time they mentioned the Big Bang theory.  I wonder if the realized they better do it soon before the show was off the air.