Barley and broth displacement

I’m making a pot of beef barley soup and have made my broth and ready to add vegetables and barley. I may have a bit more broth then I had intended and I’m kinda wondering about displacement versus absorption. If I should come close to the brim of my pot when I add the dry barley when it absorbs the broth and swells will the level in the pot increase, decrease or remain the same?
I’m actually going to remove some broth before I add the vegetables and barley but just wondering. Science was not a strong point of my school days 45 years ago.

This sounds like a letter to Marilyn vos Savant. She’d tell us the truth was actually something impossible-seeming and we’d all gasp.

But I, a mere mortal, am 99.9% sure that the level in the pot will stay the same, since the barley is just absorbing the liquid. No magic like ice expanding when it freezes or goats behind door #3.

I never have enough broth… the longer the barley is in there the more it absorbs. I think it is like rice with a 2 to 1 ratio… maybe.

It might depend on the type of barley you use, but I learned the ratio is 6 : 1.