Do you think that is really small?

This evening at the dining table Bro. Juniper produced a tiny artifact, held in the palm of his hand, yet for the life of me, for I was seated across the dining table, his palm appeared to be empty. "See," he said as he thrust his open hand under the nose of Bro. Simon. "You mean that?" Bro. Simon blurted, his brow furrowed as his nose actually touched Bro. Juniper's hand. "Exactly," replied Bro. Juniper with a bit of bravado in his voice, "a grain of sand!" And with that he plucked the grain of sand up and held it for all to see, yet I confess I still could not see that grain of sand, and now scooting his chair back, Bro. Juniper quickly rose and after clearing his throat, recited William Blake:
"To see a World in a Grain of Sand
And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand
And Eternity in an hour..."
With that Bro. Clarence, with chicken drumstick still in hand, said, "Do you think that is really small?" Bro. Juniper turned to Bro. Clarence and said, "Yes." Bro. Clarence, seated at the end of the table, finished picking his drumstick clean, then paused while wiping his hands on a napkin, then said, "In string theory, the average size of a string is somewhere near the length scale of quantum gravity ... that called the Planck length ..." and now finished with his hands, Bro. Clarence rolled the napkin into a ball, and continued, "do you understand that the Planck length is about a millionth of a billionth of a billionth of a billionth of a centimeter?" Then with the tiny compacted spitball of a napkin, he positioned it between his "spring loaded" middle finger and thumb, then released the spitball into the air, sailing over Bro. Juniper's head while saying, "I think you're poetic grain of sand is about the size of Jupiter in comparison to that spitball ..." With that, Bro. Juniper burst into laughter, and so too Bro. Clarence.