In the wake of her husband’s tragic assassination, Erika Kirk has been sharing intimate glimpses of the life she and Charlie Kirk built together. On Friday, she posted a heartwarming video that quickly went viral, capturing Charlie in full “dad mode,” teaching their young daughter the basics of physics.

Newton’s Laws at the Kitchen Table
The clip, which has already surpassed 1.3 million likes, shows the Turning Point USA founder sitting at a table with his daughter, using her sippy cup and a pair of sunglasses to walk through Newton’s three laws of motion.

“Okay, see that’s the issue, you keep on thinking when you drop [your sippy cup], it comes back up, but it doesn’t, okay?” he jokingly explained to his daughter as she appeared to be preparing to drop her cup.

He explained that an object at rest stays at rest, every action has an equal and opposite reaction, and that force equals mass times acceleration. Then he looked at his daughter and asked, “Any questions?”