Reflecting on my Christmas presents, I immediately think of the incredible gift that my sister Julia got me, these super comfortable moon boots. But why are they so comfortable? As with most things, physics offers an explanation. As we've learned way back with momentum, impulse is equal to the force multiplied by the change in time. Impulse also equals the change in momentum, and given that momentum is conserved when only conservative forces are acting on the object, the impulse does not change. Therefore, when the time that the force acts on the object is lengthened, the force felt by the object decreases. This is where the moon boots come into the scenario. Ordinary sneakers have little padding between the sole of the sneaker and the wearer's foot, so the time of impact from the floor to the foot is relatively short, meaning a relatively large force. The moon boots, on the other hand, have a great deal of padding, extending the time of impact of the wearer's foot and the floor. This reduces the force felt by walker and provides them with a lighter, more comfortable feeling as they feel almost like they are walking with less of a gravitational force (as on the moon, hence the name of the shoes).