Now you can fill an entire cup with your favourite hot beverage and carry it without spilling a drop thanks tot he SpillNot Mug Holder. By carrying the mug in the SpillNot holder by the strap, physics will keep the drink inside the cup. Wanna know why? Here’s the scientific reason: When you hold a cup of hot beverage, inertia keeps the liquid from moving. But when you walk, you create horizontal force, causing the side of the cup to press against the liquid, which then rises up and over the edge of the cup. The flexible loop handle of SpillNot cannot deliver a lateral acceleration to the saucer or the cup. As the handle moves horizontally, the saucer and cup swing up slightly in the opposite direction, balancing everything out so the liquid stays in the cup. When you are walking normally, the only force acting in a direction that is not parallel to the sides of the cup is the force of gravity. (Of course, if you apply a vertical force by jerking your hand around or dropping the SpillNot, all bets are off!). If the SpillNot is swung all the way around in a loop such that the cup is upside down at the top of the arc, the liquid does not pour out of the cup due to the force which acts in the opposite direction as gravity when the cup is at the top of the arc. (Note: Try this outside with plastic cups first. You need to experiment to get the right amount of speed in your swing.) So if you’re game to try your hand at some of the SpillNot tricks, knock yourself out (and feel free to send us video proof!).