Any number of silly knickknacks and tchotchkes line most people’s desks. While they’re fun momentary diversions or little timewasters, not many also have something to say about science and the world around us. Meanwhile, simple toys really are the best.  Taking all of that into consideration, the Flux Original Scientific Toy and Magnet Shield Bundle ($101. 99 after code ANNUAL15; 20 percent off from TNW Deals) are all but guaranteed to fascinate, a cool scientific principle right at the forefront of a fidget style device that can keep the hands busy while it also makes the mind think, how does it do that? To look at it, the Flux couldn’t seem simpler. The toy centers around a marble-sized magnetic ball. Once it’s dropped into the 2.5-inch segment of aluminum piping, you would expect it to pass harmlessly through the tube and fall out the other end. And it will — but first, the highly magnetic ball starts generating electrical current during its descent, momentarily slowing its fall  before it ultimately gets to the bottom and gravity takes over again.  If you weren’t a science whiz in school, the principle at play here is Lenz’s Law, a truth credited to Russian physicist Emil Lenz back in 1834. While it’s fun to know the hard science underpinnings of this phenomenon, it’s a lot more fun to just experiment with it in person, examining the neat process as the ball’s rate of speed abnormally shifts. The Economist said that “watching this defiance of the laws of nature is undeniably mesmeric.” Even with no batteries and no electronics, it’s hard to argue that point after some play too. You can even start devising your own games for catching or slowing the ball your way. Or just use it as an energy-dissipating fidget device. The set also comes with a wooden magnet shield to protect against the safety concerns about power magnets. Right now, you can get the Flux Original Scientific Toy and the Magnet Shield at one of its lowest prices ever while you choose from three different flux colors: brown, beige, or grey. Regularly $149, it’s already marked down by $30, plus you can use the code ANNUAL15 to take another 15 percent off your total as part of the TNW Deals’ Semi-Annual Sale. That lowers the final price to just $101.99. Prices are subject to change