The Hoverboard and the Flying Cars

There's also the hydrator oven that turns like a hocky puck sized pea into a full sized cooked peta in just a matter of moments. The movie doesn't bother to explain how this works. Then there are all the flying machines, like hover boards and flying cars. Presumably the hover boards are generating some sort of electromagnetic field that counteracts gravity somehow. And obviously we don't have those magical flying cars to day, let alone back in 20 15.