It's also slowly becoming a reality. Since 2010, nano-scale tractor beams made up of light particles have been capable of drawing in their tiny nanoparticle prey. A new, acoustic method developed by an international team of scientists has effectively supercharged the nascent technology.

Beams of light and sound function in similar ways, both existing as waves of varying frequency. Imagining them like ocean waves, you might be a bit bewildered as to how waves can tug at you instead of crashing and pushing you away.