A tractor beam reels in objects with sound
Ultrasound machine pulls on a target that is large enough to see
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2014/03/ag_REV_tractorbeam_feat_free.png?fit=860%2C460&ssl=1)
BEAM ME IN At left, waves (yellow dashed lines) from a regular beam of light or sound tend to bounce off an object (blue arrows) and deliver a subtle push. Waves from a new tractor beam, illustrated at right, bounce off the sides of an object and rebound upward. As a result, the object gets pulled toward the source of the beam.
M. Atarod