They were first referenced in 1928. In essence they are light rays that both push and pull. There are electromagnetic forces at work, and possibly gravitons.
It's extremely common for more then one force of gravity to effect an object. An example is if you are holding a cup, your force is attracting it while the Earths force is also keeping the cup upright.
In 1986, "Optical Tweezers" were invented, which were able to pull objects with lights and lasers. The optical vortex bends light to change objects momentum. It traps light, absorbing particles because of heatis pushing out the center which is moving within the air.
