Theoretical physicists from the Data Storage Institute have suggested that a fantastic "tractor beam" - a device that can move objects towards itself using radiation alone - can be created in reality.
However, while it can only move small objects. Attracting rays of light are often found in science fiction and UFO stories. However, Singaporean physicists believe that a concept from science fiction may soon migrate to real life.
At first glance, it seems that light cannot bring objects closer to the observer, it seems that this is contrary to the laws of physics. However, Dr. Haifeng Wang and colleagues have demonstrated that a single laser beam can both zoom in and out of small objects in relation to the light source.
For this, scientists propose to use the so-called Bessel beam, which have a certain pattern of radiation intensity distribution. Typically, the light of a laser beam striking a small particle is scattered back (against the path of its propagation), which causes the particle to move forward. Wang's team showed that, in theory, for small enough particles, Bessel rays would scatter forward, pushing the particle back (towards the light source). That is, the direction of movement of a small object will be directly opposite to the classical one.
In this case, the effect of the beam will vary depending on the electrical and magnetic properties of the particle. Of course, the strength of such an impact will be small. Nevertheless, there is a practical application for such an influence, Dr. Wang is sure.
“Such beams will not be able to move a person or a machine in space, since in this case the laser intensity will be so great that it will destroy the object being moved. But they are quite capable of moving biological cells from their place,”he says.
The new technology may have an unusual application - using the above-described "tractor beam" can measure the surface tension of cells. In this way, microbiologists will be able to distinguish a healthy cell from a virus-infected cell (which has more rigid walls).
“A cell attacked by malaria, for example, is more resilient than a normal, healthy cell. With the help of new technology, we will be able to distinguish one from the other,”says Wang.
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The inferences and calculations of specialists are described in detail in an article in the journal Physical Review Letters.