Being able to see things that are very far away is an important ability. It is used in all sorts of ways including studying distant stars, looking across great distances, and spying on other people. Over the generations, there have been many technologies that were invented specifically to help people to be able to see further than they could naturally. Things like telescopes and binoculars are just two very popular examples of this.

According to a new paper that was published in the journal Physical Review Letters, a technology that uses interferometry is now able to help users to see even very small things at great distances. Interferometry has been used for a long time in astronomy as it helps researchers to be able to determine things like the size of distant stars and planets. It works by superimposing waves of light in a way that creates interference patterns.

This same type of technology has now been developed into a system that can allow users to spy on others at great distances. This system uses the same concepts, using multiple lasers to compile an image of a distant object. This method is known as intensity interferometry, and it has proven extremely effective in tests.

A team from the University of Science and Technology of China used this system, equipped with eight infrared lasers, to see just how good of an image it could generate. The results, published in the paper, found that they could detect individual letters just three millimeters across on a page from a distance of almost a mile.

This technology has obvious uses when it comes to spying. Being able to read notes, a book, a computer screen, or other written words from a mile or more away (depending on its size) would be invaluable when it comes to espionage. The fact that this method seeing distant objects doesn’t require that object to have its own light source, however, means that there are other great uses as well.

For example, detecting debris orbiting our planet is difficult, and being able to see exactly what it is and where it came from has proven nearly impossible. With this technology, however, researchers could locate an object and get a clear image of it from great distances. This would allow them to learn what it is so that they can decide how it should be dealt with.

It is likely that additional improvements to the system would also allow users to see even smaller things at an even greater distance. The use cases for this type of technology are many, and will likely continue to be developed for years to come.

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