Decode the mystery that makes Venus look bigger than Jupiter

Scientists finally solved the mystery of a visual illusion that was first discovered by Galileo 400 years ago.

Galileo, the renowned Italian physicist, astrophysicist (1564-1642), was extremely confused when he saw the appearance of the planets in the sky changing depending on whether the observer made eye contact with telescope. hope.

What confuses him is that, if viewed directly with the naked eye, the planets seem to "expand" and have "bright halo" , making Venus look 8-10 times bigger than Jupiter, but This phenomenon no longer occurs if we observe with a telescope. In fact, Jupiter is four times bigger than Venus.

Galileo said the phenomenon could be a kind of illusion of size created by the human eye, but he did not know why or how the process took place. He wrote: "Or because their light is refracted in moisture covering the pupils, or because it is reflected from the edges of the eyelids and these reflected rays are diffused through the pupil or because of a some other reason ".

If you look directly with the naked eye, Venus (left) looks bigger than Jupiter, contrary to reality.(Photo: Getty Images)

The next generation of scientists Galileo went on to say that hallucinations are due to blur, ambiguity or similar optical effects. However, even though the fuzziness may distort the size, it cannot explain the reason why Venus looks bigger than Jupiter when viewed with the naked eye.

The German astrophysicist, the 19th century Hermann von Helmholtz, came closer to the truth when he called this a "illusion illusion" , rooted in our sense of objects, not because of the optical process of the eye.

Even so, until now, researcher Jens Kremkow and colleagues from the School of Ophthalmology, New York University (USA) have officially deciphered the phenomenon convincingly. According to a research report recently published in the Proceedings of the National Academy of Scienc e, this is a visual illusion that originates from the way our eyes observe the world.

Alonso's team used electrodes to record electrical signals from nerve cells in the visual area of ​​the anesthesia of humans, cats and monkeys anesthetized, when these subjects were shown images. Dark form on a light background, bright shapes on a dark background, or shapes light or dark on a gray background.

The results show that white spots on a black background look bigger than the black spots of the same size on a white background , and Galileo's shining planets aren't really as big as they might look when they look close to the naked eye. This effect also helps explain why, we find it easier to read black letters on a white background than white letters on a black background.

By tracking the effect from the way nerve cells are arranged and connected together in the retina and brain, the team discovered that illusions are likely to originate from the cells themselves. Optical of the eyes.