Only 80% of people can see this optical illusion in which a black hole expands. It is not known what the causes are, but it is known that the level of expansion between one and the other can also vary a lot.
What would it be like to approach a black hole? Well, considering that not even light can escape from them, better not be in the position of checking it out. However, there is an optical illusion that somewhat emulates what the feeling would be like. And that is not the most interesting. Actually, the most curious thing is that not everyone can perceive it. In fact, according to a study just published in Frontiers in Human Neuroscience, only 80% of people are able to see the black hole getting bigger and bigger.
But this has not been verified only by the statements of the participants. The authors of the study, from the University of Oslo, found that the pupils of these people dilated as they perceived how the black hole of the optical illusion engulfed them.
Also, not everyone perceived the same level of expansion and that is something that could also be seen by looking at their pupils. Now, what is not clear is why the results were so different between the study participants. This is something that should be studied in the future. But what have they observed so far?
The optical illusion that becomes a black hole
This optical illusion consists of a white background, covered in black dots, with a nebulous black hole in the center. By fixing your eyes you can see how that blurred center is getting bigger and bigger, taking over the entire space. At least that is what happens in most cases.
The authors of this recently published study wanted to see how this optical illusion affected different people, so they recruited 50 participants with normal vision, who were asked to rate what they saw.
They had to sit 68 centimeters from the screen and look at it for 8 seconds, trying not to close their eyes. Meanwhile, measurements were taken of their eye movements, as well as unconscious constrictions and dilations of the pupils.
The procedure was done both with the original optical illusion and with another in which the background color of the black hole was varied. Specifically, it was tested with blue, cyan, green, magenta, red, white or yellow. They also tried changing the black hole’s own color for each of those colors. The first thing that caught the attention of scientists is that when some colors were introduced, the pupils shrank as if the eyes were adapting to bright light. But even this varied greatly between people.
very different results
Only 80% of the participants experienced any growth of the black hole. Within that group, moreover, there were some who detected the optical illusion, but as a much smaller expansion than the rest.
On the other hand, the effects of the optical illusion were highly variable depending on the color of the background or the black hole that was no longer black. For example, it expanded more with a magenta background relative to blue and red. In contrast, for white holes, maximum constriction occurred on a cyan background, compared to blue and yellow.
The effect of magenta surprised the researchers very much. And it is that, according to the study, it is difficult to relate it to the ecology of light because “color is not part of the visible spectrum.” Although they could find some explanations for the different effects of the optical illusion as they change the colors, the fact that you only see 80% of it is quite curious. It is known that everything happens because the black hole tricks the brain so that the pupils dilate and let more light in. Are there brains that are more difficult to fool? I would give for a long discussion, but surely the reasons are much more complex than that. We’ll see. Now, now that we know what this optical illusion consists of, what percentage are you in?