why this photo? continue reading till the end ;)
Most people take our ability for perception for granted and never give a second thought about its limits and accuracy. Why this is important? Because the way we perceive the world, what we think is happening based on the information we gather determines our decisions and leads us through life.
The answer to the question from the title begins with what perception is.
Perception can be defined as a subjective experience of the objective world.
There are perceptions in our consciousness, and in the external reality there are stimuli. Certain types of stimuli correspond to certain types of perception. For example, electromagnetic waves of a certain length cause a feeling of one color, and electromagnetic waves of another length cause a feeling of another color (exceptions are color blinded people).
During evolution, various sensory organs specialized for certain types of stimuli were formed. The stimuli for which special sensory organs have developed during evolution are called adequate stimuli. For the sense of hearing these are air waves, for the sense of sight light waves, for the sense of taste and smell molecules from the food and air and for the touch physical force applied to our skin/body.
No special sensory organs have developed for stimuli that did not matter to man during evolution. Such stimuli are called inadequate stimuli (gravitation, magnetic forces, etc.); for those we have developed artificial senses, that is, tools to widen our range of perception (but they are some other story).
The process of perception is a complex process determined by many external, objective factors (characteristics and distribution of stimuli; example of how our brain is playing tricks with us can be mirage or some other optical illusion: even if you know that the picture is static you see that it is moving ) and internal factors (characteristics of the person who perceives: 1) knowledge experience - they give meaning to what we perceive, 2) motivation - selection of stimuli 3) emotions, attitudes, values, interests-speed and the way we interpret what we perceive specially social interactions, 4) personality traits -intelligence, self-awareness, defense mechanisms...)
That is why is said that perception is subjective
Long story short, we all perceive same world more or less differently and that is why we do not agree about many things.
Perception part has just been covered. What about information?
In the post truth era, time when there is so many info on daily basis, so many interest groups trying to convince us in something, many ways to manipulate data and Internet to spread all that around the world, it has became hard to be sure what the truth is and what to believe if we did not see something with our own eyes.
Well, that problem has been solved: we can not believe even that :)
Deepfake is more and more present on the information market and knowledge about that should motivate us to question even what we see on TVs and Internet.
After simple text fake news, edited photographs, edited voice materials, now we are one step higher with possibility to edit complete videos in a way that it can not be noticed by most people.
Physical reality, virtual reality, augmented reality, objective reality, subjective reality, many words for description but what is actually real? That is on you to decide, it is subjective ;)
You have survived so far, welcome to the new level of the game :D
P.S. Do you believe that SpaceX successfully landed its first stage booster from the Falcon 9 launched yesterday? ;P