Two of the world's leading scientists have said that the world we live in is a provable "illusion" and argue that people are deceived into believing in reality.
Cognitive scientist Donald Hoffman and senior lecturer in philosophy at the University of Notre Dame, Laura D'Olimpio, say that the world we think we live in is nothing more than a computer simulation.
The Dailymail.co.uk edition writes about this:
“Take this example: right now, you are not where you think you are.
In fact, you happen to be the subject of a scientific experiment conducted by an evil genius.
Your brain has been cleverly removed from your body and is now being kept alive in a vat of nutrients on your lab bench.
The nerve endings in your brain are connected to a supercomputer that supplies you with all the sensations of everyday life.
This is why you think that you are living a completely normal life.
Promotional video:
Do you still exist? Are you still "you"? And is this famous world a figment of your imagination or an illusion created by this evil scientist?
Sounds like a nightmarish scenario. But is it really possible to say with absolute certainty that this is not so?
Could you prove to someone that you are not really a "brain in a vat"?
The philosopher Hilary Putnam proposed this famous version of the brain-in-a-vat thought experiment in his 1981 book Reason, Truth, and History. But it, in fact, is an updated version of the concept of the French philosopher Rene Descartes about the Evil Genius from his book of 1641 "Reflections on the first philosophy."
While such thought experiments may seem like the result of an overly brisk mind - and perhaps a little disturbing - they serve a useful purpose.
They are used by philosophers to find out what beliefs we can adhere to, because of their truthfulness, and, as a result, what knowledge we are able to have about ourselves and the world around us.
Descartes thought the best way to do this was to start doubting everything and build your knowledge around that.
Only the use of this skeptical approach, he argued, can serve as the core of absolute certainty for building a solid foundation of knowledge.
He said: If you want to be a true seeker of truth, it is imperative that at least once in your life you question everything around you as much as possible.
It was from Descartes that we got the classic skeptical questions that philosophers like this one are so fond of: how can we be sure that we are awake right now, and not sleeping, dreaming?
In order to meet this challenge to our invented knowledge, Descartes further imagines that there is an omnipotent, evil demon who deceives us, which leads us to the idea that we only think that we are living our lives when, in fact, reality can very different from what we imagine.
The brain-in-a-chan thought experiment and the problem of skepticism are also used in popular culture.
Notable contemporary examples include the 1999 film The Matrix and Christopher Nolan's 2010 film Inception.
By observing the filmed version of the thought experiment, the viewer can wittily enter a fictional world and safely explore philosophical ideas.
For example, while watching The Matrix, we identify with the main character, Neo (Keanu Reeves), who discovers that the “ordinary” world is a computer-simulated reality and his atrophied body is actually in a barrel of life-sustaining fluid.
Even if we cannot be absolutely certain that the outside world is not what our senses convey, Descartes begins his second round of thinking, giving us a little glimmer of hope.
At least we can be sure that we ourselves are, because every time we doubt it means that there must be an “I” that does it.
This conclusion of Descartes leads us to the well-known expression: "I think, therefore I am."
So yes, you may well be a "brain in a vat" and your experience of the world could be part of a computer simulation program created by an evil genius.
But, be sure of at least one thing - you think.