Everybody seems to think they know the answer. There are "answers".

I read through most of the answers but it's just recycled fairytales we learned in University years ago.

After studying theories of reality and writing a thesis on it... after breaking away from academia and becoming a businessman... "Reality", "Death", "Colors", etc... all of these terms... meaning language... severely limits how we can communicate. And our language is limited because we're limited.

And we're limited because we're primitive. We have 5 senses to navigate the world. There are other senses that other things have that we don't, like bats with echolocation. Imagine if we had an infinite number of senses? What would "reality" be like to us? I'd be much different. But we still couldn't come close to imagining what it would be like. We can barely imagine 10 dimensions.

I've said this many times. You can put a human in a room with a spider, and if the spider could talk, they would both argue forever about what "reality" is. What with the spider's 8 eyes and hypersensitive sensory receptors in its shell... compared to a human with 2 eyes. Who would be "right" about reality? Well, we want to think the human would, because our brains are more sophisticated... we have a capacity for things like abstract thinking... etc. And maybe we'd be right.

But what all this comes down to is that, we really have nothing to compare ourselves to other than an imagination of something much more perfect than ourselves, like a God. How much "further" away are we from reaching a point where we "know" reality? Where we're infinite in our essence, like we'd imagine a God to be? Impossible to say.

In the end, this is a problem of limited evolution (limited senses and information processing), and solipsism. That is, we simply can't know anything but our own experience. We're hopelessly trapped inside our own perspective. No matter how many stupid theories academics propose, that are themselves just spins off of old ones, the problem of solipsism and limited perceptual tools is inescapable.

We're trapped inside our own realities, realities being perspectives that are caused by what we interpret as collections of matter interacting with one another. Our experience of our reality... the phenomenological screen... is simply a function of the collection of our matter. Different collections of matter likely produce different experiences to those things (bats vs. humans).

The research...

There was a really amazing study done years ago... the researcher hooked electrodes up to the brains and muscles of two tennis players. As they played, stroking the ball, he recorded neural activity in the brain. It turns out that, when striking the ball, the neurons that fire are in the lower brain centers, the ones responsible for reactions and motor movement. After about a 100 MS delay after the ball had been hit, the neurons in the higher brain centers would fire. These neurons are responsible for consciousness processing.

Therefore, the conclusion is that we're sort of out of sync with reality. The players hit the ball before they were aware of it. You open the door before you're actually aware of opening the door. Our brain strings pieces of choppy frames together to give us the smooth "reality" we experience. But "reality" separate from us... there is no real way of objectively knowing it. We simply experience what our collections of matter are able to present to us.

I'm surprised nobody has given Rene Decartes much discussion here. He had one of the more famous, interesting investigations into wanting to know what reality was. It's where "I think, therefore I am" comes from. As he sat in his study, watching a candle burn, he couldn't help but ponder what was real and what wasn't. He concluded that because all he knows about himself is that he is a "thinking thing", then that's what he determined himself to be, a thinking thing. I think, therefore I am a thinking thing. At the least, it removed the possibility of him doubting his own existence.

René Descartes, the originator of Cartesian doubt, put all beliefs, ideas, thoughts, and matter in doubt. He showed that his grounds, or reasoning, for any knowledge could just as well be false. Sensory experience, the primary mode of knowledge, is often erroneous and therefore must be doubted. For instance, what one is seeing may very well be a hallucination.

Like Rene, that's all we can ever know that we're thinking things, whatever that actually means. We can solve problems in our reality. We can show things like cause and effect. We can cure disease. We can invent and create things. But all this stuff is completely beside the point of the question of what reality is. And this question is not really answerable because it seeks an answer that is beyond our comprehension. The answer it seeks is to be this objective thing... a necessary truth for all eternity... a truth beyond ourselves and anything. An infinite truth. And that answer is simply impossible for us to discover and understand.

Here I am coming full circle. Notice how so many on here supplying answers put forth analogies that have to do with the present? So many compare "reality"... the universe... to computers. When you read science of past, philosophy of yesterday, you'll start laughing because you know that this is what everyone before us has done to try and explain things. That they use analogies to describe things, and those analogies are very much limited to their present. Like reading about how the body is like a ferris wheel, and how the brain is located in the chest (the heart), etc. And it doesn't work.

No, the universe (reality) isn't a computer. It's not "digital". It's not "information". It's not any of these things but whatever it is to you. If that's a simulation, great. But I can assure you that your idea of a "simulation", our notion of things like "death", etc. All these words... are primitive and literally without any meaning to the universe... to reality. The only thing that makes them relevant is that they mean something to us. Imagine a bear staring at your hockey gear in the garage. That hockey gear is associated with deep meaning to you (smells, emotions, etc.). But it's meaningless to the bear. And so is pretty much everything else in our lives. That includes material things, politics, and everything else. All this stuff is effectively meaningless to the world.

Knowing how limited you are in that you're trapped inside this perspective is the first step to having some level of understanding of reality.

Piece of advice: strip everything away to the point of nothingness, and stay there for a while, like Rene Decartes did with his Cartesian Doubt. Where nothing means anything: you've suspended all beliefs and knowledge. Then see if you understand yourself anymore. If you understand what it even means to be "human". What are you? The question of what "reality" is may not be near as important as the question of what you are.

You may come to the conclusion that we're stupid and that we've locked ourselves into a very narrow... reality ;)

This is addressed by the "simulation argument", made by the Oxford University philosopher and the director of the Future of Humanity Institute Nick Bostrom.

It goes like this:

It starts with the assumption that future civilizations will have enough computing power and programming skills to be able to create what he calls “ancestor simulations”. These would be detailed simulations of the simulators’ predecessors – detailed enough for the simulated minds to be conscious and have the same kinds of experiences we have. Think of an ancestor simulation as a very realistic virtual reality environment, but one where the brains inhabiting the world are themselves part of the simulation.

The simulation argument makes no assumption about how long it will take to develop this capacity. Some futurologists think it will happen within the next 50 years. But even if it takes 10 million years, it makes no difference to the argument. The conclusion is that at least one of the following three propositions must be true:

1. Almost all civilizations at our level of development become extinct before becoming technologically mature.
2. The fraction of technologically mature civilizations that are interested in creating ancestor simulations is almost zero.
3. You are almost certainly living in a computer simulation.
   

How do we reach this conclusion?

1. Suppose first that the first proposition is false. Then a significant fraction of civilizations at our level of development eventually become technologically mature.
2. Suppose, too, that the second proposition is false. Then a significant fraction of these civilizations run ancestor simulations. Therefore, if both one and two are false, there will be simulated minds like ours.

There is some math behind this which I'm not going to expound here. I'll link the original journal paper below for your reference.
Page on simulation-argument.com

If we work out the numbers, we find that there would be vastly many more simulated minds than non-simulated minds. We assume that technologically mature civilisations would have access to enormous amounts of computing power. So enormous, in fact, that by devoting even a tiny fraction to ancestor simulations, they would be able to implement billions of simulations, each containing as many people as have ever existed.

In other words, almost all minds like yours would be simulated. Therefore, by avery weak principle of indifference, you would have to assume that you are probably one of these simulated minds rather than one of the ones that are not simulated. Hence, if you think that propositions one and two are both false, you should accept the third. It is not coherent to reject all three. It should be emphasized that the simulation argument does not show that you are living in a simulation.

The conclusion is simply that at least one of the three propositions is true. It does not tell us which one.In reality, we don’t have much specific information to tell us which of the three propositions might be true. In this situation, it might be reasonable to distribute our credence roughly evenly between them. Let us consider the options in a little more detail.

1. Proposition one is straightforward. For example, maybe there is some technology that every advanced civilization eventually develops and which then destroys them. Let us hope this is not the case.
2. Proposition two requires that there is a strong convergence among all advanced civilizations, such that almost none of them are interested in running ancestor simulations. One can imagine various reasons that may lead civilisations to make this choice. Yet for proposition two to be true, virtually all civilisations would have to refrain. If this were true, it would be an interesting constraint on the future evolution of intelligent life.
3. The third possibility is philosophically the most intriguing. If it is correct, you are almost certainly living in a computer simulation that was created by some advanced civilisation. What Copernicus and Darwin and latter-day scientists have been discovering are the laws and workings of the simulated reality. These laws might or might not be identical to those operating at the more fundamental level of reality where the computer that is running our simulation exists (which, of course, may itself be a simulation). In a way, our place in the world would be even humbler than we thought. We may be living in a Russian nesting doll type, simulation within simulation withing simulation.

If we are in a simulation, could ever know for certain? If the simulators don’t want us to find out, we probably never will. But if they choose to reveal themselves, they could certainly do so.

Another event that would let us conclude with a high degree of confidence that we are in a simulation is if we ever reach a point when we are about to switch on our own ancestor simulations. That would be very strong evidence against the first two propositions, leaving us only with the third: You are almost certainly living within a computer simulation.

Further reading:
One of the predictions of the holographic theory (which was inspired by Hawking's work on black holes) is, the universe is a two-dimensional information structure "painted on" the cosmological horizon, the edge of space analogous to the event horizon of a black hole. It even provides a new conceptualization of entropy - as the surface of the universe expands, more information can be stored on its 2-D surface and the entropy of the universe increases as a result.
Holographic Universe

According to the Holographic Principle, the universe should ultimately break down into fundamental "pixels" of reality, like the pixels in a photographic image, in this case grains of spacetime calculated to be Planck length.

Some scientists, such as Craig Hogan of Fermilab, believe that this graininess, equivalent to quantum fuzziness, can be scaled up across the holographic universe and detected as very minute gravitational waves.
Fermilab experiment will attempt to answer whether we actually live in "the Matrix"

We can play with the bizarre possibility that we, and everything around us, are merely projections cast from some distant 2-dimensional screen, that we are ignorant of our true flatness as we live out our lives inside an enormous sphere at least 13.7 billions of light years across as projections from its inner surface.

Recently I picked up a copy of Descartes’ book ‘Meditationes de prima philosophia’ [1].In it René Descartes puts forward the notorious evidence of the existence of G-d or a Supreme Being. But that is another discussion.

One of the other things in this work is the fact that he statest hat the World as we see it, is questionable, because to experience it, to see it, we have to rely on our senses. And since the senses are flawed they cannot be trusted.

In the 20th century we made a lot of progress in science and the field of medicine. The findings from these substatiate Descartes’claim that the senses are flawed.

For instance the way we hear is distorted, i.e. we hear high frequency sounds very well, but low sounds less (that is why in a 3-way loudspeaker the tweeter is small and the woofer is big; for the woofer needs about 4 times the intensity of a high frequency sound for people to hear it at the same intensity, the same volume). For a good reason this is so. In history, to survive, we had to be able to hear the cracking of leaves and branches, but at the same time be able to hear the heavy (low frequency) thunder, without our eardrumps popping. So the ear does not relais the actual sounds as they are.
The same holds true for vision. We can see only a small part of the visual spectrum. In fact our eyes integrate several different systems, which not all work together well at all times, explaining the so called optical illusions.

A frog for instance, can only see when there is movement. Like a dinosaur. There have been experiments where a frog was put in a box full with dead flies. The frog died.The frog’s sensory system deluded him. Or her… they’re amphibious.

Long story short, the way we perceive the World around us is affected by our senses, and according to Descartes by questioning everything we can separate the wheat from the chaff, and ultimately the only thing that is left is the truth that cannot be questioned. One of these truths is the fact that we can and are thinking. Cogito ergo sum. Or perhaps it could be, cogito ergo scribere Quora.

What has al this to do with a simulation?

Simulation: from Latin simulat 'copied, represented', from the verb simulare, from similis 'like’.

A simulation is per definition fake. So is the world we perceive with our senses. So there is similarity.
We live in our own version of the World. It is just a representation, a model. In science the saying goes: ‘all models are wrong, but some are usefull.’

A professor in Britain, Nick Bostrom, from Oxford University has put out a model which lends credit to the supposition that we live in a computer simulated reality. [2]

The idea of living in a computer simulation is not new, e.g. there is:
- The Hitchhiker’s Guide to the Galaxy, a book by Douglas Adams (comical) detailing that the earth was created as a giant computer with people on it to find the question, instead of the answer, to everything.
- The Matrix, a movie where the protagonist, Neo, which is btw an anagram for One, as in the chosen one, finds out he lives in a computer generated World.

It has sparked the imagination of lots of people. And also of British professors, apparently.

A while ago I was in an electronics store in the Netherlands, Mediamarkt. There I saw a sort of sunglasses made by Sony. You can put them on, it has inbuilt speakers and it projects a picture ahead of you, equivalent to a real screen with a one meter diagonal. It won’t take long before they invent glasses with 3d capability, thereby enhancing immersion.
If you take into account the progress made in the last two decades regarding electronics, it is not difficult to project this into the future, i.e. if you extrapolate the current trend towards e.g. the 23rd century, you would think that by then computer simulations with full immersion would be… a reality.

According to prof. Bostrom this could be the case, unless… we don’t reach this stage of development (meaning when the faeces hits the proverbial fan)

All this is nice, but how would one know if this is already the case? It is one thing to ponder these things, yet another to say you can prove this without being told you’re a nutter.

The absence of evidence is not evidence of absence.
- A. Einstein

Of the only scenario’s possible that would reveil a computer simulation is when there’s a bug.
At one time the earliest mechanical computers had moving parts. There is a story that a bug had crawled into one of these machines and got sqaushed between a relais switch, jamming the system. It was written in the logbook that a “bug” had caused the malfunction and ever since that incident the word bug or computerbug was used to denote malfunction via hardware or by software.

I don’t want to be the cat’s whiskers here, but there is no other way, to tell we’re living in a computer simulation unless you can clearly and repetitively point out a bug. And up to date this World has not ever showed anything of a bug or glitch.

Bug or not, Sir Isaac Newton, even though trying to find proof for supernatural phenomenon in his private life, as he was an alchemist [3], proved that everything in this World, every law of nature, acts like clockwork. No glitch there.

A while ago I bought the excellent book “In search of Schrödinger’s cat” written in the early ‘80’s, but still in print, which explains quantum mechanics. [4] It also explains the double-slit experiment by Young [5], which some people today consider to be a demonstration of a bug or glitch.
It is not a bug, we just don't understand the dual concept of light…yet. Even Einstein had difficulty with quantum mechanics, as he was quoted: “G-d doesn’t play dice.”

Yes, we do live in our own World, our own representation of reality,seen through ‘the looking glass’ of our flawed senses. But computer simulation? No, it would hook up at some point, and this… has never happened before.

Of course, if this is a computer simulation, then this would mean that whoever created it, whoever programmed it would be the bee’s knees. ..
He/she would equate to a deity. Would equate to a G-d.

Just my € 0.02.

References

1. René Descartes. Meditationes de prima philosophia. 1647.

2. Nick Bostrom. Philosophical Quarterly (2003) Vol. 53, No. 211, pp. 243-255.

3. Michael White. Isaac Newton: the last sorcerer. University of Michigan, Addison-Wesley, 1997.

4. John Gribbin. In search of Schrödinger’s cat. Random House, 1984

5. Thomas Young. Experimental Demonstration of the General Law of the Interference of Light. Philosophical Transactions of the Royal Society of London, vol 94, 1804

We aren’t living in a computer simulation because we are actually in a Virtual Reality game, and “Real Life” is something we can’t perceive because we’re so caught up in the game.

You see, this is how it works:

Just like the beta version of the Matrix, we exist in a society where there is no crime, no want, no illness, no pain, no loneliness. Everyone loves and is loved perfectly.

It’s paradise. However, it’s missing some things: Creativity, innovation, excitement, suspense, romance. There’s no growth, no challenges, no loss, no experience to be gained. In fact, there are no contrasts to speak of, and no need for a broad range of emotions.

The Council decided that something was needed to break up the monotony so they opened a Virtual Reality Tourism Center. Most of the citizens don't think they need such a thing, but about one third of the citizens have a spark of curiosity so they sign up for adventures at the VRTC.

There’s an orientation before the VR adventure-games can begin. The guidelines are as follows:

Welcome to the VRTC Multi-Player, Interactive Adventure-Game Experience!

Please carefully read the following important guidelines before embarking on your virtual journey.

1.Before beginning the experience, you choose the major elements of your adventure-game (see the brochure and order form enclosed in this packet). Major elements consist of your mode of entrance into the game and the characters populating your early experience. Also, you choose in advance the initial challenges which will influence your play throughout the game, although as the game progresses, you can modify their impact on outcomes through your in-game choices.

2. You also choose what part you will play upon the stage of the adventure-game. Some players will choose to be the villain or arch-nemesis. What kind of adventure would it be if all the players chose to be saints? Be advised that whether you choose the role of saint, hero, villain or innocent bystander, there will be challenges and rewards. Each player and each role is vital to the game and adds dimension and drama to the play.

3. Your pre-chosen major elements cannot be changed once the game begins, but your in-game choices will decide how and when you move between each major element, and those on-the-fly choices alone will determine how long your adventure lasts.

4. All your carefully pre-chosen elements must be experienced before the game is over, no exceptions.

5. The game will introduce unfamiliar and often unpleasant sensations such as pain, fear, loss, longing, loneliness, fatigue, rejection, illness, frustration. These can be offset by sensations such as love, joy, peace, connection, pleasure, excitement, exhilaration, accomplishment, enlightenment. Of course you don't understand any of these things right now but it is our duty to warn you.

6. You will interact with other players whom you know in the Real World, but whom you will not recognize in the game. For the purposes of adventure, drama and a full range of emotional expression, many of your interactions will include hostile and/or painful exchanges. For the sake of your Real-Time relationships, we advise you to hold no grudges upon your return to Reality. It’s all in the name of adventure, and no lasting damage will be sustained by any player upon their return to Real Life.

7. The adventure-game is full of clues to help you tailor your experience to your needs and desires, however, they will not be obvious and you must seek them out. There are just as many false clues, but there will be a Still, Small Voice (SSV [TM]) whispering to you that will help you decide. It's up to you whether to listen to this voice. You may prefer to go it alone for maximum sensation and an extremely complicated adventure.

8. IMPORTANT: Once the adventure-game begins, you will become so immersed that you will completely forget where and who you are in Real Time, and the adventure will seem to be actual Reality.

9.There will be Guides within your game, called the Knowing Ones. These are adventurers such as yourself who have cracked the code of the game and are able to move at will between this world and the world of the game. Once they achieve this level, the object of the game for them becomes to reach out to adventurers who have become lost in the game and who are scared, in pain and hopeless. The Knowing Ones offer help and clues to the Lost Ones, and sometimes they spill the beans entirely. The Lost Ones who have not cultivated their Still, Small Voice [TM] will consider the Knowing Ones to be kooks.

WARNING: Sometimes the Knowing Ones can get swept up in the game again and lose their way, or perhaps they haven’t completely cracked the code yet and can have incomplete information. The SSV [TM] comes with a guarantee. It is the only way to be sure your Guide is leading you in the right direction.

10. Regardless of your awareness of the SSV [TM] within the game, you will still successfully complete your adventure. It is only your comfort level and timeline which may be affected.

IMPORTANT: There is no “winning” or “losing” the game as a whole; only the challenges you choose to pit yourself against can be won or lost, and you will be the only judge of your success. This adventure-game is for the purposes of experience, sensation, feeling and creativity alone.

10. Please be assured that there will be attendants near your VR station at all times. At no time will you be in any danger here in the Real World. At times of extreme distress, the attendants may adjust some of your settings, allowing you to get a glimpse of them or feel their presence, letting you know you are being take care of. Sometimes, these adjustments can be perceived as “miracles” within your adventure-game experience.

11. WARNING: Most adventure-games end with a traumatic (we prefer the term, "dramatic") experience such as extreme illness, severe injury, violence, intense pain, etc. Some do end peacefully but this cannot be guaranteed. By going forward with the game, you agree to this probability.

NOTE: Some adventurers believe they can prematurely end their adventure. Please be advised that this is not true. They may force a transition and end up finishing their adventure in a non-corporeal form but they will still complete their adventure. Most times, those who seem to force a transition are actually just at the end of their adventure-game and are experiencing one of the aforementioned dramatic finales.

Good luck, and enjoy!

————————————————————————————————————

When we adventurers complete the game, we become conscious once again that it was all make-believe and that we have been safe and loved and cared for all along. We are celebrated and welcomed back from our virtual journey.

We are relieved to be back in our peaceful world where we can rest and recharge and immerse ourselves in all the things we seemed to have in such short supply in the game.

After resting for a period of time, however, we often begin to long for the ups and downs and variety the adventure-game offers. It is not unusual to see a line of repeat customers outside the VRTC, waiting to saddle up for their next adventure.

Let’s divide this into categories:
1. Detectability. (Can Tell/Can't Tell)
In the simulation, either you have the capability to detect that you are in a simulation or not. This is with the physics presented in the simulation, regardless of how long it takes to think about the mathematics or build the tools.
2. Escapability (Can Exit/Can't Exit)
If a simulation is escapable, that means that given the physics and tools within the simulation, it is possible to leave it and survive, in the sense of retaining your memories and personality.
3. Happiness (Happy to stay/Unhappy to stay)
This is subjective. Is the subject happy in the simulation or not? If they are content and satisfied with their existence they may never ask the questions about 1 and 2.

Look at a few examples from popular culture [Spoiler Alert]:
In The Matrix (1999 movie), Neo can (eventually) tell, can exit the simulation and is unhappy to stay in it.
In TRON: Legacy (2010 movie), Flynn Can Tell/Can Exit/but is Happy to stay there to some extent.
In Inception (2010 movie), Can Tell (with the use of an object like the top)/Can't Exit/Happy (if he gets to be with his children)
In Dark City, Can't Tell/Can Exit/Unhappy
In Total Recall (1990 movie), Can't Tell/Can Exit/Happy (at least in the beginning)
In Vanilla Sky (2001 movie), Can't Tell/Can Exit/Unhappy
In The Wizard of Oz (1900 book & 1939 movie) Can Tell (based on the fantastic events and things such as flying monkeys which are not part of Dorothy’s normal reality) /Can Exit/Unhappy (possibly as her family was not there)
In the Nightmare on Elm Street series, Can't Tell/Can Exit/Unhappy — they don't know when they’re in a dream, but it’s definitely not somewhere they want to stay.
In The Sixth Sense (1999 movie) Can't Tell/Can't Exit/Unhappy
In Restaurant at the End of the Universe the Guide staff visit a simulated universe for research purposes and Can Tell/Can Exit/Happy to stay for hours.

The question for us is, are the machines we are building such as the Large Hadron Collider (LHC) and the Hubble Space Telescope revealing flaws in the Universe? Are the mathematics revealing errors and inconsistencies? Every simulation must have these properties:
1. a Budget even if this is in terms of energy expenditure rather than financial.
2. a Designer to create the system, as by our definition the simulation isn't a natural item.
These two properties will create boundaries for and introduce flaws into any given simulation. Simulating our Universe couldn't require more energy to run than the actual Universe.

Sure, scientists don't have all the answers to all the questions, but the results from our machines and calculations all seem to make sense, unlike when one is playing a poorly-designed video game where your character can put part of their body through a wall.
Religion has been trying to answer this for years. If the present reality is some kind of an equivalent to a simulation created by God, then when you Exit the simulation do you still retain the memories experienced while you were in the simulation?
For further entertaining reading, David Eagleman’s book SUM:40 Tales of the Afterlife explores some of these topics. For example one story has the our entire universe being constantly created on-the-fly by a single particle. Every time we humans inspect the fabric of reality in finer detail, the God ‘particle’ has to supply ever more complex and intricate details to have something ‘there’ when we look.

We are living in a simulation. It’s not computer generated in the common sense of computer, but it is generated and we are in it.

Just like a computer game mimics the real world, our universe mimics another universe, but it is like a shadow. It exists and has its own ‘realness’, but it is not reality. It is not an illusion in itself, but to think that it is reality - is illusory.

In poor light we make take one object to be another, say a rope on the ground looks like a snake. The rope is real, but the ‘snake’ that we see is illusory, but not non-existent. It is not a snake but a rope, and due to imperfect senses we take the rope to be a snake.

This universe is real, but it is not reality, just as a computer generated image is real in the sense that it exists and we can see it on a monitor, but it is not real because it exists only in the computer displayed as a certain arrangements of lights on a screen.

Our experiences of life are not real because they are temporary. Our happiness and distress come and go like the seasons, they do not stay with us so they are not real in the ultimate sense.

We, the living entities are real, but the setting that we are in is not reality. It is a creation of the three modes of material nature, goodness, passion and ignorance, and by the interaction of these modes of nature the material aspects of the universe are manifest, maintained and dissolved. The living entity is inserted into this mix and receives a body at the hands of material nature. That is our assumed identity or character, and then we go through the ‘game’ of life, absorbed in the game, and seldom wondering what is behind it.

At the end of each life we respawn in another setting as another character with different skills, powers and abilities and we play out that identity, and then move on to another and another and another. This is called samsara in sanskrit.

There are many fixed parameters in the program and they cannot be violated, but there is a lot of room to move around within the parameters, but it is all controlled by the code of the modes of nature.

The game is designed to keep you moving forward towards the end, but you are free to wander aimlessly collecting all the collectables as you go. The other players in the game are also real, but they are acting according to their characters, so some will be on your side and some will be against you. Most will be irrelevant.

There are ways to get extra powers and ways to get help as you play, but essentially everyone flies their own plane even if they are aided by ground control.

What’s the point of it? Well to have fun of course, like any game. And like many games you can lose and suffer set backs and frustrations and often have everything taken away from you at some point, even if you play exactly as the game is designed to be played. As long as you remain absorbed in the game, you can continue playing, but if you get sick of the game and want to leave it and get back to the ‘real’ world where you taste food, and feel wind, cold and heat etc. it can be done, but it’s not as easy as just exiting to desktop.

In his answer, Dan Piponi suggests that there are strong signs that the Universe is a simulation because of signs of computational efficiency.

I couldn't disagree more.

Even our classical universe shows signs that it always computes things to maximum accuracy, whether or not anyone is looking at it at any given time. For instance, distant celestial objects like the moons of Jupiter, faraway binary pulsars, stars in close orbit around the presumed black hole at the center of the Milky Way, all perform an exquisitely precisely choreographed dance, which can only be modeled by integrating the equations of motion at arbitrary accuracy. The iridescent colors of an insect's wing arise as photons bounce between transparent chitin microstructures, which would need to be simulated at the highest accuracy no matter how far you are when looking at it (so long as you can still see the insect).

In a computer simulation, you can always see subtle signs that the engine abandons objects that are not being looked at. Or not so subtle signs: for instance, seeing things that were supposed to fall remain suspended mid-air because no player is in the vicinity, so the simulation is abandoned. We NEVER see anything like this in nature. And not just because God (or whatever we wish to call the entity who runs the simulation) is a clever programmer: every time we look at things closely, we see that they have been running at maximum accuracy all along.

But there is another reason, even more deeply rooted in physics, that suggests that the Universe is not a simulation: quantum physics. There is a reason why people aren't trying to "build" a quantum computer as a simulation on an ordinary (digital) computer: Digital computers are inherently, theoretically less efficient (quantum computers being presumably able to solve some NP problems in polynomial time). So it is simply not possible to have a large-scale, high-fidelity simulation of a quantum system on a digital computer, no matter how advanced. And if it turns out that there are theoretical reasons why quantum computers cannot exist (some believe this to be the case), then not even God can have one to run the universe simulator... and as I just said, a digital computer is just fundamentally inadequate to run a high-fidelity simulation of a quantum universe.

So in my view, the very fact that we live in a quantum world is a strong indication that we do not live in a simulation.

Of course, we can never know for sure.

You don't know. You can never know. I can never know. The only thing I am sure of is, is the fact that I exist. (You may be an illusion.) How can I be so sure of the fact that I exist? Cogito ergo sum (Rene Descartes.) - I think, therefore I exist.

To elaborate :

Say that all my perceptions about this world and this "reality" are due to some Agent who has the power to control my perceptions, and create this simulation in my head. The Agent is a deceiver (like an all powerful god or evil wizard) that can make us think we are doing or seeing something when really it is an illusion.

If the goal of this Agent is to try to never let me be aware that I am part of a simulation, it needs to give satisfactory answers to the questions I will ask at some point or the other. These satisfactory answers may easily be delivered in the form of lies. For eg., I may ask “What is my purpose here?” and the Agent can easily conjure up an illusion of society and the ideology of survival, etc. It is the Agent’s simulation after all; it can do what it wants. And so like this, the Agent continues answering all my questions and deceiving me.

But there is one thing this deceiver can NOT do, and can NOT answer. *It cannot answer me when I question my own existence, because the questioner (me) has to EXIST in order to then question.* It is only logically valid. In other words, How am I able to reason and ask these questions if I did not exist?
The Agent may be able to give my existence a human form maybe, I may not look/be human in reality. But I most certainly exist. As something. Why? Because I’m able to come up with these questions. I think, therefore I am. Only I am real for sure. The rest may or may not be.

If this universe was a simulation, not everything would come to be in natural terms.

This world wasn’t made for living things. If you teleport to anywhere in the universe, you will die.

If the universe is a simulation, we would’ve been placed with a purpose, unless the simulation is not geared towards investigating conscious life, then the simulation would be pretty useless.

You came to existence through natural means such as evolution. Life wasn’t really meant to be, as far as we know it was a coincidence through sheer amount of time and space that allowed such, and we evolved by the desire to survive.

It’s also difficult to compare our technology to the creation of the universe, which gave us elements to create computers. Think about it, if there was a universe outside our own then it doesn’t adhere to the same laws, everything would look different, it wouldn't be a computer simulation out of all things, it might as well be called the creation of another reality

Even if we are in a simulation - it does not change a thing. Because this is what we call reality. The definition of reality is this world you live in. Now pretend that this world is a simulation, what does that even mean to you? Does it really change anything if it was not a simulation? It doesn’t. It is irrelevant to think about.

Thanks for reading, and please comment bellow if you disagree, so we can have an interesting conversation.

Building upon Glyn Williams answer :

• Virtual Reality Creation/Big Bang: A virtual simulation begins with an information influx from “nothing” that begins simulation time and space. Universe was also created out of nothing by a single event “big bang” that created time and space.
• Digital Processing/Quantum Minima: All digital calculations involve a minimum of quantity or quanta, say bits. Light too is quantized as photons.
• Maximum Processing Speed/Speed of light : All events taking place in virtual reality must have some maximum rate/speed. Information in our universe is generally carried by electromagnetic waves which have a maximum limit assigned to their speed.
• Non-local Effects/Wave Function Collapse : A computer processor is equidistant from all pixels of computer screen, so that with respect to the screen the effects of simulation are “non-local”. The quantum wave function collapse too is non-local. Entangled photons can effect each other even if they are on opposite sides of the universe.
• Processing Load Effects/Matter and Speed Effects : On a distributed network, nodes with a high local workload will slow down. Likewise a high matter concentration may constitute a high processing demand, so a massive body could slow down the information processing of space-time, causing space to “curve” and time to slow. Faster movement requires more processing, speeds near light speed could affect space/time, causing time to “dilate” and space to extend.
• Information Conservation/Physical Conservation laws : A stable simulation once started will not require any more information from outside, which is a case of information conservation. Physical existence properties such as matter, energy, spin, charge are all conserved and can be transformed into one other.
• Information Creation/Quantum Uncertainty : According to the information theory, information is created whenever we have a choice, which a random function generator could do in a simulation processor. Quantum theory has already suggested that randomness is inherent in the nature.
• Complementary Uncertainty/Heisenberg Uncertainty Principle : Clearly we cannot measure both position and momentum of a body at the same time. Momentum and position are both complementary physical properties , then both these values may be located in the same memory location. Also, we know that a “screen” is only calculated when we try to view it. If what we observe is really just a computer interface, then the “screen” calculation would be performed only at the time of observation and only one of the physical properties would be shown. Hence calculating one property of a self registering interface might displace complementary data.
• Digital Equivalence/Quantum Equivalence : All digital objects created from the same code are identical. All photons, electrons, quarks are identical, suggesting that they could have arisen from the same digital calculation.
• Digital Transitions/ Quantum transitions : All digital processes simulate a continuous event by a series of state transitions. A film which seems continuous is composed of frames that transit into each other fast enough so that you could not see it. But if slowed down, frames are visible. Quantum mechanics also suggests that entire reality is nothing but state transitions at quantum level. Electron tunneling from to A to B via an impenetrable membrane can be easily explained as a state transition done by our virtual processor.

Clearly then we are in a matrix.

For those who love details, http://arxiv.org/pdf/0801.0337.pdf

This is basically Plato's cave analogy expressed in computer terminology.

If you find the question engages you, it is probably because you sense a certain lack of reality or authenticity in life as you currently experience it. You must either decide to discount this feeling (and with it, the validity of your experience), or try to find something more "real" or "authentic".

The answer to the question, if it can be answered, is only attainable by attempting to "escape the cave". In the case of a simulation, you must ask "simulation or not, who is actually experiencing all this?" What is this thing we call experience? Who or what is wondering whether or not it is a simulation?

The underlying question is fundamental and timeless. The answers to all other questions only have meaning to the extent that we have to some degree answered this question.

I don't think there is any easy way to figure out if we are living inside a simulation.

In fact, if you suppose that such simulations are possible, then the number of simulated universes is probably much greater than the number of non-simulated universes (since there is only one real universe). Furthermore, if you allow people in the simulated universes to create their own universe simulators, you would get a very large tree of simulations. So, statistically speaking, you are probably in a simulation.

I've been thinking a bit about what it would mean to simulate a universe, and it leads to some amusing theories. For example, if you were to build a universe-simulator, then the number of bits you would have to represent the state of the simulation would be strictly smaller then the number of bits your universe has. One thing you could do is simulate a smaller (or simpler) universe. However, if you wanted to simulate a universe that is really similar to the one you live in, you might instead choose to do extrapolation. There may not be any good reason to simulate all the atoms in a star, since you could make pretty good approximations with Newtonian physics. In fact, you could choose to only simulate atoms when someone is using sufficient magnification, and in all other cases just wing it. Maybe instead of keeping precise position of electrons, you would simply have a distribution of where the electron could be, and whenever someone tried to detect the electron you would generate a random number from the distribution.

I don't know much about pseudo-random number generators, but it would be pretty funny if the ones being used in our universe simulator were cracked and we could predict electron positions by being able to extrapolate the pseudo-random stream.

Man, I had the weirdest thought about this just last month. There I was at 3 AM, completely zonked from practicing job tests on TestHQ, when my brain went: "Hold up... what if everything around us is just super fancy code?"

Yeah, that's pretty much what happened to me that night.

Here's what's crazy about the whole simulation thing - there's literally no way to prove it one way or the other. This smart guy Nick Bostrom came up with three options:

• • Either advanced civilizations end up destroying themselves before they can make simulations
• • Or they just don't bother making them
• • Or (and here's where it gets wild) we're probably living in one right now

But let's be real - trying to figure out if we're in a simulation is like trying to prove you're not dreaming while you're dreaming. Pretty much impossible, right?

The funny part? If this IS all a simulation, somebody went way overboard with the details. Like, who thought we needed stuff like brain freeze? Or that annoying thing where your headphone cord gets caught on every doorknob it passes? Come on, programmer person, that's just mean!

But you know what? Whether this is all ones and zeros or actual reality, it doesn't really change anything. We still feel happy when we pet dogs, still curse when we stub our toes, and still need coffee to function in the morning (at least I do!)

And hey, if this is fake, they at least did an awesome job with chocolate. I mean, have you HAD good chocolate? If that's computer code, it's some seriously epic programming! 😅

Computer simulations for games often use optimisations.

If the player is watching stuff, it is modelled realistically. But if no one is looking, a cheap approximate solution is used instead. This trick saves a lot of CPU cycles.

To discover if we are in a game, we need to look for an optimisation fingerprint. We need evidence that stuff behaves differently when no one is watching.

In our universe, the double-slit experiment suggests that light looks like a wave when no body is watching closely - but starts appearing like particles as soon as we take a closer appearance!

It's apparent that modelling every bit of light as a particle is means expensive. Therefore the world switches to a more optimal trend representation to truly save rounds.

Obviously then, we are in a Matrix.