Modern science (and scientists such as Stephen LaBerge) argues that the dream world is a simulation of the real world. In a bid to achieve authenticity, many of the features of the real world are faithfully replicated. However, our mind is not perfect: there are a few key aspects which it fails to reproduce.
Having this in mind, one can use these innacuracies in order to test reality and to discern if they are in a dream or not.
The table below states some common inconsistencies between the real world and the dream world.
| The real world | The dream world |
|---|---|
| Actions have short-term and long-term consequences. | Actions do not carry long-term consequences. |
| Free will is given to everyone whenever possible (on a non-philosophical level at least). | The dreamer is often led 'on-rails' through a situation until he or she becomes lucid or wakes up. |
| Surreal events seldom occur, and when they do, they are met with suspicion and suprise. | Frequent surreal events often go unnoticed. |
| Machines often function as intended (though not always!) | Machines malfunction easily and frequently. |
| The world, and all the objects in it, are governed by fundamental forces, and these cannot be ignored. | The dream world is far from logical. Gravity and other forces can be overcome or altered with ease. |
| A change of scene requires a car, a plane ticket, or hiking boots. | Scene changes can occur spontaneously. |
Some other more in-depth differences exist. For instance, a dreamer's own reflection in the mirror is usually misshaped and dark in dreams, while it is neat and flawless in reality.