Time seems to be the most obvious feature of reality: it flows from the past to the future, establishing the rhythm and direction of all processes. However, in fundamental physics there is still no single answer to the question of what time is and why it has an “arrow”. A new concept, developed by a number of theorists, proposes to consider time not as a fundamental quantity but as a consequence of the accumulation of information in the Universe. Conversation Gateway reports this.
The problem of time arises at the intersection of key theories of modern physics. In Albert Einstein's general theory of relativity, time is not universal: it slows down in a gravitational field and depends on the motion of the observer. In contrast, in quantum mechanics, time is not explained at all – it is simply given as an external parameter. When trying to incorporate these approaches into the theory of quantum gravity, time often “disappears” from the equations and the Universe appears frozen.
Traditionally, the direction of time is associated with the growth of entropy – a measure of disorder. However, this approach does not explain why the Universe itself began in a highly ordered, low-entropy state. Furthermore, the fundamental equations of physics are symmetric over time and do not distinguish between the past and the future.
Another view is based on the ideas of information theory coined by Claude Shannon in the mid-20th century. Over the past several decades, physicists have come to the conclusion that information is not an abstraction but a physical quantity closely related to energy, entropy and even gravity. This problem becomes especially acute in the study of black holes, where the loss of information contradicts the laws of quantum mechanics.
In the new approach, space-time is considered a medium capable of “recording” information about every ongoing interaction. Every particle collision, radiation or decay leaves an irreversible trace of information. These records cannot be completely erased or “rewound” because the information is scattered throughout the environment.
According to the authors of this concept, it is this irreversibility that shapes the direction of time. The initial states of the Universe contain fewer traces of information, later states contain more traces of information. The past differs from the future in that more information has been recorded about it. Time therefore arises not as a fundamental basis but as a result of the continuous accumulation of memories of events.
Interestingly, the same idea may have implications for cosmology. The accumulated “memory” of information about space-time can influence its shape and the motions of galaxies, simulating effects now thought to be due to dark matter. Testing these hypotheses will require new observations and experiments, from astrophysics to quantum computing.
If this approach is confirmed, it would change the understanding of time: The universe not only exists in time but continuously creates it, recording its own history.
