As an intelligent species, we experience time as apparently flowing in one direction from the past to the future, so what is time? Physicists like Prof. Stephen Hawking describe it as the fourth dimension since we are three-dimensional beings. We have height, depth plus width and we are living on an apparent time line stretching from the past to the future.
Stephen Hawking in his 2001 book, The Universe in a Nutshell (page 35) describes Time quite simply:
“General relativity combines the time dimension with the three dimensions of space to form what is called space-time. The theory incorporates the effect of gravity by saying that the distribution of matter and energy in the universe warps and distorts space-time, so that it is not flat. Objects in this space-time try to move in straight lines, but because space-time is curved, their paths appear bent. They move as if affected by a gravitational field.”
As time is the main principal of Albert Einstein theory of general relativity, there can be no doubt this is an excellent description of time. Einstein went further in his Special Theory of relativity (1905) which shows that matter (as mass) and energy can be converted into each other according to the famous equation E = m c 2, where E is energy, m is mass, and c is the speed of light. Energy is equal to matter multiplied by the speed of light squared.
I therefore believe that Time is entropic and is linked to entropy as in the second law of thermodynamics.
Entropy is the function of thermodynamic variables, as temperature, pressure, or composition, which is a measure of the energy that is not available for work during a thermodynamic process. A closed system evolves toward a state of maximum entropy as described in the third law of thermodynamics. In the case of our Universe, entropy is described as a hypothetical tendency for the universe to attain a state of maximum homogeneity in which all matter is at a uniform temperature (heat death).
Entropy sets up the arrow of time that is continuously flowing in one direction, forward into the future. A glass of wine on a table can fall off onto the floor with the glass shattering all around. We never see a shattered glass on the floor come together and rise up back onto the table, before coming to rest. There are many other examples. Trees and plants grow tall from seed, while we are born as a baby and grow into an adult, and so forth.
In the far future, the arrow of time might reverse and point the opposite way from the future towards our past. This does not mean that we will notice any difference to what we see happening all around us today. That wine glass will still fall onto the floor and shatter into pieces.
This brings me to our perceived time line on which everything we see around us and observed in the Universe exists as a ‘Now Moment,’ that is a single unit of entropy in its time of existence. Our Now Moment constantly moves forward in a cosmic game of chance. In each Now Moment, we make choices, which leads to yes or no decision that affects our future. In nature, things are the same; a wrong choice by an antelope may lead to him being killed by a lion. Another will see him safely runaway. Chance decisions in civil engineering, or in the operating theatre. All of these decisions lead to a 50/50% outcome that sets the path of our future.
Albert Einstein describes Time as relative to each individual, and so each individual makes a decision that affects his or her future along his or her own time line.
This alone cannot lead to a movement forward through time, something else must be in play, and for me I consider this Quantum-Entanglement.
According to quantum mechanics, things can have properties that take on more than one value simultaneously, but when you measure that property, they instantly "choose" one of those values. This idea can also be applied to pairs of things. An object is said to be entangled with another when it has some property that takes on multiple values in a way that depends on the other object. The instantaneous "choosing" of one value (called "collapse") has interesting implications. It means that by measuring one of the entangled objects, you can see the other object instantly "choose" a particular value, wherever it is. In some sense, this could be called transmitting information faster than the speed of light. However, there is a catch: we have no way of controlling which outcome the measured object will choose. In this sense, you could say that entanglement allows you to transmit random information faster than light.
For atomic particles to exist they must be observed, which means that they take on the desired particle be it any one of the particles in the standard model of physics. Therefore, all of the objects and forms of life in our Now Moment exist because we observe them to exist. Outside of our Now Moment, the atomic particles are in a state of Quantum superposition that is a fundamental principle of quantum mechanics. It states that, much like waves in classical physics, any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state, and conversely, that every quantum state can be represented as a sum of two or more other distinct states. Mathematically, it refers to a property of solutions to the Schrödinger equation; since the Schrödinger equation is linear, any linear combination of solutions will also be a solution. An example of a physically observable manifestation of superposition is interference peaks from an electron wave in a double-slit experiment in which an electron can pass through both slits at the same time.
In the state of Quantum superposition, atomic particles have no character and I consider that in front of all of us, there is nothing except atomic particles in a state of superposition. As we make decisions and choices that shape our future, and observations as we move into the future, these atomic particles change into the desired form shaping the world and Universe around us.
The opposite occurs at the exact same instant, in which atomic particles that formed our existence within our Now Moment, dissolves into a state of Quantum superposition. This means that we continually move forward into our future, although this would not be a smooth process without another physical effect, that of Quantum Entanglement.
Wikipedia describes Entanglement this way:
“Quantum entanglement as a physical phenomenon that occurs when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently of the others, even when the particles are separated by a large distance—instead, a quantum state must be described for the system as a whole.
“Measurements of physical properties such as position, momentum, spin, and polarization, performed on entangled particles are found to be appropriately correlated. For example, if a pair of particles are generated in such a way that their total spin is known to be zero, and one particle is found to have clockwise spin on a certain axis, the spin of the other particle, measured on the same axis, will be found to be counter clockwise, as to be expected due to their entanglement.
“However, this behaviour gives rise to paradoxical effects: any measurement of a property of a particle can be seen as acting on that particle (e.g., by collapsing a number of superposed states) and will change the original quantum property by some unknown amount; and in the case of entangled particles, such a measurement will be on the entangled system as a whole. It thus appears that one particle of an entangled pair "knows" what measurement has been performed on the other, and with what outcome, even though there is no known means for such information to be communicated between the particles, which at the time of measurement may be separated by arbitrarily large distances.
“Such phenomena were the subject of a 1935 paper by Albert Einstein, Boris Podolsky, and Nathan Rosen, and several papers by Erwin Schrödinger shortly thereafter, describing what came to be known as the EPR paradox. Einstein and others considered such behaviour to be impossible, as it violated the local realist view of causality (Einstein referring to it as "spooky action at a distance") and argued that the accepted formulation of quantum mechanics must therefore be incomplete. Later, however, the counterintuitive predictions of quantum mechanics were verified experimentally. Experiments have been performed involving measuring the polarization or spin of entangled particles in different directions, which—by producing violations of Bell's inequality—demonstrate statistically that the local realist view cannot be correct. This has been shown to occur even when the measurements are performed more quickly than light could travel between the sites of measurement: there is no light speed or slower influence that can pass between the entangled particles. Recent experiments have measured entangled particles within less than one hundredth of a percent of the travel time of light between them. According to the formalism of quantum theory, the effect of measurement happens instantly. It is not possible, however, to use this effect to transmit classical information at faster-than-light speeds.”
All of the atomic particles that are within our Now Moment are in a state of Quantum Entanglement, with those about to come into existence in our future, it allows them to change instantly from a state of Quantum superposition to their properties. Our future then comes into existence, as our past dissolves away. Therefore, there is no past, and we have no future except what we make from our own 50/50% choices and routine observations of the world and Universe around us.
This principal holds true for the many forms of nebulae, star clusters, planets as well as life and everything else in our universe. They all exist in a single Now Moment just as we do on Earth.
For humanity, this allows for Time Travel into the future other than our past which has ceased to exist. However, we can time travel into the past by using higher special dimensions. Physicists today consider that we are living in a multi-universe in which our own Cosmos is one of many universes in hyperspace. The time travel process involves hopping from our Now Moment across onto an adjacent Now Moment, so that various paradoxes do not occur. For example, you cannot time travel into the past, kill your father, which in turn means that you were never born …
I will look at time travel in a later chapter, for now we have a reasonable explanation for our individual relative arrow of time, which serves our purpose well.
The one caveat to this is that we should not lose sight of is the fact that every living thing, object or the sights we see in the Universe around us, are composed of individual atoms in a complex molecular structure. On the quantum level, our Now Moment is seen as nothing more than clouds of atoms that appear to have no physical form, so perspective is an important factor.