One of the great conundrums puzzling cosmologists today is the concept of time. We experience time as something linear; it goes in one direction, passing from prior events to future events. The intriguing thing is this: There is no reason why the laws of physics should not apply equally well in a universe where time goes backwards. In reality however, we only experience time going forwards. What is extraordinary is that this forward movement of time is not experienced at a sub-atomic level. According to an article written by Martha Henriques, (“Why Does Time Go Forwards and Not Backwards?” BBC Future, 4th October, 2022), it is only when you step back from the microscopic world to the larger macroscopicworld that directionality in time emerges – something that the Austrian physicist-philosopher, Ludwig Boltzmann, brought to our attention.[1]
So, what is it that forces the directionality on time?
One thing that might do so is “entropy.” Entropy can be thought of as a measure of disorder, a subject that features in the laws of thermodynamics. In it simplest form, these laws say that heat cannot travel from a cold object to a warm object. It always has to be the other way round. This reality therefore gives us directionality, and this may give us the reason why we experience time that only heads into the future.[2]
Puzzled?
Let me put it another way.
The second law of thermodynamics states that all high-energy states (that can be expressed by things being highly ordered) will inevitably decay into lower and less ordered energy states with time. There can be no going backwards. This means that if something becomes fantastically ordered later in time – as in the evolution of human beings – it is only because the system has imported a lot of energy from another source, for the sad reality is, overall, the universe is heading towards a cooler, less organised energy state. It is heading towards something that scientists call “heat death.”[3] At the time of the Big Bang, however, (at the very start of things), the universe had a massively low entropy level. However, ever since the Big Bang, the entropy level has increased, i.e. the level of energy and order is fading away.
Marina Cortês, an astrophysicist at the University of Lisbon, says: “The likelihood of our current Universe having initial conditions of this kind [for the Big Bang], and not any other kind, is around one in 10 to the 10 to 124 (1:10^10^124)… which is quite possibly the biggest number in modern physics, outside of philosophy or mathematics.”[4]
This prompts a number of questions: Where did the fantastic level of energy (with the potential for fuelling amazing levels of order) originally come from? What fuelled the Big Bang and gave the universe its direction in time? Where did this restless energy for linear development come from?
The “heat death” of the universe will occur when the universe reaches its maximum entropy level, i.e. when it has reached a state of maximum disorder, having no energy or structure. This means that there will be no macro-structures for time to act on. Therefore, intriguingly, time itself will cease.
What can be said by way of conclusion? Perhaps this:
It can be said that time began when matter, larger than atoms, was created. Intriguingly, this realisation did not come about as a result of recent scientific discoveries. The early church theologian, Augustine of Hippo (354 – 430AD), spoke of creation being a single timeless act through which time itself came into being.[5]
It is so nice when scientists catch up with what theologians have been saying for centuries.
Let me conclude by saying that the phenomenon of forward-facing time is totally consistent with the action of a divine mind, a divine mind who wanted events in history to be significant, although that mind itself stands outside of time.
[1] Reported by Martha Henriques, “Why Does Time Go Forwards and Not Backwards?” BBC Future, 4th October, 2022. See: https://www.bbc.com/future/article/20221003-why-does-time-go-forwards-not-backwards. (Martha Henriques is Editor of BBC Future Planet.)
[2] Ibid.
[3] There is a theory that the universe might “bounce” back into existence, but at the time of writing, it is a theory that is viewed as being less likely.
[4] Quoted in Martha Henriques, “Why Does Time Go Forwards and Not Backwards?” BBC Future, 4th October, 2022. See: https://www.bbc.com/future/article/20221003-why-does-time-go-forwards-not-backwards. (Martha Henriques is Editor of BBC Future Planet.)
[5] Augustine, Confessions XI.14, trans R.S. Pine-Coffin, (London: Penguin, 1961), 263.
