Friday, April 18, 2014

The End of Time, non-self and Nibbana

Julian Barbour wrote a popular science book, advocating his idea of a particular interpretation of the Wheeler-DeWitt equation. The name of the book is called the end of time. The Wheeler-DeWitt equation is an early attempt to combine both quantum and gravity. The search for quantum gravity still continues today, possibly because of one problem that the Wheeler-DeWitt equation posed: there is no time in it.

Having read the book, I had saw many parallels in Buddhism that matches the description by Barbour. This article is an attempt to list down the parallels. However closely Barbour's interpretation might appear to fit in with Buddhism, I do not claim that Buddhism requires this interpretation to be the true picture of reality. This is because I have neither the empirical realisation of the truths claimed in Buddhism nor do we have the experimental data to test Barbour's interpretation. The emphasis on empirical data is in accordance to Buddhism's spirit that the ultimate arbiter of what is right is empirical experience. However philosophically, it can be said that Buddhism supports certain parts of Barbour's interpretation. I invite the readers to form their own conclusion.

I shall describe The End if Time in brief and draw the parallels with Buddhist concepts along the way when suitable. I've found that a dialogue form is nicer to read, and easier to write. So here's P, a physicist and B, a Buddhist who are knowledgeable in their area but also knows the other side well too.

P: Time does not exist in the ultimate sense. That is the hypothesis by Barbour. Time is only an agreement to track changes we see in the world with another thing that changes that are more regular and accurate. In a universe with only one particle, like an electron, there is no time, because there is nothing else to keep track of any change.

B: Indeed, for Buddhist there is only the present moment, the past is gone, the future has not come.

P: Good, but that's not what Barbour's picture is. Now Barbour invites us to image a universe with three particles only. It is possible to track their evolution by taking successive "instants of time" or pictures, with only these pictures, one can rearrange the order of them and extrapolate it's path in the past and to the future. To those three particles, what is intuitive is not the Newtonian absolute space and time we develop having lived on earth, but what is real to them is only the relative configurations of their positions. Each moment in time is just a representation of these relative configurations. The collection of all possible configurations is called Platonia, it represents all that can be. These moments in time are all also called Nows, if we add in more particles until we put in the whole universe, then Platonia becomes the space of all possible configurations.

B: That sounds more like everything exist, a doctrine of the Sarvastivada school of Buddhism.  He who affirms the existence of the dharmas of the three time periods [past, present and future] is held to be a Sarvastivadin. It might be that the Sarvastivada school acknowledged that time travel as General Relativity allows is possible but the other schools do not bother with it.

P: Time travel in Barbour's picture is possible. A point in Spacetime in General Relativity represents an event, a point in Platonia represents a Now. So in general Relativity, time travel is a closed loop around a point, but this is pointless in Platonia, the time travellers only has memory of when they came from if the Now they occupy is close but not exactly the same as Now they wanted to go back to. Barbour postulate that if time travel is possible, then it has very low probability of being realised. Of course time here is conventional speech, ultimately time does not exist. You might think that time is still needed to talk about progressions from one Now to another in Platonia. However, it is possible to attribute this persistent illusion of time and motion as just memories and histories. Barbour calls things that records the past as time capsules. We only remember and infer the existence of a time before us in the Now. It is because of time capsules that we were made to believe that we travelled in time from the past to the future when in fact, there is no travelling, no motion. Just that the person in each Now are aware of the experience of their Now including time capsules. Thus each person in their Now thinks that they came from someone from another Now (in their so-called past). 

B: Memory, it's part of the aggregate of perception in Buddhism. In Buddhism, we believe that ultimately a person is made up of 5 aggregates, of form (anything material), sensation, perception, mental factors, and consciousness. Barbour's picture if imported into Buddhist terms, would have Platonia including not just the physical world, but also at least the perception aggregate too.

P: It should include all 5 aggregate to be worthy to be called Platonia.

B: Doubtless. However, the thing is, in Buddhism we recognize 4 elements that makes up the form: Earth which represents solidity, water which represents cohesion, fire which represents heat and air which represents motion. And then there is space too. What is curious is that Barbour denies the air element. I don't think it would fit in with Buddhism anyway.

P: But don't forget, the 4 elements are meditation teachings on what humans can directly sense, not necessarily it is the fundamental way the world works.

B: It's debatable, but anyway, how do you fit in entropy here then?

P: The distinction between the past and future is only because the smaller volume and thus smaller entropy Nows are correlated with the past, while the Nows with bigger volume, are the ones with higher entropy and they also has the ability to contain time capsules that describes other Nows with lower entropy, thus they are perceived as the future.

B: I still find it hard to believe that there's a me out there in Platonia doing everything else.

P: Not all Nows are created equal. The Nows that life are breathe into are the most frequent one. This can be predicted by the wave function of the universe which is given by solving the Wheeler-DeWitt equation for the whole universe. The way to solve it is to look at the structure of all that is possible and then let them cancel each other out until you get the most likely path. It's inspired by the Hamiltonian mechanics principle of least action. Since the equation applies to the whole of Platonia which is timeless, there is no time in the equation. So our existence, what we do now, is a sum of all possible us.

B: That smacks of the lack of free will. Of fatalism. Back in Buddha's time there was many other teachers teaching many other philosophy, one of which is fatalism, Makkhali Gosala. He taught that there is no point in doing good or striving, when a person's life cycle is finished, he will automatically attain to the end of rebirth. In Buddhism, a person has the habits due to unmindfulness, which leads them to be quite predictable as a biological, social, psychological machine. Yet, if we are mindful, we can choose not to be angry when the situation presents itself. We can exercise free will to change the course of our life. It is because of free will that people can choose to follow the path of Buddhism to enlightenment.

P: Barbour calls his picture as beyond free will and beautiful. You are what you are (Now) because you are what you are (in the whole of Platonia). There's also multiple instants, so instead of one possibility, if there is choices, the wave function can split up and follow those possibilities. However, each person only sees their possibility when the choice is made. I use person here as a conventional speech, ultimately each Now has a different person in it. There's no one person who travelled from one Now to another. There's just memory of each person thinking that they did.

B: This no self thing rings well with Buddhism. The parallels I can see with Buddhism is that a central concept in Buddhism is that we are deluded into thinking that something are permanent, happy and have a self. Whereas the ultimate view if we have a clear mind is to realize that all conditioned phenomenon are impermanent, unsatisfactory and thus doesn't have an independent existence as a self. This is usually summarized as non self or emptiness, empty of inherent existence. The reasoning is that all things depend on one another, for example, the fact that you are reading this is conditioned by you having the time, energy, and relatively healthy. It is also only possible if I wrote it in the first place, and it is published. And all these can be traced back to the conditions that allow humans to exist, the conditions to form earth, the sun and indeed the whole universe. So nothing ever exist independently of other things. 

P: On the surface, Barbour's picture seemed to agree with the non self of Buddhism. Yet within each Nows, Barbour allows for independently existing entities that are not subjected to causation because there is no time for cause to become effect. There are just all the possible configurations of the world including the Now in which a person experiencing the effect remembers another Now in which he or she had done a cause for the effect. There is another Now in which the memory is different but the likelihood of that inconsistent history to happen is low. Or at least Barbour claim that it should be low if we ever manage to solve the Wheeler-DeWitt equation to that detail. Herein lies that falsibility of his theory or interpretation. 

B: Thus these independent Nows are against the spirit of non-self. Yet, one can also argue that the Nows are not entirely independent, but are bound somewhat by the Wheeler-DeWitt equation which solution in turn depends on the structure of each Nows. 

P: Wow, we might need a philosopher in here to sort out our mess.

B: One last thing, another parallel concept I see is Nibbana. You kept on using conventional and ultimate view. In Buddhism we have that too. The conventional view is that the world has time, everything changes, with it, it has no self, and is suffering. However, in Nibbana, there is no time, no impermanence, still no self and no suffering. Two out of three makes Nibbana sounds like Platonia.

P: Indeed, if Barbour is right, there's nothing really to worry about death. No one died, it's just one Nows of the Platonia, memories and so on. Maybe realizing Platonia is equal to realizing Nibbana.

B: Well, some Mahayana teachings has this thing that Samsara (the conventional world, the rounds of rebirth) is the same as Nibbana, once you realize this, you realize Nibbana. These looks nice, but I doubt it, first off, Physics has practically no idea how to quantify suffering or unsatisfaction, much less the cause and the way out of it. Buddhism however is quite expert in it.

P: Sounds to me like we should construct the mathematics of suffering to introduce to the Physics world.

B: Anyway let's have a warp. A recap of the parallels and differences.

Barbour's Picture Buddhism
Time does not exist in the ultimate sense The past is gone the future has not come
Nows All exist doctrine
No one passed from one Now to another Non-self
Platonia Nibbana?
"Beyond free will" Free will is important, exercised when mindful.
Denies motion Form has the air element
Independently existing Nows?  Against the spirit of non-self.

P: So we have about 4 parallels, and 3 differences. Well, that's certainly strange, when I first read the book, I thought that it would fit in quite well. 

B: Well, that's Physics and Buddhism for you folks. No real answer, I'm going back to practicing for enlightenment. See ya!