Saturday, May 21, 2011

Causality: Time & the Quantum Vacuum

From my experience atheists and agnostics are starting to use the two contentions below at a higher frequency and are popularising them. Hence, I felt the need to provide structured written responses. If you can think of anything else to add please let me know.

1. "You cannot apply causality to the universe. Because causality presupposes time, and since the universe is all of time, the universe cannot have a cause. In other words, causality doesn't make sense outside of time; therefore you cannot ask what caused the universe. The question becomes meaningless."

The problem with this contention is that it assumes that causality presupposes time. There is no philosophical justification that causality only makes sense within time. In actual fact, there is no consensus amongst philosophers on what causality is, so in absence of a consensus the basic definition will suffice, and the basic definition is “something which produces an effect”. If you notice with this definition, time is not pre-requisite in understanding causality.

Additionally, there is a concept called “simultaneous, asymmetric causation” which means that something can be causally prior but not temporally prior (before in time) to the effect. A useful example to illustrate this is by touching your elbow on your pillow and then pushing your elbow into the pillow. The indentation seems to happen instantaneously when the elbow moves into the pillow. As you watch the elbow move so does the pillow and this seems to happen at the same moment. So the movement of the elbow is prior causally but not prior temporally. Therefore, since simultaneous asymmetric causation is possible, there is no reason to think timeless causation is impossible.

Even if this contention carries some weight the following questions still remain: how could the universe come into existence with no causal conditions whatsoever? Why did the universe begin to exist at all? To claim the universe began to exist without a cause would be truly absurd. The questioner may respond by saying "Well, what caused the cause of the universe?" and if they do they will be admitting what they first denied, that causality makes sense outside of time!

Putting rhetoric aside a simple response to the question "what caused the cause of the universe?" would be to respond by saying "nothing, it is necessarily uncaused". The main reason for this is that if we say there is a cause for the cause of the universe, then what stops us from continuing this ad infinitum? If the causes went back forever there wouldn't be a universe to talk about in the first place! For example, if I was a soldier with a gun and I wanted to shoot an enemy would I ever shoot if I had to ask the soldier behind me for his permission, and they then had to ask permission from someone behind them to, and this went on forever? No. I would never shoot. This is the same for the cause of the universe, therefore it has to be uncaused.

To simplify a response to this contention, you can argue that time only allows us to recognise that effects are a result of prior causes and not necessarily a result of time itself.

2. "There are many sub-atomic events in the quantum vacuum that do not correspond with causality, therefore it is possible that nothing caused the universe. It could have been spontaneous creation, an idea Stephen Hawking has propagated. Therefore, it is unlikely that God exists."

Some physicists claim that there are many sub-atomic events that do not correspond with causality. They claim that sub-atomic particles behave unpredictably and spontaneously in the quantum vacuum. So they conclude that things that begin to exist do not have to have a cause, or that things can come from nothing.

Firstly this contention is misleading as the quantum vacuum is not nothing, rather it is a sea of fluctuating energy, it has a rich structure and it obeys the laws of the universe. So it is something. Also, the view that sub-atomic events do not correspond with causality is not entirely true. There are many physicists that are adopting a deterministic view - meaning that these events have prior causes in the quantum vacuum - for instance the David Bohm interpretation being one of them.

Secondly, spontaneous sub-atomic events either mean that the causes are hidden to us, or there is a complete absence of causes. The position that some events “just happen” for no reason at all is impossible to prove, for our inability to identify a cause does not necessarily mean that there is no cause.

Finally, from a philosophical perspective it is extremely difficult for these physicists to justify their conclusions. This is because without the concept of causality we will not have the mental framework to understand our observations and experiences. In philosophical terms causality is a priori, which means knowledge we have independent of any experience. We know causality is true because we bring it to all our experience, rather than our experience bringing it to us. It is like wearing yellow-tinted glasses, everything looks yellow not because of anything out there in the world, but because of the glasses through which we are looking at everything. Take the following example into consideration; imagine you are looking at the White House in Washington DC. Your eyes may wonder to the door, across the pillars, then to the roof and finally over to the front lawn. Now contrast this to another experience, you are on the river Thames in London and you see a boat floating past. What dictates the order in which you had these experiences? When you looked at the White House you had a choice to see the door first and then the pillars and so on. However, with the boat you had no choice as the front of the boat was the first to appear.

The point to take here is that you would not have been able to make the distinction that some experiences are ordered by yourself and others are ordered independently, unless we had the concept of causality. In absence of causality our experience would be very different from the way it is. It would be a single sequence of experiences only: one thing after another. So to accept that sub-atomic events do not correspond with causality would be tantamount of denying our own experience!

By Hamza Andreas Tzortzis

Source

1 comment:

Anonymous said...

The author has changed his article slightly as a result of constructive criticism. Please amend. See here: http://hamzatzortzis.blogspot.com/2011/05/causality-time-quantum-vacuum.html