I'm reading Jim Holt's book Why does the World Exist? and I have come across this Hawkingesque idea about the beginning of time, early on in the book,
and I'd like to explain why I think this idea is philosophically naive.
Hawking's idea is that the question "What came before the universe?" is null and void, because at the beginning of the Big Bang there is a beginning
to time and there was no time before that. Well and good. But the argument goes on to say that this fact means that the universe does not need a cause
because there was no time before t = 0, for a cause to exist. This, to my mind, is a thundering fallacy and shows how naive Hawking is when it comes
to philosophy. First a few notes on time.
It has been said that change is the definition of time. This is weak. While change is evidence of time it is not a sufficient definition of time.
Rather, time is that order according to which change comes about. It is the WAY change happens. Einstein's general relativity describes how change
happens in physical terms and as such it can be seen to be a mathematical description of how change happens. This is the correct definition of time,
from which we get the concept of spacetime. Spacetime is a mathematical order - it is not change - and as such it is a more rigorous definition of
time. Time is the order of things. This order, abstractly, does not require the flow of time. It is a timeless order according to which change
Now when it comes to cause and effect, it is a mistake to imagine that cause and effect are necessarily separated by the flow of time. All that is
required is that there is an ordered, necessary relationship between cause and effect. The flow of time is not required. Here are some examples of
necessary relationships (cause and effect) that are not dependent on change or the flow of time.
Imagine you are drawing a triangle. You have two sides drawn and are in the process of drawing the third side. The triangle does not exist until you
have completed drawing the third side. Only when you have completed the third side does the triangle exist. But the moment the triangle exists the
area of the triangle also exists - as do many other properties. There is a necessary relationship between the triangle and its area. The triangle is
the cause and the area is the effect but both triangle (cause) and area (effect) come into existence at the same instant. No temporal separation
between cause and effect as they come into existence simultaneously.
In mathematical logic 1 + 1 = 2. There is a necessary relationship between the 1s and the 2. In this relationship time, as defined above, as the order
underlying relationships, exists, but the flow of time is not necessary. Indeed, in the mind, time exists as an order, whence necessary mathematical
and logical relationships exist in a time order that does not require the flow of time or temporal precedence. All that is required is a set of
necessary relationships. In this respect logic is to the mind what time is to the physical universe: it is the order inherent in relationships. Logic
= time. Indeed, any mathematical system is the equivalent of time in the way that general relativity is time in physical terms.
In other words, one thing can precede another without the need for simple time (the flow of time). There can be a logical precedence or necessity that
does not require the flow of time. This is why the definition of time needs to be rigorously defined, as above.
Given these facts we can see how Hawking is being naive when he imagines that there must be a flow of time for the universe to be necessarily
dependent on a preceding event. Such an event would not require the flow of time to exist. All that would be needed would be a logical or necessary
relationship between the universe an its cause.
Another way to see how the flow of time is not necessary for logical relationships is to imagine you are opening a door. To open the door you must put
the key in the lock, turn it, and push to door open. You could do this very slowly so that it takes five minutes to open the door, or you could do it
quickly, in two seconds. The flow of time, here, is not, in principle, a factor. All that is required is the necessary relationships between events;
the key must be turned if the door is to open. This logical dependency is purely geometric and arises out of the order of spacetime, not the flow of
time. Indeed, it may turn out that the flow of time is a purely human, subjective, experience. What all this means is that the universe does not need
a cause that precedes it in temporal terms but does precede it in logical or necessary terms so there is no need for an earlier cause to exist before
t = 0.
edit on 16-12-2013 by EnPassant because: (no reason given)