自然の原因だけに基づいた現実の現在の時点を知ることができますか?


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ローレンスクラウスのような物理学者は、空の空間の無の性質そのものにより、粒子、さらには私たちのような宇宙でさえも自然に発生する可能性があると説明しています。しかし、哲学的な観点からは、それが自然に発生するために時間は存在する必要がないのではないでしょうか。私が本当に求めているのは、自然を超えた超自然的な力の命令がなくても、のような現時点が存在する可能性があるのでしょうか?

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Physicists like Lawrence Krauss have explained that it is possible for particles, and even a universe such as ours, to arise spontaneously due to the very nature of the nothingness of empty space.

The terms 'nothing' and 'something' are both deeply sophisticated and mysterious terms. They have been endlessly debated throughout millennia. For example, the idea of substance since Aristotle, and before him Parmenides' idea of the one which admits of no void, provoked the invention of the atomic hypothesis by Democritus. In Buddhist philosophy we have Nagarjuna discoursing on sunyata (emptiness) in his Mula-madhya-maka-karika (Profound Verses from the Centre).

Now Krauss, a middling theoretical physicist but a wildly popular science popularizer has written a book A Universe from Nothing. His 'nothing' has a very specific interpretation. It is the vacuum in relativistic quantum field theory. These two terms need an explanation.

Now vacuum simply means space that is empty of matter. This is a concept that has been around since Greek antiquity when the atomists mixed matter and the void together to produce atoms moving in the void. Then, of course, if no atoms were available there could only be void, that is, vacuum. But of course there remains space and time. So, shouldn't one, to truly say that one has nothing, remove space and time? Now, we can physically obtain a vacuum by removing all the air from a tin can, as is routinely done, however, removing space and time is obviously not physically possible. It remains a subtle philosophical problem. Can one give meaning to this?

Interestingly, the Ash'arite theologians in Islamic Iraq at around the tenth century proposed that space and time itself were atomic and that atoms were recreated at every point of time by Allah, that is, they subsisted by the will of Allah, a theory that is known in the West as Occasionalism, and popularized by al-Ghazali. Here, of course, if there were no atoms there would be neither matter nor space nor time.

With Einstein's theory of gravity it was realized that spacetime itself is a kind of substance because it has a geometric topology. It expands, contracts and curves. One then could justifiably ask in that physical world-view what actually would a vacuum be? Is it enough to empty it of matter (the traditional view) or must one eliminate spacetime, too?

So, we have two possible indications of what it might mean to remove space and time to actually obtain the philosophical nothing.

The revival of the scientific tradition in the West starting from the Italian renaissance absorbed the Greek idea of the atom (for example, consider the corpuscular theory of light by Newton). This was fully established by the turn of the twentieth century, but it had to undergo radical reinvention due to the discovery of quantum theory and relativity when they came together in relativistic quantum field theory.

In this theory, a particle was no longer considered the fundamental notion. This was overtaken by the idea of a field: all of the four fundamental forces are fields, as are particles.

But what is a field? It differs from a particle in one essential way. It is not localized in space and time. It subsists over all space and over all time.

Now configuration of particles of differing types is a certain configuration of different types of fields. This is as true of 5 particles as it is of no particles. So here we have a new interpretation of a vacuum, the quantum vacuum that Krauss is interested in: a vacuum is a certain configuration of fields on spacetime.

Now Krauss says this vacuum configuration is unstable, so matter fields appear.

One, of course, has to question, supposing that may be a vacuum, whether it is nothing? You already have a great deal of structure. You have a spacetime and a field on it. This to me is not quite nothing. Further, one expects the laws of relativistic quantum theory to hold, that is, the laws which tell us how this initial vacuum state evolves in time. These are not nothing either.

So Krauss has accomplished a certain sleight-of-hand. He identifies nothing with the vacuum. Showing that the vacuum is unstable, he proposes that the universe has come from nothing, whereas all he has shown is that it has come from this vacuum.

From a philosophical point of view, though, wouldn't time need to exist for that to spontaneously arise

So, yes, you are right. Spacetime and the vacuum field on it are ontologically prior to something. And Krauss is silent about where these come from, and indeed about any explanation of really what a law of nature is and what it consists of.

and wouldn't it follow that the time would need a beginning

Kant gave good arguments for time with and without a beginning, and hence he deduced this question would be forever outside the possibility of answering it. We can only speculate and give good reasons for our speculations. Notwithstanding the big bang, one can still ask what happened prior to that.

What I'm really asking is, is it possible for a present point of time like right now to exist without the command of some supernatural force beyond nature to start time?

This is the theory of the First-Mover in Christian theology, and also of Occasionalism where God is required everywhere and at all times. It is a different resolution to the paradox of causality that Hume pointed out and Kant answered by making empirical reality mind-dependent.