Seven Brief Lessons on Physics
The fundamental phenomenon that distinguishes the future from the past is the fact that heat passes from things that are hotter to things that are colder.
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The predictability or unpredictability of their behaviour does not pertain to their precise condition; it pertains to the limited set of their properties with which we interact. This set of properties depends on our specific way of interacting with the teaspoon or the balloon. Probability does not refer to the evolution of matter in itself. It relates to the evolution of those specific quantities we interact with. Once again, the profoundly relational nature of the concepts we use to organize the world emerges.
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Compare ‘now’ with ‘here’. ‘Here’ designates the place where a speaker is: for two different people ‘here’ points to two different places. Consequently ‘here’ is a word the meaning of which depends on where it is spoken. The technical term for this kind of utterance is ‘indexical’. ‘Now’ also points to the instant in which the word is uttered, and is also classed as ‘indexical’. But no one would dream of saying that things ‘here’ exist, whereas things which are not ‘here’ do not exist. So then why do we say that things that are ‘now’ exist and that everything else doesn’t? Is the present something which is objective in the world, that ‘flows’ and that makes things ‘exist’ one after the other, or is it only subjective, like ‘here’?
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