S
Shadow Cypher
Guest
A thousand times a day, our experiences reveal a distinction between things unfolding one way in time and the reverse. Cream stirred into coffee forms a uniformly tan liquid, but we never see a cup of light coffee unstir and separate into white cream and black coffee. The compressed carbon dioxide gas in a bottle of Coke rushes outward when we twist off the cap, but we never find spread out carbon dioxide gas gathering together and swooshing back into the bottle. Ice cubes put into a glass of room-temperature water melt, but we never see globules in a room-temperature glass of water coalesce into solid cubes of ice. These common sequences of events happen in only one temporal order. They never happen in reverse, and so they provide a notion of before and after - they give us a consistent and seemingly universal conception of past and future.
Perhaps the most pointed example of all is that our minds seem to have access to a collection of events that we call the past - our memories - but none of us seem s able to remember the collection of events we call the future. There seems to be a manifest distinction between the things we can remember and the things we cannot. This is what we mean by time's having an orientation, direction, or an arrow.
Physics and science more generally, is founded on regularities. Scientists study nature, find patterns, and codify these patterns in natural laws. You would think, therefore, that the enormous wealth of regularity leading us to perceive an apparent arrow of time would be evidence of a fundamental law of nature. The perplexing thing is that no one has discovered any such law. What's more, the laws of physics that have been articulated from Newton through Maxwell and Einstein, and up until today, show a complete symmetry between past and future. Nowhere in any of these laws do we find a stipulation that they apply one way in time but not the other. Nowhere is there any distinction between how the laws loom and behave when applied in either direction of time. The laws treat what we call past and future on a completely equal footing. Even though experience reveals over and over again that there is an arrow of how events unfold in time, this arrow seems not to be found in the fundamental laws of physics.
Perhaps the most pointed example of all is that our minds seem to have access to a collection of events that we call the past - our memories - but none of us seem s able to remember the collection of events we call the future. There seems to be a manifest distinction between the things we can remember and the things we cannot. This is what we mean by time's having an orientation, direction, or an arrow.
Physics and science more generally, is founded on regularities. Scientists study nature, find patterns, and codify these patterns in natural laws. You would think, therefore, that the enormous wealth of regularity leading us to perceive an apparent arrow of time would be evidence of a fundamental law of nature. The perplexing thing is that no one has discovered any such law. What's more, the laws of physics that have been articulated from Newton through Maxwell and Einstein, and up until today, show a complete symmetry between past and future. Nowhere in any of these laws do we find a stipulation that they apply one way in time but not the other. Nowhere is there any distinction between how the laws loom and behave when applied in either direction of time. The laws treat what we call past and future on a completely equal footing. Even though experience reveals over and over again that there is an arrow of how events unfold in time, this arrow seems not to be found in the fundamental laws of physics.