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On causation, consciousness and time
- sorry the length is twice what was suggested! Anyway reading half will do...
Introduction
As a physics student, I remember being dazzled by the way in which time gradually disappeared from the equations, as I got closer to finishing my degree. We started with Newton’s second law, which was an explicit function of time; we then moved to thermodynamics, where it was usual to see diffusion equations in which time and space were almost symmetrical.
Suspicions grew considerable after learning Maxwell’s equations. By manipulating them, it was possible to arrive to the –now well-known– wave equation, which governs the propagation of light in vacuum. Funnily enough, his equation was almost perfectly symmetrical with respect to time and space. It was easy to see we were onto something.
Physicists soon realized the power of merging space and time, so they invented a mathematical operator, called the d’Alembertian, which grouped all space and time derivatives.
Time had explicitly disappeared from the picture, albeit not implicitly. It would take people a bit longer to devise a formalism that made the equations perfectly symmetrical in space and time. We owe that to Einstein himself, who expressed the wave equation in its current form. In his view, time had ceased to be an issue; it had finally lost its privileged status and was another part of space, just like ‘up’ and ‘down’. Time had, in a way, ceased to be.
It is a well-known fact, though, that time is strongly related to causation. If equations stop speaking about time evolution, but only talk about ‘four-dimensional shapes’, where has causation gone? How can we say something caused something if the Universe is just like an intricate, frozen, four-dimensional painting? Does causation still apply as a concept? Shouldn’t we just get rid of it, along with time?
The Universe as a shape
Causation is closely linked to time. Without time, there is no causation. Causation is a slippery concept, but at least one thing is clear: some fact, X, brings about some other fact, Y, to which it is related. The ‘bringing about’ involves time: Y is assumed to happened after X, albeit maybe only immediately after. Someone could argue that backwards causation might be possible. I’ll grant their point. However, even backwards causation involves time. If everything is determined, if there’s no passage of time, then there’s no room for causation, in the same way that nobody would say that the base of a triangle ‘causes’ its vertex. There might be an illusion of causation but no strict, objective causal relations like the ones advocated by Cartwright. If I turn on the stove, I cause the water to heat up. That’s true for a human observer, which doesn’t have access to the total information content of the Universe. However, God would disagree. He would say: “in the Universe there are two connected regions of space-time, one with you turning on the stove and another one with water boiling, each of which were determined by the laws and some initials conditions. You didn’t cause anything, because everything is determined. However, you were under that impression because of your partial perspective of my creation”. If the Universe was a frozen sphere, there would be no cause and effect.
Oddly enough, it happens to be that the Universe is a frozen sphere.
How can we make sense of that? The first thing we ought to realize is that, in the deterministic view, the Universe is made up of space, time, and the positions of each particle at each moment. Actually, if we had four-dimensional computers –and four-dimensional sight– we could plot it in our screen and we would get a geometrical shape. Of course, it wouldn’t be a nice-looking, simple shape. It would be something intricate, but a geometrical shape nonetheless, even though we would be confined to a seeing only a little 3-dimensional slice.
What are the implications of this? First, there is no time. Let me rephrase that: there is a dimension called ‘time’, the same as there is a dimension called ‘up and down’ and another called ‘left and right’. It makes as much sense to talk about causation in time as to talk about causations when moving from left to right. We are just seeing parts of a structure that is already there, that has always been there, so nothing has caused it. The present can’t cause the future because they are both part of a 4-dimensional structure which can’t be dissociated. They are regions in a shape that just is. We could say the shape is still, but one should be careful as to how to understand this. What I mean is that the structure doesn’t change. Now, this doesn’t mean the structure doesn’t change ‘in time’. There is no time involved: the structure is an all-embracing shape and it only makes sense to talk about ‘time’ inside it and with regards to our perspective. It is very difficult to visualize anything which doesn’t involve time, since we live in it. However, if one thinks about the Universe as ‘frozen’, one should bear in mind that this is just an analogy, useful because of our limited imagination. However, if one has no issues fathoming a timeless structure, one should definitely embrace this mental image. The flaw, as always, lies in our perception.
Consciousness and time
Most people will have trouble understanding how it is possible to live in a static Universe and still feel the flow of time. This is not an easy concept to grasp, mainly because it conflicts with our intuition and with our everyday view of what space and time are. I feel I cannot continue without clarifying this explicitly, for it will be very difficult to agree with my conclusions if one is not convinced that movement in time is not necessary for consciousness.
One of the best ways I know for explaining this is by reference to the film ‘Total Recall’, based on a short story by Phillip K. Dick. In ‘Total Recall’, Arnold Schwarzenegger is a spy from Mars which has some fake memories implanted in his brain, so that he believes he’s just an average person with a regular job on Earth.
After watching the movie, the first question that comes to one’s mind is: how do I know the same thing hasn’t happened to me? That is, can I be sure that I existed five minutes ago?
Obviously, memories aren’t good enough proof, since they could’ve been implanted. One could then retort to witnesses, but they could have been bought or even simulated in a Matrix-like way. The answer is we don’t really have a way of knowing if we were alive five minutes ago. All we can say is that we remember to be.
But then, can I be sure I existed a second ago? And a millisecond ago? The answer keeps being ‘no’. It is impossible to prove that I existed in any instant that is not now. However, I’m not trying to prove that I never existed until now. What I’m trying to prove is that only one instant is necessary to believe we’re moving through time. Now, one instant could be hardly considered moving. Actually, it’s quite the opposite.
That’s how physicists see time nowadays. Each and every moment of our lives exists simultaneously –simultaneously is just an easy way of saying ‘in a frozen Universe where time doesn’t flow’– and each and every one of our ‘selves’ thinks he or she has lived some number of years. I’m simultaneously eighty and ten. The only problem is that I’m incapable of seeing both states at once. Therefore, each version of me thinks he’s moving through time and that a number of years have passed, but nothing is passing, since there is no movement. The only difference between 80-year-old me and 10-year-old me is the information in our heads and our surroundings. We’re just badly communicated.
- sorry the length is twice what was suggested! Anyway reading half will do...
Introduction
As a physics student, I remember being dazzled by the way in which time gradually disappeared from the equations, as I got closer to finishing my degree. We started with Newton’s second law, which was an explicit function of time; we then moved to thermodynamics, where it was usual to see diffusion equations in which time and space were almost symmetrical.
Suspicions grew considerable after learning Maxwell’s equations. By manipulating them, it was possible to arrive to the –now well-known– wave equation, which governs the propagation of light in vacuum. Funnily enough, his equation was almost perfectly symmetrical with respect to time and space. It was easy to see we were onto something.
Physicists soon realized the power of merging space and time, so they invented a mathematical operator, called the d’Alembertian, which grouped all space and time derivatives.
Time had explicitly disappeared from the picture, albeit not implicitly. It would take people a bit longer to devise a formalism that made the equations perfectly symmetrical in space and time. We owe that to Einstein himself, who expressed the wave equation in its current form. In his view, time had ceased to be an issue; it had finally lost its privileged status and was another part of space, just like ‘up’ and ‘down’. Time had, in a way, ceased to be.
It is a well-known fact, though, that time is strongly related to causation. If equations stop speaking about time evolution, but only talk about ‘four-dimensional shapes’, where has causation gone? How can we say something caused something if the Universe is just like an intricate, frozen, four-dimensional painting? Does causation still apply as a concept? Shouldn’t we just get rid of it, along with time?
The Universe as a shape
Causation is closely linked to time. Without time, there is no causation. Causation is a slippery concept, but at least one thing is clear: some fact, X, brings about some other fact, Y, to which it is related. The ‘bringing about’ involves time: Y is assumed to happened after X, albeit maybe only immediately after. Someone could argue that backwards causation might be possible. I’ll grant their point. However, even backwards causation involves time. If everything is determined, if there’s no passage of time, then there’s no room for causation, in the same way that nobody would say that the base of a triangle ‘causes’ its vertex. There might be an illusion of causation but no strict, objective causal relations like the ones advocated by Cartwright. If I turn on the stove, I cause the water to heat up. That’s true for a human observer, which doesn’t have access to the total information content of the Universe. However, God would disagree. He would say: “in the Universe there are two connected regions of space-time, one with you turning on the stove and another one with water boiling, each of which were determined by the laws and some initials conditions. You didn’t cause anything, because everything is determined. However, you were under that impression because of your partial perspective of my creation”. If the Universe was a frozen sphere, there would be no cause and effect.
Oddly enough, it happens to be that the Universe is a frozen sphere.
How can we make sense of that? The first thing we ought to realize is that, in the deterministic view, the Universe is made up of space, time, and the positions of each particle at each moment. Actually, if we had four-dimensional computers –and four-dimensional sight– we could plot it in our screen and we would get a geometrical shape. Of course, it wouldn’t be a nice-looking, simple shape. It would be something intricate, but a geometrical shape nonetheless, even though we would be confined to a seeing only a little 3-dimensional slice.
What are the implications of this? First, there is no time. Let me rephrase that: there is a dimension called ‘time’, the same as there is a dimension called ‘up and down’ and another called ‘left and right’. It makes as much sense to talk about causation in time as to talk about causations when moving from left to right. We are just seeing parts of a structure that is already there, that has always been there, so nothing has caused it. The present can’t cause the future because they are both part of a 4-dimensional structure which can’t be dissociated. They are regions in a shape that just is. We could say the shape is still, but one should be careful as to how to understand this. What I mean is that the structure doesn’t change. Now, this doesn’t mean the structure doesn’t change ‘in time’. There is no time involved: the structure is an all-embracing shape and it only makes sense to talk about ‘time’ inside it and with regards to our perspective. It is very difficult to visualize anything which doesn’t involve time, since we live in it. However, if one thinks about the Universe as ‘frozen’, one should bear in mind that this is just an analogy, useful because of our limited imagination. However, if one has no issues fathoming a timeless structure, one should definitely embrace this mental image. The flaw, as always, lies in our perception.
Consciousness and time
Most people will have trouble understanding how it is possible to live in a static Universe and still feel the flow of time. This is not an easy concept to grasp, mainly because it conflicts with our intuition and with our everyday view of what space and time are. I feel I cannot continue without clarifying this explicitly, for it will be very difficult to agree with my conclusions if one is not convinced that movement in time is not necessary for consciousness.
One of the best ways I know for explaining this is by reference to the film ‘Total Recall’, based on a short story by Phillip K. Dick. In ‘Total Recall’, Arnold Schwarzenegger is a spy from Mars which has some fake memories implanted in his brain, so that he believes he’s just an average person with a regular job on Earth.
After watching the movie, the first question that comes to one’s mind is: how do I know the same thing hasn’t happened to me? That is, can I be sure that I existed five minutes ago?
Obviously, memories aren’t good enough proof, since they could’ve been implanted. One could then retort to witnesses, but they could have been bought or even simulated in a Matrix-like way. The answer is we don’t really have a way of knowing if we were alive five minutes ago. All we can say is that we remember to be.
But then, can I be sure I existed a second ago? And a millisecond ago? The answer keeps being ‘no’. It is impossible to prove that I existed in any instant that is not now. However, I’m not trying to prove that I never existed until now. What I’m trying to prove is that only one instant is necessary to believe we’re moving through time. Now, one instant could be hardly considered moving. Actually, it’s quite the opposite.
That’s how physicists see time nowadays. Each and every moment of our lives exists simultaneously –simultaneously is just an easy way of saying ‘in a frozen Universe where time doesn’t flow’– and each and every one of our ‘selves’ thinks he or she has lived some number of years. I’m simultaneously eighty and ten. The only problem is that I’m incapable of seeing both states at once. Therefore, each version of me thinks he’s moving through time and that a number of years have passed, but nothing is passing, since there is no movement. The only difference between 80-year-old me and 10-year-old me is the information in our heads and our surroundings. We’re just badly communicated.
