I am sure you have heard this topic discussed endlessly. Free will versus everything we do being pre-destined. I am going to write about it from a scientific perspective. It may not be right exactly but well, what’s the harm in imagining it. So, what is destiny? Destiny is the prior arrangement of what might happen in the future. In the divine sense of the word, God takes a huge book in the sky and peeps over the book whenever a child is born, and scribbles on the book what is going to happen in the poor chap’s life. This is not my version of destiny. My version of destiny is dependent on whether the laws of physics are probabilistic in nature or not. I will give an example.
Suppose you take a beam of electrons and pass it through a narrow slit. It will diffract and form an interference pattern. A priori one cannot predict where a single electron is going. Hence we think of the electron beam as a probabilistic wave which, in a probabilistic manner gives the interference pattern. Now, time for a gedanken. Imagine the electron at the slit. When it reaches the slit, is it in one place or not? Forget for the time being, that we cannot see or observe it. precisely. So, is it in one place ? Yes of course, because no object can occupy more than one place at the same time. So, the position is actually fixed at each instant. Our inability to observe that position without changing it is what makes us believe that the position is uncertain. So, in other words, left to itself, the electron will choose a path based on its history of movements. Since each electron has slightly different histories each of the electrons will go in a slightly different direction and hence you get a interference pattern. Wow, I don’t know how many laws of physics I have broken in the past few sentences but you get the logic behind the argument, I guess. The logic is, our inability to observe a single electron with precision does not mean that the path of each electron is not deterministic. It is deterministic.
Another example is of radioactive decay. It is supposed to be random. A beta particle or other radiation is emitted seemingly in random fashion. My question here again is, do we understand the sub-atomic world very accurately ? No, obviously not. We do not even know whether we have the full list of all the elementary particles. What we have is a list which is correct in the limit of our experimental accuracy. For instance, let’s say there are eight different types of protons, and they differ in their masses due to the presence of different types of ‘weirdons’. Let’s assume that each ‘weirdon’ weighs 10-8 g and our experimental setup has a least count of 10-6 g. So, can we ever find the ‘weirdons’ ? Obviously no. Besides, there is no ‘theory of everything’ yet which can explain the entire phenomenon in the universe. Hence, we can conclude that our knowledge is incomplete. Given this fact, if you consider the radioactive decay problem, is it random because we cannot predict it with any accuracy, or is it truly random ? If it is the former case as I assume it is, then we are all screwed.
Now, consider what might happen if physical laws are actually deterministic. At the time of big bang (btw, is that deterministic), the configuration of all the fundamental particles and energy, can help us in predicting exactly what the configuration would be in the next instant and so on till the time you are reading this post. Now where is our free will then ? What I am going to do next or what is going on in my mind, is wholly dependent on what the configuration was in the previous instant and that depends on its history so on and on till we get to big bang. So there is no control in our hands. The fact that we exist was already written in the initial configuration of the big banged universe. It is similar to animal development. Given the same genome, it always develops in a particular shape and size. There are environmental effects which provide some variation, but in the case of evolution of universe, we don’t even have an external environment. Then what ?
Do you see any fallacy in the logic ? Can any theoretical physicist enlighten me and let me know where I am going wrong ? I am pretty scared to think that I am not as free as I always thought I was.
Suppose you take a beam of electrons and pass it through a narrow slit. It will diffract and form an interference pattern. A priori one cannot predict where a single electron is going. Hence we think of the electron beam as a probabilistic wave which, in a probabilistic manner gives the interference pattern. Now, time for a gedanken. Imagine the electron at the slit. When it reaches the slit, is it in one place or not? Forget for the time being, that we cannot see or observe it. precisely. So, is it in one place ? Yes of course, because no object can occupy more than one place at the same time. So, the position is actually fixed at each instant. Our inability to observe that position without changing it is what makes us believe that the position is uncertain. So, in other words, left to itself, the electron will choose a path based on its history of movements. Since each electron has slightly different histories each of the electrons will go in a slightly different direction and hence you get a interference pattern. Wow, I don’t know how many laws of physics I have broken in the past few sentences but you get the logic behind the argument, I guess. The logic is, our inability to observe a single electron with precision does not mean that the path of each electron is not deterministic. It is deterministic.
Another example is of radioactive decay. It is supposed to be random. A beta particle or other radiation is emitted seemingly in random fashion. My question here again is, do we understand the sub-atomic world very accurately ? No, obviously not. We do not even know whether we have the full list of all the elementary particles. What we have is a list which is correct in the limit of our experimental accuracy. For instance, let’s say there are eight different types of protons, and they differ in their masses due to the presence of different types of ‘weirdons’. Let’s assume that each ‘weirdon’ weighs 10-8 g and our experimental setup has a least count of 10-6 g. So, can we ever find the ‘weirdons’ ? Obviously no. Besides, there is no ‘theory of everything’ yet which can explain the entire phenomenon in the universe. Hence, we can conclude that our knowledge is incomplete. Given this fact, if you consider the radioactive decay problem, is it random because we cannot predict it with any accuracy, or is it truly random ? If it is the former case as I assume it is, then we are all screwed.
Now, consider what might happen if physical laws are actually deterministic. At the time of big bang (btw, is that deterministic), the configuration of all the fundamental particles and energy, can help us in predicting exactly what the configuration would be in the next instant and so on till the time you are reading this post. Now where is our free will then ? What I am going to do next or what is going on in my mind, is wholly dependent on what the configuration was in the previous instant and that depends on its history so on and on till we get to big bang. So there is no control in our hands. The fact that we exist was already written in the initial configuration of the big banged universe. It is similar to animal development. Given the same genome, it always develops in a particular shape and size. There are environmental effects which provide some variation, but in the case of evolution of universe, we don’t even have an external environment. Then what ?
Do you see any fallacy in the logic ? Can any theoretical physicist enlighten me and let me know where I am going wrong ? I am pretty scared to think that I am not as free as I always thought I was.
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