Free Will

What Does Physics Have To Say About Free Will?




Whether free will exist or not? This seems more like a philosophical question than a matter of physics. But physics does have a say in it with different theories. This is another debate that has existed amongst physicists for a long time now. Even great physicists like Albert Einstein and Neils Bhor chose a side in this debate. In physics, the scientists don't talk about free will directly. Free will is a bit philosophical term. In physics, scientists ask questions like </b>"Whether our universe is deterministic or not?"</b>. Let's see some arguments by physicists in favor and against the deterministic universe. <h2><b><center>What Is a Deterministic Universe</h2></b></center> A deterministic universe is one in which our future is already decided. It was determined at the time of the Big Bang. Physicists who believe in the deterministic universe say that <b>events that are going to happen in the future are determined by the events that happened in the past</b>. So this would mean that everything that happens now can be determined by the conditions at the time of the big bang (or when this universe was created). This happens because all the particles in the universe follow Newton's laws and equations. This idea is known as <b>Newton's Clockwork Universe</b>. <br> <img src="" width="256" height="171" /> This also means that whatever you are going to do in the future is already determined. This is true even for small experiments. If we know the conditions at the start of a chemical reaction we can predict what would happen in the future like the final product, temperature changes, etc. Albert Einstein was a believer in the idea of a deterministic universe. He said, "God does not play dice." Through this, he wanted to say that events that happen in the universe aren't random but the universe is like a great and complex clock, simply ticking forward in a complicated, but entirely predictable manner.<br> <img src="" width="256" height="139" /> <h2><b><center>Does Quantum Mechanics <i>"Save"</i> Free Will?</h2></b></center> Some other great physicists like Michio Kaku, Heisenberg, Neils Bhor, etc. state that <b>Quantum Mechanics makes the universe indeterministic</b>. In quantum mechanics, we deal with uncertainty. <i>Some of the events in quantum mechanics are completely random</i>. According to Heisenberg's uncertainty principle, a particle can be anywhere, we can just find the probability of a particle's being at a certain position at a certain point in time.<br> <img src="" width="660" height="528" /> But to counter this argument, physicists claim that even if quantum mechanics adds randomness and uncertainty to the universe, it doesn't mean that free will exists. <b>The problem with the argument is that we cannot control the randomness that is caused at the quantum level</b>. Albert Einstien had other ideas as well. When Albert Einstien said "God does not play with dice", he did not mean to say that Schrodinger's equation was wrong but he wanted to say that a particle's correct position can be determined but some <b><i>hidden variables</i></b> in Schrodinger's equation. If we include those variables in the equation we will be able to find the exact positions of the particles. This is now known as the <b>Hidden-Variable Theory</b>. <h2><b><center>Conclusion</h2></b></center> <b>According to physics, free will doesn't exist even if quantum mechanics makes the universe indeterministic</b>. But people can still think what they want to think about this topic as the idea of the non-existence of free will can be "depressing" for them. Though does that mean that if the universe is deterministic, we can predict the future? Well yes, but that would be very difficult (impossible as of now) to do.<br> <img src="" width="256" height="134" /> The problem is that we need to find the conditions and positions of all the particles that exist in the universe at a point in time with 100% precision. Finding conditions of an experiment with 100% precision is very difficult even for simpler reactions that we perform in labs. Apart from that quantum mechanics doesn't allow us to find the exact positions of the particles.

- Ojas Srivastava, 11:24 PM, 13 Nov, 2021

Deterministic Universe

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