weenie Posted November 2, 2014 Posted November 2, 2014 Imagine this scenario: You watch a live tennis match on your tv and then use your time machine to travel in time to the beginning of the tennis match. How will it play out? Will it be completely identical, because you didn't change anything simply by traveling back in time to observe it, or will people make different decisions because they have free will? I would say it would be the same. The players are in identical circumstances in both cases, so it's logical to assume they will make the same decisions they made the first time, unless their decisions were made randomly. Doesn't this imply people are a deterministic system, if equal entry parameters mean equal results?
shirgall Posted November 2, 2014 Posted November 2, 2014 The situations cannot be identical because there is a difference in observers (called the Observer Effect). Determinism in general comes across as a way to destroy ethics and morality because we are playing the game "on rails". Did you choose to write the post asking the question or were you preordained to do it from the conception of the universe? If everything is preordained, why bother have feelings, or curiosity, or desires? 1 1
J-William Posted November 2, 2014 Posted November 2, 2014 What would a thought experiment in free will look like? Imagine a guy making a decision... Imagine my argument changing your mind... Woah!
WasatchMan Posted November 2, 2014 Posted November 2, 2014 To me this is like saying, Leonardo DiCaprio dies at the end of Titanic every time I watch it, therefore determinism. 2
Wuzzums Posted November 2, 2014 Posted November 2, 2014 The example is self-defeating. I don't know the outcome of the game therefore I choose to go into the future to find out. Then me traveling back in time (which is impossible) will change the situation forever because introducing a new variable in a system changes the system completely. So let's assume the pre-timetravel self lives in a deterministic universe and watches a match. Pre-timetravel self goes into the future and finds out how the match ends. Post-timetravel self goes and takes the place of pre-timetravel self in the past => a variable has been changed in a deterministic universe => contradiction with the premise. 1
Rainbow Dash Posted November 2, 2014 Posted November 2, 2014 To me this is like saying, Leonardo DiCaprio dies at the end of Titanic every time I watch it, therefore determinism. That is not a fair comparison. Since Leonardo DiCaprio dies at the end of Titanic every time, that just means the movie titanic is deterministic, which is an accurate conclusion; it would not imply that the entire universe is deterministic.
J. D. Stembal Posted November 2, 2014 Posted November 2, 2014 I am starting to feel like determinism posts and calls are determined beforehand. 2
Sal9000 Posted November 2, 2014 Posted November 2, 2014 The situations cannot be identical because there is a difference in observers (called the Observer Effect). The QM only works on a quantum level. When an observer does not causally interfere on a macroscopical level there is no observer effect. The wavefunctions have collapsed long before you could have messed with them. because you didn't change anything simply by traveling back in time to observe it, You created two independent timelins. This is a major change.
dsayers Posted November 2, 2014 Posted November 2, 2014 People can travel on roads because they (people and roads) are physical objects. Time is a concept. The idea that we could physically travel through a concept is science-fiction. I think the behavior of arguing for determinism is a performative contradiction. For anybody who truly believed in determinism, it would be determined for them that that trying to convince others, whose minds are already determined, would be a waste of time/effort. It would be like leaping off of a tall building to try to fly in a world where you accepted that people cannot fly; It's just not something they would even consider. 1
shirgall Posted November 2, 2014 Posted November 2, 2014 The QM only works on a quantum level. When an observer does not causally interfere on a macroscopical level there is no observer effect. The wavefunctions have collapsed long before you could have messed with them. You created two independent timelins. This is a major change. While not an expert on the physics of time travel, merely being a person that looks at a scene can change what happens in a scene. People react differently when they know they are being watched. There are many Observer Effects besides the quantum one.
RyanT Posted November 2, 2014 Posted November 2, 2014 Determinism in general comes across as a way to destroy ethics and morality because we are playing the game "on rails". I also find it really frustrating as it seem to degenerate philosophy from the pursuit of virtue in our lives to 'How many angels can dance on the head of a pin' Determinism - the Xbox in the room!
weenie Posted November 2, 2014 Author Posted November 2, 2014 People can travel on roads because they (people and roads) are physical objects. Time is a concept. The idea that we could physically travel through a concept is science-fiction. I think the behavior of arguing for determinism is a performative contradiction. For anybody who truly believed in determinism, it would be determined for them that that trying to convince others, whose minds are already determined, would be a waste of time/effort. It would be like leaping off of a tall building to try to fly in a world where you accepted that people cannot fly; It's just not something they would even consider. Computers behave deterministically. Does this mean it is pointless for me to press button on my keyboard? No, because different input will result in different output, so if I want my computer to do something else from what it's doing now, I should press some buttons. While not an expert on the physics of time travel, merely being a person that looks at a scene can change what happens in a scene. People react differently when they know they are being watched. There are many Observer Effects besides the quantum one. That's why I said we are watching the match on tv. The people playing tennis have no idea who's watching them through a onw-way medium.
dsayers Posted November 2, 2014 Posted November 2, 2014 Computers behave deterministically. Computers are not alive. They don't behave at all.
shirgall Posted November 2, 2014 Posted November 2, 2014 Computers behave deterministically. In theory, the operation of computers is deterministic, but research "chip level soft error" and why the big servers need ECC memory. As for watching the match on TV, so what? Time travel itself is probably branching the entire universe, as others have already stated on this thread. The Observer Effect shows up in lots of places in other parts of physics. Kevin has pointed out that pointless debates on determinism are off-topic, by the way, probably because the result of the argument is unalterable and unavoidable.
ProfessionalTeabagger Posted November 2, 2014 Posted November 2, 2014 In order to rationally demonstrate something philosophically and/or scientifically a thought experiment must take place in reality. This thought experiment doesn't so even though in may be instructive or fun it doesn't demonstrate anything. It is meaningless. I could just make my own thought experiment to prove disprove determinism. Say we travel back in time but we change the outcome. Determinism says there can only be one possible outcome so my thought experiment would disprove determinism as you would have a reality where two different outcomes exist at temporal point X. If anything the thought experiment helps free will because it demonstrates how the self-aware human mind can simulate possible futures and choose between them. We are radically different from all other configurations of matter and energy in that regard. Your thought experiment also assumes determinism is true because you don't even consider the possibility that the outcome will change every time.
hannahbanana Posted November 2, 2014 Posted November 2, 2014 I find this sort of situation invalid and to no purpose, because (so far, probably always) time travel is impossible, and no one knows how it would work if it was possible at all. How can you base an entire argument off of a nonexistent premise, which you can only speculate how it works? 1
ProfessionalTeabagger Posted November 2, 2014 Posted November 2, 2014 Computers behave deterministically. Does this mean it is pointless for me to press button on my keyboard? No, because different input will result in different output, so if I want my computer to do something else from what it's doing now, I should press some buttons. You are not trying to get a computer to change its mind. It's just a tool that you're are trying to get to do what you want. A computer can't change its mind because it doesn't have a mind.
DCLugi Posted November 3, 2014 Posted November 3, 2014 Philosophy deals with reality. Otherwise, here's a thought experiment. Let us say that I can fly. Does that mean the law of gravity is false? 1
Jamiroquai Posted November 12, 2014 Posted November 12, 2014 I find this sort of situation invalid and to no purpose, because (so far, probably always) time travel is impossible, and no one knows how it would work if it was possible at all. How can you base an entire argument off of a nonexistent premise, which you can only speculate how it works? Why are you focusing on the fact that time travel is impossible, though? That is completely unimportant in the OP's example. Perhaps a better way he could have phrased his theory would be to say that they played a match, and played another match the next day with the same exact conditions, same level of fatigue, and all other controllable variables. The fact that they time traveled doesn't really matter, it's just the mechanism by which we can have the same exact conditions as we did the first time in order to answer the broader question.The problem that I do see with the OP's question, though, is that it is nigh impossible for a human to accurately replicate a tennis swing, even if he/she analyzes the speed of the ball and attempts to use the exact same spin, it's just too difficult to get the same result. The same is true for pretty much all sports. You can analyze the speed and velocity that a tennis ball is coming at you from, and calculate in your head exactly how hard you want to hit the ball and whether you want to slice it/lob it/whatever, but even when you do, even if you hit the ball with the same exact part of your racket, you do not have the capacity to perfectly replicate your previous stroke. It would be like throwing dice, getting an 11, and attempting to throw the dice in the exact same way and at the exact same speed as you previously did...humans are not capable of this level of accuracy, even if they make the same exact decisions as the initial attempt.
dsayers Posted November 13, 2014 Posted November 13, 2014 Why are you focusing on the fact that time travel is impossible, though? That is completely unimportant in the OP's example. Perhaps a better way he could have phrased his theory would be to say that they played a match, and played another match the next day with the same exact conditions, same level of fatigue, and all other controllable variables. Then we'd have to focus on whether every molecule was in the same place and the participants' memories were completely wiped of the prior 24 hours, and the memories of the people who did the wiping would have to be wiped... It's unattainable. Kind of like trying to derive truth from fantasy.
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