Why what you choose doesn't matter: Part 2
How can we plunk robots down on other planets, keep energy releasing reactions that take place inside of stars under control, and make multi-ton metal machines fly? Physics.
All matter in the universe is governed by physical laws. Once we understand these laws, we can calculate how events will unfold. This is because the laws of the universe are deterministic:
If I drop exactly the same marble in a vacuum from exactly the same height onto exactly the same surface, it will bounce with the exactly the same period and come to rest in exactly the same place every single time I drop the marble.
If you're having a hard time accepting this deterministic universe thing, you can try this experiment yourself: Hold a brick over your head, then let go. Did it hit you? Try it again. Did it hit you again? Amazing. Maybe one of these times it will fly away. Think not? Then you've accepted that the laws of physics govern the physical universe in a defined, determinate and predictable way.
"But it doesn't hit me the same way every time," you say. "The dents in my skull seem to have some kind of random pattern. How can there be randomness in a deterministic universe?"
Well, for starters, the reason the brick doesn't land the same way every time is because you don't actually drop it the same way every time. So your random pattern of bumps doesn't mean the falling is different, it means the dropping is different. And even under the best controlled conditions, there is variation. The arrangement of molecules in the air differs from second to second. The brick's mass changes subtly as tiny bits of brick dust fall off. These subtle variations due to circumstances beyond our control don't indicate that the universe is not determined. They just show that it's hard to predict future states of the universe with perfect accuracy, because the elements impacting a specific situation are always very complex. This is why we know the weather tomorrow, but guess at the weather two weeks from now.
Much of statistical analysis was developed to strip out these noisy subtle complexities and unearth the underlying larger truth. Measuring the acceleration of the brick over and over and over gets us to an average of 9.8 m/s². Just because we can't predict an outcome with perfect accuracy (gee, I thought the Mars Lander would work. Anyone got another $300 million dollars and 8 years?), this doesn't show that the physical world isn't governed by deterministic laws.
So we've now established that physical things are governed by deterministic physical laws, (and you must accept this, or perform the brick experiment till you believe it), and that our minds are brains, which are physical things.
So when we put them together, we get this: If the future states of all the matter in the universe are determined by the laws of physics, and if our brains are matter in the universe, and if, therefore, our minds are matter in the universe, the future states of our minds are determined.
Guess what: Free will is an illusion.
We may believe that we are deciding. What we're experiencing is merely our little neurons chugging away. Just like doing long division in the third grade: You may not know what 65,783 divided by 23 is when you start the problem, and you may not even know what the final answer is at the end, but, assuming you know how to apply the solving algorithm, the answer you were going to get was determined from the outset. Just imagine a really slow computer, calculating π to the thousandth digit. The computer doesn't know the answer when it starts. It "knows" how far it's come. It "knows" when it's done. It's "aware" that it isn't done processing. But the computer is no more coming to a decision than we are when we choose a dessert from a menu. The output of a physical entity undergoing a physical process is determined by the laws of physics. Brains "making decisions" are governed by the laws of physics.
Actually living life while accepting that free will is an illusion is certainly challenging, as we'll see in Part III.
All matter in the universe is governed by physical laws. Once we understand these laws, we can calculate how events will unfold. This is because the laws of the universe are deterministic:
If I drop exactly the same marble in a vacuum from exactly the same height onto exactly the same surface, it will bounce with the exactly the same period and come to rest in exactly the same place every single time I drop the marble.
If you're having a hard time accepting this deterministic universe thing, you can try this experiment yourself: Hold a brick over your head, then let go. Did it hit you? Try it again. Did it hit you again? Amazing. Maybe one of these times it will fly away. Think not? Then you've accepted that the laws of physics govern the physical universe in a defined, determinate and predictable way.
"But it doesn't hit me the same way every time," you say. "The dents in my skull seem to have some kind of random pattern. How can there be randomness in a deterministic universe?"
Well, for starters, the reason the brick doesn't land the same way every time is because you don't actually drop it the same way every time. So your random pattern of bumps doesn't mean the falling is different, it means the dropping is different. And even under the best controlled conditions, there is variation. The arrangement of molecules in the air differs from second to second. The brick's mass changes subtly as tiny bits of brick dust fall off. These subtle variations due to circumstances beyond our control don't indicate that the universe is not determined. They just show that it's hard to predict future states of the universe with perfect accuracy, because the elements impacting a specific situation are always very complex. This is why we know the weather tomorrow, but guess at the weather two weeks from now.
Much of statistical analysis was developed to strip out these noisy subtle complexities and unearth the underlying larger truth. Measuring the acceleration of the brick over and over and over gets us to an average of 9.8 m/s². Just because we can't predict an outcome with perfect accuracy (gee, I thought the Mars Lander would work. Anyone got another $300 million dollars and 8 years?), this doesn't show that the physical world isn't governed by deterministic laws.
So we've now established that physical things are governed by deterministic physical laws, (and you must accept this, or perform the brick experiment till you believe it), and that our minds are brains, which are physical things.
So when we put them together, we get this: If the future states of all the matter in the universe are determined by the laws of physics, and if our brains are matter in the universe, and if, therefore, our minds are matter in the universe, the future states of our minds are determined.
Guess what: Free will is an illusion.
We may believe that we are deciding. What we're experiencing is merely our little neurons chugging away. Just like doing long division in the third grade: You may not know what 65,783 divided by 23 is when you start the problem, and you may not even know what the final answer is at the end, but, assuming you know how to apply the solving algorithm, the answer you were going to get was determined from the outset. Just imagine a really slow computer, calculating π to the thousandth digit. The computer doesn't know the answer when it starts. It "knows" how far it's come. It "knows" when it's done. It's "aware" that it isn't done processing. But the computer is no more coming to a decision than we are when we choose a dessert from a menu. The output of a physical entity undergoing a physical process is determined by the laws of physics. Brains "making decisions" are governed by the laws of physics.
Actually living life while accepting that free will is an illusion is certainly challenging, as we'll see in Part III.
posted by Kenneth at 1:36 PM
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