I was interviewed on the Dan Cofall show regarding my new book, The Artificial Intelligence Revolution. In particular, we discussed the singularity, killer robots (like the autonomous swamboats the US Navy is deploying) and the projected 30% chronic unemployment that will occur as smart machines and robots replace us in the work place over the next decade. You can listen to the interview below:
Neuroscience is revealing more and more about the true workings of the mind. It is reasonable to believe that eventually we will be able to completely model how the brain works and what actions a specific brain will take in response to specific stimuli.What does this say about free will? In other words, is our thinking and actions the result of a specifically programmed biological computer, our brain?
Our entire justice system presupposes free will, that a person committing a crime did so willfully (assuming they are sane, not mentally ill). In fact, the Merriam‑Webster dictionary defines free will as:
1. The ability to choose how to act
2. The ability to make choices that are not controlled by fate or God
However, if neuroscience is able to eventually model a specific brain and predict with certainty the actions that brain will take given specific stimuli, was the person committing a crime doing so willfully? If we as humans do not have freewill, is it permissible to punish a person, even put them to death, for their wrongful acts. Many scientists and philosophers are struggling with this question.
Let us, for this article, put aside religious beliefs and attempt to approach a scientific answer. First, let us address causality. Does every effect have a unique cause? Scientifically speaking, the answer is no. For example, we can cause an object to move using a variety of methods (causes). Now the harder question, does every cause result in a specific predictable effect? Scientifically speaking, in particular from quantum mechanics, we can argue no. At the level of atoms and subatomic particles, like electrons, quantum mechanics can only predict the future state of the physical system in terms of probabilities. In reality, our brain works via electrical impulses. Therefore, it is reasonable to argue our brain, at the micro level, is subject to the laws of quantum mechanics. If that is true, then a specific stimulus results in a spectrum of probable effects (actions and/or thoughts), not a specific well define effect. Does this suggest free will? I judge many may argue yes and just as many may argue no. In other words, I don’t think this argument will definitively end the debate regarding free will.
Science (i.e., quantum mechanics) suggests it is possible for humans to have free will, even when neuroscience is able to completely model human brains. On the micro scale, the level of atoms and subatomic particles, like electrons, it is not possible to predict a system’s future state with certainty. In fact, most first year physic majors will be exposed to the Heisenberg Uncertainty Principle, which states that there is inherent uncertainty in the act of measuring a variable of a particle. Commonly, it is applied to the position and momentum of a particle. The principle states that the more precisely the position is known the more uncertain the momentum is and vice versa. More generally, the Heisenberg Uncertainty Principle argues reality is statistically based, as opposed to deterministically based. The Heisenberg Uncertainty Principle is a fundamental widely accepted pillar of quantum mechanics.
Let’s address the question: Is it permissible to punish a person, even put them to death, for their wrongful acts. The answer is yes. If you assume from the above that humans have free will, it’s reasonable to conclude that it is permissible to punish a person, even put them to death, for their wrongful acts. However, let’s assume that you are not convinced by the above and believe that humans do not really have free will. To my mind, it is still permissible to punish a person, even put them to death, for their wrongful acts. Why? The punishment serves to reprogram their brain and make repeating a wrongful act less likely. If the wrongful act warrants putting the person to death, the punishment assures that the person will not be able to repeat their extreme wrongful behavior.
This article argues that free will is not a necessary condition to justify punishment for wrongful acts. While I think a compelling case for the existence of free will can be made scientifically using quantum mechanics, I do not think it makes a definitive case. At some future time, neuroscience may be able to reprogram brains, such that the probability of criminal behavior becomes infinitesimally small, and punishment may not be necessary. Until that time, we (civilized societies) must rely on our current justice systems.
In the conclusion of this post, we will discuss Planck time and a new hypothesis, the time uncertainty principle.
Planck Time
Planck time is the smallest interval of time that science is able to define. The theoretical formulation of Planck time comes from dimensional analysis, which studies units of measurement, physical constants, and the relationship between units of measurement and physical constants. In simpler terms, one Planck interval is approximately equal to 10-44 seconds (i.e., 1 divided by 1 with 44 zeros after it). As far as the science community is concerned, there is a consensus that we would not be able to measure anything smaller than a Planck interval. In fact, the smallest interval science is able to measure as of this writing is trillions of times larger than a Planck interval. It is also widely believed that we would not be able to measure a change smaller than a Planck interval. From this standpoint, we can assert that time is only reducible to an interval, not a dimensionless sliver, and that interval is the Planck interval. Therefore, our scientific definition of time forces us to acknowledge that time is only definable as an interval, the Planck interval.
The time uncertainty interval
Since the smallest unit of time is only definable as the Planck interval, this suggests there is a fundamental limit to our ability to measure an event in absolute terms. This fundamental limit to measure an event in absolute terms is independent of the measurement technology. The error in measuring the start or end of any event will always be at least one Planck interval. This is analogous to the Heisenberg uncertainty principle, which states it is impossible to know the position and momentum of a particle, such as an electron, simultaneously. Based on fundamental theoretical considerations, the scientific community widely agrees that the Planck interval is the smallest measure of time possible. Therefore, any event that occurs cannot be measured to occur less than one Planck interval. This means the amount of uncertainty regarding the start or completion of an event is only knowable to one Planck interval. In our everyday life, our movements consist of a sequence of Planck intervals. We do not perceive this because the intervals are so small that the movement appears continuous, much like watching a movie where the projector is projecting each frame at the rate of approximately sixteen frames per second. Although each frame is actually a still picture of one element of a moving scene, the projection of each frame at the rate of sixteen frames per second gives the appearance of continuous motion. I term this inability to measure an event in absolute terms “the time uncertainty interval.”
Summary
1. Time is real, not a mental construct, but there is no consensus on the scientific definition of time. Instead, science describe how time behaves during an interval, a change in time. Science is unable to point to an entity and say “that is time.” The reason for this is that time is not a single entity, but scientifically an interval.
2. Planck time is the smallest interval of time that science is able to define. The theoretical formulation of Planck time comes from dimensional analysis, which studies units of measurement, physical constants, and the relationship between units of measurement and physical constants.
3. Since the smallest unit of time is only definable as the Planck interval, this suggests there is a fundamental limit to our ability to measure an event in absolute terms, independent of the measurement technology. The error in measuring the start or end of any event will always be at least one Planck interval. I term this inability to measure an event in absolute terms “the time uncertainty interval.”
One question comes up frequently, is time real? In other words, is time a true physical entity or is it a mental construct? Philosophers have been pondering the nature of time for thousands of years. A philosophy of time weaves through almost every ancient culture. For example, the earliest view of the nature of time by a Western philosopher dates back to ancient Egypt and the Egyptian philosopher Ptahhotep (2650–2600 BCE). Indian philosophers and Hindu philosophers also wrote about time dating back to roughly the same period. The ancient Greek philosophers, such as Parmenides, Heraclitus, and Plato, wrote essays about the nature of time roughly around 500 BCE to 350 BCE.
Many early writers questioned the nature of time, the cause of time, and the unidirectional flow of time, often referred to as the “arrow of time.” One of the most interesting aspects when studying the philosophy of time is that some cultures, like the Incas, dating back to about the thirteenth century, considered space and time woven together. Centuries before Einstein published his now-famous special theory of relativity, which scientifically unified space and time (i.e., spacetime), the Incas philosophically unified space and time into a single concept called “pacha.”
As delineated above, philosophers have debated the nature of time for over 2500 years. The result of this debate has left us with three principal theories, listed below in no particular order
1) Presentists Theory of Time—The “presentists” philosophers argue that present objects and experiences are real. The past and future do not exist. This would argue that time is an emerging concept, and exists in our minds.
2) Growing-Universe Theory of Time—The “growing-universe” philosophers argue that the past and present are real, but the future is not. Their reasoning is the future has not occurred. Therefore, they reason the future is indeterminate, and not real.
3) Eternalism Theory of Time—The “eternalism” philosophers believe that there are no significant differences among present, past, and future because the differences are purely subjective. Observers at vastly different distances from an event would observe it differently because the speed of light is finite and constant. The farthest-away observer may be seeing the birth of a star while the closest observer may be seeing the death of the same star. In effect, the closest observer is seeing what will be the future for the farthest-away observer.
Let look at how the above theories address the question, is time real? The “presentists” philosophers would argue time is not a true physical entity, but rather a concept of our minds. The “growing-universe” philosophers would argue that only the past and present are real. The “eternalism” philosophers would argue that there are no significant differences among present, past, and future because the differences are purely subjective. Their philosophy rests on Einstein’s special theory of relativity. Essentially, the special theory of relativity holds that the past, present, and future are functions of the speed and position of an observer. In effect, this philosophy argues time is real, but subjective. This brings us to the question, what does science have to say about the reality of time?
From a practical standpoint, the science of time started with Isaac Newton (1642–1727) in the seventeenth century. Newton thought of time as an absolute. He believed that time passed uniformly, even in the absence of change. From Newton’s point of view, any event that occurs at a single point in time occurs simultaneously for all observers, regardless of their position or relative motion. Newton’s view of time as an absolute became a cornerstone of classical physics and prevailed until the early part of the twentieth century.
It is important to mention that Newton’s view of time was likely influenced by Galileo, a brilliant Italian physicist, mathematician, astronomer, and philosopher. Galileo and Newton never met in person, since Galileo died the same year Newton was born, 1642. However, there appears little doubt that Newton’s science of time was significantly influenced by Galileo’s 1638 Discorsi e Dimostrazioni Matematiche (Discussions on Uniform Motion), since Newton’s and Galileo’s views of time are essentially identical.
The science of time underwent dramatic changes early in the twentieth century, when a little-known patent examiner published a paper in the Annalen der Physik in 1905. The paper contained no references, quoted no authority, and had relatively little in the way of mathematical formulation. The writing style was unconventional for a scientific paper, relying on thought experiments combined with verbal commentary. No one suspected that the world of science was about to be changed forever. The little-known patent examiner was twenty-six-year-old Albert Einstein. The paper was on the special theory of relativity, which quietly led to the scientific unification of space and time, and the scientific realization that mass is equivalent to energy. The ink of this one paper rewrote the science of time.
This view of time holds to this day. Most of the scientific community agrees that the most accurate definition of time requires integration with the three normal spatial dimensions (i.e., height, width, and length). Therefore, the scientific community talks in terms of spacetime, especially in the context of relativity, where the event or observer may be moving near the speed of light relative to each another.
Based on Einstein’s spacetime integration, we can argue that time is a physically real aspect of reality. Let us consider an example. A clock moving close to the speed of light will appear to run slower to an observer at rest (one frame of reference) relative to the moving clock (another frame of reference). In simple terms, time is not an absolute, but is dependent on the relative motion of the event and observer. It may sound like science fiction that a clock moving at high velocity runs slower, but it is a widely verified science fact. Even the clock on a jet plane flying over an airport will run slightly slower than the clock at rest in the airport terminal. Einstein predicted this time dilation effect in his special theory of relativity, and he derived an equation to calculate the time difference. Other physical factors affect time. For example, another scientific fact is that a clock in a strong gravitational field will run slower than a clock in a weak gravitational field. Einstein predicted this time dilation effect in his general theory of relativity.
While we can argue that time is real, not a mental construct, there is no consensus on the scientific definition of time. Instead, science describe how time behaves during an interval, a change in time. Science is unable to point to an entity and say “that is time.” The reason for this is that time is not a single entity, but scientifically an interval. We cannot slice time down to a shadowlike sliver, a dimensionless interval. In fact, scientifically speaking, the smallest interval of time that science can theoretically define, based on the fundamental invariant aspects of the universe, is Planck time.
In part 2 of this post, we will discuss Planck time and a new concept, the time uncertainty principle.
Let us start our discussion by understanding the Heisenberg uncertainty principle. Most physics professors teach it in the context of attempting to simultaneously measure a particle’s velocity and position. It goes something like this:
• When we attempt to measure a particle’s velocity, the measurement interferes with the particle’s position.
• If we attempt to measure the particle’s position, the measurement interferes with the particles velocity.
• Thus, we can be certain of either the particle’s velocity or the particle’s position, but not both simultaneously.
This makes sense to most people. However, it is an over simplification. The Heisenberg uncertainty principle has greater implications. It embodies the statistical nature of reality. This last statement may not seem true, since we live and experience nature at the macro level (i.e., our everyday world). At the macro level we generally do not talk in terms of probabilities. For example, we can predict the exact location and orbital velocity of a planet using Einstein’s theories of relativity. Thus, most scientists will say that macro level phenomena are deterministic, which means that a unique solution describes their state of being, including position, velocity, size, and other physical attributes.
In practice, we only see the effects of the Heisenberg uncertainty principle at the micro or quantum level (i.e., the level of atoms and subatomic particles). At the quantum level, Einstein’s theories of relativity break down, and we are forced to use the theory of quantum mechanics. Quantum mechanics is a set of laws and principles that describes the behavior and energy of atoms and subatomic particles. At the quantum level we are unable to simultaneously measure the position and velocity of an atom or subatomic particle. The reality of the quantum level is expressed in terms of probabilities. While we can predict the exact location and orbital velocity of a planet at the macro level, we are not able to make similar predictions about an electron as it obits the nucleus of an atom at the quantum level. We can only talk in probabilities regarding the electron’s position and energy. Thus, most physicists will argue that quantum level phenomena are probabilistic, which means that their state of being is described via probabilities, and we cannot simultaneously determine, for example, the position and velocity of a subatomic particle.
What does this really mean? Do we really have two different levels of reality with different laws. The short answer is no. While we observe differences between the macro and quantum level, the differences really don’t exist. Measurements at the macro level are typically large compared to measurements at the quantum level. However, the laws of physics remain the same at both the macro and quantum level. In fact, the laws of quantum mechanics at the quantum level reduce to the laws of classical physics at the macro level. This means that all reality is statistically based, even at the macro level.
You may ask, is it possible to observe this statistical nature of reality at the macro level? The answer is yes. For example, it is possible to observe the statistical nature of reality via the creation of virtual particles that give rise to the Casimir-Polder force. The Casimir-Polder force is the attractive force between two parallel plates placed extremely close together (approximately a molecular distance) in a vacuum. Science believes the “attraction” is due to a reduction in virtual particle formation (i.e., spontaneous particle production) between the plates. This, in effect, results in more virtual particles outside the plates whose pressure pushes them together. Spontaneous particle creation is the phenomenon of particles appearing from apparently nothing, hence their name “virtual particles.” However, they appear real and cause real changes to their environment, as discussed above. Science believes that the particles form as the energy within a vacuum statistically varies and occasionally becomes dense in a specific region giving rise the virtual particles. This may sound odd, but it is a scientific fact that vacuums contain energy and that energy statistically varies giving rise to virtual particles.
How important is the Heisenberg uncertainty principle? It is fundamentally important to understanding reality, especially at the quantum level and occasionally at the macro level. It unequivocally states that the nature of all reality is statistically based.