Read The Physics of Superheroes: Spectacular Second Edition for Free Online
Authors: James Kakalios
without forcing the reader to constantly consult the back issue bins of their local comic-book shop. It is all too easy to find flaws and errors in the science referenced in comic-book stories, and this is not the aim of this book. In addition to being unsporting and uncharitable (after all, these stories were never intended to function as science textbooks, despite the occasional student’s attempts at surreptitious substitution), it is more difficult to make a point when the only illustrative examples are negative ones. Nevertheless, sometimes we will find that some scenes in comic books are simply not physically plausible, even with the granting of a “miracle exception.”
Before I begin I would like to say a few words about a common misconception concerning physicists. Despite the impression gleaned from popular movies, being a physicist does not require an encyclopedic knowledge of equations and fundamental constants, coupled with the ability to perform complex arithmetic in one’s head with robotic speed and precision. Physics is not about having memorized all the answers, but rather about asking the right questions. For when the right question is posed of a phenomenon, either the answer becomes clear or at least a path to further and more fruitful questioning is revealed.
To illustrate that asking one right question can be more important than a bushel full of correct answers, consider the simple physics experiment of tossing a ball in an arc. There are many questions we may ask, such as: How high does the ball travel? How far to the right does it move? How long is it in the air? How fast is it going? What is the geometric shape of its path? However, I would argue that there is one simple question that implies all of the above questions and gets to the heart of the issues concerning the ball’s motion. That one single question is the following: Does the ball have any choice? If the ball does not have any choice in its motion, if it lacks free will, then its trajectory is completely determined by forces external to itself. Once we determine the nature of these forces and how they influence the ball’s motion, we may then calculate the path of the ball for a given initial velocity imparted by the thrower. This calculated trajectory would then contain any and all information we may desire regarding how high the ball rises, how far it moves, its time in flight, what its velocity is, and so on. If we then repeat the toss with exactly the same initial position and velocity as before, then the ball must exactly and faithfully trace out the calculated trajectory, for the ball does not have any choice in the matter.
This is the beauty and attraction of physics, at least for those of us lucky enough to make our living from its study. The promise and potential is that if we can determine the forces acting on an object and how these forces influence the object’s motion, we will then be able to predict the development of future events. By performing careful experiments, these predictions can be empirically tested and, if correct, confirm our understanding of how nature operates. On the other hand, if the experiment contradicts our model (a far more likely outcome, initially), we modify our equations and try again, using the failed test as an important clue as to what was missing from the initial calculation. 5 In this way, our understanding of nature progresses until we have a valid model, which is then termed a theory. To dismiss any idea that survives this exhaustive vetting as “just a theory” is equivalent to describing the Hope Diamond as “just a crystal.”
Scientific knowledge comes only at the price of increased doubt: The more we learn, the more clearly we see all that remains uncertain. Doubt is to be embraced in science, for the only answers we can trust are those that survive the crucible of questioning and experimental testing. I hope to share with you in this book the true pleasure that comes from
Before I begin I would like to say a few words about a common misconception concerning physicists. Despite the impression gleaned from popular movies, being a physicist does not require an encyclopedic knowledge of equations and fundamental constants, coupled with the ability to perform complex arithmetic in one’s head with robotic speed and precision. Physics is not about having memorized all the answers, but rather about asking the right questions. For when the right question is posed of a phenomenon, either the answer becomes clear or at least a path to further and more fruitful questioning is revealed.
To illustrate that asking one right question can be more important than a bushel full of correct answers, consider the simple physics experiment of tossing a ball in an arc. There are many questions we may ask, such as: How high does the ball travel? How far to the right does it move? How long is it in the air? How fast is it going? What is the geometric shape of its path? However, I would argue that there is one simple question that implies all of the above questions and gets to the heart of the issues concerning the ball’s motion. That one single question is the following: Does the ball have any choice? If the ball does not have any choice in its motion, if it lacks free will, then its trajectory is completely determined by forces external to itself. Once we determine the nature of these forces and how they influence the ball’s motion, we may then calculate the path of the ball for a given initial velocity imparted by the thrower. This calculated trajectory would then contain any and all information we may desire regarding how high the ball rises, how far it moves, its time in flight, what its velocity is, and so on. If we then repeat the toss with exactly the same initial position and velocity as before, then the ball must exactly and faithfully trace out the calculated trajectory, for the ball does not have any choice in the matter.
This is the beauty and attraction of physics, at least for those of us lucky enough to make our living from its study. The promise and potential is that if we can determine the forces acting on an object and how these forces influence the object’s motion, we will then be able to predict the development of future events. By performing careful experiments, these predictions can be empirically tested and, if correct, confirm our understanding of how nature operates. On the other hand, if the experiment contradicts our model (a far more likely outcome, initially), we modify our equations and try again, using the failed test as an important clue as to what was missing from the initial calculation. 5 In this way, our understanding of nature progresses until we have a valid model, which is then termed a theory. To dismiss any idea that survives this exhaustive vetting as “just a theory” is equivalent to describing the Hope Diamond as “just a crystal.”
Scientific knowledge comes only at the price of increased doubt: The more we learn, the more clearly we see all that remains uncertain. Doubt is to be embraced in science, for the only answers we can trust are those that survive the crucible of questioning and experimental testing. I hope to share with you in this book the true pleasure that comes from