Newton’s surprising success at developing the laws of motion, as well

Newton’s surprising success at developing the laws of motion, as well as the development and refinement of other physical laws, led to the idea of scientific determinism. The first expression of this principle was in the beginning of the nineteenth century by Laplace, a French scientist. Laplace argued that if one knew the position and velocity of all the particles in the universe at a given time, the laws of physics would be able to predict the future state of the universe.

Scientific determinism held sway over a great many scientists until the early twentieth century, when the quantum mechanics revolution occurred. Quantum mechanics introduced the world to the idea of the uncertainty principle, which stated that it was impossible to accurately measure both the position and the velocity of a particle at one time. Because Laplace’s omniscience could never occur, even in theory, the principle of scientific determinism was thrown into doubt. However, quantum mechanics does allow for a reduced form of scientific determinism. Even though physicists are unable to know precisely where a particle is and what its velocity is, they can determine certain probabilities about its position and velocity. These probabilities are called wave functions. By use of a formula known as the Schrodinger equation, a scientist with the wave function of a particle at a given time can calculate the particle’s future wave function. These calculations can give the particle’s position or velocity, but not both. Thus, the physicist is in possession of exactly half of the information needed to satisfy Laplace’s view of determinism. Unfortunately, under modern physics theories, that is far as any researcher can go in predicting the future.

1. The passage suggests that if scientific determinism were true

A. scientists would, in theory, be able to predict the future
B. all the particles in the universe would have a measurable position and velocity
C. the theory of quantum mechanics would be false
D. Schrodinger’s equation could be used to calculate any particle’s position
E. the quantum mechanics revolution would not have occurred


2. According to the passage, wave functions

A. allow scientists to determine the position and velocity of a particle
B. are determined by the Schrodinger equation
C. provide a range of possible locations and velocities for a particle
D. allow a scientist to calculate the future state of the universe
E. threw the proposition of scientific determinism into doubt


3. Which of the following best describes the organization of the passage?

A. A paradox is introduced, competing explanations are offered, and a final resolution is reached.
B. Two opposing theories are introduced, critiqued, and reconciled.
C. An idea is introduced, its validity is questioned, and its application qualified.
D. A theory is introduced, its mathematical basis is examined, and it is rejected.
E. An argument is made, an objection to it is detailed, and the argument is revised.


4. Which of the following, if true, would most strengthen the author’s conclusion in the passage’s final sentence?

A. Some physicists believe quantum mechanics will eventually be discarded in favor of a new theory.
B. Physicists still use Newton’s laws of motion to calculate the velocities and positions of planets and stars.
C. Even if the position and velocity of a particle were known, predicting the future would be impossible because there are too many other variables to calculate.
D. There is little to no chance that the modern theory of quantum mechanics will be overturned by another theory.
E. No scientists are pursuing studies in the field of determinism.