Probability in Physics - Get Answers Here!

In summary, probability is an important concept in both classical and quantum physics. It is used in statistical mechanics and thermodynamics to derive useful formulae, and in quantum physics, it is central to the theory. In large systems such as a gas in an enclosure, the number of particles makes it impossible to track the exact evolution of each particle, so instead, probability is used to describe the likelihood of finding the system in a particular state. Therefore, understanding probability is necessary for studying physics and engineering.
  • #1
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The other day, a question popped in my head about how we use probability in physics (not limited to classical), since it is my weakest subject, and since I will be applying my math knowledge to physics, I don't want to study anything that won't be necessary.

Thanks for any replies.
 
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  • #2
What was your question?
 
  • #3
In classical physics, probability can be used to derive useful formulae in statistical mechanics and thermodynamics.

In quantum physics, probability is central to the theory. Briefly, for each quantum observable there are infinitely many states i.e. E=1, 2, 3... , and a general quantum state can be written as a linear combination (series) of these independent state, the squares of the coefficients of which are the probability that a measurement would yield that result E=2, or something.
 
  • #4
Statistical mechanics is the study of systems made up of large numbers of particles my means of probability theory.

For systems such as a gaz in an enclosure, the number of particle is of the order of 10^24. If you want to know how the system evolves in time, you must solve 3*10^24 coupled differential equations with 6*10^24 initial conditions (the initial positions and momenta of each particles). This is obviusly not feasible and even if it were, it would not be very interesting to know exactly how each particles will evolved in the gaz.

Instead, we talk about the probability of finding the system in a particular state.
 
  • #5
You're going to need statistics, if your an engineer or a physicist.
 

Related to Probability in Physics - Get Answers Here!

1. What is the role of probability in physics?

The role of probability in physics is to describe the likelihood of a particular outcome or event occurring in a physical system. In many cases, the behavior and interactions of particles and objects in the physical world are inherently probabilistic, meaning their exact outcomes cannot be predicted with certainty.

2. How is probability used in quantum mechanics?

In quantum mechanics, probability is used to describe the behavior and interactions of subatomic particles. The wave function, which describes the probability of a particle being in a particular state, is a fundamental concept in quantum mechanics. The uncertainty principle also relies on probability, stating that it is impossible to know both the position and momentum of a particle with absolute certainty.

3. Can probability be used to predict the future in physics?

No, probability cannot be used to predict the future in physics. While it can give us an idea of the likelihood of certain outcomes, it does not provide a definite prediction. This is due to the inherent unpredictability and randomness of certain physical phenomena, such as radioactive decay or the behavior of particles in a quantum state.

4. How is probability related to entropy in thermodynamics?

In thermodynamics, entropy is a measure of the disorder or randomness of a system. Probability plays a role in calculating the entropy of a system, as it is directly related to the number of possible microstates that a system can have. As the number of microstates increases, the entropy also increases, and this is reflected in the probability of a particular state occurring.

5. Can probability be used to prove or disprove physical theories?

No, probability alone cannot be used to prove or disprove physical theories. While it can provide evidence and support for certain theories, it is only one aspect of the scientific method. Other factors, such as experimentation and observation, are also crucial in determining the validity of a physical theory.

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