Classical physics vs quantum physics

In summary, classical physics is not significantly different from quantum physics, as the laws that govern the macroscopic world can be derived from quantum laws. However, we still differentiate between the two because quantum physics cannot always be described classically and the mathematics used is different. Additionally, while all dogs are animals, not all animals are dogs, similarly, all classical physics can be explained by quantum physics, but not all quantum physics can be described classically.
  • #1
jd12345
256
2
Why do we say that classical physics is a lot different from quantum physics?

The laws that determine the macroscopic world should be derivable from quantum laws. So in a way the Newtonian or classical laws are basically quantum laws( maybe a bit approximated)
So why differentiate between macroscopic and microscopic world?
 
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  • #2
Why do we say that classical physics is a lot different from quantum physics?
We don't (except by mistake). We say that quantum physics is different from classical physics :)

All dogs may be animals but not all animals are dogs.
All classical physics is a consequence of quantum - but not all quantum physics can be described classically.

Technically - classical physics is what QM does on average ... so the math is different.
 

What is the main difference between classical physics and quantum physics?

The main difference between classical physics and quantum physics is that classical physics describes the behavior of macroscopic objects, while quantum physics describes the behavior of microscopic objects. Classical physics follows deterministic laws, while quantum physics follows probabilistic laws. Additionally, classical physics assumes that the position and momentum of a particle can be known with certainty, while quantum physics states that there is inherent uncertainty in these measurements.

Can classical physics and quantum physics be reconciled?

Currently, there is no known way to reconcile classical physics and quantum physics. This is known as the "measurement problem" in quantum mechanics. While classical physics can accurately describe most macroscopic phenomena, it fails to explain the behavior of subatomic particles, which require the principles of quantum physics to be understood.

What are some real-world applications of classical physics and quantum physics?

Classical physics is used in many practical applications, such as building bridges, designing cars, and calculating trajectories of objects in motion. Quantum physics, on the other hand, is used in technologies such as transistors, lasers, and MRI machines. It also plays a crucial role in fields such as nanotechnology and cryptography.

Can classical and quantum physics coexist?

While classical and quantum physics cannot be reconciled, they can coexist in certain circumstances. For example, classical physics can be used to describe the motion of planets in our solar system, while quantum physics is needed to describe the behavior of individual atoms and particles within those planets. In some cases, classical and quantum principles can be combined, such as in the field of quantum optics.

What are some key principles of classical and quantum physics?

Classical physics is based on Newton's laws of motion, which state that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Quantum physics, on the other hand, is based on principles such as wave-particle duality, the uncertainty principle, and quantum entanglement. These principles allow for a deeper understanding of the behavior of particles at the microscopic level.

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