Particle-Wave duality

[ecoli]

I've doing some research of QM, and this specific topic has confused me some. According to a website I read, light act as a wave due to the probility of a photon being in a certain location that exhibits properties of waves. At least, that's what I think it said... here's the site http://www-theory.chem.washington.edu/~trstedl/quantum/quantum.html

 

It gave this analogy to explain this phenomenon.

 

For instance, suppose we had a dart-throwing machine that had a 5% chance of hitting the bulls-eye and a 95% chance of hitting the outer ring and no chance of hitting any other place on the dart board. Now, suppose we let the machine throw 100 darts, keeping all of them stuck in the board. We can see each individual dart (so we know they behave like a particle) but we can also see a pattern on the board of a large ring of darts surrounding a small cluster in the middle. This pattern is the accumulation of the individual darts over the probabilities of where each dart could have landed, and represents the 'wavelike' behavior of the darts. Get it?

 

 

I'm not sure if this is the greatest example, but I still don't understand it completely. I have a hard time grasping the concept of the propabilty of a particle acting as a wave.

 

Can someone explain any better please?

[Johnny5]

I have a hard time grasping the concept of the propabilty of a particle acting as a wave.

 

Can someone explain any better please?

 

Understanding quantum mechanics without knowing the whole history of physics which preceded it' date=' is difficult but I won't say impossible.

 

However, the usage of probability theory is going to be confusing no matter what you do.

 

Firstly, to even understand what ultimately you would have to, requires you to know some probability theory, so that you can make intelligent statements.

 

Quantum mechanics has led many physicists to strange statements like many universes, parallel universes, just many strange sentences.

 

All of that is a result of them trying to interpret the mathematics using their natural language.

 

Its not that they don't understand the mathematics, it's that they do.

 

But something weird is happening between the paper, and their thoughts.

 

If you want to understand anything at all, you need something as a basis.

 

For quantum mechanics, I recommend you start with just one simple formula:

 

E = hf

 

You would do better to start with that formula, than worry about probability theory right away. Probability theory didn't enter until the 1920's.

 

What I am telling you is this.

 

Your desire is to understand quantum mechanics, not probability theory.

 

Quantum mechanics is based upon an experimental discovery.

 

 

Actually several discoveries, which happened apparently within just a few years.

 

But no matter what, start off with understanding just that one equation.

 

Learn its history, learn the meaning of the symbols. Then proceed to make things more and more complex.

 

E is the energy of a photon.

 

h is Planck's constant of nature.

 

f is the frequency of a photon.

 

Ask some physicists to explain f to you, and you will get different answers.

 

Ask them what is waving with frequency f too, and again you will get different answers.

 

c = speed of light = 299792458 meters per second = f l

 

So

 

E = hf

 

c = f l

 

the f in both formulas denotes the same thing.

 

Those equations are your starting point.

 

The first one originates aroung 1900.

 

Then Niels Bohr, around 1913, came up with a model for a hydrogen atom.

 

He only had three postulates, and his theory adequately explained the wavelengths of the photons emitted by glowing hydrogen gas.

[Tom Mattson]

Can someone explain any better please?

 

"Probability waves" are so named because the probability densities associated with quantum mechanical systems are solutions to a wave equation. One is not obligated to think of probability waves in the same way as, say, propagating light waves.

[ecoli]

Understanding quantum mechanics without knowing the whole history of physics which preceded it, is difficult but I won't say impossible.

 

I am familiar with some history of physics before this point... I'm taking a classical mechanics course, and have done research into 20th century physics. So, I'm not completely lost.

 

 

Firstly, to even understand what ultimately you would have to, requires you to know some probability theory, so that you can make intelligent statements.

 

Yeah, my math background is not very strong...

 

Quantum mechanics has led many physicists to strange statements like many universes, parallel universes, just many strange sentences.

Yet, many of these things I understand, the reasoning behind and the experiments, but for some reason, wave-particle duality just is not happening for me.

 

 

For quantum mechanics, I recommend you start with just one simple formula:

 

E = hf

 

I am aware of this equation, thank you for helping...

[Johnny5]

I am aware of this equation' date=' thank you for helping... [/quote']

 

I try.

 

Sometimes it works, sometimes not.

 

Regards

 

PS: if you are taking a class in classical mechanics, then you are well on your way.

 

But again, to ground yourself I suggest these three formulas:

 

 

E = hf

c=f l

p=h/l