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Matter and Energy

  1. Jun 5, 2009 #1
    With the double slit experiment, instead of firing one electron at a time, I assume you would get the same outcome if you fired one photon at a time?

    I was thinking that maybe an electron isn't just sometimes a wave, sometimes a particle: I think that the wave property is reflective of energy itself, not the electron (1'), meaning energy itself is a wave (2'), or behaves like a wave, and is just manipulating the particle as if it is part of the wave, something that isn't seen at the macroscopic level simply because of the quantity of atoms. If energy, matter, or light can be used interchangeably, and if light has both wave and particle properties aswell, could it be that energy itself just has a greater influence at that level?

    1' (or any bit of matter)
    2' (energy of the bit of matter)
    Last edited: Jun 5, 2009
  2. jcsd
  3. Jun 5, 2009 #2
    The concepts of particles and waves that you are thinking of are classical ideas. To put it a bit blunt: these concepts simply break down at the quantum level. The double-slit experiment is precisely an example where the quantum level comes into play.

    In quantummechanics there is no notion of particle-wave duality. These concepts are replaced by one unifying picture, which is the quantummechanical description of the electron.

    An electron is always quantummechanical. In certain experiments it will look like a classical particle, in other cases it will look like a classical wave. But in both cases it will be quantum mechanical, and strictly speaking the classical picture does not play a role. But because it is so much easier to work with the classical picture, it hasn't been completely disregarded.
  4. Jun 5, 2009 #3
    Can you elaborate on what classical ideas are? Are they Newtonian ideas?
    Basically, what you're saying is that it behaves as it is described with mathematics and that it's impossible to try to visualize it with classical ideas, meaning it won't be comprehended ever?
    I'm just trying to comprehend it, and came up with this, other than the fact that I'm trying to relate Quantum Mechanics in Newtonian ideas, is there anything fundamentally wrong with what I said?

    The calculations seem almost just like a probability distribution, which is weird to actually describe a particle. If we have a particle in the box, and the probability distribution becomes even throughout the entire box, we obviously can find the electron somewhere, which means it isn't everywhere, which leads me to thinking there may still be some insight that can be found with classical ideas.
  5. Jun 5, 2009 #4


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    You might want to start by reading our FAQ in the General Physics forum. There's an entry on this 'wave particle duality' and why there really isn't such a duality in QM.

  6. Jun 5, 2009 #5
    Yes, they are

    The quantum mechanical description is just as "mathematical" as the newtonian one. The "lack" of visualization does not automatically imply incomprehensiblity. Note that a visualization of classical ideas are, in the end, visualizations of similar mathematical constructs.
    Fundamentally wrong is a bit harsch. But in a quantummechanical description of the world, which accounts for experiments such as the double slit experiment, there is no such thing as a classical part. In certain limits the theory looks to behave as if it is a classical theory, but in essence it is still quantummechanical.
    Classical ideas do not match the experiment - quantum mechanics does. A theory where you have to flip a coin to decide wether you should use a wave or a particle picture to describe the experiment sounds a lot more flawed to me.
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