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Strangely enough, when you do a quantum mechanics experiment, you get a result that says something about what you already know. If you place a detector at one (or both) of the slits, you watch individual particles go through the slits, and you get a particle result from your detector (e.g., no interference pattern). If you don't know which slit the ...

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No, if you observe which slit they traveled through then there is NOT an interference pattern. The act of observing, or more accurately, the need for the location of the electron to be resolved causes it to take on a definite position and then continue on from that position as a particle. If it is not observed or interacted with in some way that would make ...

2

Atoms do in fact have a sort of wave behavior you might say. Everything with mass does, even you! When the mass is small enough, like that of an electron or an atom, this behavior becomes more important to take into consideration. For example, when we go to look for an atom by shining light of a small wavelength on it, we can only say with a certain ...

2

This is just a short expansion of Ernies comment (answer really) above, same reference, and the only thing I want to add is the size of the molecules, not just atoms but 58- and 114-atom molecules, made of links of carbon, hydrogen and nitrogen. $\mathrm{C}_{60}$ Fullerene Double Slit experiment and Neutron Interference Pattern both provide details of ...

1

Yes, all electromagnetic radiation shows this 'dual nature' - which is to be expected since there is nothing really separating light from the other radiation in the spectrum apart from the arbitrary boundaries we have decided for it (i.e. visible light is just defined by what humans can see). As you'll discover as you learn more about quantum mechanics, ...

2

Yes, everything shows wave-particle duality to varying degrees because "wave-particle duality" is just a name for a certain behaviour of quantum objects, and everything is believed to be a quantum object. In particular, all electromagnetic radiation can be conceived of as being made of photons, which exhibit particle- and wave-like properties.

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By the Born interpretation, the probability of finding a particle near a point $x$ is $|\psi(x)|^2$. If $\psi(x) = 0$, then the probability of finding the particle is zero for all locations, which means that the particle doesn't exist. EDIT: The "amplitude" of a general wave-function isn't really well-defined, but roughly speaking it tells us "how big" ...

4

It's not a stupid question. In fact, Quantum Field Theory is the field of physics that seeks to answer exactly this question. In QFT, in addition to the electromagnetic field, there is a single electron field that extends throughout the universe. Stable ripples in the electron field constitute individual electrons. Every fundamental particle has a ...

2

From the famous Double-slit experiment, it is clear that electrons do behave as wave as well as particle. When it is detected by geiger counter, "click" sound appears & no matter how greatly the voltage is decreased along the cathode tube, "click" & never "half click" appears. So, electrons always arrive at lumps like bullets. However, unlike bullets ...

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The electromagnetic wave is a classical theory while matter waves are quantum mechanical. The wave aspect is a mathematical abstraction which allows us to predict future quantum states of the electron with a known probability.

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In quantum mechanics, things are not "particles" or "waves" - they may behave like both, or like neither. But a quantum object "is" neither of those - it is a quantum state, usually described as a vector in a Hilbert space. The Bohr model of the electron orbiting the atom is false (for one inconsistency, that of moving charges classically radiating, see ...

0

Who says electrons are not waves in the atom? Discard your bygone, quaint, outdated, perplexing, stupifying, nonsense idea that electrons move in a solar-system sort of orbits. That model(attributed to Rutherford) was an attempt to understand the atomic arena of Nature; unfortunately it was far from being correct as it had many in-built flaws. Then the ...

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I think the default that electron is a particle is taught us first because of historical reason. You have to understand the newtonian universe before the quantum mechanics; else it would be too complicated. The atomic model was first made with electron on discrete observable routes. The next step was the thinking that they have to be stable and quantized so ...

2

A "ray" in geometric optics is a locus of continuous propagation of light. Think of it as mapping where the energy is going in space. In principle there are an arbitrarily large number of them, but we draw a manageable number for visualization purposes. The various [letter]-rays were so named when people didn't know what they were beyond being things that ...

2

Individual photons are not considered rays. Because of the wave and particle nature of photons, they are much more complicated than what they are generally thought of: a projectile of light. In fact, they do not have an exact measurable position, but do travel in straight line trajectories. What we consider rays are lines perpendicular to the wave front of ...

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