Recall that the famous two-slit experiment can be used to show that 'particles' under appropriate conditions exhibit wave behaviour (thereby belying their status as particles)--namely, they produce a diffraction pattern; this pattern is produced only if each individual particle is in a state of superposition that includes the possibility of going through both openings at once, as a good wave does (see Figure 9-2A).

Caption: Figure 9-2: This set of diagrams illustrates some variations on a two-slit experiment. The source used in each case are atoms.

the case of the two-slit experiment, we need to assume, following

In both the glass reflection and the two-slit experiments, what is

Among the questions are what is Planck's constant and what is its significance, what are some quantum scales of time, why do bosons and fermions have such funny names, what are the big four absolute conservation laws, what is the

two-slit experiment and why is it important, how do electrons behave in a metal, what is superconductivity, and what is string theory.

Among them are Galileo's experiment with inclined planes that established a mathematical formula for accelerated motion, Isaac Newton's unraveling of the nature of light and color, and Thomas Young's

two-slit experiment that revealed the wavelike character of light.

[[absolute value of]A.sup.2] gives the probability measure of, say, where an impact is going to occur when an electron in state [where][Psi]> interacts with some other objects, while S explains, inter alia, the interference effect we see in such familiar experiments as the two-slit experiment. Thus, even though we cannot imagine what kind of substance the wave packet is, we know exactly how it behaves if it exists.

(1) Wave functions represent things that interfere with one another, as shown most vividly in the case of the two-slit experiment. Very briefly, in a two-slit experiment, when a single quantum object passes through the two openings, the wave packet, [where][Psi]>, splits into two, [where][[Psi].sub.1]> and [where][[Psi].sub.2]>, which determine, when the object is later intersected by a receptive screen, where the impact occurs with what probability.(4) However, [[absolute value of][Psi].sup.2] [not equal to] [[absolute value of][[Psi].sub.1].sup.2] + [[[absolute value of][[Psi].sub.2].sup.2], as it should if the object went through either opening 1 or opening 2.

On Visibility in the Afshar

Two-Slit Experiment. Foundations of Physics, 2009, v.

[3] conducted a two-slit experiment based on a different methodology but with a similar outcome and conclusions.

Two-slit experiments performed earlier by Tsuchiya et al.

Nor can such a concept become reconcilable with the dot-shaped marks which occur at the screen of

two-slit experiments from individual photon impacts, as observed e.g.