Question

Under which conditions will a stream of bullets display an interference pattern in a two-hole experiment?

the bullets have enough speed

the holes are the appropriate distance

the distance to the target is great enough

The holes are the appropriate diameter

Bullets will never display interference behavior

Answer 1

The experiment is kwown as two slit experiment of quantum mechanic.

An Experiment with Bullets :

Imagine an experimental setup in which a machine gun is spraying bullets at a screen in which there are two narrow openings, or slits which may or may not be covered.

Bullets that pass through the openings will then strike a further screen, the detection or observation screen, behind the first, and the point of impact of the bullets on this screen are noted.

Suppose, in the first instance, that this experiment is carried out with only one slit opened, slit 1 say. A first point to note is that the bullets arrive in ‘lumps’, (assuming indestructible bullets), i.e. every bullet that leaves the gun arrives as a whole somewhere on the detection screen. Not surprisingly, what would be observed is the tendency for the bullets to strike the screen in a region somewhere immediately opposite the position of the open slit, but because the machine gun is firing erratically, we would expect that not all the bullets would strike the screen in exactly the same spot, but to strike the screen at random, though always in a region roughly opposite the opened slit.

We can represent this experimental outcome by a curve P1(x) which is simply such that P1(x)δx = probability of a bullet landing in the range (x, x + δx). (4.1) 1

If we were to cover this slit and open the other, then what we would observe is the tendency for the bullets to strike the screen opposite this opened slit, producing a curve P2(x) similar to P1(x). These results are indicated in Fig. (4.1).

  (a)

Figure 4.1: The result of firing bullets at the screen when only one slit is open. The curves P1(x) and P2(x) give the probability densities of a bullet passing through slit 1 or 2 respectively and striking the screen at x. Finally, suppose that both slits are opened. We would then observe the bullets would sometimes come through slit 1 and sometimes through slit 2 – varying between the two possibilities in a random way – producing two piles behind each slit in a way that is simply the sum of the results that would be observed with one or the other slit opened, i.e. P12(x) = P1(x) + P2(x) (4.2)

Figure 4.2: The result of firing bullets at the screen when both slits are open. The bullets accumulate on an observation screen, forming two small piles opposite each slit. The curve P12(x) represents the probability density of bullets landing at point x on the observation screen.

Slit 1

Machine gun ........   Observation screen P12(x)

Slit 2   

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