Tag Info

New answers tagged

0

For Wheeler's delayed choice experiment, the 'choice' of a photon is said to be delayed from the reference frame of the experimenter. There are a couple of things to point out here. First the delayed 'choice' is not an actual thing (e.g. the photon doesn't go backwards in time through the slit and make a different choice), it arises from a common ...


1

The correct answer is that the electron doesn't behave like either a particle or a wave. The quantum field that gives rise to electrons can change its quantum state in a way that is observed in the double slit experiment. It can also change in many other ways in addition to that. Modern physics does not talk about particles as independent quantities. ...


-1

Physicists training as well as science must work with certainties. On the other hand, Young's theory quite old. In the meantime, we know that fields are quantized. Maybe the fringes behind an edge or a slit are images of the electromagnetic field between the photon (or electron) and the edges.


0

Double slit experiment with electrons is a demonstration of a quantum behavior. When we say observe we mean expose to some kind of interaction. So when electron travels from its source towards the double slit and then passes through, and hits the detector, we see that it is a particle. But, when many electrons pass through the slit we observe a interference ...


0

A free moving electron does not emit photons. If one want to see an electron you have to illuminate it. Sending photons, the electron reflect (absorb and re-emit) photons which one can detect then. By doing this the electron get disturbed and changes his direction. The fringes on the observation screen will be destroyed. Since one cannot synchronize the ...


1

When you send the photons through the double-slited wall, they form a diffraction pattern on the other side, which is a wave-like phenomenon. It makes no sense to think of the photons as "particles" anymore, since they would need to cross both slits simoultaneously in order to create the diffraction pattern. So a way to find out what's happening is to place ...


3

Your question is not silly. In the two slit expariment you measure the position if the photon, that is a particle-like quality. What happens is that a photodetector records when it absorbs a photon. That gets recorded in the memory. Some schools of physics interpret the interaction of the photon with the detector as a measurement. Others interpret that the ...


0

An electron has a macroscopic trajectory from point A to point B, it can be drawn as straight line, if no electric or magnetic fields exist on the way, up to the slit with the indeterminacy of the width encompassing the slits, and from the slits to the point it hits on the screen. When talking of the vacuum and virtual interactions one is talking of very ...


0

On axis in the 1D small angle approximation the spacing is constant. When you have point sources and you go off axis (in the direction perpendicular to the line connecting the two points) that may not be true - it is also not true when the small angle approximation breaks down (higher order fringes). You should be able to find details and diagrams in any ...


2

The interaction with the environment performs no measurement, it only may distort the wave-function. In order to observe that the pattern was damaged you don't need to have an idea of what interaction caused the damage. You need to have that idea if you study that specific interaction. An example of disturbing interaction with air particles: the collision ...


1

This answer is not about QM but about a classical system that simulates many aspects of QM very well, and might be of some ineterestto you. There are experiments using oil dropplets that bounce up and down a vibrating fluid, the horizontal motion of these droplets is due to bouncing on the waves that move on the fluid's surface, which in turn are influenced ...


1

I read about Wheelers choice experiment from Wikipedia, not from some article. There is no end to trials as that of Wheelers. What is wrong with his attempt is that the photon is a WAVE. And as any wave, it takes both paths through the interferometer. I saw in Wikipedia the statement "since in the first case the photon is said to "decide" to travel as a ...


10

It's not, rather your assumption that it's always impossible to know which slit a photon went through is incorrect. It's only impossible to know which slit it went through in an experiment where you get a double-slit interference pattern--if you wish you can set up an experiment to find out which slit the photon goes through, but the result will then be no ...


1

In the one-photon experiment you should see them. The problem is that it is very difficult to build a single-photon source and to make such an experiment.


-1

That's an excellent suggestion for an experiment since Claus Jönsson has performed his experiment with electrons at a double slit. Since the electrons must be in a vacuum, it is questionable whether the diffraction pattern shows in a cloud chamber. However, if it succeeds it may be, that in a single-photon experiment one can see the gap through which ...


1

You have to realize that wave equations and interference phenomena had been studied and understood by the nineteenth century. Plane waves are the simplest mathematical solution of wave equations, where k, is the wave’s wave number or more specifically the angular wave number and equals 2π/λ, where λ is the wavelength of the wave. k, has the units of ...


0

The experiment looks like: You can calculate the path lengths $A$ and $B$ using Pythagoras' theorem. The 100th bright fringe is positioned where the different in path length is 100$\lambda$ i.e. $$ B - A = 100\lambda$$ The resulting equation is messy but easily solved numerically. I got $s \approx 1.51$m at the 100th fringe, so the spacing between the ...


0

There are many confuse things in this question: 1) "The multiple paths the particle simultaneously travels, interfere with each other" It's not the paths that interfere, when these paths cross one another, i.e. the wave-packet on one path and the wave-packet on the other path pass through the same region at the SAME TIME. 2) "but as it is absorbed, it ...


0

Sending data to a computer is not possible without detection, and a detection for sending to some computer is a macroscopic intervention, that introduces decoherence between the two components of the wave-function, that which passed through one hole, and that with passed through the other. But the issue is simpler. For detecting which hole the photon passed ...



Top 50 recent answers are included