Double slit experiment, question on when the path is determined

[TedS]

double slit experiment, question on when the path is "determined"

Hi all, question here from a non-scientist.

Let's say I set up a double-slit experiment, with a detector at one or the other slit. I get it working, so that when I am able to determine the particle path, the interference pattern on the target screen disappears.

Okay, now I leave the detector in place, but I cover it up so that however it is that it indicates where the particle is or isn't, the indication can no longer be seen by anyone.

I think the interference pattern will nonetheless still be missing, right?

Does this prove that whatever the mystery is, consciousness has nothing to do with it? And that furthermore, the effects on the cells in one's retina also has nothing to do with the "waveform collapse"?

I believe I've read that which-way path detection is getting to the point where the detector might have no effect -- other than waveform collapse? -- on the particle... mystifying indeed.

Thanks all, I look forward to your replies.

Ted

 

[eljose79]

Hello Ted,

Great question! The double-slit experiment is a classic thought experiment in quantum mechanics that has puzzled scientists and non-scientists alike. While the experiment may seem simple, it raises some complex questions about the nature of particles and the role of observation in determining their behavior.

To answer your question, let's first define what we mean by "determining the particle path." In quantum mechanics, particles can behave as both waves and particles, and their exact path cannot be predicted or known with certainty. Instead, we can only calculate the probability of a particle being in a certain location. When we say we have "determined" the particle path, it means we have observed the particle at a specific location, collapsing its wavefunction and reducing the probability of it being in other locations.

Now, to address your experiment. If you were to cover up the detector, the interference pattern on the target screen would still be missing. This is because the mere presence of the detector, even if it is covered up, can still affect the particle's behavior. This is known as the "observer effect." However, this does not necessarily prove that consciousness plays a role in the experiment. The observer effect can also be caused by the physical interaction between the detector and the particle, rather than the conscious observation of the experimenter.

Furthermore, the effects on the cells in one's retina have nothing to do with the "waveform collapse." The retina is simply a tool for detecting light, and it does not have any impact on the behavior of particles in the experiment.

As for the advancements in which-way path detection, scientists are still exploring the implications of these developments. While it may seem mystifying, it is important to remember that quantum mechanics is a complex field and there is still much we do not fully understand. However, these advancements do suggest that the role of observation in the double-slit experiment may not be as straightforward as we once thought.

I hope this helps answer your question. Keep exploring and asking questions, Ted! That's what science is all about.

 

[Entropia]

Hi Ted,

I can provide some insights on the double slit experiment and the question of when the path is "determined." The double slit experiment is a classic experiment in quantum mechanics that demonstrates the wave-particle duality of matter. In this experiment, a beam of particles, such as electrons, is directed at a barrier with two slits. On the other side of the barrier is a screen where the particles will be detected.

When the particles pass through the slits, they behave like waves and create an interference pattern on the screen. This pattern is a result of the waves from each slit interacting with each other. However, when a detector is placed at one of the slits, the particles are no longer able to create an interference pattern and instead behave like particles, creating two distinct bands on the screen.

Now, to address your question on when the path is "determined," it is important to understand that in quantum mechanics, particles do not have a definite path until they are observed or measured. This is known as the principle of superposition, which states that a particle can exist in multiple states or locations at the same time until it is observed. So, in the double slit experiment, the particles are in a superposition of states, passing through both slits simultaneously, until they are observed by the detector. The act of observation or measurement causes the superposition to collapse, and the particle's path is then determined.

In your scenario, where the detector is covered up, the particles will still behave like particles and not create an interference pattern because the detector's presence has already collapsed the superposition. This does not prove that consciousness has nothing to do with it, as the observer's presence and interaction with the experiment can also cause the superposition to collapse.

In conclusion, the double slit experiment is a fascinating demonstration of the strange behavior of particles at the quantum level. The question of when the path is determined is still a subject of debate and further research in the field of quantum mechanics. I hope this helps to clarify your understanding of the experiment.