For one possible physical picture, consider a river that forks around an island. You could represent the river symbolically as:

River = left fork + right fork

The river exists in both locations. You could also navigate a boat along the river, i.e., along either the left fork or right fork. As long as one is clear on whether one is talking about the overall state (River) or one of simpler states (e.g., the left fork), then there need be no confusion.

Aside: The actual physical picture outside of measurement is a matter of interpretation. What physicists do agree on is that the superposition provides information for calculating the probability of measuring the particle in one of the locations.

River = left fork + right fork — Andrew M

Three Magnemite = Magneton.

Why did you start another thread about this? You're the one who started the first thread a few days ago.

Quantum superposition — elucid

Perhaps it is actually a very fast vibration between two places.

Why did you start another thread about this? You're the one who started the first thread a few days ago.

That thread is about a different subject. The other thread is about two objects occupying the same space simultaneously.

Why did you start another thread about this? You're the one who started the first thread a few days ago. — Terrapin Station

No; this is the very same thread, just in a different place....

We don't have any problem thinking of the very same object being in the very same place at two different times.

SO why should we have a problem with the very same object being in the very same time at two different places? (Apart, that is, from the contorted grammar...)

For one possible physical picture, consider a river that forks around an island. You could represent the river symbolically as:

River = left fork + right fork — Andrew M

I don't know enough about QM to know if you are right with this analogy, BUT I SURE HOPE YOU ARE :smile: This seems a great analogy that does help even idiots like me to understand.

No; this is the very same thread, just in a different place.... — Banno

Dang, you nailed that one. :rofl:

I think you are not alone in finding it odd, but that is what is confirmed by the famous "double slit experiment". There are different variations of this experiment, but the ones I'm thinking of are when particles are shot through one at a time, as it demonstrates the particle interacting with itself.

In Quantum Mechanics, there are a couple of primary interpretations: "many worlds interpretation" and "copenhagen interpretation". I think reviewing the many worlds interpretation helps it seem somewhat plausible without losing all of your sanity.

I don't know enough about QM to know if you are right with this analogy, BUT I SURE HOPE YOU ARE :smile: This seems a great analogy that does help even idiots like me to understand. — ZhouBoTong

Thanks! It's even adaptable to your favorite interpretation:

Pilot wave theory: An invisible river guides the boat.

Many Worlds: There is a boat on each fork of the river.

Copenhagen: There is no river until you launch the boat.

RQM: In your reference frame there is a boat on the river.

QBism: You should believe there is a boat on the river.

Consciousness causes collapse: Your mind creates the river. And the boat.

Instrumentalism: We don't talk about the river.

No; this is the very same thread, just in a different place.... — Banno

:lol:

"Consciousness causes collapse: Your mind creates the river. And the boat."

Hey Andrew, just curious, would that be more in keeping with an Idealist model?

Accordingly, I was thinking about the conscious and subconscious mind creating two separate realities:

"Sometimes, you are so much into cognitive processes and imagination that your existence shrinks down to only physical presence because you are mentally somewhere else. Missing road turns while driving or adding wrong ingredients while cooking are common examples in this regard."

Does that mean we can perceive two realities at one time viz. our consciousness or conscious states of Being?

Thanks! It's even adaptable to your favorite interpretation:

Pilot wave theory: An invisible river guides the boat.

Many Worlds: There is a boat on each fork of the river.

Copenhagen: There is no river until you launch the boat.

RQM: In your reference frame there is a boat on the river.

QBism: You should believe there is a boat on the river.

Consciousness causes collapse: Your mind creates the river. And the boat.

Instrumentalism: We don't talk about the river. — Andrew M

Yep, the great analogy continues. It is like listening to Michio Kaku, I usually feel like his topics of discussion are beyond me, but his explanations allow me to at least feel like I understand.

I think I know the answer to 3017amen's question, but I am far more interested in your answer :grin:

Hey Andrew, just curious, would that be more in keeping with an Idealist model? — 3017amen

"Consciousness causes collapse" has a history of being associated with quantum mysticism and is generally dismissed by physicists these days.

The other interpretations are usually considered realist by their proponents. This paper provides a useful classification into so-called intrinsic realist interpretations (including Pilot wave theory and Many Worlds) and participatory realist interpretations (including Copenhagen, RQM and QBism). So that may be of interest.

Accordingly, I was thinking about the conscious and subconscious mind creating two separate realities:

"Sometimes, you are so much into cognitive processes and imagination that your existence shrinks down to only physical presence because you are mentally somewhere else. Missing road turns while driving or adding wrong ingredients while cooking are common examples in this regard."

Does that mean we can perceive two realities at one time viz. our consciousness or conscious states of Being? — 3017amen

I read that quote as noting that sometimes we are highly focused on our immediate environment, whereas at other times we are distracted or thinking about other things. I don't see any out-of-the-ordinary philosophical implications there.

Yep, the great analogy continues. — ZhouBoTong

Glad you enjoyed it! There's a lot of interesting work being done in quantum foundations and learning it is an effective way to give one's philosophical assumptions a workout.

"I don't see any out-of-the-ordinary philosophical implications there."

Great!

Are you thinking that would simply indicate that the subconscious mind and the conscious mind are working in unison? (This is not a rhetorical question: If so, how is that explainable?)

Getting back to the OP, a critical point is that, with regard to superposition, we never actually observe one particle in two places at once. When we do make the measurement, one particle has only one location. The issue is that where particles end up on the screen in the double slit experiment suggests a wave having gone through both slits, one which determines the probability of where you'll find the particle. You get an interference pattern on your screen. But if you use some method to gain information about which slit the particles go through, that interference pattern goes away and you get what looks more like regular particle-like behavior, with no interference pattern, as if you fired bullets through the slits rather than passing a wave through.

This is one if the central puzzles of QM. What information we have seems to affect the measurement results, even if we seemingly gain information and then later throw it away. See the delayed choice quantum eraser experiment (after learning about standard double-slit). Nobody actually knows what this really means. There is no way to experimentally decide which interpretation is correct. Maybe none is.

Some also think of entanglement as maybe involving a situation of one thing being in two places. I don't. But it isn't completely clear what's going on there really.

But it is a mistake to say that QM definitely shows us particles being in multiple locations. It doesn't.

One interesting thing to realize is that nobody has ever even seen a photon in flight! Such things might not even exist except in models.

Are you thinking that would simply indicate that the subconscious mind and the conscious mind are working in unison? (This is not a rhetorical question: If so, how is that explainable?) — 3017amen

I suppose I don't really think in terms of "subconscious mind" and "conscious mind", I just see mind as an abstraction over an agent's intelligent activity. If an abstraction creates a philosophical problem, we can just go back to the concrete scenarios (e.g., a driver attentive to the immediate environment versus thinking about something else). The investigation of the processes involved seem to be a matter for science.

But it is a mistake to say that QM definitely shows us particles being in multiple locations. It doesn't. — petrichor

Agreed, the measurements are the data points. Whereas the underlying structure of the world is still a matter of interpretation.

One interesting thing to realize is that nobody has ever even seen a photon in flight! Such things might not even exist except in models. — petrichor

Since photons are the means by which we see things, I suppose we would need to bounce photons off the in-flight photon in order to see it. Unfortunately photons don't interact with each other. And even if they did, a photon would be too small to see. Nonetheless a human retina can respond to a single photon (in a dark room).

Also QM is generally considered to scale up to the whole universe. For example, quantum behavior has been observed in objects visible to the naked eye such as with the piezoelectric tuning fork experiment (with about 10 trillion atoms).