No, we haven't learned any such thing.

Quantum objects are those that are described by quantum mechanics, that provides the framework for computing the probability distribution on the space of states and the transition probabilities from one state to another.

Nonclassical objects with the de Broglie wavelengths too significant to ignore

Quantum object is the body of scientific laws that describe the madcap behavior of photons, electrons and the other particles that make up the universe. In classical mechanics, objects exist in a specific place at a specific time. On the basis of is the theoretical basis of modern physics that explains the nature and behavior of matter and energy on the atomic and subatomic level.

You first now something about them from clasical properties, ie. the cathode rays for electrons.(Thompson)

Then they surprise you with wave properties also as in diffraction(davidson gremmer), then you no longer know exactly what an electron is any more.

Quantum objects behave like particles when they exchange energy or momentum, but they behave more like waves when they are not involved in any exchanges of energy. This means that they do not behave like traditional particles because they can be in many places at the same time, and they don't behave like traditional waves because they can interfere with themselves.

Quantum theory has not been able to determine what exactly quantum objects are or why they act so differently from traditional objects, so they are generally treated as ambiguous entities, and all that we know for sure about them is how they behave.

For example, we know that there is no way to determine where exactly a quantum object is located and where it is going at the same time. This is the uncertainty principle, which is well-defined mathematically.

We also know that electrons, which are quantum objects, resist being in the same state as other electrons when they are in the same atom. Photons, on the other hand, seem to prefer being in the same state with other photons. Quantum theory can show how this works by the particle field mathematics that define fermions compared to bosons.

We also know that as objects become larger in size, they lose their ambiguous behavior and start acting more like traditional objects. However, quantum theory has no fully consistent explanation for why this happens, although the mathematics of decoherence theory does describe the transition accurately.

The Standard Theory of particle physics says that all fundamental quantum objects can be treated as "particles" as long as you don't think of them as traditional particles, and these particles fall into a limited number of buckets, defined by what forces they interact with. For example, neutrinos interact with gravity and the weak nuclear force. Electrons interact with gravity, the weak nuclear force, and the electromagnetic force. Quarks interact with gravity, the weak nuclear force, the electromagnetic force, and the strong nuclear force. Photons carry the electromagnetic force and only interact with gravity. Quarks carry the strong nuclear force and interact with the strong nuclear force and gravity. These are just some of the many fundamental particles.

If you are looking for a way to understand what quantum objects are that goes beyond what we know from experiments, then you will need to wander into the many "interpretations" of quantum mechanics. Each of these interpretation is crazy in some way, but they each offer a different perspective on what the strange behavior of quantum objects is telling us.

All macroscopically continuous regular objects (h: Zero) are microscopically discontinuous irregular (h: Nonzero) in structural nature. Their extreme shapes are respectively the usual forms of classical and quantum objects.

Thanks for attention and contribution

No, they cannot be in many places at the sametime, they simply have a

probability of being found at different positions (A PRIORI). ONCE FOUND THEY ARE AT SOME DEFINITE POSITION.

Juan,

I know this sounds weird, but, in fact, there is a possibility that they can be in many places at the same time and there are good reasons to think that they are.

You are right that whenever we measure a particle's location, we will always find it in one location. That is true. But if you measure a particle's momentum and you determine the momentum of that particle exactly, then, according to the principle of uncertainty, the particle can be EVERYWHERE.

In other words, there is no way to know where the particle is and the possibility exists that it is everywhere. When the particle is in that state, there is no way to prove that it is in one location.

There are also good reasons to think that it is not in one location when you measure its momentum.

If a wave function is nothing more than just a prediction tool for guessing where the particle will be when you measure its position, then this would be treating a quantum wave function like the odds of rolling a six with a single die. It is not that sort of probability function because a quantum wave function can interfere with itself, such as when a particle is shot through a two-slit experiment.

The only way a wave could interfere with itself is if it was in more than one location at a time. The math literally says that the wave function goes through both slits at the same time. This is why we see the interference pattern.

According to quantum theory, entanglement is defined as two particles sharing a single quantum state, which means a single quantum wave function. It has been fairly well proven that this wave function is non-local and reaches across space. That is what the function literally describes and that is what experiments have verified.

The probability functions that predict the odds of rolling a die and getting a six say that the die will end up as a 1, 2, 3, 4, 5, OR 6. Which side it will land on is unknown until the die settles down, but this is only because it is so difficult to calculate exactly how the die will bounce. The wave function does not describe an OR state because the possibilities literally interfere with each other. And it does not describe an AND state because it is only one particle.

Picturing the particle as going through one slit OR the other cannot be the full story because this does not explain the interference pattern. This means that the wave function is describing more than just the probability of where it will end up when it is detected.

If you are interested in reading more about this, here is an interesting paper:

Chapter Taking Heisenberg’s Potentia Seriously

Roger Penrose also describes this in his recent book, "Fashion, faith, and fantasy in the new physics of the universe," see page 24.

Another way of looking at this is that quantum states are not like classical states in physics where objects are in particular locations, with specific velocity and momentum. As Bowman says in his book, "Essential Quantum Mechanics" (2008), quantum states do not represent values, they represent functions. This means that quantum states, such as the location of a particle, cannot be represented by numbers until you measure the particle's location because quantum states are dynamically changing functions. This means the location state of a particle is not tied to a single location until it is measured. This is what quantum theory tells us.

You say determine the particles momentum exactly, the particle can be everywhere. Agree, but emphasis on the word CAN, notice you do not say IS.

And I would use the word anywhere instead of everywhere.

As long as you do not measure, you do not know where the particle is, agree.

But the character of this statement isjust probabilistic, you must distinguish probability from reality.

One thing is to say that the probability of raining is 50%, and quite another to say that it is raining.

So all in all I think you have a little too literal understanding of some quantum statements.

So we end up almost agreeing after all. There is a probability density so the particle CAN show up

anywhere.

I wont disagree about your entaanglement or nonlocality concepts.

Juan,

Yes, I do see the wave function as representing something real. I realize that I am in the minority with this, but it is fully in line with what we know about quantum mechanics.

Here is the issue that suggests this is more than just a tool for predicting outcomes: If you shoot photons through a single slit, one at a time, they will create a typical bell-curve distribution pattern, as we would expect for particles.

However, when you open a second slit, suddenly there are regions on the screen where photons no longer land. What is it that keeps photons from landing in those dark areas of the interference pattern?

It seems to me that there is something real that keeps photons from landing in the dark areas.

So, yes, I think we are close in how we see this, only I do see wave functions and quantum states as representing something real. I realize that many others do not. Quantum theory, as it stands today, cannot prove one way or the other. So both views are valid.

I guess that is why "maybe" is the best answer.

https://www.springer.com/gp/book/9783642376283

Hi Juan and Doug,

Allow me to share my thoughts...

1. is the wavefunction real? ...yeah, sure why not.

Actually I remember a study to suggest that with very little assumptions, this can be shown to be true; i.e the wavefunction is in one-to-one correspondence with an element of reality (10.1103/PhysRevLett.108.150402)

2. Is the particle in more than one place at the same time? No I think not. (Superpositions do not mean this)

Perhaps, one nice way of looking at this I feel is as follows: whenever you make measurements, you are literally asking questions. When you try to measure the electron's position, you are already "asking" the electron to behave like a particle. You gonna get an answer, one or the other, depending on your apparatus...not necessarily a true reflection of the nature of the electron. So when some of my students in their first quantum mechanics course ask me, what is an electron? Wave or Particle? I say, an electron is an electron. Wave or particle would be features relevant to our understanding of nature around us (classical) which we tend to impose on the poor electron! Then I hope he or she gets to learn quantum field theory later for further enlightenment.

Jesni

There are all kinds of opinions, but the most comon one with respect to the wave function is that it means

nothing physically, other than its square modulus (probability density) and the ability to interfere with other wave functions

This has always sounded a bit strange

regards, juan

Quantum objects are those having significant matter waves associated with them; otherwise, the objects are classical ones

Jesni,

Thanks for your response. I agree with you that the wave function represents an element of reality. And as you said, there is good evidence to support this.

However, as Juan says, most physicists take the position that the wave function does not of itself represent something real. Lee Smolin just published a new book on this subject. He agrees with the position that the wave function represents something real. He goes into great detail to explain why and to show the controversy. His book is called, "Einstein's Unfinished Revolution: The Search for What Lies Beyond the Quantum."

On your second point, you say that you do not think that the particle is in more than one place at a time. I liked the things that you said about this, but nothing you said explains why we should think a particle is not in more than one place at a time when it is not being measured.

Here is what I think is most interesting about this question: Classical objects act like things that always exist in one place at a time, and they always have clear trajectories when they move. In other words, they need to go through space and time to get to another point in space. The problem is that this is not how quantum particles act.

An electron does exist in one place when it is measured, but it has no clear trajectory as it moves. We only find it in another place after we make another measurement. Did it move through space and time to get from one place to another? The answer is that we have no way of knowing. This means that it is possible that it does not move through space and time.

This idea goes against the way classic objects work, which is why it is natural to think that something is wrong. But I believe what this is really telling us is that locations in space are only relevant to "measurements." Measurements, in this case, mean more that just experiments set up by people, it also includes any form of exchange of energy. Whenever there is an exchange of energy of any kind, the transaction must happen in space-time.

However, when there is no exchange of energy with a particle, then we have no way of knowing where it is or where it is going. And there is no evidence that quantum particles move through space-time to get from one place to another between measurements because we can only see locations in space when there are exchanges of energy.

I believe that what this is telling us is that space-time is only about transactions of energy. Classical objects act like they always exist in specific locations in space-time because they are always involved in transactions of energy.

The quantum nature of exchanges of energy means that there are lots of times, for an individual particle, when it is not involved exchanging energy because energy is never exchanged continuously.

Quantum theory says that quantum states don't exist in space-time, which is why we use Hilbert space to describe them mathematically. This leaves the question of what Hilbert space represents and what do quantum states represent? They describe mathematical dimensions that do not map to space-time directly. A growing number of physicists are now raising the possibility that they represent something real, but they do not exist in space-time.

In other words, it looks as if quantum states represent a reality that lies outside of space-time because quantum states represent influences that are not defined by exchanges of energy.

In fact, exchanges of energy appear to originate from quantum states, not the other way around. This is shown in the math by the exchange of virtual particles (or wave functions) between charged particles that create the attraction or repulsion that leads to exchanges of energy.

Quantum "Dots" are Quantum "Objects"

A quantum dot is a very small region of space or matter containing at most

one or a few electrons.

We have not talked about small or large --- but, by the name itself --- all quantum dots are quantum objects.

They are theoretically treated in the quantum-mechanical approach. Am I right?