Quantum Wave Inversion

[Edgard Neuman]

Hi,

I have this idea and I wonder if it's possible using to quantum theory :

When using sound waves, it's known  (I can't find an article about that but I read some) that we can reverse signals recorded from multiple microphones, to reemit synchronized waves (even though a complex medium) that peaks at the position of the previously recorded emiter, creating a virtual sound source. And we can even use the time-print given by the records (with some calculation) to generate any sound at this position.

So could the same process be used to create a converging probability wave of particle ? 

We would need a big number of devices that somehow leak a wave/particle in a specified direction (with a little propability) but synchronized and converging to a point where the sum of probability would excess 1, thus creating a real particle ex-nihilo. (yes, I already dream of the Star Trek replicator)

thank you for your answers

Edited July 11, 2018 by Edgard Neuman

[Markus Hanke]

3 hours ago, Edgard Neuman said:

synchronized and converging to a point where the sum of probability would excess 1

For a wavefunction to be physically meaningful, one of the conditions it has to fulfil is that it needs to be normalised:

[math]\displaystyle{\int_{-\infty }^{\infty}\psi^{*}\psi dV=1}[/math]

The squared norm of such a wavefunction can therefore never exceed 1 - this should be obvious, since such a concept as “more than 100% probability” does not make much sense.

3 hours ago, Edgard Neuman said:

thus creating a real particle ex-nihilo

This does not follow, and is not possible either way. 

Edited July 11, 2018 by Markus Hanke

[Edgard Neuman]

Thanks,

but still, since particles (of the same type of course, and it must be bosons) are indistinguishable, you can add several waves and so the probability on a given volume can go has high as you want...you are talking about the integral for one given particle.. but that's not the probability at a given location where you can simply have more than one particle.. in quantum physics, waves do add, and the probability is the square of the complex vector.. 
We can still manipulate the field to make the probability go more than 1 in a given location.. the all point of the idea is just to make a particle appear at a controlled location
(and yes, one of the emitter would then actually loose a particle, I never meant to break the conservation laws).. 

Edited July 11, 2018 by Edgard Neuman

[Markus Hanke]

9 hours ago, Edgard Neuman said:

so the probability on a given volume can go has high as you want

The probability cannot exceed 100%, which corresponds to you obtaining some particular measurement outcome with certainty. I think you may be confusing the probability amplitude (which is not constrained) with the square norm (which is always normalised to 1).

9 hours ago, Edgard Neuman said:

in quantum physics, waves do add, and the probability is the square of the complex vector..

The wave function is a probability density distribution (i.e. a probability amplitude), so yes, you can add them, and the amplitude can go as high as you want it to go. However, the square norm has to be normalised to 1 - this is called the normalisation condition, and is one of several fundamental requirements that a function must adhere to in order to qualify as a physically meaningful wave function in quantum mechanics.

Of course nothing will stop you from mathematically constructing some complex-valued function the square norm of which exceeds one - but by definition this will not be a physically meaningful probability amplitude.

9 hours ago, Edgard Neuman said:

the all point of the idea is just to make a particle appear at a controlled location

This just means that you find a particle in some small enough volume of space (i.e. roughly at a “point”) with certainty - meaning with 100% probability. The square norm of the wave function, integrated over that small neighbourhood, will be 1. 

Edited July 12, 2018 by Markus Hanke

[Edgard Neuman]

Thanks,

I see my mistake. Just in the not quantum physics case, if you add particle (with probabilities Pa and Pb) in a volume, the probability is that volume would be the probability of finding one or the other (or both), so it's P(a or b)=Pa+Pb-(Pa*Pb). I'm always talking about volumes, not points. 
But that doesn't make my idea wrong : if you superpose multiple waves, you can still manage to make a peak at some chosen location.. meaning the probability of finding a particle here gets high, no ? I mean, there is only one probability field for a particle type at the end.. the value is given by Feynman diagram.. The idea in the end is nothing magical really. What I really wonder is to what point you can control wave to make complex peaks.. 
The process for sounds is very powerful.. by reversing all records of a room with multiple mics, you kind of reverse all the waves at the same time and you recreate all the sounds emitted in that room..  
We can't "record" a quantum wave by classical ways, but maybe we can build a quantum device that preserve the waves in some way (isolated like in a quantum computer) and emit it backward

Edited July 12, 2018 by Edgard Neuman

[Markus Hanke]

13 hours ago, Edgard Neuman said:

if you superpose multiple waves, you can still manage to make a peak at some chosen location..

Yes, at least in principle.

13 hours ago, Edgard Neuman said:

meaning the probability of finding a particle here gets high, no ?

Yes, the probability can get high, but it can never exceed 100% (which represents “with certainty”).

[Edgard Neuman]

45 minutes ago, Markus Hanke said:

Yes, at least in principle.

Yes, the probability can get high, but it can never exceed 100% (which represents “with certainty”).

Yes I understood that. Thanks again.

I think the problem is the quantity "the probability of finding a particle at a particular point" is not appropriate (because of the "or" operation needed) . 
So the right quantity to use would be the average quantity of particle you would find in a volume (or even a point ?). This value can add properly and exceed 1. 
 

Edited July 13, 2018 by Edgard Neuman

[Markus Hanke]

13 minutes ago, Edgard Neuman said:

I think the problem is the quantity "the probability of finding a particle at a particular point" is not appropriate (because of the "or" operation needed) . 

What “or” operation? The probability is just the expectation value of a Hermitian operator.

14 minutes ago, Edgard Neuman said:

So the right quantity to use would be the average quantity of particle you would find in a volume (or even a point ?).

This problem is that this quantity is not one that observers agree on. The number of particles in a given volume of spacetime depends both on the state of motion of the observer who measures this, as well as the geometry of that volume of spacetime itself. 

[Edgard Neuman]

Quote

What “or” operation? The probability is just the expectation value of a Hermitian operator.

when you consider two particles in a volume, the probability of finding a particle at a position is the probability of finding one "or" the other.. 

Quote

This problem is that this quantity is not one that observers agree on. The number of particles in a given volume of spacetime depends both on the state of motion of the observer who measures this, as well as the geometry of that volume of spacetime itself. 

Yes but I'm talking of "volume" in a general way of set of position (where events take place) in the space you consider quantum physics is happening (might it be space time, Minkowsky space, hilbert space, or euclidian space)..  not a particular space extend in a single (RR is for special relativity in french) frame. 

Edited July 13, 2018 by Edgard Neuman

[studiot]

1 hour ago, Edgard Neuman said:

when you consider two particles in a volume, the probability of finding a particle at a position is the probability of finding one "or" the other.. 

 

Fine, now please show mathematically how you can correctly add the probabilities of finding each spearately to get a value greater than unity.

You are suggesting that if I take a control volume, V and introduce two balls sequentially into it, bouncing about at random then

The probability of finding the first particle in a specific part is therefore  [math]\alpha V[/math], and the second [math]\beta V[/math]

where alpha and beta are some fractions, less than or equal to unity.

Clearly if the control volume fraction of V is greater than one half then alpha plus beta will be greater than unity.

This is because the combined probability for your either ball in the volume is not simply alpha + beta.

Can you provide the necessary statistics?

 

 

 

[swansont]

6 hours ago, Markus Hanke said:

 This problem is that this quantity is not one that observers agree on. The number of particles in a given volume of spacetime depends both on the state of motion of the observer who measures this, as well as the geometry of that volume of spacetime itself. 

People do this, just not in a way that relativity is a problem. The observer is in the same frame as the device that holds the particles. 

[Markus Hanke]

2 hours ago, swansont said:

People do this, just not in a way that relativity is a problem. The observer is in the same frame as the device that holds the particles. 

True.
I sometimes have a tendency to think of things in the most general and wide-ranging way, often unnecessarily so.

[YoungBoysWithDreams]

I am not a university student. I am just in high school but am studying physics and chem. I am just sitting here wondering why do we have energy. I mean look at computers communication there is 0 and 1. on and off. Off will always be a granted but why is there an on. nothing has a purpose because for something "not to be real" makes more sense, because It is nothing (empty) there is no reason for it to exist. but for things to exist makes zero sense. 

So if energy can be off why do we have an on. such as a 1 and 0. our brains the same electrical pulse no electrical impulse = movement. Where does this energy come from?. people lack the understanding of nothing but, to be honest in physics its the only thing that makes sense. [X = 0]we don't have to even question why it equals nothing because nothing is nothing. but as soon as it x = 1 how does x have 1. 

I mean look at the 3rd dimension as a cube. then the 2nd dimension is a square. then the 1st a dot. but a dots a really small circle. not a square. again x =  1 doesn't make sense how did we get 1?

if everything started from nothing how can we turn it into something? but again how can we start with something because that makes 0 sense.  how can something just exist?  I see on seeker that they trying to find smaller and smaller particles, but how does that help. no matter how small we go we will find something smaller because there is no such thing as nothing if something exists. 

 

but then you think about it everything has energy nothing can ever not have any energy.  but 1 cant = 0. unless we live in a quantum state. where we between 2 dimension oscillating or collided. because the idea of these two living separately makes more sense then existing at the same time. 

 

I know I'm all over the place but that's the most sense I can make out of the whole idea of physics. I mean it makes sense with my idea of explosions and sound waves that these low energy objects can release a wave of energy. such the way the "big bang released everything else". like I said it in high school this is prob very wrong and very scifieeeee but not understand how something started when studying it makes you think why am i doing this.

[ali1382]

Well, 0 can't be 1, but it can be: 0=(5+4*9999999)*(9^2-81), so maybe the world and energy are the same, but more complicated.

[Mordred]

On ‎2018‎-‎07‎-‎19 at 9:08 AM, YoungBoysWithDreams said:

I am not a university student. I am just in high school but am studying physics and chem. I am just sitting here wondering why do we have energy.

we have energy to describe how much work a system or state can perform. Which is the definition of energy. (The ability to perform work). It takes work to change from a 1 to a zero on a computer for example.

Edited July 20, 2018 by Mordred

[studiot]

14 hours ago, Mordred said:

we have energy to describe how much work a system or state can perform. Which is the definition of energy. (The ability to perform work). It takes work to change from a 1 to a zero on a computer for example.

The post you replied to doesn't belong here but here

 

 

There was some kind of screw up in the system last night.

I blame Trump.

[StringJunky]

1 hour ago, studiot said:

The post you replied to doesn't belong here but here

 

 

There was some kind of screw up in the system last night.

I blame Trump.

No, it was a quantum wave inversion in action.