*Physical Review Letters*.

In physics there are two categories: classical physics and quantum physics. In classical physics, objects, e.g. a car or a ball, have a position and a velocity. This is how we classically look at our everyday world. In the quantum world objects can also have a position and a velocity, but not at the same time. At the atomic level, quantum mechanics says that nature behaves quite differently than you might think. It is not just that we do not know the position and the velocity, rather, these two things simply do not exist simultaneously. But how do we know that they do not exist simultaneously? And where is the border of these two worlds? Researchers have found a new way to answer these questions.

**Light on quantum mechanics**

“Our goal is to use quantum mechanics in a new way. It is therefore important for us to know that a ‘system’ really behaves in a way that has no classical explanation. To this end, we first examined light,” explains Eran Kot, PhD-student in the research group, Quantum Optics at the Niels Bohr Institute at the University of Copenhagen.

Based on a series of experiments in the quantum optics laboratories, they examined the state of light. In classical physics, light possesses both an electric and a magnetic field.

“What our study demonstrated was that light can have both an electric and a magnetic field, but not at the same time. We thus provide a simple proof that an experiment breaks the classical principles. That is to say, we showed light possesses quantum properties, and we can expand this to other systems as well” says Eran Kot.

**Classical and non-classical mechanics**

The aim of the research is both to fundamentally understand the world, but there is also a practical challenge in being able to exploit quantum mechanics in larger contexts. For light it is no great surprise that it behaves quantum mechanically, but the methods that have been developed can also be used to study other systems.

“We are endeavouring to develop future quantum computers and we therefore need to understand the borders for when something behaves quantum mechanically and when it is classical mechanics,” says professor of quantum physics Anders S. Sørensen, explaining that quantum computing must necessarily be comprised of systems with non-classical properties.

**Explore further:**
Pure mathematics behind the mechanics

**More information:**
prl.aps.org/abstract/PRL/v108/i23/e233601

## CWonPhysOrg

## Origin

## JES

## Origin

## ryggesogn2

## antialias_physorg

Mesurement and reality trumps the human need for stuff to fit to analogies every time.

## Moebius

## antialias_physorg

The mode of measurement is irrelevant for this (the pgysics behind the Uncertainty Principle is independent of measurement apparatus types)

It's due to the two variables (e.g. impuslse and loaction) being conjugate variables (you have to take do a fourier transfrom to get from one to another). A localized entity in one space is completely delocalized in its fourier transformed space.

What you are thinking of is the 'observer effect' (i.e. that some interaction must take place between the measured entity and the observer to convey the information from the former to the latter). The Uncertainty Principle, however, does not depend on the observer effect.

## andrew_hughmann

## antialias_physorg

There are a number of such conjugate variables we know of. Speed(impulse) and location, action and angular momentum, energy and time...

## geokstr

And what we don't even know we don't know no doubt dwarfs what we simply don't know.

## Terriva

The only reason, why proponents of mainstream physics pretend, these simple analogies cannot be used for explanation of quantum mechanics is, they point clearly to the aether model, which was misinterpreted with mainstream physics before years and now the physicists are trying not to lost their face (and social credit) before layman publics. It's really as simple, as it is.

## Terriva

## Lurker2358

In fact, when you detect the kinetic energy of a cosmic ray particle striking a detector, it is only logical that you MUST know both the position and the kinetic energy.

If you know the kinetic energy, you know the velocity, based on parameters of identifying the particle type that struck the detector you can find the particle's rest mass, and therefore calculate it's velocity backwards using kinetic energy formula.

So I continue to disagree with this claim in QM.

The position is absolutely forced, because it's at a precise location on the detector, and the velocity is recoverable by taking kinetic energy of impact, and with a few subsequent measurements you can identify what type of particle it was, gives rest mass.

Ek = (1/2) mv^2

## julianpenrod

For those who understand what's around them, the claim of not being able to monitor the electric field andthe magentic fields of a photon simultaneously is questionable in the extreme. The description of a light wave, actually, is a pair of coordinated oscillating electric and magnetic fields. The oscillating electric field gives rise to the magnetic field. But, at the same time, the oscillating magentic field gives rise to the oscillating electric field! In other words, the electric field creates the magnetic field that creates the electric field which vcreates the magentic field! Because they are not separate values in Heisenberg's uncertainty inequality, it's questionable if you could view one but not be able to view the other.

## vacuum-mechanics

This is the familiar conventional way explanation for propagation of light wave. But it seems impossible, the reason because both electric and magnetic field were created at the same time, and this will contradict to the principle of causality! May be this unconventional view could give some hint.

http://www.vacuum...id=21=en

## julianpenrod

## antialias_physorg

Because what you're measuring when you measure rate of change is two positions and two times (initial position/time and final pÃ¼osition/time) from which you compute velocity.

For microscopic entities that doesn't work because your initial measurement interacts with the particle and changes its velocity/direction/position/whatever...so that your final measurement will be off.

So what you do instead is you measure the impulse (which is velocity times mass) when the entity strikes a detector. Knowing the mass you can calculate the velocity (without knowing the position exactly). Conversely you can make measurements of the position (using 'which way' detectors) without knowing the speed.

## Lurker2358

But that's what I said in the second half of the post.

If you know "where" the particle struck on the detector, and you also know it's kinetic energy, then you in fact do know both it's position and velocity at the same time.

The claim is BS...

## Lurker2358

Causality need not be flawed at all.

Many oscillating systems exist in nature. Creating an oscillating system from scratch does not in any way violate causality.

to illustrate, research the little 2-d game "Life," and consider the "kite" configuration. You can create any "Kite" configuration from scratch, and then if you follow the rules and run the game forward a few rounds, then it will oscillate, changing it's orientation, but always existing.

Perfect example of two or more states oscillating between one another, or being co-dependent on one another, and yet in no way violating causality.

Try it.

"There's no practical us for Radio." - Lord Kelvin.

Just remember that. Even brilliant people make absurd mistakes. one day so much we think we know will be vain.

## Smashin_Z_1885

S.Z. 5 14' -1908

1885

1840 Aug. 22

## Smashin_Z_1885

The music; however, is never discovered.

S.Z.

## antialias_physorg

en.wikipedia.org/wiki/Shot_noise

Note that shot noise is not a factor of how good your detector is (i.e. you can't reduce it, no matter what technica tricks you apply*) but is a fundamental distribution due to the uncertainty principle.

* you can go as low as the uncertainty limit, however, in 'squeezed' states.

http://en.wikiped...nt_state

## Anda

U are the only one in the world that understand quantum behaviour (it's so simple to u).

Why these morons haven't give u yet the Nobel prize you deserve... It's a global conspiration!

## Terriva

## Terriva

## Deesky

You must be operating under the Dense Brain Model (DBM), which exhibits both microscopic intelligence and macroscopic stupidity.

## Noumenon

You have to be careful to define the detector you're speaking of precisely. For example, in bubble chambers, entire paths of subatomic particles can be obervered and their momentum can be determined given their curvature in a magnetic field. This does not violate the uncertainty principal.

These bubbles are in the macroscopic scale, far larger than the product of uncertainty in position and momentum for a specific point.

## Noumenon

## Origin

## Origin