“The fateful slumber floats and flows
About the tangle of the rose;
But lo! the fated hand and heart
To rend the slumberous curse apart!”
The diagram below illustrates an interference pattern which is produced when a stream of particles , such as photons or electrons , are fired through two slits .
Using a single particle accelerator we would expect that the single particle would do one of three things :
i) Hit the barrier
ii) Pass through the upper slit
iii) Pass through the lower slit
Either way you would not expect to see the interference pattern , which should only appear when a series of different particles interact with each other as they exit the barrier .
Not true .
Let’s assume that a single particle passes through one of the slits , the interference pattern still appears , why is this ? It is as if the single particle has split into two and passed through both barriers , or even spookier , it is as if the single particle is in two places at once . This is quantum superposition . In quantum mechanics a particle can be in one , two , or maybe even several places at the same time , or maybe even none at all . Further , it is theorized that a particle may even exist in every variation of it’s state and position , until it is actually observed .
An interesting aspect of quantum mechanics is that when you try to measure whether the particle has split , or whether it is in one place or the other , the whole system collapses and the interference pattern does not appear . The act of attempting to measure where the particle is , or how it behaves , directly affects the whole system . Even looking at a quantum system can affect it , so how do you measure something if you do not even know where it is ? This disruptive effect is known as Heisenberg’s Uncertainty Principle , if anything it illustrates that we are more connected than we care to imagine .
To simplify this idea , imagine tossing a coin , looking away and letting it land , the coin can land on heads , tails , or even on it’s edge (unlikely , but possible) . Quantum superposition says that the coin now actually exists in all three states simultaneously , only when you look at the coin does the state of superposition collapse and the coin is revealed in a single position , i.e. heads , tails or on it’s edge .
Back to the Future
Recent research takes a different approach in that it measures a quantum system from both a forward perspective (preselection) and also take a retrospective approach (postselection) . The quantum system is presented with a specified outcome which can hopefully ‘measure’ where the particle superposition occurs . This is known as ‘Two-State Vector Formalism’ .
The image shows that the particle , in this case a photon , is in ‘some of the places some of the time’ , as opposed to all of the places all of the time . Which on the face of it does deflect from the theory that a particle does exist in all of it’s states at any given time .
What does this experiment and other similar experiments prove ? Not a lot really .
What it does show is that the act of choosing an outcome for the quantum system seems to affect the end result .
In real world terms it can be compared to selecting a result for a particular sports match ahead of the event , when the match ends , the result is exactly what you have previously predicted .
It may also hint at the possibility that what we imagine time to be in the real world , i.e. a linear concept unfolding in front of us , is something completely different in the quantum world .
The full article can be found at the link below :
A few related experiments can be found at the links below :
- Experimental demonstration of a quantum shutter closing two slits simultaneously
- The Case of the Disappearing (and Re-Appearing) Particle
The video below may help to further explain this .
Quantum mechanics promises to revolutionize communications and computing , it also promises to connect the two together via artificial intelligence .
It appears that God does play dice .
It also appears that there are organizations that want to play God at dice .
- Curiouser and curiouser as the Quantum Cheshire Cat appears
- Young’s Double Slit Experiment
- Two-State Vector Formalism (PDF)
Also related :
- NONLOCALITY AND ENTANGLEMENT
- Quantum Entanglement in Physics
- Quantum Superposition And Entanglement Explained
- Physicists find quantum coherence and quantum entanglement are two sides of the same coin
Further related :
- NASA Crashed Probe Into Dark Side Of The Moon, Then Returned To Take Pictures Of The Impact
- Laser communications set for Moon mission
- LADEE: NASA’s Moon Mission to Study Lunar Dust Secrets
- Quantum Entanglement: Love on a Subatomic Scale
- Quantum Communications at NASA (PDF)
- China Launches Relay Satellite for Mission to Moon’s Far Side
- What exactly is the ‘spin’ of subatomic particles such as electrons and protons?
- Quantum probes dramatically improve detection of nuclear spins
- Quantum teleportation of patterns of light
- Experimental Quantum Teleportation (PDF)
- Complete quantum teleportation using nuclear magnetic resonance
- Nuclear magnetic resonance
- Approximate Quantum Cloning with Nuclear Magnetic Resonance (PDF)
- Quantum Computing and Nuclear Magnetic Resonance (PDF)
- How Quantum Computers Work
- Quantum Computing Has Applications in Magnetic Imaging
- A New Spin on Quantum Computing: Scientists Train Electrons with Microwaves
- New Magnetic Resonance Technique Could Revolutionise Quantum Computing
- Quantum Game Theory & it’s applications
Further reading :
- Time’s Arrow Traced to Quantum Source
- Why the Many-Worlds Formulation of Quantum Mechanics Is Probably Correct
- Quantum Coherence and the Hidden Secret Behind Our Bodies
- Nature’s Mind: The Quantum Hologram
- Quantum Biology: Algae Evolved to Switch Quantum Coherence On and Off
- Birds measure magnetic fields using long-lived quantum coherence