Feeds

Scientists provide a measure of uncertainty

What would Heisenberg’s position be?

SANS - Survey on application security programs

A group of Canadian PhD researchers claim to have obtained information beyond the “Heisenberg limit” using a technique called “weak measurement”.

Heisenberg’s Uncertainty Principle limits the amount of information that can be known at the quantum level: the more you know about the position of an object, the less you can know about its momentum. As this article at Phys.org puts it, “any attempt to measure a particle’s position must randomly change its speed”.

The University of Toronto researchers have looked at measurements of a single property – polarization – and how to obtain information about polarization without disturbing it.

The answer is to use a technique described as “weak measurement”, in which the quantum system is probed with a very small interaction, so as to obtain information about it with a minimum of change. The idea is to try and work around the problem Heisenberg originally framed, the “observer effect”.

Lee Rozema, a University of Toronto PhD student and lead author of the study, designed an apparatus to measure a photon’s polarization, making a weak measurement of the photon before it was sent to the apparatus. That pre-measurement, they found, induced less disturbance than predicted by Heisenberg’s precision-disturbance relation.

By repeating the experiment many times, the researchers say, they were able to “get a very good idea about how much the photon is disturbed”.

As the American Physical Society notes, while Heisenberg’s statement of the minimum uncertainty any quantum system must possess is “rigorously proven”, doubt has been cast on his calculation of the observer effect in recent years.

There is a practical application to all of this. Systems like quantum cryptography use the precision-disturbance relation to decide whether or not a communication has been “sniffed” (so to speak). Work such as Rozema’s suggests that the mathematics used to decide whether or not a quantum channel is secure might have to be revised. ®

3 Big data security analytics techniques

More from The Register

next story
So, just how do you say 'the mutt's nuts' in French?
Vital linguistic question interrupts LOHAN spaceplane mission
95 floors in 43 SECONDS: Hitachi's new ultra-high-speed lift
Guangzhou skyscraper denizens to hold on to hats
Most Americans doubt Big Bang, not too sure about evolution, climate change – survey
Science no match for religion, politics, business interests
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
LOHAN and the amazing technicolor spaceplane
Our Vulture 2 livery is wrapped, and it's les noix du mutt
Liftoff! SpaceX Falcon 9 lifts Dragon on third resupply mission to ISS
SpaceX snaps smartly into one-second launch window
STEALTHY NANOROBOTS dress up as viruses, prepare to sneak into YOUR BODY
Cloaking techniques nicked from viruses tackle roadblocks on way to medical frontier
prev story

Whitepapers

Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.