Category: Secrets
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I know why the phase-locked wineglass sings
Here’s a neat party trick to impress your friends. Rub your finger around the rim of a wineglass and friction causes it, and any liquid it contains, to oscillate. When this vibration produces an audible pure tone, the wine glass is said to “sing”. Now Ana Karina Ramos Musalem and pals at the Weizmann Institute…
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Entangled atoms could “sense” quantum gravity
The notion of quantum gravity has mystified many physicists, not least because there has never been a prospect of measuring the fabric of the universe on this scale. That looks set to change. A few years back, a number of physicists suggested that atom interferometry might do the trick. The thinking was that two atoms…
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2D image created from a single pixel sensor
Ghost imaging is a curious phenomenon that has had numerous physicists scratching their heads in recent years. It works like this: take two beams of entangled photons and aim the first at an object. The transmitted photons from the object are then collected by a single pixel detector. The second beam is aimed at a…
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Solving stiction in MEMs devices
Microelectromechanical devices were supposed to change the world, so where are they? A few designs have leaked out, such as the accelerometers in air bags. But most have remained stubbornly, and literally, stuck in the lab. One of the troubling secrets about MEMs is that many designs simply don’t work because their moving parts become…
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Loop quantum cosmology: a brief overview
Abhay Ashtekar, a physicist at the Pennsylvania State University is one of the founders of loop quantum cosmology and also a part-time populariser of science. Today, he uses both of these attributes to produce a fascinating overview of loop quantum cosmology that non-specialists will find enlightening. A recommended read. Ref: arxiv.org/abs/0812.0177: Loop Quantum Cosmology: An…
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Quantum test found for mathematical undecidability
It was the physicist Eugene Wigner who discussed the “unreasonable effectiveness of mathematics” in a now famous paper that examined the profound link between mathematics and physics. Today, Anton Zeilinger and pals at the University of Vienna in Austria reveal this link at its deepest. Their experiment involves the issue of mathematical decidability. First, some…
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Steganophony–when internet telephony meets steganography
Steganophony is the term coined by Wojciech Mazurczyk and Józef Lubacz at the Warsaw University of Technology in Poland to describe the practice of hiding messages in internet telephony traffic (presumably the word is an amalgamation of the terms steganography and telephony). The growing interest in this area is fueled by the fear that terrorist…
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Anonymizing data without damaging it
If scientists are to study massive datasets such as mobile phone records, search queries and movie ratings, the owners of these datasets need to find a way to anonymize the data before releasing it. The high profile cracking of data sets such as the Netflix prize dataset and the AOL search query data set means…
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Cloaking objects at a distance
One of the disadvantages of invisibility cloaks is that anything placed inside one is automatically blinded, since no light can get in. Now Yun Lai and colleagues from The Hong Kong University of Science and Technology have come up with a way round this using the remarkable idea of cloaking at a distance. This involves…
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Breakthrough calculations on the capacity of a steganographic channel
Steganography is the art of hiding a message in such a way that only the sender and receiver realise it is there. (By contrast, cryptography disguises the content of a message but makes no attempt to hide it.) The central problem for steganographers is how much data can be hidden without being detected. But the…