Month: March 2011

1000x Bandwidth

Stealthy radar systems and the ability to transmit large amounts of data over long distances are a step closer thanks to a technique that could improve the efficiency of modern optics by 1000x. Traditional methods of transmitting data, such as fiber optics or laser-based radar, require 100 photons to transmit 1 bit of data. Now a team can transmit 10 bits on 1 photon – a 1000x improvement. The researchers exploit a phenomenon known as entanglement, in which the quantum state of one photon is linked to that of another, regardless of how far apart they are. Once created, each entangled pair of photons is separated by passing a laser beam made up of them through a filter made from a nonlinear crystal. This splits the beam in 2 so that each exiting beam contains 1 photon of an entangled pair.

4th domain of life?

The researchers analyzed metagenomic data and used them to search the Global Ocean Sampling (GOS) Expedition dataset for novel lineages in 3 gene families commonly used in phylogenetic studies: trees that use small subunit ribosomal RNA, recA, and rpoB genes — highly conserved genes that appear in nearly all organisms, including the domains of prokaryotes, the bacteria, and archaea. They found some deep branches in the recA and rpoB phylogenetic trees that might represent viral genes. However, they acknowledge that the novel sequences possibly come from a new 4th major branch of cellular organisms on the tree of life.

not found in a petri dish or in nature but by trawling dna. there’s also

viruses make up the majority of the genetic information on the planet, more than the genetic information of all other species of life combined.

40% of the DNA in your gut is from an unknown domain of life. the notion of biological dark matter means there might be a 4th4th-domain-of-life domain of life.

Beyond the Heisenberg limit

Assuming that the particles interact with the object, but not with one another, the accuracy of such measurements grows in proportion to the number of particles in the beams, N. By allowing such particle interactions, scientists have now demonstrated a way to break this so-called Heisenberg limit. They used a beam of photons to measure the small magnetic field produced by a gas made up of 1m ultra-cold rubidium atoms. Normally, the spin of each photon would rotate by a certain amount, thanks to its interactions with the magnetic field of the atoms. But the frequency of the photons was chosen so that the photons also interacted with each other when they were in the gas, so that the presence of one photon altered the way a second behaved. These interactions led to a measurement accuracy that grew in proportion to N3/2 – greater than Heisenberg’s limit

i wish i understood this better, but how is that possible?

Symmetry holds

The dynamics of a physical system is linked to its phase-space geometry by Noether’s theorem, which holds under standard hypotheses including continuity. Does an analogous theorem hold for discrete systems? As a testbed, we take the Ising spin model with both ferromagnetic and antiferromagnetic bonds. We show that—and why—energy not only acts as a generator of the dynamics for this family of systems, but is also conserved when the dynamics is time-invariant.

expanding the rules of symmetry beyond physics to cs, economics etc

Veggie Burgers

“I just think it’s important to accommodate everybody. And I don’t think somebody should feel like they’re eating an inferior burger. If you’re going to do a veggie burger, it should have that richness and mouth feel and overall texture. When you pick it up, it should eat like a burger.”

veggie burgers coming of age

House Music

Soundscapes for every life situation

Why have a housemate when you can simply listen to endless loops of air-conditioning units, refrigerator hum, distant TV voices, pet sounds, keyboard clacking, footsteps over hardwood floors, and more? The specially curated Household Collection has it all (almost), including someone “handling a wallet,” “peeling a rubber glove off,” and “opening a bedroom door.” There’s also Household Collection 2.

The Information

The Information isn’t just a natural history of a powerful idea; it embodies and transmits that idea, it is a vector for its memes (as Dawkins has it), and it is a toolkit for disassembling the world. It is a book that vibrates with excitement, and it transmits that excited vibration with very little signal loss. It is a wonder.

A history of information theory. How civilization acquired software. Very interesting read.

Acclaimed science writer James Gleick presents an eye-opening vision of how our relationship to information has transformed the very nature of human consciousness. A fascinating intellectual journey through the history of communication and information, from the language of Africa’s talking drums to the invention of written alphabets; from the electronic transmission of code to the origins of information theory, into the new information age and the current deluge of news, tweets, images, and blogs. Along the way, Gleick profiles key innovators, including Charles Babbage, Ada Lovelace, Samuel Morse, and Claude Shannon, and reveals how our understanding of information is transforming not only how we look at the world, but how we live.