Watch a swarm of 1000 mini-robots assemble into shapes - tech - 14 August 2014 - New Scientist

Watch a swarm of 1000 mini-robots assemble into shapes - tech - 14 August 2014 - New Scientist: To do the assembling, the desired end shape is first transmitted to all the robots and then four stationary robots are positioned by hand to mark the shape's starting point. Next, some of the robots start to shuffle until they reach a place-holding robot and then fan out from that point to stop in the right place. Each robot can only communicate with the others nearby. Successive robots build up the shape by stopping near the robots already in place. It can take about 12 hours for 1000 robots to fill in a pattern.

How bird flocks are like liquid helium | Science/AAAS | News

How bird flocks are like liquid helium | Science/AAAS | News: Using tracking software on the recorded video, the team could pinpoint when and where individuals decide to turn, information that enabled them to follow how the decision sweeps through the flock. The tracking data showed that the message to turn started from a handful of birds and swept through the flock at a constant speed between 20 and 40 meters per second. That means that for a group of 400 birds, it takes just a little more than a half-second for the whole flock to turn...

The team proposes that instead of copying the direction in which a neighbor flies, a bird copies how sharply a neighbor turns...

Interestingly, Cavagna adds, the new model is mathematically identical to the equations that describe superfluid helium.

Meet the electric life forms that live on pure energy - life - 16 July 2014 - New Scientist

Meet the electric life forms that live on pure energy - life - 16 July 2014 - New Scientist: Unlike any other living thing on Earth, electric bacteria use energy in its purest form – naked electricity in the shape of electrons harvested from rocks and metals...

First they measure the natural voltage across the sediment, before applying a slightly different one. A slightly higher voltage offers an excess of electrons; a slightly lower voltage means the electrode will readily accept electrons from anything willing to pass them off. Bugs in the sediments can either "eat" electrons from the higher voltage, or "breathe" electrons on to the lower-voltage electrode, generating a current. That current is picked up by the researchers as a signal of the type of life they have captured...

"This is huge. What it means is that there's a whole part of the microbial world that we don't know about..."

Muscle-powered bio-bots walk on command | News Bureau | University of Illinois

Muscle-powered bio-bots walk on command | News Bureau | University of Illinois: The new bio-bots are powered by a strip of skeletal muscle cells that can be triggered by an electric pulse...

“Skeletal muscles cells are very attractive because you can pace them using external signals,” Bashir said. “For example, you would use skeletal muscle when designing a device that you wanted to start functioning when it senses a chemical or when it received a certain signal. To us, it’s part of a design toolbox. We want to have different options that could be used by engineers to design these things.”

The design is inspired by the muscle-tendon-bone complex found in nature. There is a backbone of 3-D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint. Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature | Science | WIRED

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature | Science | WIRED: Turing called this the reaction-diffusion process, meaning that it’s driven by reactive molecules that can diffuse between cells. He called these molecules “morphogens”...

...a team of scientists based at Brandeis University reproduced the system Turing envisioned...

If Turing’s theory was right, then the population of cells would ultimately assume one of six different patterns...

In fact, this is mostly what the team found — they saw five of the six predicted patterns; but they also found a seventh pattern that Turing had not predicted....

Muscles act as metamaterials due to collective behavior, physicists show

Muscles act as metamaterials due to collective behavior, physicists show: Upon further search for possible mechanisms of negative stiffness, scientists in a new study have found that biological muscles exhibit a mechanical response that also qualifies them as metamaterials: when a tetanized (maximally contracted) muscle is suddenly extended, it comes loose, and if it is suddenly shortened, it tightens up...

Quite surprisingly, the cooperation at the nanoscale in muscles was found to be similar to magnetism; moreover, the critical point at which muscles seem finely tuned to perform near is, in this case, a direct analog of the ferromagnetic Curie point.

Physicists Create Crystals That Are Nearly Alive

Physicists Create Crystals That Are Nearly Alive: The researchers developed self-propelled particles that would turn on in response to blue light. When the light is on, the randomly swimming particles collide and cluster. A chemical reaction set off by the light causes the particles to crystalize. When the light turns off, the particles stop and split apart...
Palacci and Chaikin are now working on a particle that has a metabolism and can self-replicate, but lacks mobility.

First Toy Multiverse Created in a Laboratory, Say Physicists

First Toy Multiverse Created in a Laboratory, Say Physicists: Cobalt is ferromagnetic so the nanoparticles tend to become aligned in a magnetic field. In fact, if the density of nanoparticles is high enough, the field causes them to line up in columns. When this happens, the nanocolumns form a metamaterial which is mathematically equivalent to a 2+1 Minkowski spacetime...


The secret here is to keep the density of nanoparticles just below the threshold required to form nanocolums. That’s just over 8 per cent of the fluid by volume in this case. When that happens, natural variations in the density cause nanocolumns to form in small regions of the liquid. In effect, tiny universes are leaping in and out of existence. Smolyaninov and co can even “see” these universes by their effect on polarised light passing through the fluid.

That’s a fascinating result that demonstrates the potential of self-organisation to create metamaterials.

Physicist Derives Laws of Thermodynamics For Life Itself

Physicist Derives Laws of Thermodynamics For Life Itself:  His idea is to examine every combination of states that are possible in this box and to consult an omniscient microbiologist about whether each state represents a bacterium or not. In that way, it ought to be possible, at least in principle, to gain an idea of the statistical physics involved.

Next, he asks the microbiologist to take another look at the box after a period that is roughly equivalent to the time it takes for bacteria to divide...

This sets an important bound on what is thermodynamically possible in this system: in effect, England derives the second law of thermodynamics for the system...

Giant living power cables let bacteria respire

Giant living power cables let bacteria respire: IT IS the ultimate in subsea communications: bacteria living in sulphurous mud beneath the seabed respire by transforming themselves into long, insulating cables and shuttling electrons from one to another. This phenomenon has now been imaged for the first time, allowing us to see how some microbes pull off such a feat.

Some bacteria get energy by oxidising the hydrogen sulphide gas in the sediment on the ocean floor. Because there is no oxygen in the sediment to accept the electrons that are produced, bacteria such as Geobacter grow tiny filaments along which the electrons travel until they reach the oxygen in the seawater. This allows the respiration reaction to be completed.

...They found that individual bacteria, despite being only 3 to 4 micrometres long, are capable of organising themselves into giant power cables made up of several thousand bacteria. These cables can stretch to around 1 centimetre in length...

As the bacterial cells divide, the team found, they remain trapped end to end inside an ever-growing cable made up of their outer membranes. This sheath has internal fibrous ridges running along its length...

The images show the extent of the bacteria-communications network - a cubic centimetre of sediment can contain up to 1 kilometre of compacted cable...

Quantum Horse Races and Crystals of Light

Quantum Horse Races and Crystals of Light: Bloch’s team and others bring them to heel by cooling them to a temperature of nanokelvins and pouring them into an optical lattice, which, depending on your poetic frame of mind, you might call an optical egg crate or a crystal of light... The atoms are spaced perhaps 400 nanometers apart, so they reach a density of about 100 trillion atoms per cubic centimeter—which is a lot of atoms per cubic centimeter, but still only about a hundred-thousandth the density of hydrogen gas at room temperature and pressure. So these systems let physicists explore a domain they seldom otherwise enter, a frigid, sparse realm where quantum is king...

There are all sorts of other fun experiments you can do. Last year, Bloch’s team tracked the insulator-superfluid transition and showed that the system goes through a “hidden” phase of matter—a subtly patterned arrangement that conventional theory doesn’t capture...

Yet another experiment touches on the fundamental question of what determines the speed of events in the world... They began with an insulator, dialed up the interaction energy, and watched the atoms start to self-organize. A wave of activity spread though the system at twice the speed of sound. What governed the velocity was that atoms did not passively roll on the wave, but actively contributed to it. Some quantum gravity theorists have speculated that the speed of light represents the Lieb-Robinson bound of some underlying quantum system out of which space and time emerge.

Tiny Kilobots to go on sale

Tiny Kilobots to go on sale: Along with its lithium-ion battery and rigid legs, each Kilobot incorporates an LED bulb, two motors (which vibrate the legs), a wide-angle infrared transceiver, and a microcontroller. An unlimited number of the little guys can be programmed via a computer-linked overhead infrared controller in under 40 seconds, and each have the ability to act autonomously, based on the parameters of that programming.

Honeybee anti-waggle song tells others to buzz off - life - 18 September 2011 - New Scientist

Honeybee anti-waggle song tells others to buzz off: By setting up good and bad nest sites, he found that scouts that favoured a particularly good site "beeped" other dancers, butting them and making high-pitched sounds. This made the other scouts dance less, and boosted the popularity of the preferred site,

Life-like cells are made of metal - New Scientist - New Scientist

Life-like cells are made of metal: "I am 100 per cent positive that we can get evolution to work outside organic biology," says Lee Cronin (see photo, right) at the University of Glasgow. His building blocks are large "polyoxometalates" made of a range of metal atoms – most recently tungsten – linked to oxygen and phosphorus. By simply mixing them in solution, he can get them to self-assemble into cell-like spheres.

Evolving software inspired by natural selection | Santa Fe Institute

Evolving software inspired by natural selection | Santa Fe Institute: In effect, evolutionary computation starts with a glitchy program, creates a group of slight variations on the original, and keeps the best variations as part of the next generation of the program. Then, repeat until the software does what it’s supposed to do...
Evolutionary computation needs a few additional tricks to make it scalable, but unlike other approaches it works for a wide range of programs, and it’s surprisingly fast. The researchers looked at 16 programs and about 120,000 lines of code with a range of problems from infinite loops to buffer overflows. They found they could repair a program in under six minutes, on average. Humans would take considerably longer -- they would “at least have to read the code” first, Forrest says.

DNA Origami Revolutionizes Metamaterial Manufacture - Technology Review

DNA Origami Revolutionizes Metamaterial Manufacture - Technology Review: The idea here is to cover gold nanoparticles with short strands of single strand DNA. At the same time, the complement of this strand is built into a bigger DNA structure called a scaffold. When the nanoparticles are placed in solution with the DNA scaffold, the complementary DNA strands bond together, attaching the nanoparticles to the scaffold...
Kuzyk and co have used this process to bind nine gold nanoparticles just 10nm across to strands of DNA, forming a helical shape. So the particles form the steps in a tiny spiral staircase...
The result is a fluid that takes on the optical properties of the helical nanoparticle structures. Any circularly polarised light travelling through the spiral will excite electronic waves called plasmons on the surface of the gold nanoparticles.

First life: The search for the first replicator - New Scientist - New Scientist

First life: The search for the first replicator: Sutherland was being deliberately messy by including the phosphate from the start, but it gave the best results. That's encouraging: the primordial Earth was a messy place and it may have been ideal for making nucleotides. Sutherland now suspects there is a "Goldilocks chemistry" - not too simple, not too complex - that would produce many key compounds from the same melting pot.

"Sutherland had a real breakthrough," Holliger says. "Everyone else was barking up the wrong tree."

RNA reactor could have served as a precursor of life

RNA reactor could have served as a precursor of life: "Using computer simulations, the scientists analyzed a scenario in which a hydrothermal RNA reactor emerges with the ability to perform intermolecular information transmission. The scene begins inside porous rocks on the sea floor, where strong temperature gradients produce thermal convection, and the convective flow transports molecules inside the narrow pores. Due to temperature variations, nucleotides in the pores accumulate in a small region and randomly form bonds with one another. Through folding and hybridization, the polynucleotides can form longer sequences, eventually resulting in RNA strands."

Kilobots bring us one step closer to a robot swarm

Kilobots bring us one step closer to a robot swarm: These small and simple robots are about the size of a US quarter that moves around on a set of vibrating legs. These small robots are able to communicate with each other by blinking lights mounted on their cases. While each individual unit may not seem that advanced or impressive the real impact is what happens when the robots work as a system.

[1104.3152] Polyethism in a colony of artificial ants

[1104.3152] Polyethism in a colony of artificial ants: We explore self-organizing strategies for role assignment in a foraging task carried out by a colony of artificial agents. Our strategies are inspired by various mechanisms of division of labor (polyethism) observed in eusocial insects like ants, termites, or bees. Specifically we instantiate models of caste polyethism and age or temporal polyethism to evaluated the benefits to foraging in a dynamic environment. Our experiment is directly related to the exploration/exploitation trade of in machine learning.