Stories tagged communication

Mar
13
2010

Photon computing

Diamond nanowires emit photons: A Harvard-based team has manufactured a matrix of diamond nanowires with defects called nitrogen vacancies. When stimulated with green light, these defects emit one red photon at a time. Such a construct is promising for the new field of quantum computing
Diamond nanowires emit photons: A Harvard-based team has manufactured a matrix of diamond nanowires with defects called nitrogen vacancies. When stimulated with green light, these defects emit one red photon at a time. Such a construct is promising for the new field of quantum computingCourtesy Zina Deretsky, NSF

Most computers and communications rely upon controlling the flow of electrons. Such devices would be faster and more secure if they used particles of light (photons).
A research team led by Marko Loncar just published how a "diamond nanowire device acts as a nanoscale antenna that funnels the emission of single photons from the embedded color center into a microscope lens."

"This exciting result is the first time the tools of nanofabrication have been applied to diamond crystals in order to control the optical properties of a single defect," said Loncar.

Faster and more secure

Not only is communicating through optical fibers more efficient, there is no easy way for eavesdroppers to "tap the line".

"The resulting device may prove easy to couple into a standard optical fiber. This novel approach is a key technological step towards achieving fast, secure computing and communication." nsf.gov/news

Learn more about diamond-based nanowire devices

Digging deep into diamonds Harvard Gazette

Feb
04
2010

Pssst!: I think you would look just wonderful in a tiny hat! Also, watch out for ferrrets.
Pssst!: I think you would look just wonderful in a tiny hat! Also, watch out for ferrrets.Courtesy USFWS
According to a scientist at Northern Arizona University, prairie dogs may have the most complex non-human language. That means that this prairie dog (specifically, the Gunnison’s Prairie Dog) may linguistically exceed even dolphins, whales, non-human primates, and box turtles.

But I’ve watched prairie dogs before, and it doesn’t seem like they’ve got a lot going on. What do they even have to talk about?

My assumption would be that they mostly focus on how other prairie dogs would look dressed up in tiny clothes, and what sort of clothes they might wear, and if male prairie dogs would have to wear suits and female prairie dogs would have to wear dresses, or if any prairie dog would be allowed to wear a suit or a dress.

Apparently not.

The scientist, who has been studying prairie dogs for thirty years, says that the rodents have developed their sophisticated “bark” to warn the other members of their colonies about the specific details of approaching predators. The tiny sonic variations of each bark can contain information about what sort of animal is approaching, what color it is, and from which direction it’s coming.

Prairie dogs react to different predator species in different ways. For something like a coyote, they will retreat to the mouth of their burrows and stand up to watch the approaching animal. For a badger, on the other hand, they will “lie low to avoid detection.”

To test his hypothesis about the complexity of prairie dog barks, the scientist recorded barks associated with different predators in a variety of situations, and then observed the behavior of all the members of the colony after the bark was heard. He then replayed those recordings to other prairie dogs when there were no actual predators nearby, and found that they reacted in precisely the same way as the threatened animals.

It’s like if an axe murderer burst into a crowded gymnasium. Someone might shout, “Run! There’s an axe murderer at the door!” and everyone would run away from the door and try to get behind something axe-proof. If, then, you were to shout, “Run! There’s an axe murderer at the door!” into a crowded (but murderer-less) gymnasium, people might still run away from the door to get behind something axe-proof because of the specific information in the warning. It would be a different reaction than if you were to just scream, or if you shouted that acid was raining from the ceiling, or that the world’s biggest clown had was digging up through the floor.

It’s sort of the same with prairie dogs, really.

Jul
06
2008

The shrinking radio: Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley.
The shrinking radio: Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley.Courtesy Zettl Research Group

Tiniest radio yet

A fully integrated radio receiver, orders-of-magnitude smaller than any previous radio, was made from a single carbon nanotube (CNT).

When a radio wave of a specific frequency impinges on the nanotube it begins to vibrate vigorously. An electric field applied to the nanotube forces electrons to be emitted from its tip.

This nanotube radio is over 10,000,000,000,000,000,000 times smaller than the Philco vacuum tube radio from the 1930s.

The single nanotube serves, at once, as all major components of a radio: antenna, tuner, amplifier, and demodulator. (Berkely physics research)

See and hear a nano radio

Videos from an electron microscope view of the nanotube radio playing two different songs are linked below.

Oct
21
2007

A conceptual mock-up of the new phone: by the author.  (Original image courtesy of Wikimedia Commons)
A conceptual mock-up of the new phone: by the author. (Original image courtesy of Wikimedia Commons)
A new cell phone uses bone conduction to transmit sound to your inner-ear. So, now, instead of having to lift the thing all the way up to your ear, you can just press it to your jaw instead.

The conduction of sound through bone is part of the reason we all think our recorded voices sound so weird – they’re missing the resonance of our skull and jawbones. Using bone conduction for something like a cell phone should allow for the operator to hear and be heard better making calls in noisy environments.

Some potential issues occur to me. What about people who, like me, have beards insulating their jawbones? Are we to be left behind? Or what if we don’t want to look like this person? Some of us have enough social concerns with having to be seen holding a remote control to our heads every time we make a call (which may not be all that often, but still).

No doubt this has all already been considered by scientists.

Mar
27
2006


Humpback Whale: A Humpback Whale dives beneath the surface Courtesy NOAA

Scientists Ryuji Suzuki, John Buck, and Peter Tyack used information theory to prove that humpback whale songs have syntax--rules that govern the structure of language.

Like humans, the whales use a hierarchy of communication: they make sounds to build phrases that they can combine in different ways to create songs that last for hours.

The scientists wrote a computer program that breaks down the elements of the whales' songs (moans, cries, and chirps) and assigns a symbol to each one. Then they analyzed the structure of the songs.

Suzuki says,

"Information theory was the right choice because it allows one to study the structure of humpback songs without knowing what they mean."

Sight and smell are limited in marine environments, so sea mammals often use sound to communicate. During the humpback whale breeding season, all the males in a population sing the same song. And the song evolves over time.

Suzuki says,

"Humpback songs are not like human language, but elements of language are seen in their songs."