Friday, April 27, 2007

Bionic eyes



Anyone of a respectable age remembers the six million dollar man. A man who was "rebuilt" using bionic parts that gave him super strength, hearing, and eyesight amongst other things. These days bionic parts are called neural prosthetics, they are devices that directly stimulate parts of the central nervous system or even the brain itself. The best known example is the cochlear implant that can restore hearing to the deaf by directly stimulating auditory nerves inside the ear.

There has also been some very limited success in restoring sight by implanting devices into the retina. Images from a camera are converted into electrical signals which are then used to stimulate nerve cells in the retina.

Researchers at Harvard Medical School have found another possible way to restore sight. Instead of implanting a device into the retina, they suggest implanting a device directly into the visual cortex. They have recently done this with monkeys who could "see" points of light when none were there. As the researchers sent signals into the monkey's brain the monkey would turn to look at the light that they "saw" but that wasn't in reality there.

Neuroprosthetics, though currently primitive (when compared to sci-fi standards), hold hope for many people and not just the hard of hearing or the visually impaired. For example, work is underway that has the goal of developing bionic limbs for amputees. There have already been several people who have received bionic arms which they control by thought (c.f. Luke Skywalker's arm). Other researcher are working on ways to connect brains directly to computers and even other brains, creating artificial telepathy or techlapathy as it has become known.

There is even a society of generally healthy people (transhumanists) who want implants to make themselves "better." They want x-ray vision, super strength, artificially enhanced intelligence and memory, etc. In other words they want to be rebuilt as bionic men and women. And if their brains are all connected to each, can anyone say "Borg collective?"

Here's the abstract of the research article on bionic eyes.

Wednesday, April 25, 2007

Planet discovered in star's Goldilocks zone



There has been a third planet discovered orbiting the star Gliese 581 in the constellation Libra. The planet is approximately 5 times as massive as the earth and is closer to its star than Mercury is to the Sun.

There have been over 200 exoplanets discovered so far, but most of them have been hot gas giants which are unlikely to support life, at least as we know it. However, Gliese 581 is a red dwarf type star, which means it is a lot cooler than the Sun, and this new planet is orbiting in the stars Goldilocks zone, not too hot - not too cold - but just right for water to exist in its liquid phase.

So if the planet is of the rocky-type, has water, and if its atmosphere is of the right composition, not too thick and not too thin, then it may be habitable. Those are pretty big ifs and planets like these are not thought to be rare but what is significant is that this planet is only 20.5 light years away from the Earth. This distance is large but not insurmountable.

Wednesday, April 18, 2007

Raise shields

Once outside Earth's protective magnetic field astronauts become exposed to dangerous radiation from the Sun. The Apollo astronauts were exposed to this radiation, called solar wind, on their short trips to the Moon and back. Fortunately for them, there were no major solar storms recorded during their missions. Until recently, not much had been done to tackle the problem of exposure to solar radiation. For example, current astronauts on the international space station have to retreat to a thick-walled room during times of increased solar radiation.

Looking towards the future, British scientists have announced plans to build a magnetic shield that would protect astronauts by deflecting dangerous radiation from the sun. The technology is similar to that currently used in experimental nuclear fusion reactors where a magnetic field is used to contain plasma. The proposed deflector shield would use the same magnetic field technology to keep solar radiation out. Such a shield could be deployed on spacecraft or on planets, and could be turned off when not needed.

This technology will be important to future space exploration, such as NASA's planned moon base or a NASA's planned trip to Mars. In both these missions, unprotected exposure to solar radiation could cause serious problems for the astronauts.

Deflector Shield (Star Trek Wiki)
BBC News Story

Sunday, April 15, 2007

Photosynthesis on other worlds

Research at the California Institute of Technology's Virtual Planet Laboratory suggests that if plant life exists on other planets the dominant color of photosynthesis could be yellow, orange, or even red instead of the usual green. The particular color would depend on the type of star(s) the planet which has plant life orbits and the planet's atmosphere, which filters the light. For example there is a bacteria on earth that uses infra-red light in photosynthesis because it lives in murky water where little to no visible light reaches.

This is good news for science fiction, where plant life has often been unimaginative, though H.G. Wells' depiction of red plant life in The War of the Worlds in 1898 is an important exception. Other sci-fi ecosystems of note include Harry Harrison's psychic plants in Deathworld and Alan Dean Foster's silicon based life in Sentenced to Prism.

Press release.

Tatooine like planets may be quite common

In science fiction most solar systems are portrayed as single-star systems, with planets orbiting a single star, much like as in our own solar system. Notable exceptions exist of course, maybe the most famous examples being the six-star system in Isaac Asimov's short story 'Nightfall,' and the double-star (binary) system of Tatooine (where Luke Skywalker grew up).

In reality, binary systems are more common than single-star systems and about one-in-four extra solar planets cataloged orbit around a single star in a binary systems where the stars are relatively far apart, about 1,000 AU. It was not known if planets would form in binary systems where the stars that are close together, about 1~3 AU. Recent observations however, suggest that in these systems planets will form more often than not, making Tatooine like planets a real possibilty.

NASA press release.