Friday, June 02, 2006

HealthFirst-Repairing humans

By Leslie LoBue
(05/18/06)-- Over the years, we've heard miraculous stories about people getting artificial arms, legs, even hearts.
Some doctors say they can create artificial brains, or at least brain parts, that may help millions of people with diseases like Alzheimer's, Parkinson's, and epilepsy.
The future of the human race is about to take a turn.
"I think all human beings have wanted to be better than well. we have always wanted to transcend the limitations of the human condition," said James Hughes, the executive director of the World Transhumanist Association.
Hughes believes the world is headed for a superhuman future. "We have continued to invent new technologies to extend the reach of the human body.  New tools and new ways of modifying the way the body works."
In Los Angeles, neuroscientist Theodore Berger has developed the first artificial brain part - a hippocampus to help people with Alzheimer's form new memories. "There's no reason why we can't think in terms of artificial brain parts in the same way we can think in terms of artificial eyes and artificial ears," Berger said.
Information would come into the brain the same way, but would be re-routed to a computer chip, bypassing the damaged area of the hippocampus.  "What we're hoping to do is replace at least enough of that function, so there's a significant improvement in the quality of life."
The technology could also help stroke, epilepsy and Parkinson's patients.
At the medical college of Wisconsin, Doctor Jay Neitz  is also on the super-human frontier. "Since we are human beings and we like to try new things, we could say 'Wow, wouldn't it be cool if we had a whole other dimension of vision?'"
Primates and humans have three photo-receptors and can see four basic colors - red, green, blue and yellow. Here's a newsflash: Birds, fish and reptiles have four photo-receptors.
"It is clear that it does allow them to see things that we cannot see. they must have this whole extra dimension of color that we miss out on."
Neitz is studying gene therapy to give humans that extra dimension. By injecting modified genes directly into the eyes of colorblind monkeys, he expects to change their world. "It's hard to imagine that you would even know what it would be like to have this extra dimension of vision," he said.
Neitz says we could see ultraviolet, infrared and all the new shades we'd get by combining them. "I personally, I like the idea of being able to make ourselves better."
"I think this is an intrinsic part of human nature, of the human condition that we see that we are limited. we live in a limited world, and we are trying to push beyond those limits," Hughes said.
Now, it's up to technology to see how far beyond  those limits we can go.

Nanotubes Might Not Have the Right Stuff

By Bill Christensen

posted: 02 June 2006
06:27 am ET

Scientists and science fiction fans alike have big plans for carbon nanotubes; it has been hoped that a cable made of carbon nanotubes would be strong enough to serve as a space elevator. However, recent calculations by Nicola Pugno of the Polytechnic of Turin, Italy, suggest that carbon nanotube cables will not work.
American engineers worked on the problem in the mid-1960's. What type of material would be required to build a space elevator? According to their calculations, the cable would need to be twice as strong as that of any existing material including graphite, quartz, and diamond.
Science fiction writer Arthur C. Clarke recognized the materials problem; his ingenuity was equal to the task of creating just such a material. In his excellent 1978 novel The Fountains of Paradise, he thought up a special form of carbon, something called a "continuous pseudo-one dimensional diamond crystal," to serve as the cable material. To the delight of sf fans and aerospace engineers, Japanese researcher Sumio Iijima (at NEC) discovered carbon nanotubes, which are one-dimensional carbon fibers exhibiting strength 100 times greater than that of steel at one sixth the weight, and high strain to failure.
In something of a "downer" for space elevator fans, Pugno has calculated that inevitable defects will greatly reduce the strength of any manufactured nanotubes. Laboratory tests have demonstrated that flawless individual nanotubes can withstand about 100 gigapascals of tension; however, if a nanotube is missing just one carbon atom, it can reduce its strength by as much as thirty percent. Bulk materials made of many connected nanotubes are even weaker, averaging less than 1 gigapascal in strength.
In order to function, a space elevator ribbon would need to withstand at least 62 gigapascals of tension. It therefore appears that the defects described above would eliminate carbon nanotubes as a usable material for a space elevator cable. Pugno will publish his paper in the July edition of Journal of Physics: Condensed Matter. Nanotube enthusiasts counter that ribbons made of close-packed long nanotubes would demonstrate cooperative friction forces that could make up for weaknesses in individual nanotubes.
Read more about Arthur C. Clarke's one-dimensional diamond crystal; in Carbon Nanotube Ribbon for Space Elevator a method of creating meter-long nanotube ribbons is described. A robotic lifter that would traverse a space elevator ribbon has also been tested. Read more about the current controversy at Nature.

I think we will be able to overcome the defect problem, at least to the point where we will be able to create the Elevator.  I think the benefits we would reap from this will drive us to do so no matter the cost.