Saturday, February 17, 2007

Google Ate Blogger

Apparently I need a Google account to continue using blogger. Not too sure what all is involved in this. I don't really like Google, and stopped using them a few years ago because of their involvement in writing the censorship and spy software to police the Chinese internet. Whatever happened to "don't be evil"? That pissed me off, so I'll have to figure out what to do now.

Sight to the Blind!!!!!!

Let’s give it up for the Doheny Eye Institute, Southern California, and whoever else worked on this project. This sort of thing really lifts my spirits. These people have laid the groundwork for technology that will restore sight to the blind! Particularly people with problems related to the retina, including macular degeneration and retinitis pigmentosa.

They’ve developed an artificial retina implant that sends signals to the retinal nerves. This implant communicates by way of radio receiver to a small camera in a pair of glasses. So far, the resolution is pretty low, but I have confidence that if we can get mega pixels in a digital camera, they can figure out how to improve their system with time and development. They’re conducting medical trials now, for which thousands of people have already volunteered.

It reminds me a bit about the motor cortex reader implant that I read an article about a year ago (don’t have the links…). Apparently another group of researchers managed to read the motor commands sent out by the area of the brain responsible for directing our movement. They could get a monkey to manipulate an artificial arm, or people to manipulate mice on a computer screen.

Imagine how liberating this sort of technology will be for quadriplegics who cannot feel any part of their bodies, to be able to control something! Imagine how liberating it will be for the blind to see again! This sort of technological development is something I love to hear about. These guys deserve our investment and support.

Thursday, February 01, 2007

Question about Quantum Computing:

Okay, so I’ve sort of started to grasp what quantum computing is and how it works (after comments from some of my co-workers the other day). And I hate not understanding certain things – if things are explained to me and I still don’t understand, it bugs me to no end; and I in turn usually bug them to no end with more and more specific questions until I begin getting it at a basic level. I think my internet research to date has given me a preliminary concept though and I’m going to put it up and ask a few questions about it.

(Quantum physics stuff especially bugs me because people try explaining things like uncertainty or Bells inequality with buzzwords “multiple universes” and “superposition of concepts”, like “well sometimes it’s a particle and sometimes it’s a wave”. This doesn’t give me much of a picture of what’s going on, just a series of stories told about the topic. Someday I’m going to wade through an entire QP textbook, nasty field equations and all, just to keep myself sane when the topic comes up.)

Okay, well here is what I’ve gathered about how quantum computing works so far: You start with some data that you want to perform operations on. There is some process whereby several bits of information are encoded in one or more “quibit” vectors. These vectors can be imposed (method unknown) on the state of things like fluorine atoms suspended at extremely low temperatures, ect; where we can preserve quantum superposition of these states. (Quibits being quantum superpositions of on-states and off-states, the superposition can hold the whole vector (with analog probabilities assigned to each vector basis) worth of information, rater than just digital on or off states.)

Okay, so now you have many digital bits worth of information represented by the analog orientation of these quibit vectors. You can now perform other superposition operations between quibit vectors (addition, subtraction, and negation are apparently the limit. conditionals currently require us to collapse the state, reconvert the info, and digitally operate). You are effectively performing operations on all these different pieces of digital info simultaneously by adding the vectors.

Then you reconvert the quibits back into digital information so that you can see what you have. Actually, when you collapse the superposition of states of a quibit you just get either 1 or 0. But when you send the info through multiple times, you get 1 with probability a and 0 with probability b, {a,b} being the components of the resultant quibit vector, which can be re-converted back into digital info using the reverse of your encoding method.

(missing anything so far?)

Okay, so this brings me to some of my questions:

1. Maintaining superposition of states in fluorine atoms is a pain in the butt, requiring cool, yet bulky and expensive lab toys like near-absolute-zero temperatures and big NMRI machines to manipulate and read the state of the atoms. What would prevent you from doing the same operations with analog electric signals? If you have an analog signal a and b, you still have a 2d analog vector in which you can encode some number of digital bits and perform the same addition, subtraction, and negation operations. Furthermore, you don’t have to destroy the info (like you destroy quibits when you read them) to read an analog vector. One pass should give you the straight values of a and b, and thus the resultant vector.

2. QCs are supposed to allow us to solve currently infeasible problems much faster than conventional computers due to our ability to encode some arbitrary amount of information in quibits which can be passed through simultaneously. However, can you do something like matrix inversion without conditionals? Gaussian elimination requires you to look at what you have several times to see what the magnitude of the leading values are in the row are. Other iterative methods of inversion require matrix multiplication. (Can you “multiply” information within a quibit without having to collapse it to read how many times to add another quibit?)

To be continued.