We are aware of the world around us as being composed of three spatial dimensions. Theoretical physicists of our time however have been dabbling with theories that postulate reality as being composed even higher dimensions. Einstein named "time" as being the fourth dimension in his "special relativity" theory. Later, "string theory" took up the number of dimensions to 10 and "M theory" pushed it up to 11. Imagining higher dimensions can be a bit unwieldy without walking through the steps that reach the higher dimensions.

I found a neat narrated animation at Imagining the Tenth Dimension website that starts from the 0th dimension and builds up to the 10th dimension with demonstrations of how it may apply and how we may perceive it. Check it out

I've been feeding my curiosity in Quantum Computation with works from the great pioneer in the field - Prof. David Deutsch. It is not that I like computers but because that the ideas behind quantum computation are so fundamentally profound and far-reaching that I just can't not keep an eye on it! Read up David Deutsch's paper Physics, Philosophy and Quantum Computation for a synopsis of the promises of quantum computation and the implications of quantum constructor theory. There are a couple of other interesting papers available on his site.

If you are all-excited and orgasmic about it and can't wait to bite your teeth into it then check out the "Introduction to Quantum Computation" lectures by David Deutsch. As the page says, you should be able to follow it easily if you understand what a vector space is and what eigenvalues of a matrix are.

I got reminded of Self Organising Maps(SOMs) at last week's Neurocomputation lecture. I learnt SOMs last year while on a craze to teach myself about neural nets. They are fascinating little buggers I tell ya!

The knowledge of SOMs had come in pretty handy earlier this year when I designed and programmed a blog analyzer/classifier intended to be contributed to the mvblogs.org project. The "classifier" part utilized SOMs to do the magic. However, sadly, I never got around to finishing an "analyzer" (which does the text and language processing) that I was happy with and soon enough my interest waned out and the effort died. I will probably tackle it sometime soon, now that my interest has been rekindled Anyway, onto SOMs...

What are SOMs?
Self Organising Maps, also known as Kohonen networks in honour of its inventor, are a very interesting type of (artificial) Neural Network. It features an input neuron layer that is directly mapped to all the output layer neurons - where the output neurons are represented as being arranged as a grid.

A SOM when presented with training data, is able to train itself in such a way that "similar" data is placed closed together on the grid. By "similar" I refer to the manner in which any number of the attributes of the input data can be represented on the output by mapping the variation of the attributes. Any type of data that can be broken down or converted to a vector of numbers so that it can be mathematically manipulated can be fed to the input of a SOM. Possible input data may include text blocks, books, images, surveys etc. This makes SOMs extremely powerful and useful as a tool for making a simple 2D/3D representation of highly complex, multi-dimensional data.

The algorithm for a SOM is quite simple and very elegant. If you are keen to learn more, try the paper "The Self Organising Map" by the creator Teuvo Kohonen himself. Alternatively, this simpler guide may be more accessible and a shorter read :p

SOM eye candy
One of the coolest demonstrations of an application of a SOM is color classification. In such a setup, a SOM is fed a set of colors - as vectors with components in RGB, CMYK or whatever representation we choose - and set to the task of "organizing" them. At the end of the run, the SOM has the colors all arranged neatly by (mostly) placing similar colors close to each other.

Here is a simple sample case where I fed a SOM a collection of 80 random colors.


I then set the SOM to churn and after 500 ticks the output has the output grid has the colors neatly arranged!


Interesting stuff eh?

Time travel is one of those sci-fi fantasies that had fascinated me since I was a very young kid. I reckon most people are fascinated by the idea as well but reject it as being impossible or utterly crazy. However, I for one, have always kept a hold on to the idea that time travel may indeed be possible sooner than never...

I found the link on Digg today to a documentary by the BBC titled "The World's First Time Machine". It follows research by Prof. Ronald Mallet on his quest to build the world's first working time machine - to attempt and succeed at the feat. He thinks that building and testing this machine would pave the way for solutions and answers to the puzzles and complexities involving time travel, including exploring the practical truths of the Grandfather Paradox.

- View the video at Google Video
- Download the video in AVI format

Prof. Mallet's paper "Weak gravitational field of the electromagnetic radiation in a ring laser" is a good read on the principles by which his time machine operates and the theory that goes with it.

I have no idea as to the validity of his claims but I would eagerly watch this quest for time travel. Let us hope there comes a message from the future when the machine is turned on, an event which is suggested in the documentary as being possible!

Enjoy.

This is a guide to becoming a techno rebel: a guide to becoming a radio pirate and raiding the silent airwaves with your own content. This is a follow up to my recent call for relaxing the grip on radio broadcasting in the Maldives.

One of the easiest transmitters to build is a FM transmitter. A basic low power transmitter can be assembled in a few hours, using a minimal set of equipment and components and best of all, it can be done without denting the wallet too much. I am going to describe how to build a very low power FM transmitter. Do not expect this to cover the entire country, an atoll or even an island - it surely will not. However, it will be able to transmit around a block (maybe more with a good antenna) which is more than enough to tread into the world of radio and let yourself be heard.

Notes on construction:
- You need basic familiarity with electronics to undertake this project. If you studied GCE O' level Physics (or A? level Physics) then you should be familiar with the basic knowledge to go ahead with the construction.
- You can build this using a variety of construction techniques. The preferred method would be using strip board or perf board however point to point wiring would work too. Have a look here for a quick intro to circuit construction methods. Strip boards ARE available in Male'.
- The components given below can be interchanged for a equivalent and values can be approximated. So go ahead and scrounge around broken electronic items for the required components - chances are you will find most of them in broken TVs, Radios and even some toys.

Components:
- 100 Ohm resistor ( brown black brown )
- 100k Ohm resistor ( brown black yellow )
- 15pF ceramic disc capacitor
- 5pF ceramic disc capacitor
- .001uF ceramic disc capacitor
- 1uF electrolytic capacitor
- BC548 or BC108 or equivalent transistor
- Length of insulated copper wire
- Two 1.5 Volt AA size batteries
- Audio jack

Schematic:


The tuning coil used is a length of the insulated copper wire wound around a small pencil about 6 times. The circuit can be tuned to the broadcast FM range by adjusting the coil appropriately. Turn on a FM radio and set it to the frequency you want this circuit to transmit at. Next, try squashing and/or spacing the coil turns until it is tuned to the desired frequency.

The audio can be fed to the transmitter via a tape player, a PC or even an Ipod. All that remains is for you to make your killer radio programs and broadcast it. Have fun!

Haha. I am still laughing. There had been a recent rumour, spread via email and SMS text messages here in Male' (and possibly the rest of Maldives as well) that Mars was coming so close to earth that it would be visible tonight to the naked eye almost as large as the full moon. The message had apparently been passing around quite fast and people were talking about it excitedly - even the Kasauti stuck housewives, the bling sporting I-am-so-cool youth littering Male' and even much of the rebels-without-cause political acivitists that make up the majority of this sad city seemed to chattering up about it. As I walked along the road tonight, I saw people looking up at the sky to grab a glimpse of this so-called spectacular event. Some had flocked out to road from the confines of their homes to get a better look. I even saw a man looking up eagerly into the sky with a set of binoculars!

However, the sad truth is this is all a hoax. Yes, you've been duped had you believed the whatever SMS or friend who told you about it. In fact, Mars came closest to earth in 2003 and at the time it was so close that the red dot that signifies Mars on the night sky outshined the brightest and largest stars in the sky - it even easily grabbed the attention away from Venus and Sirius that usually are visible the brightest on the Maldivian night sky. Technically, the planet was around 56 million km way from earth and would be closest it comes to planet earth in 60,000 years! The news was mentioned in popular media outlets. Read about the event from these articles at NASA, RedOrbit and BBC.

A bunch of my close friends and I watched the planet through my telescope back then and was in awe of the clarity with which the mysterious red planet appeared. The close proximity of the planet made it easy to view not only with the naked eye but was a total delight to witness with the aid of a telescope. I would have captured images but my telescope wasn't as cool as the one that President Maumoon supposedly has in his mini-observatory in Theemuge.

Anyway, if this hoax has ignited and interest in the stars and events taking place in the mostly dark canvas of the night sky, then let me point you to SkyMaps.com where they have a freely downloadable map of the sky for each month to make your viewing easy. The constellations, planets and stars are shown for easy spotting and the celestial events for the month are also listed on the maps. It surely can contribute toward an exciting educational evening with friends/lover as you try to spot the stars and map the heavens

Enjoy

Fresnel lens (pronounced fre-nel) are a very interesting variety of lens. They are a type of lens that enables the construction of large lens with short focal length while maintaining a low weight and volume in comparison to the traditional lens types. These lens are found in video projectors and are also a favourite science toy. They pack so much power in such a small and light package that a good quality fresnel lens of manageable size can easily be used to focus the sunlight so as to instantly vaporize/burn the many things that surround us. The careless handling of a fresnel lens on a bright sunny day can result in burns on the part of the body that the lens may accidently focus the beam on! Read this for some details on using a fresnel lens to melt asphalt and metal coins.

I had purchased an A4 size Fresnel lens earlier this year as part of my experimentation with building a projector on my own. I took out a left over lens today and had some "burning" fun with this (powerful) lens...