Occam's Machete

Cosmologists have long tried to come to grips with the implications of the expanding universe.  They follow the arrow of time back to what they assume must be a single point from which everything expanded.  They also assume that something happened all thos billions of years ago and everything afterward is a result of that single event.  I’m not sure why, in fact, those assumptions don’t seem logical to me.  Lately explanations for the Big Bang have pointed at possible interactions between parallel universes.  Why would a collision between two universes happen in a single point or at a single moment for that matter?

This might seem idle speculation; of the sort String Theorists are often accused, if it weren’t for recent observations of the cosmic background radiation.  Calculating the distribution of energy in the universe based on what we see in the microwave background recent research shows a lopsidedness amounting to 10%.  In other words one half of the observable universe has 10% more microwave radiation than the other.  The the radiation is thought to be from the very first light of the universe red shifted into microwave, it may be an indication of early structure to the universe.  In other word it may not have started from a uniform point source.  Furthermore some researchers have proposed an explanation of the structure.

Another data point is the recent work done by Quantum Physicists to model the early universe.  At very least their calculations hint that the universe has a smallest possible size which corresponds to the maximum allowable energy density.  General Relativity will run backwards to predict virtually infinite energy density but not so if you use quantum mechanical measures.  What happens when the universe gets so small that it reaches the maximum density—it expands.  If it can’t reach a point why would we think it every reaches a maximum?  Only if it starts to collapse will it every reach a maximum and currently we think if will expand at ever increasing rates forever. 

Let’s suppose that the universe began from some volume that magically appeared from nowhere—or from outside the current universe.  What is to say that this appearance happened at a point in time?  Why do we assume that this creation from outside isn’t still going on or at least did for some time after the universe came into being?  Might the early inflationary period be tied to some type of continuing creation event?  I have never heard a good explantation of teh inflationary period let alone any proof that it really happened.  As usual I’m left with more questions than I started with.

Powerset released their nlp based search engine/information extraction and gisting engine/information navigation service yesterday.  I know—it’s a mouthful but that is the point of this post.  They are trying to do a lot of things and succeeding better at some than others.  Here is a partial list:

• Query flexibility:  Powerset does nlp on your queries so you can ask questions like, “Who are the actors in Pulp Fiction?”  This would be a negative feature if it were required but you can also type, “actors pulp fiction.”  I haven’t been able to tell if they are doing any synonym checking on the queries. 
• Search history:  Powerset mines your history for past searches and displays close matches as you type into the search box.  This is virtually useless.  What are the chances that I want to search for the exact same thing again?  Google makes suggestions based on what everyone searches for and I have come to rely on it as a sort of query tuning.  Wouldn’t it be nice to include truly similar queries taking into account semantics and synonyms?  The Google experience could be improved but Powerset chose to step backwards.
• Auto-tag Cloud:  Here Powerset made some interesting improvements to the user experience.  First they use terms found in a document in a tag cloud rather than relying on spotty user generated tags.  They also separate nouns and verbs referenced in the document into separate clouds.  This has some utility but they currently show too many words and use them only as a way to navigate the information in the document as opposed to information on the web in general.
• Gisting: This is where Powerset fails to live up to their hype.  The idea of gisting long documents to produce something that is easily skimable is a powerful idea but they make so many mistakes that the implementation is distracting and of marginal use.  Hopefully they will improve this with better tuned nlp n-gram extraction.

Currently Powerset only extracts information from Wikipedia.  At some level I wonder why we need that but if you look at the techniques they are using and *imagine* it working across the entire web it would be nice.  What disappoints me is that it does no better at finding things and cross-referencing stuff.  I could find very few examples of cross-document references in the preview.
These days we hear of many applications of nlp in creating semantic data from unstructured text.  This has some great applications but when it comes to finding stuff on the web I don’t need a service that reads single articles for me I’d rather a have service finds related information.  That is what I spend most of my time doing while researching things on the web.  When planning a trip to Turkey I need information on tickets, hotels, weather, history, news, and not just history but the history of the Byzantine Empire, the Ottomans, Greece, Rome, etc.  Why doesn’t a service mine the web for these connections, ones based on related concepts?  A service like this would draw perhaps more from categorization technology than raw nlp.

Gravitational lensing has been used to show the effects of massive objects between the observer and some distant observed objects.  It is easy to understand how a massive object will bend light and some rather striking images show the effect.  What is interesting is that gravitational lensing can actually be used to map dark matter in the universe.  If you know what an object should look like you know when its light has been bent causing the image to be distorted even when the light is bent by invisible dark matter. 

As with many ideas that seems complex the trick is rather simple.  Look first at this image of the galaxy cluster Abell 2218.  Here you can see that the shape of the distant galaxies have been distorted by the large galaxy at the center of the picture.  Our eye picks out the distortion easily because we are used to seeing elliptical galaxies, not the bent slivers in this image.  It turns out that the amount of the curve can be used to measure the magnitude of the lensing and therefore the magnitude of the gravitational effect.  In this image the gravitational effect is from a visible object but if you imagine the same picture with no central bright blob you would still notice the distorted curved galactic ellipses.  And that is exactly how gravitational lensing is used to measure dark matter. 

There are problems with this type of distortion measure though since dark matter is highly diffuse.  Any photon moving through the center of a diffuse cloud of dark matter will move straight through it since the effect of the dark matter is to tug equally in all directions.  But when a photon moves near a diffuse cloud of dark matter it will tug more in the direction of the center of mass, so the photon bends in that direction.  By measuring the very slight curve in what should be a nice regular ellipse astronomers can calculate a line to the the center of mass of the cloud of dark matter.  By measuring the curvature of several galaxies they can triangulate to find the location of the dark matter. To get more precise they need to subtract the lensing caused by visible matter but you get the idea.

By putting together many observations astronomers are getting a better idea of the large scale structure of dark matter in the universe.  Here is one map of dark matter structures.  And here is link to a new study that describes the process in much greater detail (though I can't find an image to go with it.)

It looks like another go around in the net neutrality debate. Comcast announced today, “a 54 percent rise in fourth-quarter net profit to $602 million, or 20 cents per share, from $390 million, or 13 cents per share, a year earlier. “ At the same time they defend their practice of restricting the bandwidth used for certain practices that they find questionable [1]. This comes at a time when the congress is debating a new try at legislating net neutrality.

Is there anything wrong with Comcast throttling bittorent traffic? After all it is traffic that primarily steals revenue from Comcast itself. I mean if you download a movie and watch it rather than pay the PPV fee to Comcast it would be like, oh I don”t know, like the phone company (DSL) letting people use Skype. The fact that in both cases the pipe owners are getting paid regardless of the use of their pipe makes the question interesting. Do we have the right to demand unrestricted access using their pipes? Of course we do and this is my concern. The real issue here is that consumers have the right to know what they are paying for and to have a choice. This is the essence of the free market. If we know that Comcast is choking traffic for their own reasons we might just choose DSL. The legislation being considered would make it illegal for Comcast to throttle based on traffic type. That would keep a level playing field but seems counter to the principal of allowing companies to choose the features of their own products.

If we assume that capitalism is basically sound then how do we put market forces to work to solve this problem. First we would need to make the restrictions on access transparent to users so they can exercise their choice. Then we would need to have a choice. Fortunately in most places in the US we can get high speed internet access from either cable or DSL. We can vote with our money. Congress should protect our interests until such time as market forces take over and we can choose what is in our best interest for ourselves. Maybe we should be looking at breaking up the duopoly of one cable company and one phone company rather than regulating internet access. I know, that seems a bit much to ask for but it does make sense doesn‘t it?

My wife has a laptop that is getting a little old. It runs Windows XP and she uses it mostly for browsing and email. Lately it has gotten really slow. Some disk access silliness is killing the OS. I could troubleshoot the thing or…

A year ago I had an old laptop that had been running its native Windows XP for several years until it got too slow. I tried defraging the disk and other tricks to no avail. I probably could have sussed it out but, you know, I have better things to do. Like installing Ubuntu 7.04 Feisty Fawn on it which was fun, in a perverse sort of way, and gave me a screaming fast machine with most of the 40G drive free. On the other hand the wifi was intermittent and tended to be hard to reestablish once it was dropped. Also It was difficult to get my bluetooth mouse to pair up automatically. I hacked the scripts for it but, you know, I have better things to do so I even though I could get it to work it wasn’t very reliable.

To make a long story longer, along came Ubuntu 7.10 Gutsy Gibbon. One day I saw the “Upgrade” in the desktop version of the software updater. I should say that one of the greatest things about Ubuntu is its use of the old debian apt-get mechanism to keep the system up to date. When security or bug fixes come along they are automatically made available to all users. The download and installation is automatic too. This even works for upgrades of the OS so the Upgrade Manager was offering me the nifty new 7.10 (they try to do an upgrade twice a year).

I did the upgrade with hopes that it would imporve some of the rough edges of 7.04. It took many hours of download and configure. The upgrade asks you to edit conflicting config files, which would probably scare a casual user, but I got through these ok. When I was done the wifi worked flawlessly and my bluetooth mouse paired automatically and connected instantly when I turned it on (even faster than my Macbook Pro).

I pimped it out with a nice theme for the new Compiz-Fusion window manager complete with some slick Mac-ish icons and had a pretty sweet machine with plenty of free disk and all the bells and whistles. Back to my wife who had finally given up using her laptop. One night she sees me playing with my old machine and says, “That looks pretty cool.” I set up Thunderbird to get mail from her account and she hasn’t used her old machine since.

I guess I have to install Ubuntu on her old machine now since mine has been taken over…