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01 October
2008

The Large Hadron Collider is scheduled to have it's first actual particle collisions soon, as opposed to just being "warmed up".

[ I wrote this article a while back, and had it cached until collision time. I didn't expect, and the time, that the LHC would get so much coverage. ]

From the LHC web site:

There are many theories as to what will result from these collisions, but what's for sure is that a brave new world of physics will emerge from the new accelerator, as knowledge in particle physics goes on to describe the workings of the Universe.

There are some people who believe that is a particle accelerator that will be able to create small black holes. This would be truly microscopic and not the same as Einstein black holes (they would be much smaller than a neutron).

These black holes should evaporate quickly and be no threat, although there is a minority of people who fear it could destroy the world if the black holes persist. The seems unlikely since cosmic rays have as much energy as the LHC beams, and they haven't destroyed the earth yet. On the other hand, cosmic rays have very high velocities while the LHC could produce occasional low velocity black holes. Thus, this does not appear to be a very credible threat. More importantly, there are other cosmological arguments to suggest such non-evaporating black holes cannot exist. On the other other hand, it should be a good excuse for an end-of-the-world party. There's another end-of-the world mechanism as well, based on strangelets made of special quark matter, but it too seems to be ruled out and I don't have the stamina to explain it.

With respect to data processing, the LHC is supposed to produce 15 petabytes of data per year (i.e. (15 thousand terabytes -- 15,000 trillion). The entire Google index of the web, in comparison, has processed one trillion links as of mid 2008 and index a far smaller number (according to the Google blog).

Live picture. CMS construction at Point 5. Click to enlarge and refresh.

The full story on why the LHC is considered safe can be found
at the CERN web site itself.


By Gregory Dudek at | Leave a comment |    
10 March
2009

I was part of the NSERC Computer Science Grant Selection Committee again this year. Like last year, we met in Ottawa for a week of grueling but interesting reviews of grant applications on computer science research from all over Canada. There are two CS committees (330 and 331) but they are in the process of being merged and this year I was part of the review committee for a diverse set of projects. In some cases, there were proposals from people whose work I was familiar with, but in most of those cases I was not part of the processes, and often not even allowed in the room, due to both the vagaries of the semi-random selection process combined with the stringent conflict-of-interest guidelines.

For several decades the core of the scientific granting system has been the Discovery Grant (formerly the Operating Grant) that is awarded in a per-investigator basis. Most front-line active science researchers in Canada have one of these, and the modest funding levels were determined by annually making small adjustments to the researchers previous grant. For active performers, this meant a gradually increasing funding level over the course of one's career. All in all this system worked extremely well and, despite limited amounts of funding, it provided stable effective funding for Canadian research and training. In the last decade or so, however, limitations on the amount of available research funding have prevented a few researchers from "ramping up" as fast the the organization would have liked. As a result, a drastic new process was instituted last year in several areas (despite concerns from many of the GSC members), and came this year to Computer Science.

As of this year, award levels have been largely decoupled from past funding and, in fact, the GSC members vote on scores for the grants without really knowing in advance either who will get funding, what scores assure funding, or what the final cutoff will be. That is, the GSC awards various scores, but the translation of these scores into actual dollars is only determined later. Apparently this new system produces largely acceptable results, but as a member of the GSC is was quite disconcerting to be evaluating a proposal without being able to explicitly vote that it should be funded. Also, although past performance is going to be directly coupled to funding, there is, in principle, the potential for less stability in the funding rates. This will certainly cause trepidation on the part of researchers (and could thus lead to very conservative behavior the year before a renewal is requested). All in all, I will be very interested in how well this works and what changes in funding result. I suspect some strong junior researchers may experience big increases in funding while some more senior researchers may get an unpleasant surprise.

NSERC GSC 331 members
NSERC GSC 331 members



By Gregory Dudek at | Read (3) or Leave a comment |    
14 March
2009

I was talking to a colleague (Luc) recently and mentioned I had an interest in astronomy which converged to a limited extent to my former interest in photography. In this context, I thought I would share an early attempt at capturing solar flares. There were taken using a small hand-held camera.

These photos don't compare well with the serious pictures from a big telescope, or (of course) from a solar observation satellite like SOHO, but I was pretty happy with them as personal successes. Better yet, I wasn't even blinded in the effort. This was, incidentally, a quiet day on the sun but I took the pictures then because the local viewing conditions were acceptable.

Click on any image to see a bigger version.


Solar Flares



This makes my pictures seem pretty dismal, but here's the latest picture and a link from the EIT (Extreme ultraviolet Imaging Telescope) on the SOHO satellite for reference. SOHO was built by the ESA and is being operated by NASA.

If you want to try this yourself, you can get the latest solar weather report here, but the sun has been very quiet for quite a long time now -- we're in a solar minimum now. The peak in activity is supposed to be in 2011 or 2012 and it is supposed to be strong. There have also been observations of an unprecedented reduction in activity in the Sun's Great Conveyor Belt, which has effects for the next 20 years and is expected to lead to reduced solar activity in solar Cycle 25 in 2022 (and thus increased cosmic ray incursion on earth and in earth orbit -- i.e. better-irradiated astronauts).

References: Predicting The Strength Of Solar Cycle 24 Using A Flux-transport Dynamo-based Tool, Mausumi Dikpati, Giuliana de Toma & Peter A. Gilman, 2006, Geophys. Res. Lett., 33, L05102, doi:10.1029/2005GL025221

Radiative Processes and Small-scale MHD in the Convection Zone and Photosphere

By Gregory Dudek at | Leave a comment |    
Rate item 155: Rating: 9.5/10 (2 votes cast)
16 July
2009

I mentioned earlier that one of our robots was up North. Well, it's been visiting an outpost -- the McGill Arctic Research Station -- of McGIll University and the Canadian government on Axel Heiberg Island in the territory of Nunavut, Canada. This is very far North -- there's not much other land as far north except Komsomolets Island in Russia and Northern Greenland.

Philippe Giguere from our lab has taken the robot up there as part of an experiment dealing with sensing in harsh environments in the context of developing tools for space exploration and, in particular, astrobiology. The robot is being used to deploy an exotic automated microscope that can detect signs of life in hostile environments, much as one might wish to do on the another planetary body like Europa or Mars. Of course, this experiment only tests a small fraction of the suit of technologies that would be needed for a genuine extra-terrestrial mission, but is still very satisfying to work on in this context. Sending Philippe instead of going myself made a lot of sense in terms on scheduling and logistics, but I am certainly envious and a bit disappointed I didn't get to go. The mission seems to have gone very well based on the reports back to home, and the robot carried the holographic microscope successfully.

This location is, incidentally, pretty close to the North magnetic pole. Among the other interesting features of this location, the Earth's lines of magnetic flux point almost straight down so that a magnetic compass is pretty much useless there.






By Gregory Dudek at | Leave a comment |    
16 November
2009

I gave a talk on recommender systems at the Drupal Camp Montreal meeting. The nice people at DBN.ca did a great job of
recording the talk and have put it on line. It's not super-technical but it gives an overview of recommender systems in general and a bit about how our particular system, Recommendz.com, operates.


By Gregory Dudek at | Leave a comment |    
02 October
2010

Sparked by a piece on the CBC radio program Quirks & Quarks, I noticed the article "Social organization in a flatworm: trematode parasites form soldier and reproductive castes" by Hechinger et al. It discusses the development of social hierarchies in flatworms, somewhat akin to the social specialization seen with ants and bees. In particular, the parasitic trematode worms have a special warrior subtype that is specialized to right with other worms that may try to infest the same host. "Soldiers do not reproduce, have relatively large mouthparts, and are much smaller and thinner than reproductives." Until recently, people didn't realize that worms had social organization.

The article is here, but only the abstract is available for free.

It is interesting to note how little physically-encoded social specialization there inn mammals. There are mammals that do special jobs, including of course in human society, but it's not usually so deeply encoded in the body plan. Why don't groundhogs, or antelope, develop the sprecialized roles seen so often in "lower" animals?


By Gregory Dudek at | Leave a comment |    
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