Social Media Front Page Addiction, or SMFPA, is ruining lives. Or at least that’s what it said on the front page of Digg a couple days ago. Or maybe it was Reddit. Who are we kidding it was probably both. From the linked story,

After being kicked out of his house two weeks ago, June Kiyotu, “asianassassin69″ on Digg and Mixx, spends most of his waking hours at the public libraries in his area that offer free internet access. “I know it’s a problem, but you can’t understand how FPing (front paging) a story makes me feel. Nobody can.”

Rick Shaw, Director of PopUrHere, a half-way house for recovering FP addicts, says the solution is in recognizing the problem. “We reach out to everyone we find who shows signs of SM-FPA. If they are submitting dozens of stories at different hours of the day and night, we know we’ve found someone who needs our help.”

Really? Seriously? No one can understand how it feels to be recognized by a selection of your peers? We have half-way houses for this crap now? (This is a fake article. It’s a joke people. I’m using it as a “framing device” for the rest of my article.) I can make fun of these kinds of people day in and day out, but there is a small ring of truth to these stories. Even I, on occasion, get pretty caught up in it. But I have found more recently that, unlike reading a good book or doing some work for my thesis project, succumbing to “SMFPA” almost without exception is guaranteed to make me completely and utterly furious. Why you ask? Because, as it turns out, it’s really easy to get a story up to the front page of these sites if you just troll for articles that are sure to piss people off. With that in mind, I’d like to give you all a selection of my thoughts on the various front page articles from these social media sites today. Maybe this will be somewhat cathartic for me. After this point perhaps I won’t go to work already pissed off by what I read as I drink my morning coffee …

1) All of the ten most important things we did as scientists this year apparently fell into one of two categories: biology (including evolution and biological medicine), and astronomy.

1b) And one of those “most important scientific discoveries” was apparently the discovery of a really old clam (#8).

1c) Time magazine makes 50 top ten lists for the year. I imagine this happens every year.

See that? With only one link to an article I’m able to extract a lot to be angry about.

2) Any of about 100 articles about Mike Huckabee and various things he has said over the past 20 years.

3) Whatever ArsTechnica article made it to the front page that day. Today it was something about an ISP injection.

4) The RIAA is an evil, terrible organization. In a previous case, the RIAA submitted the following statement to the US Supreme Court (the Grokster case):

The record companies, my clients, have said, for some time now, and it’s been on their Website for some time now, that it’s perfectly lawful to take a CD that you’ve purchased, upload it onto your computer, put it onto your iPod. There is a very, very significant lawful commercial use for that device, going forward.

In their supplemental brief submitted today, they state specifically that any ripping of CDs for personal use is strictly forbidden and illegal. This new case is Atlantic vs. Howell.

I’m sure you all see where I’m going with this. So I’m pretty convinced that this is what these people do all day. They sit on their computers just praying for something interesting to happen on an obscure enough website such that they have the time to be the first to promote it to the front page of whatever their favorite social news site happens to be. I guess I’m happy to let them do it. Me, I think I’d rather read a book or do some work. But during those times of infinite frustration or at the end of a very long day, at least there will always be something moderately interesting and relatively unsurprising to read.

(Disclaimer: I actually do think that RIAA copyright bullying, ISP neutrality, Huckabee being a questionable candidate, and the publics extremely narrow view of what science is are important issues. If Digg or Reddit fix any of these issues, please let me know.)

Cheers.

Normally most of what I read in Phys. Rev. Lett. (PRL) is somewhat beyond the scope of vdov.net. However, two days ago there was a neat advance (arXiv here) on a very simple application of molecular dynamics to the microscale swimming problem. Microscale swimming is quite a bit different than what we associate with the swimming of people, animals and large machines. The Reynold’s number associated these types of processes are generally large (Re >> 1), whereas in a microscale swimming process the Reynold’s number of usually orders of magnitude below 1. Thus the importance of inertia in a microscale swimming process is effectively zero, the consequence of which is that a viscous-only flow is fully reversible.

In a viscous only flow, the Navier-Stokes equations are simplified as the inertial components (and therefore any time derivatives) must be zero. The standard Navier-Stokes equation for a Newtonian fluid reads as,

This is a lot simpler than you think: the left hand side of the equation is characteristic of inertial forces, and the right hand size consists of a pressure gradient term, viscosity term and a body forces term (gravity, etc.). In the limit of very low Reynold’s number, these equations simplify to the Stokes equations, given as (neglecting any body forces),

With continuity equation for an incompressible fluid as,

we have a relatively nice description of the problem. So what does this all mean for microscale swimming? These Stokes equation have no time dependence and the solutions to the equations are time-reversible. So, in a viscous enough fluid at relatively low velocity, swimming in the traditional sense won’t work. Any motion in one direction will be completely countered by the equal and opposite motion. So a flapping wing or paddle is pretty useless in these types of conditions. Certainly you or I couldn’t swim at low Reynold’s number. So microscale species develop inventive ways of getting around this problem. A lot of these solutions are detailed in the classic Life at Low Reynold’s Number (I found a free link to the paper … AIP would like to charge you for it). There are many methods of solution to the Stokes equations, the details of which I will certainly not discuss here. If you want to know more about some of the more interesting ones (Boundary Element, Streamfunction or Green’s Function methods), take a graduate class in numerical methods or fluid dynamics.

This is all great and good. What the paper in PRL has done is simply apply a reasonable molecular dynamics (MD) approach to the power and efficiency of these problems. It’s an extremely simple application of MD to a pretty easily understood phenomena, and therefore perhaps appropriate here on vdov.net. In the paper, they investigate various biological and microbiotic designs (such as biflaps motion, flagellum, legs and snaking motion), and extract infomation about the power vs. efficiency of each design. This information has some pretty important ramifications, some of which might include some interesting work on the efficiency of microscale therapeutics. The paper is extremely easy to read and the majority of the conclusions drawn should be understandable to the reader without any simulation or fluids experience.

Why then, you might ask, would I care about any of this? Well it turns out this type of fluid to molecular reduction is precisely what I am trying to do to study the collisions of droplets in a spray or on a surface. The problem specification in my situation is perhaps more involved and I certainly won’t detail it here, but this is a wonderful example on how MD and computational fluids can talk to each other. Secondly, I’m looking to put more science on the vdov.net front page, and this paper seemed like a nice place to start. All of you current or future PhDs out there are welcome/encouraged to post anything interesting at any time.

Cheers.

Quite a title eh? Well this is sort of a random stream-of-consciousness kind of post. So be prepared. But this place was getting a little dull recently so I thought I’d rehash some of the things I’ve done to my machines recently and perhaps review them a bit. So here goes.

I think I read (though I can’t seem to find the reference anywhere) an interview with Linus Torvalds recently in which he said something like the following (if you know the reference feel free to let me know, I’m pretty sure it was on Kernel Trap this year sometime):

I don’t use Debian or any other ‘low-level’ Linux flavors because I feel like Linux should be easy to use and manageable for day-to-day work, etc.

Those of you that know me well probably know that I have made nothing short of a career in the past 3 years going exactly in the opposite direction here. Recently however, I decided to take the plunge for a number of reasons. They are briefly: 1) I’ve got way too many machines to take care of these days, 2) I love Debian but on laptops I find it a bit annoying to have to configure dynamic things every time I move and 3) Recently I screwed up a bunch of my machines and decided it was time to reinstall them, 4) Being ridiculously OCD I needed to have all my machines running the same software and they all basically need to look the same. Lastly, and definitely most importantly, Ion3 was really having trouble running a lot of the software I needed to run, including Fluent (ANSYS), Gambit, Matlab, etc. So all these things together, along with my acquisition of a brand new laptop, made me decide to take the plunge and reinstall all my machines with … (drum-roll), 64-bit Ubuntu.

Generally I’m pretty happy with my choice. I loved the Ion3 window manager and Debian in general, but Ubuntu is basically Debian with some fancy crap built on top of it. So the backend is basically the same. Plus the update cycle is way better in Ubuntu … well, at least faster. As far as using Gnome, I’m not completely sold yet. I sort of like it … I guess, and I’m getting used to it. But I do miss the simplicity of Ion3. I don’t, however, miss configuring everything manually in Debian for my laptop or the huge number of problems I had with applications really not liking the Ion3 windowing model.

Oddly, Ubuntu Gusty’s (7.10) compositing window manager (Compiz Fusion 0.52) is pretty annoying. There are really no real benefits to it so far as I can tell, other than Aero/Aqua-type effects. And there are plenty of annoyances. As I first got back to reinstalling my systems, basically everything that didn’t work with Ion3 well also didn’t work with Compiz, so I had to disable it out of the box on all of my machines. Annoying.

Alec turned me on to ‘unison’ as a nice little remote folder syncing utility, which is quite wonderful. I use it now to sync my document tree between my 3 work machines (work laptop, work desktop and home desktop). It’s designed for just 2 machines but it works equally well with 3.

I also got a nice new laptop recently, a Dell Latitude D430, which is their ultra-portable business machine. I’ve used it extensively already and generally I’m quite happy with it. Ubuntu runs great on it — I haven’t really been able to detect even the slightest hitch yet — it’s got fantastic battery life and the performance sacrifices due to ultra-portability and long battery life really don’t affect me in the slightest. It’s really going to be brilliant to be able to work on a plane or while traveling, not to mention when I just need to get out of lab for any number of reasons (there are lots of them).

I’m not sure I have much else to say. Lots of real work to get done since my OP is over, as my boss wants to publish pretty soon and I really don’t have enough yet done to do that. Hopefully I’ll be writing paper #2 in February. I doubt anyone will really care about this post but it’s here for you if you like; I had to write something, this place is dead. Hey you … write something for vdov.

Cheers.