Aug 272011

I never thought Apple computers were hip. Every so often, I thought about buying Apple hardware, but if I did so, I’d want a development system, so my shopping cart at rapidly ballooned to some 2,000 dollars… by which time I inevitably realized that I’d be buying expensive toys that would become obsolete long before I’d find the time needed to become proficient with Apple’s development tools.

And now here is an interesting article, from the Ottawa Citizen no less, elaborating on something that I felt all along: that despite its hip image, what Apple sold to the masses all along was really mediocrity.

Of course this probably means that I am not one of the cool kids, but if that is the case, so be it… life is way too short to worry about coolness.

 Posted by at 8:11 pm
Aug 172011

I am not usually in the business of recommending software or hardware products, and it’s certainly not something anyone pays me to do… but recently, I began using two products, both of which have exceptional value, even though one came free of charge and the other cost only 150 dollars.

The free product is Secunia’s Personal Software Inspector (PSI), a software application that turned from something I never heard about into something I cannot live without virtually overnight. It is an application that keeps tabs on all the software installed on your computer and lets you know if any of them are out of date and require updates. Like antivirus software, PSI sits quietly in the background most of the time, but it pops up an unobtrusive warning whenever a new update becomes available, and even offers a direct link to the manufacturer’s download site. It is nice, incredibly useful, it recognizes hundreds of installed applications, and, well, it works as it is supposed to and doesn’t cost a penny.

The product I paid money for is a Cisco RV042 small business router. It does what small business routers do, connects your internal network to an external (DSL, cable, etc.) Internet connection. What makes it special is that it allows your internal network to be connected to two external connections at the same time, and it performs dynamic load balancing and failover functions between the two. I now set up my network architecture to take full advantage of it… and in the coming days, it will be working overtime, as I am planning a major change to my DSL service which will likely involve some unpredictable downtime. The router has other useful functions, too, not the least of which is that it can act as a VPN server, allowing a remote computer to connect to the internal network. The best part is that, like Secunia’s software, it simply works as advertised.

 Posted by at 8:47 pm
Aug 122011

Back when I was learning the elementary basics of FORTRAN programming in Hungary in the 1970s, I frequently heard an urban legend according to which the sorry state of computer science in the East Bloc was a result of Stalin’s suspicion towards cybernetics, which he considered a kind of intellectual swindlery from the decadent West. It seemed to make sense, neglecting of course the fact that the technological gap between East and West was widening, and that back in the 1950s, Soviet computers compared favorably to Western machines; and that it was only in the 1960s that a slow, painful decline began, as the Soviets began to rely increasingly on stolen Western technology.

Nonetheless, it appears that Stalin was right after all, insofar as cybernetics is concerned. I always thought that cybernetics was more or less synonymous with computer science, although I really have not given it much thought lately, as the term largely fell into disuse anyway. But now, I am reading an intriguing book titled “The Cybernetic Brain: Sketches of Another Future” by Andrew Pickering, and I am amazed. For instance, until now I never heard of Project Cybersyn, a project conceived by British cyberneticists to create the ultimate centrally planned economy for socialist Chile in the early 1970s, complete with a futuristic control room. No wonder Allende’s regime failed miserably! The only thing I cannot decide is which was greater: the arrogance or dishonesty of those intellectuals who created this project. A project that, incidentally, also carried a considerably potential for misuse, as evidenced by the fact that its creators received invitations from other repressive regimes to implement similar systems.

Stalin may have been one of the most prolific mass murderers in history, but he wasn’t stupid. His suspicions concerning cybernetics may have been right on the money.

 Posted by at 3:03 pm
Aug 122011

I am reading a very interesting paper by Mishra and Singh. In it, they claim that simply accounting for the gravitational quadrupole moment in a matter-filled universe would naturally produce the same gravitational equations of motion that we have been investigating with John Moffat these past few years. If true, this work would imply that that our Scalar-Tensor-Vector Gravity (STVG) is in fact an effective theory (which is not necessarily surprising). Its vector and scalar degrees of freedom may arise as a result of an averaging process. The fact that they not only recover the STVG acceleration law but the correct numerical value of at least one of the STVG constants, too, suggests that this may be more than a mere coincidence. Needless to say, I am intrigued.

 Posted by at 2:15 am
Aug 052011

As I’ve been asked about this more than once before, I thought I’d write down an answer to a simple question concerning the Pioneer spacecraft: if the “thermal hypothesis”, namely that the spacecraft are decelerating due to the heat they radiate, is true, how come this deceleration diminishes more rapidly, with a half-life of 20-odd years, than the primary heat source on board, which is plutonium-238 fuel with a half-life of 87.74 years?

The answer is simple: there are other half-lives on board. Notably, the half-life of the efficiency of the thermocouples that convert the heat of plutonium into electricity.

Now most of that heat from plutonium is simply wasted; it is radiated away, and while it may produce a recoil force, it does so with very low efficiency, say, 1%. The thermocouples convert about 6% of heat into electricity, but as the plutonium fuel cools and the thermocouples age, their efficiency decreases (this is in fact measurable, as telemetry tells us exactly how much electricity was generated on board at any given moment.) All that electrical energy has to go somewhere… and indeed it does, powering all on-board instrumentation that, like a home computer, ultimately turn all the energy they consume into heat. This heat is radiated away, and it is in fact converted into a recoil force with an efficiency of about 40%.

These are all the numbers we need. The recoil force, then, will be proportional to 1% of 100% − 6% = 94% plus 40% of 6% of the total thermal power (say, 2500 W at the beginning). The total power will decrease at a rate of \(2^{-T/87.74}\), so after \(T\) number of years, it will be \(2500\times 2^{-T/87.74}\) W. As to the thermocouple efficiency, its half-life may be around 30 years; so the electrical conversion efficiency goes from 6% to \(6\times 2^{-T/30.0}\) % after \(T\) years.

So the overall recoil force can be calculated as being proportional to

$$P(T)=2500\times 2^{-T/87.74}\times\left\{\left[1-0.06\times 2^{-T/30.0}\right]\times 0.01+0.06\times 2^{-T/30.0}\times 0.4\right\}.$$

(This actually gives a result in watts. To convert it into an actual force, we need to divide by the speed of light, 300,000,000 m/s.) With a bit of simple algebra, this formula can be simplified to

$$P(T)=25.0\times 2^{-T/87.74}+58.5\times 2^{-T/22.36}.$$

The most curious thing about this result is that the recoil force is dominated by a term that has a half-life of only 22.36 years… which is less than the half-life of either the plutonium fuel or the thermocouple efficiency.

The numbers I used are not the actual numbers from telemetry (though they are not too far from reality) but this calculation still demonstrates the fallacy of the argument that just because the power source has a specific half-life, the thermal recoil force must have the same half-life.

 Posted by at 12:46 pm
Aug 022011

I am catching up with my reading of recent issues of New Scientist, which arrived all at once after our recent postal strike.

Cephalopods are smart. So smart in fact that they are tool users, the only invertebrates we know about that have this ability. Yet they evolved entirely differently from us, having split from us some half a billion years ago on the evolutionary tree. Some argue that cephalopods deserve extra protection; on the other hand, we don’t even know how to anesthetize them properly.

I also wonder if the SETI folks are taking notice. We think we are so smart that we can talk to aliens? How about learning first how to communicate with a giant squid. Compared to aliens, these guys are our cousins after all.

 Posted by at 12:41 pm
Aug 022011

Finally, a voice of reason.

I just read an opinion piece in New Scientist by Erle Ellis. His message is simple: Welcome to the Anthropocene. Ellis believes that the geological epoch called the Holocene is over; the landscape of the Earth has been altered irreversibly by humans, but not all such change is bad or unwelcome. In any case, there is no turning back. The question is not how to undo what we have done, but how to create a better, more sustainable Anthropocene, as we have become the creators, engineers, and stewards of this world.

This has also been my opinion for a long time. Humans are no less “natural” than apes, ants, whales, or trees. By extension, a skyscraper or a factory are no less natural than an anthill or a bird’s nest. However, it has happened in the past that a species overwhelmed and destroyed the environment in which it once thrived. Humans can suffer the same fate… except that we do possess oversize brains and the ability to plan ahead in the long term. What we need is not some romantic notion of a “pristine planet”, but to learn how to manage a planet of finite resources that is dominated, and irreversibly altered, by our presence.

 Posted by at 12:27 pm
Aug 012011

First the first time in seven years (!), my main Internet connection is down, and will likely stay down until at least Tuesday. This being a long weekend, no telco technician is available until then, and they determined that the fault is likely a partial short in the physical circuit. Bloody hell.

Now I am scrambling to reroute everything to a backup server, provided courtesy of a good friend of mine. I asked him to only move around on tiptoes until Tuesday, and I am begging Murphy not to strike again until then…

 Posted by at 1:17 am