Our paper on the temporal behavior of the anomalous acceleration of Pioneer 10 and 11 is now published online by Physical Review Letters, and it is an Editor’s Suggestion, featured in Physical Review Focus.
Aug 192011
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is an application that keeps tabs on all the software installed on your computer and lets you know if any of them are out of date and require updates.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.
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 suspicious attitude 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 considerable 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.
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.
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.
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.
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.
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…
Jul 302011
Every summer, on every Canadian TV channel, during just about every commercial break, a commercial for Marineland in Niagara Falls is shown… with a song that just drives me bonkers. I’d sooner listen to a hundred pieces of chalk scratching a hundred chalkboards. Will they ever stop?
Jul 292011
Using the Internet in China just got a little harder. Not content with operating one of the most heavy-handed Internet censorship regimes in the world, Chinese authorities decided that free Wi-Fi makes it just too easy for all sorts of unsavory electronic communication to take place without appropriate supervision by Big Brother… so they ordered public Wi-Fi access providers to install costly software to record the identities and monitor the Web activities of users.
This is why I am not really afraid that the 21st century will belong to China. Sure, they became an economic giant, but this kind of institutional paranoia is ultimately self-limiting. Now if one day, they suddenly kicked out the Chinese Communist Party and replaced its one-party rule with a pluralist society… but then again, if that were to happen and China became the world’s most populous liberal democracy, why would I need to feel worried about their economic prosperity?
Jul 282011
Hungary’s ruling party Fidesz, which enjoys a two-thirds parliamentary majority allowing it to tweak the Constitution on a whim, prides itself, among other things, as the true guardian of the nation’s cultural traditions.
The other day, Thomas Melia, Deputy Assistant Secretary of State responsible for the Bureau of Democracy, Human Rights, and Labor in the State Department of the United States, told the US House Subcommittee on Europe and Eurasia that Hungary’s new constitution, media law, and law on churches are causes for concern.
Tamás Deutsch, a founding member of Fidesz, former government minister (responsible for Youth Affairs and Sports, 1999-2002) and current member of European Parliament responded on Twitter with the following words: “Who the fuck is Thomas Melia? Why do we have to deal with this kind of shit every day?”
How cultured. It must be a proud day for every Hungarian.
Jul 282011
Here is a picture, shown a few nights ago on Jay Leno’s show, of United States Senate majority leader Harry Reid and minority leader Mitch McConnell. If you can’t easily tell which is which, you are not the only one:
Just how ridiculous is it that a few days before the debt ceiling deadline, they are simply incapable of coming to an agreement? That even though they seem to agree on the basics (the debt-ceiling must be raised, a long-term solution to tackle the deficit problem must be found) gaining a political advantage over their opponent is more important than resolving a crisis that will likely have long-term repercussions not only for the economy of the United States but that of the entire world?
Looking at the recklessness and ineptitude of today’s politicians (and not just in the United States, I don’t want to be an America-basher here) it does make me wonder how long we have before World War Three…
Jul 242011
The city shut down The Fresh Fruit Company at the Byward Market for non-payment of rent. But what about all the food still in the store that is now left there rotting?
Jul 232011
I hate to make a political point in the wake of a terrible tragedy but… I wonder if those who advocate profiling based on race, religion, and ethnicity are now in favor of subjecting young, blue-eyed, blond Christian males speaking with a Scandinavian accent to extra scrutiny.
Jul 222011
Now this is one stunning picture, taken from the ISS of the plasma trail of Atlantis during the spacecraft’s fiery descent into the atmosphere:
Jul 222011
Human memory is far from perfect.
During the winter of 1988-1989, I was renting a small office on Ottawa’s Bank Street with my business partner John. We spent many a late night working on a difficult project, and it was one cold winter. I distinctly remember one night when the temperature dipped to −36 degrees Centigrade, and I not only had a hard time starting my car (only to rush back to the building to warm up and then run out to the car again after a few minutes in the hope that it would have warmed up a little by then) but its engine never reached its normal operating temperature during the 10 km drive home.
Except that it never happened. The -36°C, that is. The coldest historical temperature I can find for that winter is −27.2°C, which occurred in early March 1989; earlier, in January, it went down to −27.0°C one night.
I also distinctly remember that the first winter my wife spent here in Ottawa, she was renting a stall on the Byward Market and that on Christmas Eve day, the temperature never climbed above −24°C.
Again, never happened. On December 24, 1992, the high temperature was +2.7°C. Perhaps a year later, then? Yes, that was a cold Christmas Eve day, but not near that cold; the high temperature was -10.0°C.
Then there is that very cold winter in Budapest that I recall. It was brutal; my old Lada’s engine half froze. Eventually I managed to get it running without overheating, and then I spent half the night looking for a gas station that was selling antifreeze. Eventually I found one, way outside of Budapest. I do recall hearing on the radio that the temperature was -29°C. It wasn’t… according to the historical weather records that I can locate, the coldest night was on February 12, 1985, with a temperature of −24°C. Brutally cold by Budapest standards to be sure, but still 5 degrees warmer than what I remember.
At least I do know for a fact that today, the temperature reached +36°C. I think I owe an extra prayer of thanks to the gods of air conditioning.
Jul 222011
Ali Velshi is a Canadian-American journalist working for CNN. So how could he not know something even I happened to know: that the Montreal Gazette is one of the oldest continuously published newspapers in the world, beating The New York Times, The Times of London, and Le Figaro?
Jul 192011
RadioAstron, aka Spectrum-R, is in orbit. If it successfully opens its 10-meter dish antenna a few days from now, it will join the list of great space-based telescopes. It also signals that Russia is still a strong space-capable nation, doing much more than cheaply ferrying foreign astronauts to the International Space Station, filling the gap left behind by the retirement of the Shuttle program.
Tomorrow will be the 42nd anniversary of Armstrong’s “One small step”. How many years do we need to wait for the next small step taken by a human, be it in the dust of the Moon, the red rocks of Mars, or the cold surface of an asteroid?
Jul 192011
I found out that I am less squeamish than I thought.
I went out for a walk this morning, and in the middle of a sidewalk, I suddenly spotted a mouse. First I thought it was a small furry mouse toy, as it looked like a perfect little mouse, completely motionless. But then I realized it was the real thing, probably dead… but no, wait, it was still kicking. When I touched it with the toe of my shoe, it squeaked loudly and tried to crawl away… but even though I was trying to steer it towards the grass with my shoe, it didn’t get very far. I think it was badly injured, probably a broken leg or something. Eventually, fears of hantavirus and whatnot notwithstanding, I just grabbed it by the tail (loud squeaks followed) and threw it in the grass.
I mean, what was I supposed to do, step on the poor thing? Yes, I know, too much empathy is bad for your health, but apart from their size, mice are not that different from other mammals… they have hearts, lungs, a sizable brain, and the ability to feel fear and pain. In all likelihood, this poor critter has since been found by a cat, but at least it’s not expiring in the middle of a sidewalk half crushed to death when someone steps on it.
Yes, I avoided touching my face afterwards and washed my hands as soon as I got back home.
Jul 162011
Last night, my wife and I watched Barney’s Version on Blu-ray. I really loved Mordecai Richler’s novel, and the movie is true to its spirit; it is, in fact, a remarkable well done film. Too bad it didn’t do particularly well in the box office; it deserved better.