Feb 172015

Today, I successfully hacked one of my Rogers cable decoder boxes. No, not to do anything illegal, just to get composite video and demultiplexed stereo audio out of them, to make them more usable with the dual-tuner TV card that is in my desktop workstation.


This is the first time ever that I used the services of a custom printed circuit board manufacturer. My design worked on the first try. I am mighty proud of myself.

 Posted by at 7:57 pm
Feb 142015

Vaccinations are not without risk, some say. Why should the evil government compel me to expose my child to a known risk, they ask. Why is it my problem if someone else’s child is not vaccinated, they argue.

Well… it boils down to simple math, really. Suppose that once infected, a person remains infectious for a period of time denoted by \(\delta t\). The virulence of the disease is measured by the number of people that a single patient can infect during this period of time. It is called the basic reproduction number, denoted by \(R_0\). If this number is greater than one, we have the potential for an epidemic.

So then, after some time \(t\) has elapsed, the number \(N(t)\) of people who are infectious at that moment \(N(t)=N_0R_0^{t/\delta t}\), if \(N_0\) was the number of infected people at \(t=0\). At least this will be the correct number during the early stages of the epidemic; later, infection rates slow down as a growing number of people will have already caught the disease and the survivors will have developed immunity to it.

But we are interested in the early stages indeed, because the idea is to prevent an epidemic in the first place. So this simple model is adequate.

Now what happens when you vaccinate people? Even if everyone gets vaccinated, vaccines are not 100% effective. If the efficiency of a vaccine is given by \(\epsilon\) (a number between 0 and 1, with 1 meaning 100% efficiency), the aforementioned formula is modified: \(N(t)=[(1-\epsilon)R_0]^{t/\delta t}\). If \((1-\epsilon)R_0<1\), we win: an epidemic is avoided.

But what happens when not everyone gets vaccinated? Some people obviously cannot be: very young babies, people with compromised immune systems, etc. Let’s say the vaccination rate is given by \(\rho\). Once again, the formula for \(N(t)\) needs to be revised: \(N(t)=[(1-\epsilon\rho)R_0]^{t/\delta t}\).

And this is where the problem lies: if \((1-\epsilon\rho)R_0>1\), the potential for an epidemic exists.


Take the case of measles, for which \(R_0=12…18\). Even if we take the lower limit of the given range, \(R_0=12\), it is one of the most virulent contagious diseases out there. The measles vaccine is supposedly 95% effective: \(\epsilon=0.95\). So then, \((1-\epsilon)R_0=0.6\), and we are good: in a fully vaccinated population, measles would disappear in short order. This is indeed what happened when measles vaccinations became common in much of the world starting in the 1970s.

But now, let us think about \(\rho\). The math is easy: If \(\rho<0.965\) (that is, if more than 3.5% of the population are unvaccinated), \((1-\epsilon\rho)R_0>1\). Herd immunity is lost: the disease spreads.

And lest we forget, measles is a very deadly disease. Parents who play Russian roulette with their children on the basis of unsubstantiated fears concerning the vaccine’s effectiveness and side effects forget that often the only reason their child survives the infection is because they have access to first-world health care… the same health care that would have prevented the illness in the first place, if not for the parents’ arrogant stupidity.

These parents should be reminded that in poorer parts of the world, their counterparts often risk their lives to get their children vaccinated. Like parents in Somalia who, defying a ban on polio vaccination by al-Shabaab, smuggle their children to government-controlled areas to get the life-saving vaccine. Obviously these Somali parents are a lot smarter, a lot wiser than first-world anti-vaxxers, be it new age parents who prefer “happy thoughts” (or whatever) over medically approved methods, or nutty right-wingers who distrust the government on everything.

In short, if your political or religious views, or your scientific illiteracy compel you to be as stupid as a doorknob, please find a way to express your stupidity without endangering the health and lives of others.

 Posted by at 3:42 pm
Feb 132015

Canadian liberals, rejoice: The network often dubbed “Fox News North” is no more. Reportedly, Sun News Network will stop broadcasting as early as 5 AM Eastern time this (Friday) morning.

I am certainly no fan of right-wing ideological propaganda and hatemongering, so it’s not like I will personally miss Sun News. But I still don’t cherish the idea that it was forced to close, after the CRTC denied it a license that would have granted the network a more lucrative spot on the cable dial. A core concept in a democracy is that even voices we despise can be heard. And if your views are based on real values, surely they would not be shaken by the fact that there was a news channel out there that occasionally challenged them.

To be sure, Sun News wasn’t exactly high quality television, but still… I don’t think their demise will make Canada a better place. Not to mention the 200+ jobs that are lost as a result.

 Posted by at 12:37 am
Feb 102015

notrussiaAs the fighting in Ukraine intensifies, we often hear Russia’s complaint: that the West, gloating over its “victory” at the end of the Cold War, is encircling Russia and is imposing its will upon the country.

But then the other day, I was reading another piece of news about a planned G7 meeting and it hit me. Imposing its will? Nonsense. The West welcomed Russia. It accepted Russia as a full-fledged member of the international community. It even made Russia a member of the G8, for crying out loud.

But this was not good enough for Mr. Putin’s Russia. Being a member of the international community means accepting its rules (even when you are the United States of America, much to the chagrin of that country’s politicians, especially its conservative lawmakers.)

There was also a deep-seated suspicion that if the West gains from this relationship, Russia must be losing something. As George W. Bush remarked recently, for Mr. Putin politics is a zero-sum game. A very tangible something appeared to be the loss of control over the “near abroad”, especially former Soviet member states. The state of the Baltic countries may be a fait accompli, but a line has to be drawn somewhere… and it appears it has, and it now includes Ukraine.

After all, Mr. Putin declared more than once in the past that he viewed the collapse of the Soviet Union the greatest political disaster of the 20th century. If you are the strongman of a nuclear superpower and thus have the means to do something about it, what would you do about the greatest political disaster? Try to undo it, no?

So in the second decade of the 21st century, Mr. Putin embarked on a decidedly 19th century style pursuit, as he is trying to bend Ukraine to his will. It’s not an open war just yet (Russia claims it’s not involved; if freedom-loving Russian soldiers spend their leave in Ukraine, that’s nobody’s business) but it’s getting close, especially as the West ponders providing arms to the government in Kyiv.

And very rapidly, we find ourselves in a geopolitical situation that is just as scary, if not scarier, than the worst moments of the Cold War. Mr. Putin enjoys tremendous support at home thanks to his nationalistic agenda, which sadly resonates all too well in those parts of the world. Abroad, he reminded us that he commands the strike capability of a nuclear superpower, so it is a very bad idea to mess with him. And the nationalist beast is a hungry one, which requires constant feeding. What next, after Ukraine? Another attempt at a “hybrid war” (of destabilization, irregular troops), this time in NATO’s Baltic member states? What if this provokes a decisive NATO response, in accordance with the NATO charter? Mushroom clouds over battlefields, followed by mushroom clouds over cities?

Last year, we commemorated the 100th anniversary of the start of the War to End All Wars. Maybe we (along with Mr. Putin and his supporters) ought to be reminded that the next world war will likely be the war to end all wars, albeit for the wrong reasons: it will end all wars not because we lose the appetite for bloodshed, but because nobody is left alive to fight.

Or worse yet, maybe this war will be won by our machines.

Anyone with a time machine, please let me know if my wife, our cats and I can get a free ride back to the 1960s…

 Posted by at 9:03 am
Feb 082015

cat-dead-aliveI have some half-baked ideas about the foundations of quantum physics (okay, who doesn’t.) When I say half-baked, I don’t mean that they are stupid (I sure hope not!) I simply mean I am not 100% sure about them, and there is more to learn.

But, I am allowed to have opinions. So when I came across this informal 2013 poll among (mostly) quantum physicists, I decided to answer the questions myself.

Question 1: What is your opinion about the randomness of individual quantum events (such as the decay of a radioactive atom)?

a. The randomness is only apparent: 9%
b. There is a hidden determinism: 0%
c. The randomness is irreducible: 48%
d. Randomness is a fundamental concept in nature: 64%

(“Jedenfalls bin ich überzeugt, daß [der Alte] nicht würfelt.”)

Question 2: Do you believe that physical objects have their properties well defined prior to and independent of measurement?

a. Yes, in all cases: 3%
b. Yes, in some cases: 52%
c. No: 48%
d. I’m undecided: 9%

(Note that the question does not say that “well-defined” is a synonym for “in an eigenstate”.)

Question 3: Einstein’s view of quantum mechanics

a. Is correct: 0%
b. Is wrong: 64%
c. Will ultimately turn out to be correct: 6%
d. Will ultimately turn out to be wrong: 12%
e. We’ll have to wait and see: 12%

(Einstein’s views are dated, but I feel that he may nonetheless be vindicated because his reasons for holding those views would turn out to be valid. But, we’ll have to wait and see.)

Question 4: Bohr’s view of quantum mechanics

a. Is correct: 21%
b. Is wrong: 27%
c. Will ultimately turn out to be correct: 9%
d. Will ultimately turn out to be wrong: 3%
e. We’ll have to wait and see: 30%

(If I said “wait and see” on Einstein’s views, how could I possibly answer this question differently?)

Question 5: The measurement problem

a. A pseudoproblem: 27%
b. Solved by decoherence: 15%
c. Solved/will be solved in another way: 39%
d. A severe difficulty threatening quantum mechanics: 24%
e. None of the above: 27%

(Of course it’s a pseudoproblem. It vanishes the moment you look at the whole world as a quantum world.)

Question 6: What is the message of the observed violations of Bell’s inequalities?

a. Local realism is untenable: 64%
b. Action-at-a-distance in the physical world: 12%
c. Some notion of nonlocality: 36%
d. Unperformed measurements have no results: 52%
e. Let’s not jump the gun—let’s take the loopholes more seriously: 6%

(I don’t like how the phrase “local realism” is essentially conflated with classical eigenstates. Why is a quantum state not real?)

Question 7: What about quantum information?

a. It’s a breath of fresh air for quantum foundations: 76%
b. It’s useful for applications but of no relevance to quantum foundations: 6%
c. It’s neither useful nor fundamentally relevant: 6%
d. We’ll need to wait and see: 27%

(I wish there was another option: e. A fad. Then again, it does have some practical utility, so b is my answer.)

Question 8: When will we have a working and useful quantum computer?

a. Within 10 years: 9%
d. In 10 to 25 years: 42%
c. In 25 to 50 years: 30%
d. In 50 to 100 years: 0%
e. Never: 15%

(The threshold theorem supposedly tells us what it takes to avoid decoherence. What I think it tells us is the limits of quantum error correction and why decoherence is unavoidable.)

Question 9: What interpretation of quantum states do you prefer?

a. Epistemic/informational: 27%
b. Ontic: 24%
c. A mix of epistemic and ontic: 33%
d. Purely statistical (e.g., ensemble interpretation): 3%
e. Other: 12%

(Big words look-up time, but yes, ontic it is. I may have remembered the meaning of “ontological”, but I nonetheless would have looked up both, just to be sure that I actually understand how these terms are used in the quantum physics context.)

Question 10: The observer

a. Is a complex (quantum) system: 39%
b. Should play no fundamental role whatsoever: 21%
c. Plays a fundamental role in the application of the formalism but plays no distinguished physical role: 55%
d. Plays a distinguished physical role (e.g., wave-function collapse by consciousness): 6%

(Of course the observer is a complex quantum system. I am surprised that some people still believe this new age quantum consciousness bull.)

Question 11: Reconstructions of quantum theory

a. Give useful insights and have superseded/will supersede the interpretation program: 15%
b. Give useful insights, but we still need interpretation: 45%
c. Cannot solve the problems of quantum foundations: 30%
d. Will lead to a new theory deeper than quantum mechanics: 27%
e. Don’t know: 12%

(OK, I had to look up the papers, as I had no recollection of the word “reconstruction” used in this context. As it turns out, I’ve seen papers in the past on this topic and they left me unimpressed. My feeling is that even as they purport to talk about quantum theory, what they actually talk about are (some of) its interpretations. And all too often, people who do this leave QFT completely out of the picture, even though it is a much more fundamental theory than single particle quantum mechanics!)

Question 12: What is your favorite interpretation of quantum mechanics?

a. Consistent histories: 0%
b. Copenhagen: 42%
c. De Broglie–Bohm: 0%
d. Everett (many worlds and/or many minds): 18%
e. Information-based/information-theoretical: 24%
f. Modal interpretation: 0%
g. Objective collapse (e.g., GRW, Penrose): 9%
h. Quantum Bayesianism: 6%
i. Relational quantum mechanics: 6%
j. Statistical (ensemble) interpretation: 0%
k. Transactional interpretation: 0%
l. Other: 12%
m. I have no preferred interpretation 12%

(OK, this is the big one: which camp is yours! And the poll authors themselves admit that it was a mistake to leave out n. Shut up and calculate. I am disturbed by the number of people who opted for Everett. Information-based interpretations seem to be the fad nowadays. I am surprised by the complete lack of support for the transactional interpretation, and also by the low level of support for Penrose. I put myself in the Other category, because my half-baked ideas don’t precisely fit into any of these boxes.)

Question 13: How often have you switched to a different interpretation?

a. Never: 33%
b. Once: 21%
c. Several times: 21%
d. I have no preferred interpretation: 21%

(I am not George W. Bush. I don’t “stay the course”. I change my mind when I learn new things.)

Question 14: How much is the choice of interpretation a matter of personal philosophical prejudice?

a. A lot: 58%
b. A little: 27%
c. Not at all: 15%

(I put my mark on a. because that’s the way it is today. If you asked me how it should be, I’d have answered c.)

Question 15: Superpositions of macroscopically distinct states

a. Are in principle possible: 67%
b. Will eventually be realized experimentally: 36%
c. Are in principle impossible: 12%
d. Are impossible due to a collapse theory: 6%

(Of course it’s a. Quantum physics is not about size, it’s about the number of independent degrees of freedom.)

Question 16: In 50 years, will we still have conferences devoted to quantum foundations?

a. Probably yes: 48%
b. Probably no: 15%
c. Who knows: 24%
d. I’ll organize one no matter what: 12%

(Probably yes but do I really care?)

OK, now that I answered these poll questions myself, does that make me smart? I don’t feel any smarter.

 Posted by at 2:52 pm