Having heard on the news all the phony reasons as to why President-elect Obama must give up his Blackberry, I was planning to write down my strong opinions here. But, it’s no longer necessary… it appears that Newsweek has done it, and I agree with them on all counts: Obama should keep his Blackberry, as it is time for the United States to have a 21st century president.
Wow. It doesn’t happen every day that a cat is found after being lost for 13 years. I hope his owners will be able to nurse him back to health.
I just looked at the channel lineup of Sirius Satellite Radio. They have three classical channels: Opera/Classical Vocals, Classical Pops, and Traditional Classical. 100% Commercial Free, they say.
OK, no commercials. How about commentary? How about radio personalities that inform and entertain, tell you stories about the music you hear?
And narrowly defined as they appear to be, do any of these channels have room for something unexpected? Say, a little Kurt Weill, a little Heitor Villa-Lobos? Astor Piazzolla? A surprise piece of Canadian folk music wedged between two traditional classical pieces, such as Norm Hacking singing about orange cats?
These satellite channels, just like the CBC’s own new Internet channels, seem nothing more than glorified playlists to me. If I wanted a randomized playlist, I have several hundred CDs to choose from… lovely music, all of it, but who will show me something new?
Not the CBC, not anymore. Yesterday, while I was driving somewhere in town, I was listening to CBC Radio 2, as my car radio is still tuned to 103.3 MHz out of habit I guess. What I heard was some hapless, untalented artist’s barely recognizable rendering of an old Abba song. I grieve for a world-class radio station that has been put to premature death by mediocre bureaucrats engaged in cultural vandalism.
In the year 1086, William the Conqueror ordered a survey of England. The result of this became known as the Domesday Book, a detailed account of the material wealth of England on that day of accounting, or reckoning, or doom (dom in Old English), i.e., on domesday.
900 years later, the BBC engaged in a cultural heritage project. The BBC Domesday Project was a multimedia survey of the United Kingdom, published using the latest technology: laser disc. Remember laser discs? Not compact discs, laser discs. 12 inches wide, big, shiny, designed originally to store near broadcast quality analog video.
The two Domesday discs contained professional video segments, numerous photographs encoded as single-frame analog video, along with a large amount of data (including geographic data and data from the 1981 census), as the discs could store about to 300 MB of digital data, a huge data capacity at the time.
All you needed to view the BBC Domesday disc was a specially manufactured laser disc player, along with an Acorn computer with specialized interface hardware.
Of course today it is a tad hard to find a laser disc player of any kind, never mind a specially manufactured model. As to the Acorn with the custom interface and coprocessor, good luck finding one on eBay!
The original creators of the BBC Domesday project knew about possible obsolescence; yet despite their efforts (they sent copies of everything to the UK National Data Archive, where apparently everything promptly disappeared) the data were almost lost.
Although it appears that the BBC Domesday project has been largely rescued, it highlights a bigger problem: what happens to our society’s written record if the medium on which it was written becomes obsolete? Some people speak of the digital dark ages, a period in history (i.e., the present) that will become inaccessible to future researchers, as our collective memory is written in a form that will not be compatible with the hardware of the future. Indeed, to some extent it has already happened… how many people have computers today that can read 5.25″ floppy disks, for instance? Or, what happens to Web sites when the people who maintain them are no longer around? Never mind 900 years, will any of our “domesday books” still be readable just 90 years from now?
There are protests throughout America today in support of same-sex marriage rights. One thing that troubles me is how phony the arguments are on both sides.
Those in favor of same-sex marriage portray it as an equal rights issue. As if gays and lesbians were ever barred from entering into a marriage! Of course they are free to marry… a person of the opposite sex. Broadening the definition of marriage to include same-sex unions is an unprecedented step. That is not to say that it is wrong to take this step, but it’s not quite the same as, say, allowing women to vote.
But those opposed to same-sex marriage have equally phony arguments. They have a right, they say, to the traditional definition of marriage, as if broadening the definition of marriage ever threatened traditional, heterosexual unions. They are worried that pastors and ministers will be forced to marry homosexual couples, not that there is a precedent of a pastor or minister ever having been forced to marry anybody.
Why can we not have a reasoned discussion instead? The argument in favor of same-sex marriage is strong. It is about the rights of two people to care for each other, to be able to act as legal guardians of one another, inherit from one another, visit one another in hospital, and so on. Denying a decent, loving couple these rights just because it doesn’t agree with our idea of a “marriage” just doesn’t sound right.
On the other hand… is it really necessary to provocatively call this “marriage”? I don’t mind it, but many do. If it is indeed about rights and not the symbolism of the word itself, what’s wrong with same-sex unions?
On the third hand… if we recognize marriage as a relationship that legalizes the love and care people feel for one another (as opposed to the potential to procreate), why would we artificially limit it to two people? What is wrong with legalizing polygamy?
On the fourth hand… if, as opponents of same-sex marriage say, marriage is indeed about procreation, what about childless heterosexual couples? Should older or infertile people be allowed to marry?
I believe these are valid questions for a reasoned discussion. Unfortunately, neither plebiscites aimed at changing a state’s constitution to deny a hard-earned right, nor street protests with empty slogans lead to reasoned discussion.
It is always creepy when fact meets fiction. I’ve been watching the latest episode of Terminator: The Sarah Connor Chronicles, which is a surprisingly good quality sci-fi series. I then checked on Google News if there are any news about the show’s rating or popularity. Instead, what I found was a story about a robot in Japan, greeting amusement park visitors, selling tickets, and using face recognition software to profile customers. Not only does it sound a little like Westworld, one commenter actually suggested that it might be time to call Sarah Connor to finish this one off, which is why Google News found this entry in response to my search.
Many textbooks and many popular science books tell you that the event horizon, the so-called “point of no return” in the vicinity of a black hole is nothing special. Apart from increasing (but finite!) tidal forces, an observer would not notice anything special when he crosses the horizon. But is this really true?
If this statement were true, it would mean, in essence, that there is no measurement an observer could perform in his immediately vicinity to determine if his vicinity is at or near the event horizon. But this may not be the case; there may, in fact, be a quantity that is measurable (at least in principle).
The curvature of spacetime is described by the Riemann tensor \(R^{\mu\nu\rho\sigma}\). The gradient (covariant derivative) of this quantity is \(R^{\mu\nu\rho\sigma;\kappa}\). Forming the scalar product of this quantity with itself, we obtain an invariant scalar quantity,
\[ K=R^{\mu\nu\rho\sigma;\kappa}R_{\mu\nu\rho\sigma;\kappa}. \]
If we calculate \(K\) for the Schwarzschild metric of a nonrotating, uncharged black hole, we get
\[ K=720m^2\frac{r-2m}{r^9}. \]
This quantity becomes zero and changes sign at the Schwarzschild horizon \(r=2m\).
So never mind what the books say. In principle, an observer can measure the curvature tensor and its gradient, and therefore, can construct an instrument that measures this invariant \(K\). (Note that although I used the letter \(K\), this is not to be confused with the better known Kretchmann invariant.) If this is true, what other effects might there be that make the event horizon a special place?
There is another thing to think about. Often you hear that the Rindler horizon seen by an accelerating observer, or the cosmological horizon in an expanding universe are “just like” the Schwarzschild horizon (perhaps even suggesting that we might be living inside a black hole.) But this cannot be so! Two observers who are not moving the same way do not see the same Rindler horizon or the same cosmological horizon. These are only apparent horizons, their presence, even their existence dependent on the observer’s motion. In contrast, the Schwarzschild horizon is real: two observers can agree on its location regardless of their own location and motion.
I just received the latest Microsoft security newsletter, and I was surprised to find that according to Microsoft, there is a debate about security vs. obscurity. Which may go a long way towards explaining why Microsoft products are so notorious when it comes to their (lack of) security!
That is not to say that there are no valid points in favor of obscurity measures; as the example discussed by Microsoft clearly demonstrates, it is always beneficial to make an attacker’s life a little harder. But it is a real stretch to call this a “debate”.
That is because it is not an either-or proposition. You can never have security through obscurity, and no amount of obscurity will make an otherwise unsecure system secure. But the security of a well-secured system can be improved by a little bit of obscurity, and in that sense, obscurity can supplement (but never replace) real security.
Reading on, it seems to me that some of the contributors to Microsoft’s “Great Debate” realize this. Too bad the person in charge of giving the article its title didn’t.
It appears that, in the end, it was French president Sarkozy who prevented Putin from occupying Georgia and forcibly removing Saakashvili from power. If news reports are to be believed, Sarkozy simply asked Putin if he (Putin) wanted to end up like Bush. Putin conceded that Sarkozy had a point there… and the invasion stopped short of reaching Tbilisi.
I am not sure what this says about the Bush presidency, though.
This fine lady below is America’s newest four star general. It is perhaps fitting that the the first ever promotion of a female officer to four star general status happens just during the transition to the first ever administration of an African-American president.
General Dunwoody
Now that this nice lady received her fourth star, I wonder what it will mean for the question concerning women in combat roles in the US military.
I am still evaluating WordPress, but I thought it’d be instructive to write something about physics. (For one thing, it’d allow me to check how well I can include HTML equations in a WordPress post.)
Notably, about neutrino masses. The Standard Model (SM) of particle physics says that neutrinos are massless. Fermions in general are organized into left-handed doublets (with neutrinos and leptons forming one pair, while up-type and down-type quarks forming the other) and right-handed singlets, but there is no right-handed neutrino. An important claim of fame of the SM is that it is a theory that is unitary and renormalizable.
Trouble is, there is now plenty of observational evidence telling us that neutrinos are not massless. Why is that a problem? You take a left-handed neutrino that is massless, and it moves at the speed of light. You take a left-handed neutrino that is massive, and it moves slower than the speed of light. So, you move fast enough to catch up with it, pass it, and look back, and what do you see? A right-handed neutrino, that’s what. But in the SM, no right-handed neutrino exists.
So what happens when you add a right-handed neutrino? There are two basic choices: the neutrino may be represented by either a Majorana spinor or a Dirac spinor. Without going into needless detail, the first choice basically means that the neutrino is its own antiparticle, ν = ν. So why is this a problem? Because neutrinos carry lepton numbers (very simplistically, an electron can be thought of as the sum of a W– particle that carries its electric charge and an electron neutrino that carries its “electronness”. That “electronness” is the lepton number. Now if a neutrino is its own antiparticle, that means that two neutrinos (each carrying a unit of “electronness”) can annihilate, and the two units of “electronness” disappear: lepton number is not conserved. In addition to aesthetic concerns, there are also stringent experimental limits on the violation of lepton number conservation.
The other possibility is that neutrinos are Dirac neutrinos. Dirac neutrinos have genuine antiparticles, so lepton number violation is not a problem. One big problem, however, is the smallness of the neutrino mass; as I understand it, the main objection is that the dimensionless coupling constant that governs the neutrino mass in the Lagrangian is small (of order 10–12) and this worries a lot of people.
Yet another alternative is to account for the observed neutrino oscillations by putting in new interaction terms. While this can be done without a right-handed neutrino, it breaks the renormalizability of the standard model. Loosely speaking, this means that one can no longer assume that things happening at a low energy scale are not affected by things that only happen at high energy. This is not how we experience nature. On the contrary: we can build mechanical devices (relying on low-energy interactions between surface atoms) without worrying about chemistry; we can perform chemical experiments without worrying about nuclear physics; we can do nuclear physics without having to worry about the internal structure of protons and neutrons; and so on. In other words, most physical phenomena can be “renormalized”, treated as if the upper limit of its applicability was infinite, and still yield meaningful results; you only need to worry about higher energy phenomena once you reach that higher energy scale. Why would neutrino physics be different?
Today, I decided to download and install WordPress, a web logging tool. It’s time for me to join the 21st century, get rid of my homebrew Day Book, and start using a modern web logging tool instead. (I refuse to call it a “blog”. I really dislike that word.)
A little confusing, but I think I also know how to include an image. My test image is my favorite Halloween cat. I think it’s nice to start a brand new web log with a friendly black cat.