Confession: I had the hardest time understanding relativity. Not such a big deal for the average Joe, but quite a handicap for a physicist like me. I could certainly apply the equations, that was straightforward enough. The inner logic of it all, though, escaped me.

Take the twin paradox, for instance: one of two twins leaves for an extended trip to another star, and the other one is left behind. When the traveling brother sees the other one on screen, the latter's speech is slowed down, a relativistic effect. I saw that on Ustinov explaining relativity. The Earth-stuck twin, in turn, sees the fast brother talking at twice the speed. Says Asimov.

I had the good venture of spending my high school years in Rome, just at the time when you get acquainted with the fine arts. My memories are still vivid with entering the churches of San Luigi dei Francesi and Santa Maria del Popolo and seeing the Caravaggios in there.

They are an unforgettable sight. They hang high up, far out of reach, and you have to drop a coin to turn on the lights that allow you to see them. And when you do, get ready for them, because they are not what you'd expect in a church.

Caravaggio's paintings are spectacular in a way you can't readily appreciate, because they are so contradictory. They are vulgar in their depictions of the commonest things, and yet sublime. They are photorealistic, yet give up any pretension of accuracy when even major positional problems face the painter with the ugliness of reality.

Get ready for a flood of P.K. Dick novel reviews, since I am getting caught up on old reading. I even went out of my way to order all the ones I didn't buy yet on powells.com, and they are going to arrive any time soon.

The Game Players of Titan is the typical P.K. Dick novel: an uncertain society after a catastrophic development, extraterrestrial life (in this case not imagined), a mystery to solve, and an unusual setting with a great many surprises.

Titan is the largest moon of Saturn and the second-largest moon in the solar system. It is quite notable because it's the only moon with a real atmosphere, and hence there has been speculation it might harbor life. In this particular case, it's life that (a) is silicon-based, (b) communicates between themselves and to humans telepathically, and (c) is not well disposed to humans, a race almost destroyed.

There you go: buy a 400 page book, and then discover that it's a 100 page book plus 300 pages of "original material" with commentary and other stuff. Disappointing, not because it's really only 100 pages, but because I had packed it for the beach - and I can definitely read 100 pages in under an hour, leaving me without much to do but counting grains of sand and waves crashing onto shore.

Anthem is yet another one of Ayn Rand's messages of individualism. For those of you who don't know her (anyone?), she is a philosopher that created this school called Objectivism. The goal of Objectivism is to assert the individual's rights with respect to the collective or society and to affirm that it is immoral for society to downsize the individual for the good of the all. Worse, it is inefficient: society, according to Ayn Rand, grows faster and better if everyone is left to their own devices.