Sunday, April 27, 2008

At last, at long last!

(Also via Instapundit) Holographic computer memory finally comes to market. Next month, in fact. Man, I've been reading about this for well on 20 years, and I can't believe they're finally selling them.

The drive is $18,000, at least for now, but each removable disk holds 300 GB. And it's photographic, which means it's got a much longer life than most digital media (they're saying 50 years for this). I wonder if this will be a solution for the huge memory requirements of the LSST observatory, which will be recording half a petabyte (1 petabyte=1000 terabytes) of data per month. For 10 years. Imagine adding 500 1-TB hard drives every month to some warehouse-sized room. That's the amount of computer storage they're going to need. Now, the LSST doesn't come on line until 2012, and we can expect disk space to get denser and denser by then, but it's an amazing amount of material they're going to be storing. I'll bet they're looking at these holographic drives as a possibility.

Let the North seceed!

Via Instapundit, here's an annoying and insulting article by a damned Yankee who understands less about the South than a tick does about gardening. As far as Hirsh's throwaway line about the North seceeding, go right on ahead! Just be sure to take D.C. with you.

Dutch food and fun with computer translations

Ever since I went to Holland and got to have "slagroom" in my coffee, I've been trying to figure out how to make it myself. Slagroom is a kind of whipped cream, but it seemed a lot thicker than whipped cream here. I've tried taking heavy cream, adding various amounts of sugar (or powdered sugar), and beating it longer than you would for regular whipped cream. It seems to get close, but I'm not sure. In Holland, I was actually given a knife to cut it and put it in the cup.

Anyway, I've found a Dutch-language Wikipedia entry on slagroom, but not reading Dutch, I tried the "translate this page" option on Google. It worked out nicely, but with a few quirks I got a laugh out of. For one, you've got something like a mathematical degeneracy--multiple words being translated into the same one in English: Cream is one of several types of thin cream that of the whole milk is geschept. ...and the occasional untranslated word which sounds like Yiddish.

And here's my favorite: Traditionally eaten on whipped cream is also a lawyer. Well, the Dutch sure know something about tort reform! (The double-entendre was accidental, but I'm proud of it.)

Saturday, April 26, 2008

Democracy and the ability to lose

I remember a historian making the argument that American democracy was not demonstrated (or proven, maybe) with the election of George Washington in 1789, so much as with the election of Jefferson in 1800. In that year, the Federalists lost their first election, and Jefferson's Democratic Republicans came to power. It was a peaceful, orderly transfer of power from one party to another. You've got to have that, if you want a stable democracy.

In that vein, read Jerry Pournelle's comments on the Democratic party today:

And meanwhile the Democrats seem to be drifting toward the concept of prosecution of former office holders by criminalizing policy differences. That's a certain formula for civil war; perhaps not immediate, but inevitable. The absolute minimum requirement for democratic government is that the loser be willing to lose the election: that losing an election is not the loss of everything that matters. As soon as that assurance is gone, playing by the rules makes no sense at all.

I don't think we're heading towards civil war, but this attitude does undermine the stability of our system. An Instapundit reader adds some historical context to this, on the Roman civil war.

Re: E pur si muove

Figulus: it's unbelievable to me that there really are geocentrists out there in this day and age. (And, ironically, using such technology as the internet!) I've seen Robert Sungenis' website and read some of his arguments for it, and what strikes me about both him and the fellow you were debating is that they try to (mis)use some general principles of physics qualitatively but can't handle them quantitatively. You mentioned that General Relativity (GR) reduces to Special Relativity (SR) in the low-gravity/low-acceleration limit, which reduces to Galilean relativity in the low-velocity limit. The differences are incredibly small in the low-end case, so if we have a major problem there with Galilean relativity, we're going to have a major problem with the more sophisticated versions, too.

These guys have got to learn how to calculate. I doubt they can actually work their way through the numbers to get quantitative results from GR.

I had a student who had a similar problem last year--he's fascinated by physics, but he didn't have the math experience to go with it. So he'd come in and want to solve all kinds of cutting-edge problems conceptually, and his solutions would be wildly impractical. He knew some concepts, but he didn't know how to apply them to get actual answers. This year, he's taken all kinds of math courses and is starting again at the introductory physics level, and the difference is amazing. He gets the correct answers almost instinctively now, because he understands how to apply the concepts mathematically. And his flights of fancy are tempered by the mathematical reality. He's going to go on with great success now, I can tell. Grad school, definitely.

Thursday, April 03, 2008

E pur si muove

Two month's ago I got into an argument with some geo-centrists over at a liturgy blog. Comments are now turned off at that particular blog, which is just as well, since geocentrism is not really on topic for a liturgy blog. But in my zeal to fight the errors of the Bloch-heads (as I called them here), I figured I may as well respond here.

For the backstory, read the relevent comments here. The argument is between me (Rob F.) and RBrown and a few others.

RBrown said, "Since when is it falling prey to resentment or a lack of charity to say that someone is wrong?"

My apologies. I assumed that you must have some animus against Galileo because it seemed so farfetched to me that you would say that he did not understand his own Principle of Relativity, or that he secretly did not believe it.

RBrown later said, "I’m sure it made perfect sense for Galileo—but it also made sense for him to say that Scripture was wrong."

Galileo never said that Scripture was wrong. He said the earth moved; that's not the same thing, unless you interpret scripture to mean the earth does not move. That would be an erroneous interpretation of scripture, obviously.

RBrown also said, "Once again: Time is intrinsic to Motion—thus Motion cannot be considered to be relative as long as Time is considered to be absolute."

Position as well as time is intrinsic to motion. You can have relative motion if you have relative position, which is what Galileo said. If you have relative position, you do not need to have relative time as well. It doesn't hurt to have both, but you do not need both; one will do fine. As a matter of fact, we do have relative time as well, but Galileo had no reason, none at all, to assume that.

RBrown said regarding Einstein's General Theory, "Once again, I refer to the General Theory of Relativity. In the Special Theory Einstein assumes the uniformity of all inertial frames of reference. In the General Theory, however, inertial frames are jettisoned, replaced with curved Space-Time."

Since Einstein's General Theory (EGT) reduces to his Special Theory (EST) in low gravity fields (and his Special Theory reduces to Galileo's Principle (GP) at low velocities), it seems to me that proving that the earth revolves at low velocities in low gravity with Einstein's Special Theory (or Galileo's Principle) is equivalent to proving the same thing with Einstein's General Theory. After all, if GP is wrong at low gravity and low velocity, then EGT will be wrong too.

But let me offer a thought experiment that does not rely on Galilean or Lorentz invariants to prove my point. Consider the time dilation due the Earth's rotation around the Sun. Take two clocks, A and B, on Earth and synchronize them. Move A to the Sun and let both clocks keep ticking for some centuries. Then take A and move it back to Earth and compare it with B. There will be a discrepancy between A and B. Now correct for the effect of gravitational time dilation. There will still be a remaining discrepancy. This remaining discrepancy will be due to the time dilation in B due to the continuous acceleration of the Earth. If it were the Sun that were moving, the remaining time dilation would be in A. But EGT predicts the time dilation to be in B. That's because according to EGT, like EST and GP, says it is the Earth that is revolving around the Sun, and not the Sun around the Earth.

I do not expect this thought experiment to be carried out by NASA any time soon. I simply propose it to demonstrate that EGT cannot support geocentrism.

This thought experiment is quite analogous to subatomic particles revolving around a storage ring in a laboratory. It has been observed that such particles have their lifetimes dilated with respect to the laboratory clocks exactly as predicted by Einstein. This dilation demonstrates that it is indeed the particles that are revolving in the lab, and not the lab that is revolving around the particles!

These direct observations, along with observations of stellar parallaxes mentioned above by Fr. Augustine Thompson and observation of the aberration of starlight also mentioned previously, serve to demonstrate that there is indeed a qualitative and measureable difference between revolutional and rotational motion on one hand and translational motion on the other, and while translational motion is relative, neither revolutional nor rotational motion is, at least not entirely.

Any way you look at it, it still moves.