Showing posts with label Theory of Everything. Show all posts
Showing posts with label Theory of Everything. Show all posts

Tuesday, October 7, 2008

Broken symmetry

The 87-year-old American physicist Yoichiro Nambu, born in Japan, has been awarded half of the 2008 Nobel Prize in Physics "for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics". Today, he's a professor emeritus at the University of Chicago.

Nambu's mind-boggling work deals with a mysterious concept, spontaneous symmetry breaking, which can nevertheless be described in a simple context. Symmetry breaking? Let me talk rather about egg breaking...

Real-world eggs are more or less symmetric with respect to an axis that goes through the middle of the egg from the blunt end to the pointed end (where the adjectives "blunt" and "pointed" are purely relative). Here's an interesting experiment that you can perform in front of a friend... not necessarily a good friend. Tell him/her that you're going to hold an egg in front of you, fixed between the palms of your two outstretched hands: your left palm pushing in on the blunt end, and your right palm on the pointed end. Next, you are going to squeeze the egg between your palms, harder and harder, until something happens... Roughly speaking, the egg will explode in one of four general directions. If you friend is unlucky, he/she will get sprayed with fallout. Otherwise, you might get hit in the face with your scrambled egg, or the fragments might fly either upwards or downwards. The interesting question is: Why would an essentially symmetrical egg "choose" to explode in one of these four general directions rather than in another?

In a real-world experimental situation, it's easy to imagine obvious reasons why an egg-squasher might succeed in obtaining one outcome rather than another. To put egg on your friend's face, for example, you would only need to wriggle your palms around in such a way that they channeled the eggy projectile away from you. But let's be theoretical, and imagine a perfectly symmetrical egg held between ideally innocent hands in a weightless environment. It would still explode, and the fragments would still fly out in one of the four general directions. In other words, within a perfectly symmetrical context, a disparity has suddenly appeared. How? Why? What caused the unbiased egg, brought up—like a member of British royalty—to be impartial under all circumstances, to "choose" one of these four directions?

An explanation of Yoichiro Nambu's answer to these questions would lie far beyond the scope of this humble blog and the talents of this ever-curious but unpretentious blogger. Let me simply say that, in the weird world of quantum physics and string theory, inhabited by a mysterious creature known as the Higgs boson, all sorts of unthinkable things can indeed arise spontaneously. Even nothingness can suddenly be transformed into somethingness. Astonishing, no?

Saturday, September 6, 2008

Giant atom smasher

The Fabric of the Cosmos by Brian Greene is one of the most beautiful and exciting books I've ever read, on a par with the masterpieces of Richard Dawkins. Published in 2004, Greene's book evokes with eagerness the possibilities of the Large Hadron Collider [LHC] in Geneva, whose first beam will be produced next Wednesday. Results obtained from this giant atom smasher could have either a positive or a negative influence upon the willingness of physicists to accept the celebrated theory of strings.

A nice way of getting a feeling for the LHC is to watch the following CERN rap video:



The LHC is theoretically capable of generating microscopic black holes. Brian Greene writes: "These black holes would be so small and would last for such a short time that they wouldn't pose us the slightest threat (years ago, Stephen Hawking showed that all black holes disintegrate via quantum processes—big ones very slowly, tiny ones very quickly), but their production would provide confirmation of some of the most exotic ideas ever contemplated."

Various naive observers (including certain individuals who should know better) have been trying to create a state of consternation by proclaiming that our planet Earth might get sucked into one of these tiny black holes produced by the LHC. Click the logo to read the CERN press release on this theme.

To be perfectly frank, I quite like the idea of a little black hole in Switzerland that starts sucking up the surrounding territory: first the city of Geneva and its lovely lake, then the Swiss Alps, and so on. Ideally, stuff should slide into the "throat" of the black hole sufficiently slowly for onlookers to have time to appreciate the visual show, while knowing full well that they themselves will soon be victims of the gluttonous hole. Sooner or later, though, the fat little black hole would end up inevitably gorging itself, and it would then roll around sluggishly, maybe burping from time to time, incapable of downing an extra village or mountain. Literally, the hole has stuffed itself. A brave French gendarme could then simply creep up behind the groggy black hole and smash it to smithereens with a swift blow of a hammer... and humanity would be safe up until the next time.

Tuesday, December 25, 2007

Glad Xmas tidings

For all kinds of news and good wishes, there's an ideal time. So, I was happy to take advantage of this Xmas season in an attempt to provide my daughter with a relatively clear bird's-eye view of the Cosmos as I now see it. In the domain of glad tidings, at this time of the year, it goes without saying that I'm faced with a lot of heavy-handed competition, particularly from the pope and his crowds of followers, including the hordes who hear him on TV. I'm thrilled to learn that primeval Bethlehem would appear to be getting back into the stride of Xmas celebrations, since I'm fond of that celebrated town, which I know quite well. Christianity was already a thousand years old when the Crusaders built a church there, above the alleged manger with little or no room for a newborn child. Here at Gamone, I've had ample opportunities of seeing the kind of context in which lambs are born. I've also had the privilege of lingering alone, for a matinal half-hour or so, in the crazy Greek Orthodox grotto at Bethlehem that is alleged to represent the place where Jesus was born.

The Bethlehem Nativity tale is total make-believe of the most superficial kind, but it's nice mythology. Personally, I'm far more moved by the equally absurd tomb of Rachel, on the outskirts of Bethlehem.

Today, everybody (including, probably, the Roman pope) knows perfectly well that all those stories are nothing more than stories. OK, fine, no problem. Why shouldn't we carry on telling such nice old stories to our children, and to anybody else who wants to hear them? Fair enough, but it's not very honest to transmit supposedly glad tidings to friends when the alleged news is obviously false, like the tale of Bethlehem. Today, that's called disinformation [from the Russian dezinformatsiya of circa 1950].

My own glad Xmas tidings are based exclusively upon science, reason, logic and philosophical cogitations of a non-religious kind. Trying to expound this subject to my daughter provided me with an opportunity of translating my thoughts into French... which was an excellent exercise for somebody like me who wants to straighten up the ideas in his mind.

I don't intend to try to summarize here, in my humble Antipodes blog, the sense of the Cosmos... as I sense it. For the moment, I shall content myself with this portrait of an intellectual actor who has enlightened me in a primordial fashion: Alan Turing. His conclusions have accompanied me constantly over the last half-century, ever since my discovery of computing. I referred to him at length in my book entitled Machina Sapiens. Insofar as I might evoke the hero concept, Turing is certainly one of my greatest intellectual heroes. Why? He made it clear to us that a theoretical universal computing machine is capable of computing anything and everything, including tasks that have been relegated to the domain of so-called artificial intelligence. Before you can get around to comprehending the sense of the Cosmos, you have to assimilate this seemingly modest but extraordinary conclusion of Turing, which would appear to justify all present and future activities in the domain of so-called virtual reality, including the perfectly plausible science-fiction notion that we humans, today, might in fact be virtual-reality puppets. To be truthful, Alan Turing was simply talking about everyday digital computers such as our delightful Macs. During his short and tragic time on the planet Earth, my hero was unable to imagine the amazing and almost unthinkable phenomenon of quantum computers. But that's another story, infinitely better than Bethlehem...

Saturday, July 28, 2007

Acquiring knowledge

My article of 23 July 2007 entitled Wandering in a spiritual wonderland [display] includes a photo of an iron nugget that Alain discovered during our excursion to the Grande Chartreuse. Since then, Natacha and Alain have shown me several other mineral specimens they found while wandering around in another Carthusian site [which I've never visited personally]: the former monastery of Saint Hugon, about 40 km north-east of Grenoble, alongside the road to Albertville [in the Savoie département]. One of these specimens was a small rectangular fragment of iron whose surface was similar to that of the first nugget. The other day, the three of us sat outside at Gamone, under the linden trees, gazing at the mineral specimens on a table in front of us, and trying to understand their origins.

In this kind of situation, I've often had the impression that, if I were to concentrate sufficiently upon such-and-such an object that intrigues me, it would end up releasing some of its secrets, providing me with a better understanding of its nature. That was how I felt, a couple of years ago, when I tried to seize the nature of this mysterious object that I unearthed in nearby Châtelus, on the other side of the Bourne:

Since I found this object at a place where there's a legend about an ancient Roman settlement, I imagined it immediately as a sculptured fish. But it was equally likely that natural forces had given rise to this form. No doubt, if I were to show this "red fish" [as I call it] to an archaeologist and then a geologist, I would soon learn which of these two hypotheses is correct... but I've never done so. Instead, I've spent a fair amount of time simply gazing intensely at this object, hoping that it might suddenly send me a message revealing its nature. But no such message has ever reached me yet.

Getting back to the iron specimens from the two Chartreux territories, there were two basic questions:

(1) We referred to these specimens as "iron" because they were attracted by a magnet. But what was their exact geological nature?

(2) How come these specimens were lying around in open fields, waiting to be picked up by a passer-by with keen eyesight such as Alain?

In fact, once Natacha and Alain started out "thinking aloud" with me, I soon realized that they already possessed a good deal of information concerning such specimens:

— They had learned that there was a very special kind of iron ore in the vicinity of the monastery of Saint Hugon. What made it so special was the fact that the ore melted at a relatively low temperature, which meant that it could be transformed into iron by means of a simple wood-fueled furnace.

— The monks soon realized that the most profitable approach to marketing this precious raw material consisted of carrying out an elementary smelting process at the exit from their mines, using the ample timber resources they had on hand. Then the resulting crude iron could be brought down into the valley by mules, and subsequently transported to large-scale furnaces for final processing.

Little by little, as we talked about these operations, we started to obtain answers to our queries about the specimens placed on the table in front of us. They were fragments of crudely-smelted iron that had probably dropped off the back of mules on the way down to the valley. The special variety of iron ore found near the Saint Hugon monastery apparently existed also in the vicinity of the Grande Chartreuse. A final query: How come the two specimens have such a lovely smooth brown surface, with no traces of rust, even though they've been lying out in the open for centuries? There again, Natacha and Alain had acquired information that enabled us to obtain an immediate answer to this question. The ore of Saint Hugon contains a certain amount of manganese, which tends to give the resulting iron a kind of "stainless steel" quality. So, there we had a fairly good comprehensive picture of the context in which these two iron specimens had been found.

Now, why am I relating all these trivial anecdotes? It so happens that they take me back to my recent article about the work of David Deutsch entitled Brilliant book [display].

One of the four so-called strands proposed by the author for a future Theory of Everything is inspired by the philosophical ideas of Karl Popper. Scientists used to claim that they acquired knowledge by a famous process known as induction, which consists of examining things in the real world while hoping that the things in question will end up revealing spontaneously their inner secrets. One of the most celebrated examples is that of Isaac Newton watching an apple falling from a tree, and using this observation to induce the laws of gravitation.

Popper pointed out that the time-honored explanation of the creation of scientific principles by induction is a convenient piece of fiction. Nobody can truly acquire knowledge simply by waiting for real-world happenings and things to "reveal their inner secrets". Newton's apple didn't transmit enlightenment into his head. If there was a revelation, it came from Newton's brain, not from the fallen apple.

What really happens in a context of alleged induction is illustrated eloquently by the brainstorming carried out by Natacha, Alain and me concerning the two specimens of Carthusian iron. These objects did not radiate out magically a beam of information about themselves, enabling us to acquire knowledge about their nature. On the contrary, our emerging knowledge concerning the specimens was based upon information that was forged in our brains, and this information came from our reading, our talking, our experiences and our imagination. Rather than stating that the specimens gave rise to a phenomenon of induction, we can conclude that our brains created this knowledge, in much the same way that a writer invents a good story. And, talking of stories, maybe it's time I ended this one, which is becoming long and complicated...

Thursday, July 26, 2007

Brilliant book

This excellent book by the Oxford physicist David Deutsch came out a decade ago, but I've only just got around to reading it. Seeking to lay the foundations of a vast theory of everything, Deutsch introduces four great domains of knowledge that he refers to as strands:

— Quantum physics

— Epistemology, inspired by the work of Karl Popper

— Theory of computation, inspired by the work of Alan Turing

— Theory of evolution, inspired by the work of Richard Dawkins.

It's rare to find an eclectic author who's prepared to blend such different disciplines into a synthetic whole.