Archive for the ‘science’ Category

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Handicapping the Tunguska event

June 29, 2008

This isn’t the “all manner of thing will be well” post I adumbrated. It’s a stray FISA thought brought on by a scientific anniversary.

Every so often, Nature publishes a themed issue. For 26 June, the theme is astronomical collisions.
The lead editorial talks about the catalog of near-earth asteroids that’s been developed since the 1980s. When the catalog was originally proposed, the idea met with some active resistance from astronomers. It wouldn’t really give us any new science, just a lot of boring detail, and the acquisition would have an opportunity cost on more instructive research.

But now we have all the asteroids capable of producing a mass extinction event under our sights; it’s a good thing that we do, and it’s been good PR for astronomy. There’s a tendency to consider the job done. However, there’s a huge population of lesser asteroids that could still be pretty devastating, from the point of view of the layman, if not from a planetary perspective. The editorial recommends beginning the larger survey, but in an incremental way rather than as Big Science.

Imagine an unspotted asteroid laying waste to a significant chunk of land, as happened in the Tunguska region of Siberia 100 years ago this week; and imagine if that area, unlike Tunguska and a surprising amount of the globe today, were populated. The politician or scientific adviser who had dismissed such a disaster as being too improbable to bother with would be in dire straits. Politicians know in their bones that unlikely events matter.

Last summer, Director of National Intelligence McConnell took congressional Democrats aside and told them a terrorist hit on DC was likely over the August recess. It was a lie. The Dems swallowed it hook, line and sinker. And so the “Protect America Act”, authorizing massive warrantless wiretapping of American citizens, was passed.

Over at the Unclaimed Territory blog, Glenn Greenwald, peace be upon him, has been pointing out that fear of “looking weak on terror” by letting the PAA lapse is groundless. Several Republicans have run against Dems in Republican districts lately, using precisely that attack. And the Democrats who have said, “No, surveillance has to be overseen by courts and Congress, it can’t be left to one man’s say-so” have won handily. That fear tactic has been defanged. And the polls show it, too.

That’s right as far as it goes, and it’s true that many Vichy Democrats are paralyzed by exactly that outmoded bogeyman. But I would suggest that there’s another political calculus, which may be behind Obama’s decision to defuse the FISA issue, even if he has to temporarily deep six the Constitution to do it. A calculus based not on fear of being called soft on terrorism for opposing the FISA extension, but on what would happen politically in the case of a Tunguska event.

Not to put too fine a point on it, if Obama were to lead an assault on HR 6304, and succeed, and if before the election there were another major Al Qaeda attack in the US, Bush would flood the media with a false but unfalsifiable claim: that the warrant that would have prevented the attack was tangled in the (nonexistent) “red tape” of the old FISA laws. And with that, any chance of keeping the White House out of the hands of McCain and his neocon handlers for the next four years would be blasted to green glass.

That probably won’t happen. But it isn’t all that unlikely. It wouldn’t take another September 11. Close enough to Election Day, a Madrid level attack would suffice. The chances of such an attack in any given year are surely over 5%. Considering that Al Qaeda wants to keep the neocons in power, once they have an operational plan, they will try to time the attack to coincide with an election. So it’s more likely this year than at any time since 2004. Given Al Qaeda’s resurgence in Waziristan, and the rate at which opium wealth has been pouring into their coffers, it is really more likely than at any time since 2001. And AQ may feel they need to move quickly, because although their wealth and military strength have been growing, their brand is hurting of late. Recent surveys, in Iraq and elsewhere, indicate they are getting a rep for blowing up fellow Muslims rather than infidels, and are being taken less seriously as a result. They need a return to America, or at least to Europe, to bolster recruiting.

Obama is free to forthrightly champion the rule of law – by loudly opposing telecom amnesty and, more substantively, by cheering the restoration of habeas, as he did earlier this month. No October attack could be laid to the telecoms having to spend a little time in court, nor to the fact that a few Guantanamo inmates are finally allowed to spend a little time in one. He can meet any political risk in those stances head on, by educating the public. But if he were to squash the FISA amendments, and Al Qaeda chose October to make its next move, the nation would no more be in the midst of a teachable moment than it was through the awful panicked year of 2002.

I don’t know if that’s his reasoning. (For that matter, I don’t know whether the congressional leadership would give up their love affair with amnesty on his say-so anyhow.) But if it is, he might well be right that the time to fully crank up the country’s long overdue basic instruction in the Bill of Rights will only come once he stands safely behind the Bully Lectern.

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Darwinism proven by Bible Code methods

November 10, 2007

Some years ago, actually, but I just caught up with it. We have Noam Elkies, number theory maven at Harvard, to thank for the discovery.

If God weren’t an evolutionist, he would never have allowed “Ape’s son, IMHO” to be an anagram for homo sapiens.

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Mirkwood comes to Midland

September 1, 2007

The New York Times reports that a state park in Texas has become home to a spider web several acres in size.

Sheets of web have encased several mature oak trees and are thick enough in places to block out the sun along a nature trail at Lake Tawakoni State Park, near this town about 50 miles east of Dallas.
The gossamer strands, slowly overtaking a lakefront peninsula, emit a fetid odor, perhaps from the dead insects entwined in the silk. The web whines with the sound of countless mosquitoes and flies trapped in its folds…
Mr. Dean and several other scientists said they had never seen a web of this size outside of the tropics, where the relatively few species of “social” spiders that build communal webs are most active…

The Times doesn’t mention the possibility, but one predicted consequence of global warming is that tropical species will extend their ranges northward. Maybe the spiders have congregated to reward all those Texas oilmen for providing them with new habitat.

The Grey Lady is also mum on the explanation I find most likely: once both Tom DeLay and Karl Rove headed back to the Lone Star State for good, word went out on the grapevine that the nucleus had formed for a creepy crawler flash mob.

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The Kandy Kolored Citronella Flaked Slimelined Baby

June 9, 2007

nudibranch cuthona behrensi

You can talk about your Amazonian butterflies, your Cuban hummingbirds, your Costa Rican poison tree frogs. But for sheer variety in bejewelled unearthly beauty, give me sea slugs every time.

The more polite name for them is nudibranchs, and they’re seemingly endless in their variety. My attention was drawn to them again when the Smithsonian Tropical Research Institute announced the discovery of five nudibranch species at a whack. One of them was Cuthona behrensi, pictured above. (Click here for the larger original, and here for a pdf file including medium sized pics of all five.)

While trolling the net for that pic, I stumbled across the delightful slugsite.us, and in particular its Opistobranch of the week gallery. Take a leisurely browse, and you’ll be looking at those plodding plug uglies in your garden with a new respect. They may be poor relations, but they come from a royal family.

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Three for the show

April 27, 2007
My Peculiar Aristocratic Title is:
His Most Noble Lord Nicteis the Mad of Goosnargh on the Carpet
Get your Peculiar Aristocratic Title

Three links of interest (with thanks to OBC’s indispensable recaps on Salon Tabletalk):

Do birds fart? The sagacious Laura Erickson again resolves one of the burning questions of the cosmos.

Learn your Peculiar Aristocratic Title. (Mine resides in splendor at the head of this post, along with the link.)

And Chatham, England has decided to pack in the tourists with a Dickens theme park. Having read nearly all of Boz at least once, I’m ready to consume a bit of underdone potato, and have the Spirit of Englands Past waft me across the pond to sample this marvel when the clock strikes one.

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Your garden is full of quantum computers

April 24, 2007

It hasn’t made a big splash in the media, but the revelation about photosynthesis in Nature two weeks ago might be the sleeper science story of the year. (You’ll need a subscription or an academic account to follow the link.)

Photosynthesis has always posed a conundrum. It’s unreasonably efficient. While materials scientists struggle to get solar cells up to 30% efficiency, green plants everywhere chug happily along, converting photons to bound chemical energy with effiiciencies topping 95%.

How on earth do they manage it? That solar cell just converts a photon’s energy to charge, in a single step, and then drains off the charge. But in the light-eating organism, the photon excites an electron in one atom, and the excitation goes through a long cascade of other atoms in a complex molecule like chlorophyll, presumably losing energy all the way, until it finally creates a high-energy bond in a carbohydrate at the other end.

In a world run according to classical physics, not much energy could trickle through that whole process. But direct measurements have now indicated that what passes through the photosynthesizing molecule isn’t a series of distinct particles. It appears to be a single quantum wave, which doesn’t lose its coherence.

Let me unpack that just a bit more. In the two-slit experiment, the textbook example of a quantum process, an electron passes through a shield with two openings to land on a target plane. And what we learned in the ’20s and ’30s is that the electron will act like a wave which passes through both slits at once. The peaks and troughs of the wave passing through one slit will intefere with those of the wave passing through the other slit. At some points on the target plane the two parts of the wave will reinforce each other – the electron will be more likely to show up at those places – and at some they’ll cancel each other out, so the electron can’t show up there at all. Until the rest of the world interacts somehow with the electron, forcing the wave to collapse into a particle, it will retain this wavy character. The wtave state is said to be “coherent”, until such time as a collapse makes it decohere.

What Nature tells us is, that the excited electron at one end of the photosynthetic complex remains coherent, taking all possible paths through the molecule to the other end. And it appears that the complex is so cunningly arranged, that the inefficient, energy-losing paths cancel each other out, while the efficient paths enhance one another. As a result, hardly any energy is lost. It’s a process analogous to the “try all possible answers” method by which quantum computers are expected to filter out all but the right answer to a difficult factorization problem.

Such sustained coherence isn’t supposed to be possible very far from absolute zero. Thermal disturbances ordinarily force decoherence. But it seems that evolution, that clever artificer, has found some way to fend it off.

What does all this signify?

Weird as it is, quantum mechanics really does undergird the seemingly solid physical world. Over the years, we’ve grown used to quantum effects, whether we know it or not, since transistors – and with them our whole panorama of blinking, beeping, mousing, clicking, vlogging consumer electronics world – would be so much dead silicon in a classical Newtonian world.

Every so often some maverick will come along (Roger Penrose being the most credentialed) to suggest that something about our mental lives, from free will to consciousness itself, rests in some vaguely defined fashion on quantum strangeness. And those mavericks are generally laughed out of court, with very little hearing. Brains, neurons, proteins, are so big, and quanta are so small!

Now, the likes of Frank Capra may not deserve much hearing. But the bald assertion that quantum effects can’t figure in to the workings of the brain, because neurons, and even neural synapses, are several orders of magnitude larger than elementary particles, never really made sense. Geiger counters are several orders of magnitude larger still, but their macroscopic behavior will differ, depending on how the Schroedinger wave cookie crumbles.

Thanks to this article, the notions that free will, or consciousness itself, might be quantum-generated effects within the brain, have instantly become orders of magnitude more respectable.

In amore practical terms, the new result raises the faint possibility that plants and microbes may eventually teach us how to triple the efficiency of our solar systems. Why faint? Precise calculation of the quantum states of something as simple as a lithium atom push the limits of today’s supercomputers. To model the green sulphur bacterium’s “Fenna-Matthews-Olsen antenna complex” , its chlorophyll cradled by the attendant chromophores that maintain its subtle balances, would push the limits of Douglas Adams’ Deep Thought.

Some enterprising bioengineer may find an ingenious workaround to avoid brute force calculation. But unless she does, chlorophyll will keep most of its quantum secrets until long after we humans have either solved our CO2 problems by other means, or brought our own quantum computer technology into its full maturity , or descended into barbarism.

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Human wave physics goes pragmatic

April 16, 2007

Hajj, Jabarat Bridge For some years, specialists in fluid dynamics have taken an interest in wave phenomena in crowds, analogous to the well-known compressible fluid dynamics that create stop and go vehicular traffic. The most vivid motivation has been the fact that trampling deaths have become more common as more and more pilgrims attend the Hajj. Rather than a few tens of thousands, millions now seek to make their way across the Jamarat bridge near Mecca. Now there’s been a lifesaving breakthrough. As Science News reports:

In collaboration with Saudi authorities, physicists at Dresden University of Technology in Germany studied video recordings of the 2006 stampede. They wrote visual-recognition software to track and measure the motion of individuals in the crowd and, by following those individuals, analyzed the crowd’s movements as the disaster unfolded…”We tried dozens of different measurements,” says team member Anders Johansson, but he and his colleagues found only one factor, which they called crowd pressure, that proved useful. It combines crowd density and the rate of change in the velocity of the flow.

The team found that critical thresholds in crowd pressure correlate with the onset of stop-and-go patterns and turbulence. The findings are due to appear in Physical Review E.

…Salim Al-Bosta, a civil engineer in the Saudi government, says that measures based on the research helped the Hajj run smoothly this year. Image-recognition software now tracks the flow of pilgrims and warns organizers to slow the influx of pilgrims to the site when crowd pressure approaches a critical value, he says.

This would be very cool just as pure research. That it also has such a positive human benefit plasters a huge grin on my beak.

Next challenge for the physicists: model and provide corrections for the dynamic which inexplicably lowers average IQ by forty points when large numbers of Americans enter voting booths.