It is hard to remember how thickly spread the sky is with not just stars, but galaxies: so thickly spread that there are even some galaxies behind quasars.
The Sloan Digital Sky Survey sounds almost a little dull: catalog the stars and then, masking them off, systematically look for galaxies. But it has been a hugely powerful tool for discovery.
Yes, there are exceptions, and I could probably point at a few. But on the whole, bet on the parents.
Some parents won't be good teachers. Among them are the nut cases (white or black supremacists "Ancient Egypt was black"), the criminal (we already see 2'nd generation gangsters, and some 3'rd), and the feckless and stoners. But their kids will suffer whether or not their parents are the primary teachers, so concentrating on the minority is a waste of time.
Instead look at the big picture in this story: well-educated youngsters freed from the dangerous environment of the typically miserable black neighborhood schools.
The BBC reports that black parents in the US are turning to homeschooling. The reporter trots out the usual complaint that the public schools will suffer because of the loss of motivated parents, as though it were a parent's duty to sacrifice their children in the faint hope of improving things for somebody else's children in the distant future.
The black families tend to be more single-mother, which is a serious hardship for teaching, but cooperatives will help. This looks positive, and I'm a little surprised it hasn't been a bigger movement before.
~
Lest we forget Pi day!
I'm old enough to remember when dropping the deck was a horrible thing to contemplate, and punched cards are easier to deal with than little bits of lead type.
I re-read The Fifth Head of Cerberus and discovered that what I'd thought was the story was only the first section. And that I'd either forgotten or missed a lot. So...
Reading the New Sun again was like reading it for the first time (except for a bare handful of scenes I remembered). I suppose in my defense reading volume 1 one year and volume 2 a year later isn't conducive to making connections, and by the time the 4'th book came out the first was pretty hazy. Especially when distracted by grad school and babies.
It was weirder than I remembered, creepier than I'd remembered, and with more layers in it than I thought. It follows the story of Severian, a journeyman in the Guild of the Seekers of Truth and Penitence, told from his own (not perfectly forthcoming) point of view as the eventual Autarch; set in a very distant future with a failing Sun and cooling Urth. I have not read the "coda" that ends the series.
The series is, of course, a science fiction adventure, but with so much allusion and mystery and even allegory that it is challenging to read. Which isn't quite the right way to describe it--you can read it straight through without bothering about the details or the inconsistencies, and follow it OK. Except that what you think was happening wasn't always quite what was really happening. Mystery writers drop in little details that you should pay attention to--so does Wolfe.
It is well written--far better than much of the modern fiction I've read--but I won't say "read it." Some friends would be put off by the unpleasant nature of the protagonist, or by his dealings with women, or by who his companions turn out to be; and I can't fault them for that. If (Heaven help us) someone ever tied to make a movie of this it would be a horror movie.
What the researchers from Stanford and SLAC did was interesting enough without the hyperbole and mis-statement. On a smooth copper surface they used a scanning electron microscope to position carbon monoxide molecules in a pattern that mimicked the holes in a graphene lattice. Electrons in the copper surface avoid the CO molecules on the surface, and so behave as though they were really in a graphene lattice. But more than that, when the researchers put the CO molecules on in a distorted pattern, the electrons behaved as though the lattice was distorted e.g. by a magnetic field. And all worked out as calculated.
So this might be a test-bed for predicting how materials behave in strong magnetic fields--up to the point where real fields would start causing substantial distortions in real molecules. Then the model would fall down.
The drawback is the rather tedious placement of the molecules. I find it amazing that we can do that at all, much less plant so many, but they do it.
In any event, the effects in the Himalayas are quite dramatic: Everest is about 9km high, but the Moho boundary is pressed 30km deeper below the Himalayas than below the surrounding land; and similarly under the Andes.
You can't expect perfect equilibrium--for the weight of rock above to equal the weight of rock pushed down. Spalling and erosion will remove a lot of the excess above, and on a timescale much faster than continental drift. Still, that's a lot of rock "under water".
Of course there may be some biases in their reconstruction; they can't measure the depth directly, and there could be some error in the correction terms they use to account for the continental rock.
Something else to keep an eye on.
Before you click Back, or even click on the link, I should explain a few things.
The first is that the “nature” of a particle not does not predict its mass. In fact, if you try to find the mass of a quark, you discover you aren’t so sure what kind it is, and if you are sure what kind it is you can’t be sure of the mass. The same is true for neutrinos, though at very much smaller masses.
So you have to think of an electron neutrino as being made up of a little of mass type I, a little of mass type II, and a little of mass type III—in a quantum-mechanical way, of course. You don’t chop a little of this and a little of that into a lumpy neutrino salad. You have a blend that will appear to be either type I or II or III, with some probability for each. Likewise a type I will, if you poke at it, be an electron, muon, or tau neutrino with some probability for each.
A neutrino (or anti-neutrino) flying away from the reaction that generated it has to, in some sense, find which mass type it is going to be as it flies. And as it travels through matter, it is in some weak sense poked a little. So the picture is of an electron anti-neutrino that finds itself as a mass type I anti-neutrino as it flies through air and rock, but when it interacts with the detector far away it turns out to be a muon anti-neutrino. It "oscillated" from being one type to another (and it can do that even without matter around.)
Those mixing proportions involve the "mixing angles." The handiest way to describe this sort of relationship between types of neutrinos is with vectors and matrices, which are just ways of bundling lots of detailed equations into something simple to handle. (Trust me, it makes things much easier to keep track of. Remember solving linear equations back in high school algebra? A pain. But a lot easier when you use matrices.) And it turns out to be handy to describe the various components of the matrix in terms of some angles.
We don’t know if there are only 3 types of neutrinos (and their anti-particles, of course): a fellow named Majorana developed a theory with a different kind 70 years ago, and nobody has been able to prove him wrong.
His neutrinos were their own anti-particles, just like photons are anti-particles for photons. He disappeared mysteriously—perhaps he was his own anti-Majorana.
If you know the components of the mixing matrix, you can tell if there’s something missing; some new type of neutrino we haven’t seen yet. That’s why people are especially interested in these details. At any rate, two of these angles are quite small, and this is rather large: about 6 degrees. At Dawa Bay that means that some electron anti-neutrinos coming from the reactors were detected as electron anti-neutrinos at the close detector but a measurable proportion were missed at the far detector. They had "oscillated" into muon anti-neutrinos, but they didn’t have the kinetic energy to generate a muon in the detector, so the detector couldn’t see them. I suppose if we had detectors where muons instead of electrons orbited the nuclei, that might have spotted some of those missing neutrinos. Of course muons decay quickly, so we can’t build any such detectors. Phooey.
Ok, now try the link. (Dawa Bay is in China. There are several reactors there, and an international physics neutrino experiment. The area is high security, of course, and since the French built some of the facilities I understand that the restaurants are very good. They'd better be--you don't get to get out much.)
Update: changed 4'th paragraph to be more precise. If you "poke at" a neutrino, you are probing it with matter and will find out its "flavor" or electron/muon/tau neutrino type. A moving neutrino, though, has to be within shouting distance of being of mass type I, II, or III.
Obviously this is a generalization; we’re all over the map. But it does seem to describe quite a few of us. Several things seem to feed into this effect.
I don’t know how many people spell it out this way, but we generally act as though we have a small set of roles and outside those roles we have the experts (or "those called and gifted") do whatever needs doing. This helps make the economic machinery go, albeit somewhat expensively (replace your own toilet if you’re strong enough to lift it, and don’t call the plumber). Unfortunately that tends to reduce us to cogs in the machine. And while maybe your preacher can explain the gospel very clearly, the fellow down the hall isn’t going to accept your invitation to go to church; if he’s going to hear the gospel you have to tell it.
Similarly, in the public square we tend to want the more articulate to do the speaking, because we mumble too much and can’t keep all the details straight. It can take a long time to become thoroughly informed about even as simple a topic as assisted suicide.
I don’t know if they still do Town Hall meetings in New Hampshire where everybody in town is invited to pipe up about town business. In this neck of the woods when I hear of a Town Hall meeting I know that a politician wants photo-ops with friendlies; uncomfortable questions aren’t welcome. We don’t practice democratic debate much.
Tied in with this is the problem that the washing won’t get done if we don’t do it; and the homework won’t be done if we don’t supervise it. We can spend 15 minutes writing a letter that a clerk will read, check a counter for, and discard. Or we can spend several hours going to an evening meeting where no one will listen to us. Or we can take a day off work to go to a protest and not get paid.
So the upshot is that I should tend my own affairs, for which there is little enough time already.
I want to say that we imbibe the Zeitgeist with our mother’s milk, but it happens with adults too, and remarkably quickly. It is hard to avoid following the fashions.
The received wisdom is that because religious conflicts are so intractable, one should at all costs avoid stirring these up. And for some reason all moral questions are assumed to be religious. So you should avoid talking about moral questions outside of your tribe.
We also have an ambivalent attitude to choice. Sometimes we are determined to protect people from themselves (drug use: prescription or illegal) and sometimes we revere the individual’s perceived right to "do what he wants with his own life." Where the distinctions are to be made between "protection" and "liberation" is never made clear; it is part of the atmosphere. True, the atmosphere differs between tribes, but I never hear any first-principle discussion of this apart from libertarians.
If the moral question can be phrased in a way that makes it sound like a right, large numbers of us, even those who disagree, find it hard to object to someone else’s rights. This is, in part, because few of us have ever learned anything about the philosophical concepts involved.
I remember the calls for revolution from the 60’s and 70’s. Except for some few holdouts most people seem to have decided that the price was too high for the possible benefit. We have a very complex society; if a revolution disrupted it plenty of innocent bystanders would starve; an ironic effect for revolutions supposed to benefit the poor. We owe it to those in precarious circumstances to think of the consequences of our dramatic changes. (And of our less dramatic proposals and their unintended consequences)
I think we have an instinctive sense that our social environment is equally delicate, and that our social compacts can disintegrate if we press secondary issues too hard. In the conflict over each small hill we ask: "Is this little thing worth dying for?" and typically decide not. Only the really big things tend to rouse us.
Arguing in the public square demands time and effort that we could devote to more clearly spiritual work: prayer, helping our neighbors, and so on. Any government is made by men, not God, and tends to be directed by the prince of this world. Making the compromises to achieve some good tends to involve approving some evil. How can any of this be perfect or pure? Best to stay home or in church or someplace where you can work on trying to live a holy life.
I cannot speak for all of us, but quite a few worship in ways that require nothing much beyond showing up most of the time and tossing a regular check in the basket. The band, or the priest, handle all the details. Whether this is acceptable to God is beyond my competence to decide, but it doesn’t encourage cultivation of the spiritual disciplines of insight and humility needed to engage fruitfully in the public square.
That makes it very easy to be appropriately angry or worried (within our tribe) and not feel as though anything is demanded of me.
The upshot is that we typically don’t get involved: Sometimes for excellent reasons. Often that’s exactly what we should be doing, and I don’t like seeing churches in lock step with political parties.
I’d be more specific, but I’m trying to give up politics for Lent. I reckon that this is big-picture environment stuff and not advocacy. Even this annoyed me some; and trying for a more peaceful spirit was one of the goals.
And enough others to keep me from my chores for quite a while.
I remember on the playground in California there'd sometimes be great whirls of wind, and we'd try to dash into them before they dissipated. We were pretty sure they weren't tornadoes, though we called them that out loud, and we'd have been terribly disappointed to learn they weren't even dust devils; just vortices from the wind whipping around the buildings.
I gather that even dust devils can be destructive and even dangerous sometimes.
I think I'll pass. If I can. Last Friday I got about a 15minute late start, and took the wrong turn in Rockford (something I've never done before) to blow another 15 minutes, and went for a leisurely lunch instead of a McD's fly in and out. So we were stuck in traffic north of Henryville for two hours instead of being a part of the event. Glad to be late.
What they are probing is what an average N2 molecule looks like at a particular time relative to the impulse of an ultra-short laser pulse. The laser pulse ionizes the molecule and then, under the influence of the electric field of the laser pulse, the electron returns and scatters off the ion.
They measure the distribution of the scattered electrons in both position and energy, and from that reconstruct the shape and momentum of the thing they scattered off.
In addition, the time at which the electric field of the laser pulse pulls the electron back towards the ion will vary depending on the wavelength of the laser light, so by varying the wavelength they can bounce the electron off the ion at slightly different times. This can give them an image of what the ion looks like at different times.
This is something I've been watching--birds having 5% smaller brains in the radiation area, and mice that tolerate radiation better than outsiders.
I still think it would be easy to compare growth rates of the offspring of captured mice to those found nearby. It should be slower.
It can get a little frustrating to look at the "Brazil plots" (so called because they look sort of like the flag of Brazil) at update after update and not see any dramatic changes, but the walls of the valley creep outward bit by bit and the peak of the hill rises little by little.
Unfortunately, unless we come up with some amazing new methods, I think CDF and D0 are about tapped out here. They won’t be getting any more data.
And I'm working on a different experiment now, so I won't have a lot of Higgs updates in the future.
I think I know what will became of Youngest Son's spare time...
A team using Rossi x-ray satellite data (first link) found one neutron star that seems to have the long-expected behavior; and maybe a clue as to why that behavior might actually be rare. This neutron star spins at only about 11Hz, compared to the O(200-600Hz) that seems to be more typical. The story says one possibility is that there is friction between the fast-moving star surface and the in-falling plasma that could change the way the plasma heats up.
The plasma is swept towards the magnetic poles, resulting in large local currents whose own magnetic fields interact with the current and the existing field of the star to produce pinches and reconnections and similar chaotic effects. (Visualize the lively nature of the corona of our sun.) You expect the in-falling plasma to still have considerable angular momentum, so it should be whirling down to the poles very fast, perhaps rotating faster than the star itself. (In fact the star is expected to slowly speed up thanks to the gas from the accretion disk falling on it.)
The picture in my mind is of a tornado of plasma and magnetic fields; and I'd expect that while some energy will be radiated away in reconnection radiation (X-rays, highly accelerated particles, and the like), much of the rest will be imparted to the plasma long before it hits the surface: arriving already hot and not moving as fast as the naive calculation would expect. This should be a bigger deal for the slow-rotating star with a larger difference between its own rotation and the tornado rotation. Unfortunately I'm not sure whether pressure or temperature matters more for this kind of nuclear ignition, so I can't predict whether the fast-rotating star's faster impacts or the slow-rotating star's higher temperatures would cause more frequent bangs.
China is 95% of the rare earth supply these days--processing is hard and dirty. Turns out they have some other ideas about that: a kind of fern accumulates some of the lighter rare earths; up to 1/1000 of the dry leaf weight. It isn't fast, but it doesn't require a lot of energy beyond grinding up the ore and spreading it around. If the pathway can be bred to be more efficient that could cut out some of the work involved.
That certainly sounds like a lot, until you realize that Venus' rotation period is 243 days. That's still a big change, but not as proportionately huge as you might at first think. And Venus' atmosphere is fiendishly thick and heavy and moving very fast--at speeds up to 100m/sec. If Wikipedia can be believed, the mass of Venus' atmosphere amounts to 1/10,000 of the total mass of the planet, and is moving far faster than the surface; up to 60x faster.
A back of the envelope calculation says that about a 10% increase in wind speed would decrease the planet's contribution to the total angular momentum enough to account for the slowdown.
Why would winds speed up? Maybe they didn't speed up, they just changed direction so that they were less cyclonic and more circum-planetary. If so, you'd expect them to change again down the line, and let poor Venus speed up a smidgeon again.
