Saturday, April 28, 2012

Saturday afternoon at the airport

My better half and I kept each other company on the drive back while the happy couple got reacquainted behind us. It took a year and a half for Immigrations to let Middle Daughter’s husband into the States; and that was on top of a year and a half before they were married. (Don’t get me started on how well our wonderful bureaucracy works: I work with a lot of non-Americans who can tell endless stories of INS foolishness.)

O’Hare isn’t a very comfortable place even when you’re used to it, and I gathered that Madrid hadn’t been all that wonderful either: nothing had looked good to eat but a glass of wine. And the temperature was 45F when we trooped outside--not quite what he was used to. A pity he couldn’t have arrived in March when it was warm.

We’ll try to make him welcome with broken French, but I can only make out one word in ten, which complicates conversation with requests for translation. It doesn’t make for smooth and easy exchanges. (I didn’t take the opportunities to sharpen my French when I had them...)

It is good that he’s finally here. We're going to take some getting used to.

Charles Taylor

The verdict--guilty of aiding and abetting the Sierra Leone atrocities, not guilty of commanding them--doesn’t seem much of a surprise to me (in fact it is quite fairly judged), but it stirred a ruckus in Liberia where he’s still popular. And even where he’s not popular, I get the sense that some folks aren’t keen on blaming a fellow Liberian, no matter how bad he may be, for problems in another country.

And there’s the rub. This is not clearly lawful. On the contrary, the special court has no standing to try Taylor. Sierra Leone, yes; if he was delivered into their custody. But the special court, if I understood their brief correctly, was not acting on behalf of Sierra Leone but taking upon itself the authority to try him. And if you ask, no, I don’t think the Nuremberg trials stood on any firmer ground.

Suppose I took upon myself the authority to try the Saudi king for crimes against humanity in supporting the mutaween. I could find him guilty in absentia and try to arrange for someone to execute him. I wouldn’t be alone in condemning him. A lot of people would agree that he’s guilty, even if they might not go along with such a sentence. The point is that there is no chain of authority that would give me the authority to do so, and there is no chain of authority giving the ICC authority over Charles Taylor. Adding the magic phrase "crimes against humanity" doesn’t suffice as an incantation. Iran did the same thing with Salmon Rushdie and "blasphemy," remember? If you claim that "blasphemy" is a lesser offense, the Iranians can respond that you are a child of your culture and you haven’t thought the matter through.

The matter may be different for countries that explicitly defer to the ICC. But even there, the deference can be revoked.

I’m not saying Taylor shouldn’t hang. He deserves to, and a 40-year sentence would be dangerously merciful (I mean that literally—his supporters in Liberia may still make trouble). I’m saying I don’t see any legal way of achieving justice here. Neither Sierra Leone nor Liberia have the facilities to safely try him or the political stability to take responsibility for a trial on their behalf elsewhere.

I wonder which makes for a worse precedent, hanging a foreign dictator when you catch him or pretending you have the right to try him. Probably both, in this broken world where there are sometimes no good choices.

Friday, April 27, 2012

There's gold in them thar asteroids

Well, maybe. Everybody has heard about the Cameron/Page/Schmidt plan to launch platforms with an eye to mining near-Earth asteroids. Naturally the lawyers are interested, and there's some harumphing that this isn't really legal.

Never mind that the presence of mine-able quantities of platinum is extremely speculative, and that if they did luck out and bring home enough to pay for the enterprise the price of platinum would plummet. (Platinum was the example around the water cooler.)

Can the lawyers win this one? Nobody can enforce anything in space. Nobody has the reach to do much of anything outside of low Earth orbit. If CocaCola wanted to spray-paint their logo on the Moon (silly idea, most of the time it would be obscured), a minute after liftoff there'd be nothing anybody could do.

Of course lawyers win. Sooner or later you have to come home, and then what happens to your cargo? Your only hope is to land in a compliant little country whose Colonels won't be tempted to take on your security team. Otherwise, meet taxes, import duties, and fines; and maybe revenue-sharing among the space powers.

So never mind the mining--at least for a decade or two. Or three.

What could be done with platforms? What could be done with space platforms that would pay for their construction and maintenance, on a timescale impatient investors can handle?

The problem I see is that almost none of what they can do best would be that marketable on Earth. Science is wonderful, but I have to admit it doesn't make a lot of money right out of the gate. (A few years down the road, or maybe a lot of years down the road, yes.)

If mining runs into jurisdiction problems, and solar concentrators aren't trusted ("What say we tilt this array a tenth of a degree or so?"), and manufacturing delicate items for harsh re-entry isn't quite as economical as it sounded, what have we got left? Tourism? Colonies?

Friday, April 20, 2012

And now a mystery on a mystery

Nobody knows what dark matter is, though it seems pretty clear that it is there, even in our galaxy. But one group says there's not much around where the Sun is. They come up with limits on the local density that suggest that Earth-based dark matter searches have poor prospects.

The preprint explains their assumptions. They're looking at the velocities of stars above and below the galactic plane, and using those to estimate the mass density that would induce that distribution. They're not assuming spherical symmetry. I haven't studied the paper closely yet, but their result is that "Only the presence of a highly prolate (flattening q >2) DM halo can be reconciled with the observations". Click on that link and think what the rest of the galaxy looks like. Hmm. Interesting if true; almost as though dark matter doesn't like normal matter, or that the galactic black hole had something like a dark matter magnetic field or ...

DAMA won't like this result. They claim to have a signal with evidence for dark matter.

UPDATE: 4-May. I've talked to two people about this one. One said his team considered the star velocity measurements to be very tricky, and was dubious of the result. The other said that their group was non-committal except for one fellow (knowledgeable about such things) who said that the calculation model was "dumb." No explanation of why: maybe there are stability problems with the calculation. Or maybe not, I don't know the gentleman.

And gamma rays come from all over

A dark matter search looks for gamma rays from dark matter annihilations. It seems a little bit of a stretch, but if the lowest energy dark matter object is a Majorana particle then you should sometimes get gamma rays when they annihilate. Fermi LAT doesn't see that. In fact,
The team discovered that the pulsars, active galactic nuclei, and the all the rest of the gamma-ray sources pinpointed by the LAT account for only about 10 percent of the gamma-ray photons that have been detected. Extragalactic diffuse emission, a glow that pervades the universe and originates in distant, indistinct sources, comprises approximately 15 percent of the total.

So where does the other 75% come from? What is going on out there?

Somewhere our calculations are a little off, or we're overlooking something obvious.

So then, where _do_ they come from?

Cosmic rays are a puzzle. Protons and iron nuclei hit the upper atmosphere and splatter in showers that typically just leave muons by the time they reach the ground. But where do they come from? And why does the spectrum have such a long tail--out into 10^17 eV , or a million ergs--and more? What (not) on earth can generate such high energies?

To accelerate and shape these kinds of things needs huge magnetic and electric fields, and most stellar activity isn't that dramatic. Gamma ray bursts are. These are so far (luckily) extra-galactic explosions that generate more energy in a few seconds than the sun will through its lifetime, sending so many gamma rays that some of them survive the trip to Earth through all the intervening gas and dust. So if you see two similar oddities, maybe they're related. Maybe gamma ray bursts (GRBs) generate the ultra-high energy cosmic rays too.

It isn't easy to pinpoint the direction of a gamma ray. It interacts with a bang too, but with layers of detectors you can mostly make out the direction from the shape of the shower. Gamma rays have no charge, and so aren't bothered by the twisty galactic magnetic fields that bend protons around in random directions.

You can't tell where a cosmic ray originally came from. It might have gone in some great arc and swept around to hit the Earth from the opposite direction. Galactic magnetic fields aren't very strong, but they are huge and a little bend for a long time makes a difference.

So if we can't use the direction of the cosmic rays to verify that GRBs create them, what can we do?

It turns out that cosmic rays can splatter against photons, especially when there are so many of them coming out of a GRB. One of the by-products is pions. Pions decay to muons, and muons to electrons which aren't going to survive the journey to Earth. But along with those decays come neutrinos. They'll be headed in almost exactly the same direction as the original proton (for high enough energy protons--which is what we're interesting in figuring out). So they should point back to their origin, as ordinary cosmic rays do not.

Cue the neutrino detector IceCube. The short answer is no, we don't see nearly enough neutrinos coming from GRBs. (No, my name is not on that paper.)

So, now what? Either cosmic rays don't come from GRBs after all (and they were such a good candidate), or something is badly mistaken about the interaction cross section of neutrinos at ultra-high energy. Low energy neutrinos have a famously small interaction cross section, but unless there's something unexpected interfering that cross section should rise significantly at these ultra-high energies. Or something else intervenes. I'm puzzling about that one.

How (some) antibiotics work

This research comes at a useful time: we're running out of usable antibiotics. They find that quinolones, beta-lactams and aminoglycosides (OK, I'm as wise as I was before, but those are classes of antibiotics) kill bacteria using hydroxyls to partly oxidize guanine. These defective guanines are taken up into bacterial DNA as though they were normal guanine (or as though it were thymine!)--but then they trigger the defect alarm, and the DNA-repair mechanism tries to split the DNA to splice it out. If there are too many of these, the DNA-repair kit winds up cutting the DNA in two places simultaneously, which it can't recover from.

That's cool. I don't quite understand why this mechanism effects bacteria and not normal body cells. Understanding that is the next step before you can develop some new antibiotics. Which I hope happens soon.

In honor of Dr. Who

Granted, they are only levitating the disk when in water, but the Dundee scientists are also making that rubber disk rotate using shaped ultrasonic pulses (with 1000 transducers!). With appropriate beaming, you could "massage" small organs inside a body without cutting it open.

Tissue near the focus would also tend to be "massaged", though not as strongly, and there might be bruising--but that might worth it when trying to shove bone fragments back into place.

A pity it won't be any good for loosening recalcitrant screws...

Monday, April 16, 2012

Randomizing carbon nanotubes into a "sponge"

I'd not have thought of trying it, but some scientists figured that carbon nanotubes would be more generally useful if there was some way to making a robust mesh or nest of them. Adding boron when making them seems to make the tubes "kink", and therefore link and even bond together. The result is a spongy mass that is "hydrophobic" but sucks up oils.

Obvious use: cleanup.

To demonstrate, Hashim dropped the sponge into a dish of water with used motor oil floating on top. The sponge soaked it up. He then put a match to the material, burned off the oil and returned the sponge to the water to absorb more. The robust sponge can be used repeatedly and stands up to abuse; he said a sample remained elastic after about 10,000 compressions in the lab. The sponge can also store the oil for later retrieval, he said.

They think of uses for filters, scaffolds for bone growth, or as the framework for composite materials. (I wonder how loose the boron is--would this be suitable for all uses of carbon nanotubes or just the ones that don't leach out the boron.)

It would be very interesting to find out what happens with contaminated oils, such as those from car oil changes. Do the metals stay with the sponge (presumably eventually clogging it) when the oil is baked off?

I'm not sure I'd try dumping this on an oil spill in the ocean--I suspect it wouldn't be good for fish to eat.

Watch it bounce, or soak up oil.

I notice that the lead scientist in the group is a grad student. Good for him.

Solar weather videos

NASA has some new the effects of the Sun's weather on the Earth. The first one seemed ... odd. The narration was polysyllabic and rapid, but the animation was alternately superb and cheesy, as if they were trying to capture the attention of young children. Playing it straight would have been a little more dramatic.

Sunday, April 15, 2012

Hunting cranes?

We're debating "Should we or shouldn't we?" here in Wisconsin the past couple of weeks. Cranes are still not that common--certainly not common enough to think of as game birds.

I'm not a big hunter--not since I shot rice birds (a pest) before I went to college. There's just not been a lot of time for that, and I live in cities, where you typically don't pot wildlife out the back window. I see nothing wrong with it in theory--a hunter is participating in the environment just as much as someone just watching it all.

But why cranes? They're noisy and would be pretty trivial to nail--so there's no challenge. I've not heard that they're especially delicious, and the taxidermy I've seen is pretty shabby. All I can think of is that some people want to "shoot one of everything."

Eh. No, this is a silly idea.

On the other hand I can think of a target :-)

Surveillance drones. Simple rules:

  • Shotguns-only within city limits
  • no hunting:
    • within 100 miles of a national border or ocean
    • within 20 miles of a nuclear power plant
    • in airport approaches
    • within 5 miles of hobbyist air zones
  • Bag limit 5 per day.

Friday, April 13, 2012

You shall be like

I know I’m not supposed to think I’m the center of the universe, but wherever I go, there I am.

Most of us find it easy to think of ourselves as the special case that deserves the special consideration. I’ve not run across many exceptions, and most of them seemed to have achieved that exceptional state by discipline rather than natural bent. Don’t ask. I’m still (intermittently) working on it. It isn’t enough to simply be a unique instance of humanity, we have to be the most important instance of humanity and the pinnacle of wisdom.

There’s nothing new here. History is full of us.

But these days there’s a new twist to the old story. It used to be that only Pharaoh was told he was a god. I hear of more and more people who believe that being human is a limitation; that they are sui generis. Their own freedom to choose is or should be unbounded. If pressed about limitations their typical answer is that modern society, or modern technology, or future technology(*), have done away with such things. They can choose their own limitations—or not, as they please.

I have no trouble with the idea that exercising choice makes us co-creators and to that extent is an image of divinity. But I’d have thought it obvious that our choices are contingent and that paying attention to the rules of our existence was critical for making good choices. I could train night and day and never be worth anything as a pro boxer. When every cell in your body is XY it is pointless to stuff yourself with chemicals and whack off chunks to make yourself a grotesque doll.

I wonder about the trajectory of these would-be demi-gods. Do they typically hit a wall and quietly change their tunes? Do they worship "choice" more than actually committing to a choice, and flit fruitlessly through life? Or do some of them actually do something great?

(*) Yes, I’ve read a surprising number of people who (apparently quite seriously) referred to a topic from science fiction as though it were accepted technology. And I’ve run into a few in person. Not many, but enough to worry me.

Not this again..

BBC science reporting is iffy. Here they report that Majorana particles have been detected in the lab. Majorana was an eccentric physicist who disappeared mysteriously. He proposed a theory (unprovable at the time and still not completely ruled out) that a neutrino was its own anti-particle. The most promising way I know of to test this is to look for nuclear double-beta (2 electrons come out at once) decays and see if the electron's energy curve has the proper behavior at the endpoint--and that is notoriously difficult to do because it relies on knowing fine details about nuclear structure.

This isn't the same thing at all. This is a collective phenomenon, where a kind of wave of electrons in a metal can move around and act like it annihilates other waves of the same kind. This is cool and all--they can emulate Majorana behavior--but it isn't really a discovery of a fundamental particle. Good work, but the story is misleading...

Sunday, April 08, 2012

Simply Jesus by N.T. Wright

The thesis of the book is fairly simple: the popular versions of the liberal and conservative views of Christianity are defective, because they omit an accurate understanding of the Kingdom of God. The popular conservative view is too pietist (Jesus died so we can go to Heaven when we die: and that's it) and the liberal view too tied to this-worldly means and measures (to the point of idolatry of the state, IMnsHO).

This obviously isn’t fair to the saints in both camps, but is a good enough description of the pop versions that the book is needed as a corrective.

Wright is a historian with details at his fingertips: he is able to make short work of claims that "Jesus never did miraculous healing." Central to his thesis is the question of what Jews of that era would have thought of the term "Kingdom of God" and he constructs a fairly convincing argument that this need not have meant immediate rule of God everywhere.

Jesus showed what the Kingdom of God was going to look like, and it isn’t

  • Somewhere else. It starts here and will be here.
  • State-based. (History bears this out, though Wright doesn’t go into that.)
  • Obviously victorious by the world’s standards. Jesus wasn’t.
It is
  • The obligation of Christians to work towards it.
  • Expressed in mostly-obscure charity. It is rarely (Wilberforce) well known.

Of course Wright’s approach is a model like the others, and no doubt needs a little corrective itself. But never mind the minor details: if Jesus returned tonight and we joined in welcoming Him, what would He say about our contribution to His Kingdom?

Read it.

How do you spend Good Friday?

I’d asked Good Friday off without specific plans, except that I would be helping my better half chauffeur some of her ESL class around. I had a vague idea of trying to spend some time in prayer, and maybe try a fast.

First on the agenda was getting a dresser (on the West side) for Middle Daughter, prefaced by a breakfast of sausages. The dresser turned out to be an exceptionally heavy oak piece which barely fit in the van and demanded an unconventional seating arrangement. But it arrived without hernias, and in time for Middle Daughter to join in taking some kids to Shedd Aquarium (which detoured to Field because of utter disorganization in Shedd’s call handling; beware).

We were early but the two Chinese children and their mothers were already waiting for us. We brought them to see a horse barn, and the city-bred children got to watch a multitude of chicken breeds clucking up in hopes of food while geese honked disapproval of such visitors at the wrong time. The kids brushed and fed treats to a docile miniature horse, and watched amazed at such tiny girls leading such large horses around the ring while a cat tried to teach freeze-tag to a mouse.

Noisy dogs they knew already, but had never seen a rabbit up close, nor newly shorn sheep, nor goats begging treats while resting their feet on round fence rails, nor donkeys quarreling about something obscure. The Lost and Found box, sitting in the sunshine, always seems to harbor a sleeping cat.

Milk bottling at a dairy was new, but they knew their ice cream flavors and put away strawberry and blue moon with gusto.

The obvious thing to do with your wife after such a field trip is to stop at Husnus for lunch.

Not much in the way of fasting. Follow the day, not the calendar.

But we did follow the calendar too. The custom of our church’s Good Friday evening service is to leave in silence. Silence is an underrated part of worship.

Friday, April 06, 2012

Tick talk

We already know that ticks are hard to crush, that they like to hang on plants and wait (sometimes for months) until something warm blooded walks below them, that they suck blood and spread diseases, and that they look like some kind of space alien.

It turns out that they can survive vacuum and a scanning electron beam as well. True, the beam injured them and they died two days later, but that's still extraordinary resilience on the tick's part. (I don't know if all ticks are this sturdy, or just this variety.)

"The phasers don't work, sir."

Good Friday

The "lamb slain from the foundation of the world" has always been the suffering servant.

We like to think that ways to participate in God's nature are the way of joyful victory over all adversity, or barring that the way of detached superiority. But both victory and detachment grow our feelings of superiority and pride and that poisons us. So the humble way of the suffering servant makes us more like God in this wrecked world and Jeremiah is a man after God's heart too.

"The Father turns His face away" is a popular line but I think they read too much into "he became sin who knew no sin" when they try to model relationships of the Trinity on human courtrooms. You can think of the cross that way, but that's only one facet. This is how God already feels.

Malaria news

The BBC pointed to this report in the Lancet (free subscription required) and it looks like bad news. Artemisinin still works, but in Cambodia it isn't working as well as it used to.

This seems to represent a real adaptation of the malaria parasites, and if it spreads we have a big problem. There's nothing on the horizon to replace artemisinin. True, different areas may still have parasites susceptible to mefloquine or something else, but over time the resistance spreads. We may wind up going back the bad old days of DDT.

There are a few things I wasn't expecting in the report. They are able to do genetic matching, and find that 1/3 of infections are from multiple strains of plasmodium. Their data analysis excluded about 3% of patients whose malaria clearing rates didn't match a nice log plot. That could be bad measurements (not unheard of) or might be something interesting in how the disease works--I'm not expert enough to guess. And they were worried because a reduction in malaria rate meant that patients tended to lack resistance (nobody get immunity, I guess) and might get sick faster with something there was no treatment for.

Sunday, April 01, 2012

Palm Sunday

It is easy to celebrate Jesus when he votes for your candidate and promises that all will be comfortable from here on out. Funny how that doesn't last when all of a sudden it doesn't look so comfortable.

This looks like a good week to be reading Simply Jesus by N.T. Wright.