Refining the Drake equation: earth like planets more common?

One of the explanations of the Fermi Paradox is that earth-like planets are very rare, so technologic civilizations are very rare. This was the premise of a 6/17/2000 Scientific American article that inspired my interest in this topic. Since then, however, every discovery in plantetology has increased the prevalence estimate for earth like planets. Now new models of planetary formation suggest gas giants support, rather than oppose, the formation of earth like planets:

A Plethora of Alien Seas -- Berardelli 2006 (908): 1 -- ScienceNOW

.... The researchers found that when gas giants migrate, they fling lots of rocky debris away from the star and into the habitable zone, where liquid water can exist on a planet's surface. There, the debris frequently coalesces into Earth-sized planets.

This kind of early evolution also perturbs the disk, causing comets outlying billions of kilometers away to dive toward the star. Enough of these ice balls hit the terrestrial planets to deliver large quantities of water. "We were very surprised to learn that these planets are water-rich and probably covered in global oceans," he says.

The findings suggest that thousands of planetary systems within the Milky Way could harbor Earth-like planets, says Rory Barnes, a planetary scientist at the University of Arizona in Tucson. Still, he cautions that the key question is how many planetary systems have hot Jupiters...

Of course, when you increase the value of one term in the Drake equation, given the 'great silence', you decrease another term. The one that keeps shrinking is the lifespan of technological civilizations interested in travel, exploration, and communication. The civilizations must either all die or all lose interest in communication. (The other explanation for the great silence is the one favored by odd couple of religious fundamentalists and simulationists -- it's by Design.)

TouchGraph AmazonBrowser

TouchGraph AmazonBrowser V1.01 is a graphical network browser for Amazon products. I came across it via Amazon's Solutions Catalog. There's other fascinating stuff there.

Tom Tomorrow - 10/22/2001

Tom Tomorrow is a genius, and brave as well.

Salon.com Comics | This Modern World

"They can't shake the foundations of our secular humanism ..."

The joy of blogs: DeLong vs Mankiw

Greg Mankiw is a very smart Republican economist who worked for Bush and perhaps voted for him (ok, not so smart). Brad DeLong is a smarter economist who despises Bush.

That's the background. The joy is reading the dialog between the two. This one goes to Brad, but Mankiw has his go0d days. His discussion of Healthcare is quite rational and he's strong when he points out that even if inequality is a 'winner take all' phenomena that doesn't mean one should rule out social policy to reduce it:

This analysis, however, does not tell you what to do now. Even if rising inequality is exogenous, the government could still respond to it by making the tax code more progressive. That is a coherent policy viewpoint, driven as much by political philosophy as economics, about which reasonable people can disagree. I am the first to admit that the study of economics by itself does not tell you how to balance efficiency vs equality. And it certainly does not tell you whether it is more noble to be an egalitarian or a libertarian.

In the DeLong vs. Mankiw battles the two often agree on the economics but disagree on policy and values -- but DeLong is usually more careful about what he writes. Mankiw can be sloppy, as with a recent post on reproductive rates and social conservatism.

Still, Mankiw is a Republican I can live with, and I'd even respect him if I knew he didn't vote for Bush in 2004.

Aging or Cancer: pick your poison

If you slow the rate of biologically programmed aging, you increase the rate of cancer. Unless you can reduce the number of times cells divide (but who knows what tradeoff that has ...):

Gene Found to Switch Off Stem Cells During Aging - New York Times

September 6, 2006
By NICHOLAS WADE

Biologists have uncovered a deep link between lifespan and cancer in the form of a gene that switches off stem cells as a person ages.

... The gene involved in the new finding has the unmemorable name of p16-Ink4a but plays a central role in the body’s defenses against cancer. It produces two quite different proteins that interact with the two principal systems for deciding whether a cell will be allowed to divide.

One of these proteins had also been noted to increase substantially with age. The cells of a 70-year-old person produce 10 times as much of the Ink-4 protein as do those of a 20 year-old, Dr. Sharpless said. To help understand why this was so, Dr. Sharpless genetically engineered a strain of mouse in which the gene was knocked out.

... All three teams report essentially the same result, that in each type of tissue the cells have extra ability to proliferate when the Ink-4 protein can no longer be made. At the same time the Ink-less mice are highly prone to cancer, which they start to develop as early as one year of age.

... a calorically restricted diet is one intervention that is known to increase lifespan and reduce cancer, at least in laboratory mice. The reason, he said, is probably because these diets reduce cell division, the prime source of cancer risk...

... Dr. Morrison said it had long been known that older patients don’t do as well in bone marrow transplants as younger ones, and the new finding might explain why.

... The researchers say they do not yet know what stimulus makes cells increase their production of the Ink-4 protein as a person grows older. Their suspicion is that the usual factors implicated in aging, such as mutation and oxidative damage to tissues, would turn out to play a role in making cells produce more Ink-4...

Note the implication that you can now measure someone's biological age by their Ink-4 protein production. I've long thought that aging was non-linear, that we age in bursts (much as the folk story of 'he aged a year in a day'), possibly triggered by environmental events. It would be interesting to plot weekly Inf-4 levels in 20 individuals over the course of 2 years.

This is not a surprising result. As long as I can remember biologists have suspected that there was a tradeoff between aging rates and cancer.

This seems to fit with the most surprising lay article I've recently read, the discovery that lifespan seems random, that longevity is not hereditable. I'm still fascinated with that result, even though I don't entirely believe it (dogs are my favorite example, there longevity is clearly hereditable and even breed specific). I'm guessing aging rates are hereditable, but they don't translate into longer average lifespan because of the resulting increase in cancer rates (and vice-versa, lower cancer risk doesn't translate into longer lifespan because of faster aging). Still, that's not a complete answer; I think a combination of biological research and simulation modeling will be needed to understand why lifespan is not significantly inherited.

The extinction of the northern animals

Animals are shifting to higher elevations and more northern latitudes in the UK...

BBC NEWS | Science/Nature | British species migrate northward: "

... The York scientist said there was still great uncertainty as to how individual species would fare as the global climate continued to warm; but the prospects for many were not good, he argued.

Some would benefit from the higher temperatures and changes in vegetation that this would bring; others would struggle as their habitats were overtaken.

'Some 'cold-adapted northerner' species might be perfectly happy with a warmer climate until the 'heat-loving southerners' arrive and displace them,' he said.

'Global temperatures and CO2 levels are expected to be higher than those experienced for millions of years, such that few of the individual species that currently exist, and none of the combinations of species we currently possess, will have experienced such conditions previously.'

The results of the range change analysis were recently published in the journal Global Change Biology.

One would expect disruptions in competitive relationships everywhere; even when biomes are similar a transition from one to another is unlikely to happen in a perfectly synchronized fashion. The real extinctions will occur, however, at the extremes. If you're a northern animal, even if you enjoy the warmth, someone will migrate in who's adapted better to your new environment. We know from relatively recent research that seemingly small differences in adaptation to local environments in competing non-predator/prey species result in rapid exctinctions.

So many of our northern species will die off, and many new species will be created. The Creationists will get to see evolution occuring in their own backyards ...

On Mars: hysterical success

This has gone beyond astonishing into the realm of hysteria. Beyond all the mess of life on earth one of the two Mars rovers closes in on yet more riches of science:

BBC NEWS | Science/Nature | Rover nears crater science trove:

..."We have a fully functional vehicle with all the instruments working. We're ready to hit Victoria with everything we've got," said Byron Jones, a rover mission manager at Nasa's Jet Propulsion Laboratory in California....

..."Spirit and Opportunity had primary missions lasting just three months. Though both are showing signs of wear, they are roving the Martian surface after more than 30 months."

This is absurd. I want to know why those bots are still working. Are the martians doing onboard maintenance?

Global climate change: it's time to think radical

Scientific American’s global climate change issue (9/06) outlined a painful and politically almost inconceivable approach to keeping terrestrial climate within the bounds of human evolutionary history.

Alas, each bit of research on climate change seems to worsen the picture. The latest article on methane release is typical (note my emphasis, below):

BBC NEWS | Science/Nature | Methane bubbles climate trouble

… Scientists from Russia and the US measured methane bubbling from a number of thawing lakes.

Writing in the journal Nature, they suggest the methane release is hastened by warmer temperatures, positively feeding back into global warming.

… "Thaw lakes in north Siberia are known to emit methane, but the magnitude of these emissions remains uncertain," the scientists write.

"We show that methane flux from thaw lakes in our study region may be five times greater than previously estimated."

… The study depended on the systematic deployment of bubble traps on two lakes in the Cherskii region of Siberia, supplemented by ground-based and aerial observations of a further 95 lakes.

Katey Walker from the University of Alaska at Fairbanks and her colleagues calculate that across the region, thaw lakes lakes emit 3.8 teragrams (Tg, million million grams) per year.

The contribution of these lakes is small compared to the IPCC estimate of total global methane production, 600 Tg per year.

More than half of this total comes from human activities, notably farming.

The importance of the Siberian release may lie in the relationship between warming and methane production.

If a high release rate of a greenhouse gas is being triggered by rising temperatures, that will in turn stimulate still higher temperatures - a positive feedback mechanism…

These particular lakes produce about 1/150th of global methane, or 1/75th of what humans (esp. farmers — is that cow gas?) produce. So what’s the impact? This BBC news article is missing some context. This 1995 journal article helps:

… the total annual global source strength of atmospheric methane, an important greenhouse gas, is estimated to be 500 teragrams, with anthropogenic sources accounting for 340 teragrams. With an estimated sink strength of 460 teragrams per year, the annual increase of atmospheric methane is 40 teragrams.

So if 40 is the right denominator here, then this region alone is causing a 5–10% increase in net methane growth (we’ve apparently gone from 500 to 600 TG/year output in 10 years, but I assume agricultural sinks have also grown, so I can’t guess the actual net increase). Siberia is not the entire world of permafrost, so, bottom line, this probably does represent a significant increase in net atmospheric methane accumulation. It’s just hard to see that from the BBC article.

The feasibility of the almost unattainable ‘conservative’ path to climate restraint seems to have shrunk considerably. When the climate models are updated with the new data, it seems possible that we’ll need both the ‘conservative’ approaches and some new, fairly radical, technologies as well.

I can’t imagine the world my children will inherit …

General weirdness on the net: ultrasound, autism and satire

This is weird.

On August 7th Yale researchers published an article purporting to show a subtle derangement of neuronal migration in mouse fetuses (feti?) exposed to over 30 minutes of ultrasound.

On August 8th, writing in a disabilities blog I author, I cautiously noted that if one is hunting for a possible explanation of a rise in autism rates in the late 80s, it's worth looking at further experiments in this domain.

On August 19th, Wayne McDonald, wrote a satirical article relating ultrasound to autism and school violence -- inspired by the Yale press release.

On September 1st the Autism Society of America, to their almost immediate embarassment, referenced the ultrasound article in their weekly email newsletter - ASA-Net. (One assumes they are reconsidering their automated clipping service.)

Was there any connection between my August 9th posting and Mr. McDonald's satire? Probably it's merely synchronicity, but the web works in mysterious ways.

The story will be even more peculiar in the (very unlikely) event that there does turn out to be a real connection of some sort.

Mental illness, Zubaydah and the Republican right

DeLong contrasts Bush's description of Abu Zubaydah with Don (One Percent Doctrine) Suskind's description. Briefly, Bush claims Zubaydah was a senior terrorist leader and that much value was gained from torturing him (ok, Bush doesn't use the word torture, instead he lies). Suskind says Zubaydah was mentally ill and was tortured because his captors were ... ummm .... nuts.

What makes this contrast plausible to me, beyond Bush's record of staggering incompetence and seeming organic brain disorders, is the right wing's rejection of the concept of mental illness. It's almost a pathognomonic feature of cultural conservatives that, for them, mental illness doesn't really exist, that it cannot affect judgment or decisions, and that delusions are fundamentally a form of deliberate deception. Medieval inquistors of witches shared a common value set, as do modern Scientologists.

It's easy to believe that Bush and his ilk, confronted with a mentally ill terrorist, would believe he was being deceptive, and would think torture would produce truth.

Greylisting: slouching towards weighted reputations of sending services

Years ago, I pointed out that the right way to deal with spam was differential filtering based on the managed reputatation of the sending service. This reasonable approach was greeted with ... well, almost nobody read it or listened with any interest. Jon Udell, who is brilliant, agreed that it was probably the way we'd go.

Basically, it's subtle, it's hard to encapsulate, and it's not sexy. So rather than get there quickly, we're slouching slowly in that direction. I was pleased to read about Greylisting recently -- it's one more step in the right direction.

BTW. The wrong direction is Microsoft/Intel's Palladium identity management technology, but, alas, we'll go that way too.

HyperScope: Does innovation live?

Shades of the 1990s, HyperScope is a reimplementation of classic hypertext and information representation in modern browser-side Ajax. Maybe innovation is not quite dead!

I'm particularly intriguted that the file format is OPML. It suggests that OmniOutliner could be adapted to generate these documents fairly readily ...

Attacking Inequality: Redistributing wealth

When the NYT hid its main editorialists behind a $50/year paywall, I put the WaPo OpEd column on my news page. Mostly I've been disappointed, DeLong is all too correct in lambasting the decaying WaPo.

I was surprised then, to read something interesting by Sebastian Mallaby (emphases mine):

Attacking Inequality:

Economic growth no longer seems to help the majority of workers; the proceeds flow to the top fifth or so of the workforce, and the top within the top has done especially handsomely. But the tough debate is what to do about this trend. The surprising answer is: tax reform...

... if you eliminated just a quarter of the subsidies in the tax code, you would liberate about $180 billion a year -- enough to finance a big expansion in the earned-income tax credit plus a cut in the regressive payroll tax. And this sort of redistribution would not risk higher unemployment or compromise economic growth at all. Democrats on the left and right ought to be embracing it.

Hmmphh. This was such a surprisingly clear invitation to electoral disaster (touch the mortgage tax break?!) that I figured Mallaby must be an agent provocateur. There might be a bit of that, but his bio is interesting ...

Sebastian Mallaby grew up in Britain and has been a correspondent in Japan and Southern Africa. He joined the Washington Post editorial page in 1999 after 13 years with The Economist of London, and is the author of "The World's Banker: A Story of Failed States, Financial Crises, and the Wealth and Poverty of Nations," to be published in September 2004... [jf: Marginal Revolution loved the book]

Ok. Let's take him seriously then. This topic, of course, is the nitty gritty. It's the big problem, compared to which the rest of the culture wars are a side-show. It's the problem of the weak.

Sure our democracy is in an increasingly sorry state. Sure there are a lot of rigged games (CEO compensation, rampant insider trading). Sure the GOP program of financing education by local taxes is an unspeakably repulsive recipe for economic segregation and class stratification. Even so, the big problem is the one that made Marx (for better and worse) -- what duty do the strong owe the weak? Or, if you're a Libertarian, how much should the strong invest in the weak to avoid distasteful smells wafting over the walls? Even if our democracy is repaired, even if our regulatory bodies are restored, even if we finance education globally, still we will have the strong and the weak.

Mallaby's last sentence is telling. It's easy to miss it -- I almost did. As the strong accumulate more of society's economic output, the ranks of the unsettled weak grow. They are messy to dispose of -- eventually the prisons overflow, and other methods are tough on the squeamish. It won't work anyway, chop off the bottom 5% and there's a new bottom 5% -- that's the way statistics work. Ignoring mere compassion, if the Weak are not appeased we either grow an American version of Hugo Chavez (rather than the Teddy Roosevelt II we really need) -- or we will dispose of our democracy altogether.

Read the column. This is one of the significant challenges to our generation. (Global climate change and technological disruption are slightly bigger challenges -- perhaps too big for mere humans to manage.)

Windows Live OneCare: Firefox? What's that?

This is what Firefox users get when they sign up for the Windows Live OneCare trial:

In order to complete installation of Windows Live OneCare, you must be running Internet Explorer 6 or later as your Web browser. Please switch to Internet Explorer and then restart Setup by typing http://www.windowsonecare.com/purchase into the browser address field.

Antitrust? What antitrust? That's ancient history. The old restraints are fading fast. It's kind of sweet to see the old rabid pit bull back, even if it is showing signs lately of corporate dementia.

Live OneCare will eliminate all other consumer antiviral solutions within 1-2 years. You can't run a PC without antiviral software, and you can't run OneCare without IE. What's complex about that?

No problem here. I'll fire up my old copy of IE and install. We're an OS X household mostly, one day XP will run only as an occasional session within OS X. Microsoft will own that XP/Vista environment completely. I don't have a dog in that fight (I used to, but the rabid pit bull finished it off).

Update 9/26: I tried OneCare for a month or so -- free. It's really not ready for release. It's too hard to turn it off or control it, and it's too mysterious. Tries to hard to be invisible.

Dogs and non-euros

Our beautiful and very friendly looking, but somewhat irascible dog (Molly), died. We now have a somewhat demonic looking (Kateva) but actually friendlier mongrel. I can't say whether it's this change, or the transitions in American society over the past 15 years, but I have been struck by how many people are afraid of our dog. There seems to be an ethnic distribution to this.

The usual cliche is that black (african) americans are, on average, less accepting of dogs. My limited exposure would not contradict that, but I think it's perhaps inverting the question. I don't see a great deal of difference between black Americans and recent immigrants from everywhere outside of Euro-land.

So the peculiarity perhaps is in western europeans or "Euros", who seem culturally more accepting of dogs than most other ethnic community. There's a long history of working dogs in western europe, and I'm not sure that history occurred elsewhere. If true, it's the Euros who are "odd", not the rest of the world.

Dogs are much more popular in Japan than they were 30 years ago, and even in China there are now pet dogs, so perhaps things will change. I suspect, however, than as America becomes minority-Euro we'll see more "no dog here" signs. It will become harder to travel with the family dog, so we should see even more upmarket kennels ...