P vs NP: terrific essay

I've read quite a few discussions about computational complexity and P=NP theorems, including several following a claim of a proof that, as expected P!=NP.

So I have a basis for comparison when I say that Julie Rehmeyer has written the best ever short discussion of computational complexity. It's ostensibly about "crowdsourcing peer review", but you ignore all of that. It's really about explaining the basic problem with bold excursions into the deepest realms of modern mathematics.

So where did Ms. Rehmeyer come from? Her LinkedIn site tells us she's a Wellesley/MIT alumn, which would explain some of it. Surprisingly, she doesn't seem to have a personal blog. That is different. Most freelancers keep a blog even if they only point to recent publications.

No of 1 trials: lipid variability

In Nov 2009 my Chol was 249, LDL 181. These are unhappy numbers, though risk calculators still gave me about 20th percentile male risks (lipids aren't everything). I resigned myself to statins in a year or so.

Ten months later my Chol was 189, LDL 125. Those are good numbers, they don't merit statins.

I didn't change much between those two tests. The main difference is I weigh about 15 lbs less now than in 2009 [1], but that just moved me from the high end to the low end of recommended weight for my height and build. My diet isn't dramatically different. 

I really wouldn't expect that modest weight reduction to make a large difference in lipid levels. If I'd thought the effect was this big I would have dropped the weight years ago.

Weird. It's just another anecdotal "n of 1" data point, but it reinforces my suspicion that we still don't understand the basics of human metabolism very well.

[1] Thanks to the radical "eat substantially less" diet. I'm a forager, it's relatively easy for me to both lose and gain weight.

Another MSP house blows up

This is the 2nd or 3rd time in the past year a Minneapolis St Paul house has blown up, presumably due to a gas explosion, while sewer line construction work was being done ...

House explodes in Richfield; no one injured | StarTribune.com

... The 3:50 p.m. explosion in the 7600 block of 11th Av. S. leveled the house, set its ruins on fire and sent flames up the sides of two adjacent homes .... The homeowner was away, and his two daughters were in school, according to Richfield Fire Chief Brad Sveum. He confirmed that the family's dog was missing...

We don't know this one was a gas explosion. In similar recent episodes the culprit has been a methodology of constructing gas and sewer lines that led to occasional intersection. When sewer line work is done the gas line is punctured. It's assumed there are many unknown intersections out there, just waiting for sewer line work to expose them. I assume some of these are caught prior to explosion.

It does remind me how crude our world is, that we still pipe astoundingly explosive gas into our homes to create heat. By now we were all supposed to have fusion reactors in the basement (those explosions would be even more impressive).

I wish voters would show more interest in exploding houses, and less interest in Glenn Beck.

Update: To everyone's surprise, the dog turned up. Fur singed all about, but otherwise pretty well.

The Transparent Society - 1920 edition

I've mentioned David Brin's prescient 1999 book, The Transparent Society, a few times. In today's panopticon it's a premature cliche, but he deserves credit for working through so many of its implications.

Credit is also due a work I learned of through a throwaway comment of Melvyn Bragg in a 1999 (30 min!) program on Utopias (Anthony Grayling, John Carey). Lord Bragg mentioned a 1921 novel by Yevgeny Zamyatin called "We". The novel is described in an Amazon review by Leonard Fleisig ...

... WE takes place in the twenty-sixth century where a totalitarian regime has created an extremely regimented society where individual expression simply does not exist. All remnants of individuality have been stripped from its inhabitants including their names. Their names have been replaced with an alpha-numeric system. People are not coupled. Rather, each individual is assigned three friends with whom they can have intimate relations on a rigid schedule established by the state. Those scheduled assignations are the only times the shades in a citizen's glass houses can be closed. Apart from those hourly intervals everyone's life is monitored by the state. As in Orwell's 1984, language has been turned on its head. Freedom means unhappiness and conformity and the submission of individual will to the state means happiness...

Yes, rather like Huxley or Clockwork Orange or 1984. Orwell was a fan but Huxley denied having read We. 

We certainly belongs in a "panopticon" reading list. Glass houses are the ultimate transparent society.

See also:

• We - full text pdf

Archives of In Our Time: Smolin, Gribbin and Greene

Every physics hobbyist should be familiar with the names of Smolin, Gribbin and Greene. All are literate physicists who've written excellent books and essays on tough topics, while still doing exciting research. If you're in this club, you'll love these superb In Our Time programs from the archives.

• Grand Unified Theory - 2000 - Brian Greene and Martin Rees
• Time - 1999 - Lee Smolin and Neill Johnson
• Quantum Gravity - 2001 - John Gribbin, Lee Smolin and Janna Levin

I'm a fan of Gribbin and Greene in particular. I tagged several Gribbin posts back when I was catching up with modern interpretations of Quantum Mechanics - before we started doing entanglement experiments with grossly macroscopic entities. Greene wrote the best modern physics book of the past decade (the non-string bits are the best), I'm way late to give it a review.

These gentleman turn out to be verbal gymnasts as well as physicists and writers. Really, it's not fair - but at least they share.

See also:

• Putting 'In Our Time' on your iPod (2006) - turn Real Audio stream into MP3
• In Our Time archives - EVERY EPISODE from Oct 15 1998 onwards
• Our Time: Symmetry, Moonshine, String Theory and E8
• Gordon's Notes: In Our Time (tag)

Torture is now an American state secret

This does not surprise me. We are a very sick nation ...

"State Secrets" Trump Justice Again | Mother Jones

... the Ninth Circuit Court of Appeals ruled that the so-called "state secrets" privilege protects the government and its contractors from a lawsuit brought by five men who say they were kidnapped, flown to foreign countries, and tortured on the behalf of the American government. Even the ACLU, which supported the men in their suit, acknowledged that the decision "all but shuts the door on accountability for the illegal program."

The 6-5 ruling (PDF) in the case, Mohamed et. al. v. Jeppesen Dataplan, rests on the "state secrets" privilege. In the years after September 11, the controversial doctrine has basically acted as a "get out of court free" card for the Bush and Obama administrations in cases related to torture and domestic spying ... the Obama administration, which continued the Bush administration policy of intervening in the case on Jeppesen's behalf, was still able to get a dismissal by saying the magic words "state secrets." ...

... This is a sad day not only for the torture victims whose attempt to seek justice has been extinguished, but for all Americans who care about the rule of law and our nation's reputation in the world. To date, not a single victim of the Bush administration's torture program has had his day in court. If today's decision is allowed to stand, the United States will have closed its courtroom doors to torture victims while providing complete immunity to their torturers. The torture architects and their enablers may have escaped the judgment of this court, but they will not escape the judgment of history.

This is very much in the tradition of states that sanction torture.

Mimicry - more than we imagined

The more we look around, the more mimicry we see ...

Basics - Surviving by Disguising - Nature’s Game of Charades - Natlie Angier - NYTimes.com

...  scientists recently discovered that in some ant species, the queen is a consummate percussionist, equipped with a tiny, uniquely ridged organ for stridulating out royal fanfares that help keep her workers in line. Who knew that the queen was such a squeezebox? Her freeloaders sure did. The scientists also discovered parasitic butterfly larvae in the colony that use their abdominal muscles or other body parts to precisely imitate the queen's stridulations, an act of musical piracy that induces worker ants to flutter and fuss and regurgitate food right into the parasites' mouths...

Dogs mimic humans to communicate with them. I mimic my dog to play with her. Humans mimic one another to facilitate communication, each participant in a conversation adapts to find a common ground. A way for very diverse minds to get along.

The disposable brain - lessons from our elastic axons

The human brain is misplaced. It ought to be inside our pelvic-abdominal cavity, where humans carry babies. Instead it's stuck at the top of a tall biped, fully exposed to all traumas.

Intelligent design, my ass.

Thanks to its bad neighborhood the poor brain is being constantly banged about. Every so often it gets plastered against its membranous sac, typically when a head meets an rapidly moving object such as a sidewalk or a baseball bat. This is not good for something with "the consistency of custard". Evolution has struggled to adjust (emphases mine) ...

The Brain: What Happens to a Linebacker's Neurons? | Carl Zimmer | DISCOVER

... axons are remarkably elastic. They can stretch out slowly to twice their ordinary length and then pull back again without any harm. Axons are stretchy due in part to their flexible internal skeleton. ... When an axon stretches, these microtubules can slide past one another. If the movement is gradual, the microtubules will immediately slide back into place after the stretching stops, with no harm done.

If Smith delivers a quick, sharp puff of air, however, something else entirely happens. Instead of recoiling smoothly, the axon develops kinks. Over the next 40 minutes, the axon gradually returns to its regular shape, but after an hour a series of swellings appears. Each swelling may be up to 50 times as wide as the normal diameter of the axon. Eventually the axon falls apart.

These kinks form, Smith believes, when microtubules are stretched so rapidly that they snap ... Normally, enzymes inside neurons are constantly taking apart microtubules and building new ones with the recycled parts. But now the enzymes attack the broken ends of the microtubules, causing the internal structure of the axon to dissolve...

... Smith’s findings could shed light on a common but puzzling brain trauma known as diffuse axonal injury. This happens when people experience sudden accelerations to the brain—from a bomb’s shock waves, for example, or from whiplash in a car crash ... When pathologists perform autopsies on people with diffuse axonal injury, they see severed axons with swollen tips, just like what Smith sees in his experiments.

Smith’s research also suggests that even mild shocks to the brain can cause serious harm. ... A moderate stretch to an axon, Smith recently found, causes the sodium channels to malfunction. In order to keep the current flowing, the traumatized axons start to build more channels.

Smith suspects that such a mended axon may be able to go on working, but only in a very frail state. Another stretch—even a moderate one—can cause the axon to go haywire ... The axon dies like a shorted-out circuit.

... Preliminary brain studies show that axons are still vulnerable even months after an initial stretch...

Just in case you're not depressed enough yet, wherever you read "axons" substitute the phrase "young axons". Any wagers on how well older axons stretch? Also note that "even months after" doesn't mean they're not vulnerable "years after".

It's interesting, after reading this article, to search PubMed with the phrase "microtubule amyloid axonal injury".  A 2006 paper looked at animal model transient accumulation of neurotoxic amyloid precursor protein after injury. Amyloid protein has, of course, long been associated with Alzheimer's dementia. Head injury is also strongly associated with dementia risk; head injury avoidance is about the only "intervention" known to reduce the risk of Alzheimer's disease. (Don't make too much of this injury/amyloid connection though, researchers have been banging on it since the 1990s. It's not straightforward.)

Short of radical genetic engineering, or spending our lives watching TV with thickly padded carpets, what can we do about our fragile brains? Sure, football is dead. Yes, soccer will lose the header. Sure we can change the rules of hockey. Yes, horseback riding is almost as crazy as riding donorcycles. But, really, have you watched any TV lately? There are worse things than dementia.

Today's helmets are not the answer. Current bicycle helmet designs, for example, don't materially change the rate of anterior impact deceleration. Their primary benefit is to facilitating head gliding and reduce abrasions; they aren't designed to reduce the deceleration injuries that matter -- without severing our wimpy cervical spines. (On road bikes effectiveness is further diminished by paradoxical automobile driver behavior.)

We need to revise our sports (so long NFL), but we also need much better helmets. Air bags anyone?

See also:

• Gordon's Notes: Helmets: good for inline, not so good for bicycling?
• Helmet: building a better bicycle/inline helmet - Ideas? - rec.bicycles.misc | Google Groups (2002)

How to use Amazon reviews

I wrote a negative Amazon review of Apple's battery charger (2/6 batteries were defective). As expected "0 of 2 people found the following review helpful".

This is very common with certain items, such as Apple products, Microsoft products, Christian conservative books, and other products that have "fans". It also happens with lawn mowers and dehumidifiers [1], but in those cases the negative feedback comes from manufacturer employees and retailers.

The "helpful" metric on Amazon reviews is not only worthless, it's harmful. It points people away from important reviews. It's also used to create reviewer rankings, so those are also worse than worthless. (By using these metrics Amazon is setting itself up for emergent fraud.)

There's another weakness of Amazon reviews -- name changes. Just as Google's Ballmer Schmidt tells teens they'll need to rename themselves as adults, so to do vendors change model numbers to dodge bad reputations.

There are workarounds for both problems. Here's how to use Amazon reviews:

• Always read the negative reviews, even on a 4.5 star product. The two star reviews are usually the best, some of the 1 star reviews are nonsensical.
• Remember statistics, a 50 review product will usually have meaningful negative reviews.
• Look at other models by the vendor to defeat name change strategies. Amazon keeps older model information around for a while, so you can usually find the previous model number. Vendors don't change their behaviors as quickly as they change their model numbers.
• When looking across a product category, sort the category by sales, not by average rating. The rating averages are not discriminating and are unreliable.
• Give more weight to True Name (authenticated) reviewers. If a review seems unusual, look at other reviews by the same person.

- footnotes

[1] Based on my experiences with appliance purchases over the past few years, I think Sears or even Best Buy are better options than Amazon -- because it is practical to use the warranty.

Why not Depo-Provera dart wild horse mares?

Horses are tougher than they look. Millions used to live in awful conditions before the internal combustion engine filled the world's glue factories. Now, in the absence of wolves and mountain lions they're overflowing their bounded western world and the private lands that stockpile the overflow.

Modern Americans are more sentimental than they were 100 years ago, so we're unwilling to shoot them all. Were I a horse I'd rather be shot than starve or be eaten alive by wolves, but nobody asks the horses.

So why can't we hire cowboys to shoot mares with Depo-Provera in late May? It's cheap stuff, its used with horses, and it's designed for deposition. Shoot a capsule of it into the mare buttocks around mating time.

It's been done for lions.

After the Google Hack: Life in the transparent society

My Google Account (Gmail and more) was hacked on 9/3/10, a day before I wrote about the risks of online backup.

I had a 99th percentile password. It had six letters, four numbers, no words or meaningful sequences. It wouldn't be in a dictionary. On the other hand, like Schneier and other security gurus, I didn't change it often. I also had it stored locally on multiple desktop and iPhone apps. As far as I know it wasn't stored on any reasonably current web app.

If my password had been a bike lock, it would have been one of those high end models. Enough to secure a mid-range bike on the principle that better bikes with cheaper locks were easy to find.

That wasn't enough. For some reason a pro thief [2] decided to pinch my mid-range bike. They didn't do any damage, they didn't seem to send spam [1]. They seem to have unlocked my bike, peaked around, and locked it again.

Why would a pro bother? Trust me, I lead an intensely narrowcast life. It's interesting to only a few people, and boring to everyone else.

On the other hand, it wasn't always so. "I coulda been a contendah." I knew people who have had interesting lives, I still correspond with some. If a pro was interested in me, it was most likely because of someone like that. My visitor was probably looking for correspondence. Once they found it, or confirmed my dullness, they wouldn't have further interest in me.

Fortunately even that correspondence is quite dull.

I've changed my password. The new one is 99.9th percentile. Doesn't matter, I doubt I'm much more secure.

This isn't a complete surprise. Passwords died as a high end security measure about ten years ago. What's more surprising, except in retrospect, is that you don't have to really do anything or be anybody to get some high end attention. You only have to be within 1-2 degrees of separation of someone interesting. Security and "interest" are "social"; even a dull person like me can inherit the security risk of an interesting acquaintance or correspondent.

Welcome to the transparent society. If you put something in the Cloud, you should assume it's public. Draw your own conclusions about the corporate Cloud business model and online backup, and remember your Gmail is public.

footnotes --

[1] Of course they could erase the sent email queue, but I haven't gotten any bounce backs. Anyway, there are much easier ways to send spam.
[2] Russian pro, Chinese government equivalent, etc. Why pro? Because the hacker didn't change my password after they hacked the account, they didn't trash anything obvious, they didn't send out spam, and the access was by an abandoned domain. I'm not vulnerable to keystroke logger hacks except at my place of employment and wifi intercepts are relatively infrequent. Still, it's all probabilities.

Was my Google account hacked?

Ominous warning this afternoon of a possible Google account hack ...

Gordon's Tech: Scary events in Google password land...

... I was told my account had been accessed from an atypical location 1 day ago. The next thing I saw was that it was accessed from ductus.com (WA)...

... The best answer is that this is a false alarm. That's bad enough.

The less best option is that either my Google password has leaked or Google has a global security issue. A dictionary attack would be unlikely to work on my prior password. The tucows domain would then have been a hacked attack vector....

I'm looking for other reports like mine.

Update 10/13/10: Yes, it was.

Lessons in history: iTunes U and the quiet revolution in university education

Amidst all the noise and turbulence of humanity, what will become historic? Some things are obvious. If there are history books in 100 years, they will include a paragraph about 9/11.

Other historic events slide in slowly, and are little noted. I think the transformation of university and even secondary education is like that. Consider a two recent little noted stories (emphases mine) ...

iTunes U Downloads Top 300 Million (Apple press release)

... In just over three years, iTunes® U downloads have topped 300 million and it has become one of the world’s most popular online educational catalogs. Over 800 universities throughout the world have active iTunes U sites, and nearly half of these institutions distribute their content publicly on the iTunes Store®. New content has just been added from universities in China, Hong Kong, Japan, Mexico and Singapore, and iTunes users now have access to over 350,000 audio and video files from educational institutions around the globe....

and then there's Sal Kahn (quote excludes stupid parts of this Fortune article [1])

... Khan Academy, with Khan as the only teacher, appears on YouTube and elsewhere ... Khan's playlist of 1,630 tutorials (at last count) are now seen an average of 70,000 times a day -- nearly double the student body at Harvard and Stanford combined. Since he began his tutorials in late 2006, Khan Academy has received 18 million page views worldwide ... Most page views come from the U.S., followed by Canada, England, Australia, and India. In any given month, Khan says, he's reached about 200,000 students....

Kahn, contrary to the silly Fortune article, isn't in the same league as iTunes U, but he's part of a the same quiet revolution as the UK's university lecture podcasts, OpenAccess Journals, MIT's Open U, and, yes, wikipedia. It's a revolution presaged by the vast lecture hall I visited in Bangkok in 1981, by the early morning TV lectures of decades past, and by the BBC's long history of radio education.

The transformation of higher education has been underway for ten years out of sight of the rich world. It is going to come to places like France's infamous Nanterre University, and it will come to America after the college bubble bursts.

Sometimes change that moves slowly can be powerful.

Team Obama naivete - I am more than surprised

Honestly, I'm stunned. I never thought Team Obama was naive or stupid. They were, I assumed, smart professionals. Any talk about GOP enlightenment and cooperation was just a smokescreen for public consumption. Rahm Emanual was a knife fighter, not a fool.

I assumed that, until I read Krugman today (emphases mine) ...

Rahmism - Krugman - NYTimes.com

... Look: early on the administration had a political theory: it would win bipartisan legislative victories, and each success would make Republicans who voted no feel left out, so that they would vote for the next initiative, and so on. (By the way, read that article and weep: “The massive resistance Republicans posed to Clinton in 1993 is impossible to imagine today.” They really believed that.)...

Tell me it isn't so. Tell me they weren't so deluded about the Party of Torture. Tell me they weren't so deluded about the fragile, one foot over the cliff-edge, home of Beck and Limbaugh, American nation.

Give me evidence too, because this looks very bad.

I thought they were smarter than that.

What the world needs: a divided thickness blanket

Forget "sleep numbers". At a certain age and level of entropy, the marital challenge is not mattress firmness, it's temperature. A particular gender is intermittently far too hot, another is shivering.

The answer, of course, is a variable thickness blanket. One half designed for insulation and warmth, the other a wicking material that provides cool comfort.

Do you hear me China? Start making this thing!