BBC NEWS | Technology | Mouse brain simulated on computerReally. There's nothing to fear about this. The gap between a mouse brain and a human brain is vast. It could be another four years before they have a real mouse brain, and assuming performance doubles every year and there are no real breakthroughs in applied quantum computing it might be forty to fifty years before the next stage begins ...
US researchers have simulated half a virtual mouse brain on a supercomputer.
The scientists ran a "cortical simulator" that was as big and as complex as half of a mouse brain on the BlueGene L supercomputer.
In other smaller simulations the researchers say they have seen characteristics of thought patterns observed in real mouse brains...
...The three researchers, James Frye, Rajagopal Ananthanarayanan, and Dharmendra S Modha, laid out how they went about it in a very short research note entitled "Towards Real-Time, Mouse-Scale Cortical Simulations".
Half a real mouse brain is thought to have about eight million neurons each one of which can have up to 8,000 synapses, or connections, with other nerve fibres.
Modelling such a system, the trio wrote, puts "tremendous constraints on computation, communication and memory capacity of any computing platform".
The team, from the IBM Almaden Research Lab and the University of Nevada, ran the simulation on a BlueGene L supercomputer that had 4,096 processors, each one of which used 256MB of memory.
Using this machine the researchers created half a virtual mouse brain that had 8,000 neurons that had up to 6,300 synapses.
The vast complexity of the simulation meant that it was only run for ten seconds at a speed ten times slower than real life - the equivalent of one second in a real mouse brain.
On other smaller simulations the researchers said they had seen "biologically consistent dynamical properties" emerge as nerve impulses flowed through the virtual cortex.
In these other tests the team saw the groups of neurons form spontaneously into groups. They also saw nerves in the simulated synapses firing in a ways similar to the staggered, co-ordinated patterns seen in nature.
The researchers say that although the simulation shared some similarities with a mouse's mental make-up in terms of nerves and connections it lacked the structures seen in real mice brains.
Imposing such structures and getting the simulation to do useful work might be a much more difficult task than simply setting up the plumbing.
For future tests the team aims to speed up the simulation, make it more neurobiologically faithful, add structures seen in real mouse brains and make the responses of neurons and synapses more detailed.
Saturday, April 28, 2007
Mouse brain simulations. Plenty of time left.
Friday, April 27, 2007
Time, entropy and baby universes
How Did the Universe Start? | Cosmic VarianceWhere entropy increases, there goes time. Or so it goes.
... The baby-universe idea at least has the chance to give rise to a spontaneous violation of time-reversal symmetry and explain the arrow of time. If we start with empty space an evolve it forward, baby universes can (hypothetically) be born; but the same is true if we run it backwards. The increase of entropy doesn’t arise from a fine-tuning at one end of the universe’s history, it’s a natural consequence of the ability of the universe to always increase its entropy. We’re a long way from completely understanding such a picture; ultimately we’ll have to be talking about a Hilbert space of wavefunctions that involve an infinite number of disconnected components of spacetime, which has always been a tricky problem. But the increase of entropy is a fact of life, right here in front of our noses, that is telling us something deep about the universe on the very largest scales.
Update 4/28/07: Infinitely expanding universes birthing within infinitely expanding universes. Requirements for human observation to collapse probability waves. All interpretations of self-consistent mathematics, but way beyond bizarre. Which leads to the scary thought. Could he be right? Brrrr.
Broder - the Hindenburg of pundits
The Blog | Paul Begala: David Broder Is a Gasbag | The Huffington PostWicked and justly deserved. I thank the miracle that brought Reid to the senate leadership every day.
...And so Mr. Broder lashes out at Reid, smearing and sneering at the man he calls 'the leading light of Searchlight, Nev.'
Mr. Broder has moved with ease from the elite comfort of the University of Chicago to the smug confines of Arlington, Virginia. And so he looks down at a man who rose from among the hard-rock miners and hard-luck hookers of Searchlight, Nevada to be the most consequential senator of his time. While David Broder was thinking great thoughts at his elite university, Harry Reid was working his way through Utah State. While David Broder was pontificating, Harry Reid was working his way through law school as a cop on Capitol Hill....
A decline of the American general staff
Now others with much more to lose are also speaking. Phillip Carter highlights Lt. Col Paul Yingling, deputy commander of the 3rd Armored Cavalry Regiment, on the crisis in American generalship. Writing in the Armed Forces Journal Yingling accuses his leaders of lacking courage. That doesn't require the same courage as falling on a grenade, but many a soldier might prefer a battle wound to abandoning their military career.
I haven't read the full article, but the excerpt makes clear where the cowardice lay. Men who knew better went along with Cheney and Bush to preserve their power and careers. They deserve to be publicly shamed for that act of cowardice.
Tenet speaks: the interesting parts
Ex-C.I.A. Chief, in Book, Assails Cheney on Iraq - New York TimesI'll comment on each interesting part. For the record, I think we forget the powerful influence Tony Blair had on many democrats in the fall of 2001. Even then we didn't trust Bush at all, but Blair we trusted. We weighed his opinions very seriously and we were wrong to do so.
...Mr. Tenet takes blame for the flawed 2002 National Intelligence Estimate about Iraq’s weapons programs, calling the episode “one of the lowest moments of my seven-year tenure.” He expresses regret that the document was not more nuanced, but says there was no doubt in his mind at the time that Saddam Hussein possessed unconventional weapons. “In retrospect, we got it wrong partly because the truth was so implausible,” he writes.
... He also expresses skepticism about whether the increase in troops in Iraq will prove successful. “It may have worked more than three years ago,” he wrote. “My fear is that sectarian violence in Iraq has taken on a life of its own and that U.S. forces are becoming more and more irrelevant to the management of that violence.”...
... The book recounts C.I.A. efforts to fight Al Qaeda in the years before the Sept. 11 attacks, and Mr. Tenet’s early warnings about Osama bin Laden. He contends that the urgent appeals of the C.I.A. on terrorism received a lukewarm reception at the Bush White House through most of 2001...
...Mr. Tenet expresses puzzlement that, since 2001, Al Qaeda has not sent “suicide bombers to cause chaos in a half-dozen American shopping malls on any given day.”...
- To the best of my knowledge the "truth" is that the UN inspections worked, but Saddam kept the story of WMDs alive to keep Iran at bay. It's possible he also thought he had more capability to resurrect WMDs than he had at that point. Seems plausible only in retrospect.
- He's casting his vote for a deadline to leave Iraq.
- Tenet is leveling a very serious charge at Bush -- that he and his team neglected warnings of an imminent threat, presumably because they were coming out of an administration they despised. He's not the first to say this. Arguably, this is among the greatest of the many sins of Bush/Cheney, and like all their sins it was rooted partly in arrogance and hatred.
- Tenet is not the only one to wonder what the heck happened to al Qaeda in America.
Edwards on Iraq: Fight Bush, set the deadline
As long as Cheney/Bush and their flock of raging incompetents is in power, however, the "set a deadline" movement is justifiable. John Edwards has firmly placed himself in that camp:
The Question I Wasn't Asked / John Edwards '08 BlogI pray John Edwards knows the American people well. I don't see that kind of energy and engagement in the people around me ...
... What should we be doing — right now — to end the war in Iraq?
As you've heard, the Senate has followed the House and passed a bill to fund our troops with a timeline to bring them home and end the conflict. Both houses of Congress have now passed funding bills that reflect the will of the American people that we must end the war in Iraq.
The president has said he will veto this legislation, which will defy the American people and deny our troops the funding they need. When that happens, the president will be the one blocking support for our troops, not Congress.
With so much at stake, Congress must stand firm.
If Bush vetoes the funding for our troops, Congress must send the same bill back to the president -- and they should do this again and again--as many times as it takes for Bush to understand that the American people are right and the war must be brought to an end.
In the next few days, the will of Congress will be severely tested. Bush will be doing everything in his considerable power to convince the nation that Congress is responsible for his reckless decision not to fund the troops. Plenty of people in Washington will say the political risks are just too great and Democrats in Congress should just back down.
If there ever was a time to replace political calculation with political courage, that time is now. If Congress shows courage, they can end this war.
But where will they find that courage in the face of Karl Rove's media machine? They'll find it if all of us speak up as loudly as we can in the next few crucial days and demand that our representatives do what is right. Political courage has always been found in the voice of the people - and our voice is needed today...
Beg the BBC: Set 'In Our Time' Free!
As I drove to work I started to compose a post in praise of an In Our Time episode on Anesthesia. I was going to connect it to a post I'd written on paleolithic suffering, the poignant prayers of 19th century futurists, and Vonnegut's Wheel of Samsara, with an oblique reference to poverty. I'd comment on how Bragg's guests connected the changing social perception of the benefits of pain and suffering to the availability of other options, and confess how whimpy I feel when reading my son stories about extraordinary survivors.
A cross-reference to my tech ravings would mention my whizzy car stereo that plays IOT MP3s and directions on how to capture the audio stream to an MP3 ...
That's when it hit me. Reality.
Only a complete geek loon like me is going to turn a useless streamed IOT program (it's not background music) into a useful MP3 file.
It's time to rebel.
The BBC has been running its experiment of "7 day downloads" for years now. The experiment must end. We need to convince BBC Radio Four to liberate its shelf-ware. Do it now! Send the BBC Radio Four some feedback. When you've sent your feedback in, pass on the feedback link or a link to this blog. Let the BBC feel your pain.
Here's what I wrote ... (edited to improve it, I admit)
I urge you to declare your MP3 download experiment a smashing success and make your archives available as MP3 files for downloading.
Put an audio ad at the beginning and end of each programme. Ask Apple to sell them for $1.00 a tune. Whatever, just do it.
Streaming simply doesn't work. I'm often blogging on excellent IOT programs, but it's a bit pointless since nobody is going to listen to them on their computer. In an era in which car stereos increasingly work with MP3/AAC CDs and iPods (mine works with any USB drive) it's the car radio where IOT will be listened to.
I beg you, stop dangling these unreachable sweets in front of your suffering public and liberate IOT.
Thursday, April 26, 2007
The cat is undead until you open the box ...
This summary from a physics journal fills the gap. "Realism" is a way of saying that the "way of things" is not altered by the act of our observing them. The research seems to affirm an interpretation of quantum mechanics that gives special power to the act of perceiving, namely the power to collapse a wave function .... (emphases mine)
Quantum physics says goodbye to reality (April 2007) - News - PhysicsWeb... Some 40 years ago the physicist John Bell predicted that many hidden-variables theories would be ruled out if a certain experimental inequality were violated – known as "Bell's inequality". In his thought experiment, a source fires entangled pairs of linearly-polarized photons in opposite directions towards two polarizers, which can be changed in orientation. Quantum mechanics says that there should be a high correlation between results at the polarizers because the photons instantaneously "decide" together which polarization to assume at the moment of measurement, even though they are separated in space. Hidden variables, however, says that such instantaneous decisions are not necessary, because the same strong correlation could be achieved if the photons were somehow informed of the orientation of the polarizers beforehand. [jf: In the transactional interpetation the "informing" can occur by meaning-free "messages" that travel back in time.]
Bell's trick, therefore, was to decide how to orient the polarizers only after the photons have left the source. If hidden variables did exist, they would be unable to know the orientation, and so the results would only be correlated half of the time. On the other hand, if quantum mechanics was right, the results would be much more correlated – in other words, Bell's inequality would be violated.Many realizations of the thought experiment have indeed verified the violation of Bell's inequality. These have ruled out all hidden-variables theories based on joint assumptions of realism ... [reality exists when we are not observing it].... and locality ... [separated events cannot influence one another instantaneously]. But a violation of Bell's inequality does not tell specifically which assumption – realism, locality or both – is discordant with quantum mechanics.
Markus Aspelmeyer, Anton Zeilinger and colleagues from the University of Vienna, however, have now shown that realism is more [?] of a problem than locality in the quantum world. They devised an experiment that violates a different inequality proposed by physicist Anthony Leggett in 2003 that relies only on realism, and relaxes the reliance on locality. To do this, rather than taking measurements along just one plane of polarization, the Austrian team took measurements in additional, perpendicular planes to check for elliptical polarization.
They found that, just as in the realizations of Bell's thought experiment, Leggett's inequality is violated – thus stressing the quantum-mechanical assertion that reality does not exist when we're not observing it. "Our study shows that 'just' giving up the concept of locality would not be enough to obtain a more complete description of quantum mechanics," Aspelmeyer told Physics Web. "You would also have to give up certain intuitive features of realism."
This article is the best so far, but there were a few awkward phrases. I've tried to edit it minimally to clarify.
My current (weak) understanding is that locality fell a while ago. There was still hope of preserving realism, but now realism is at least partly gone. We're well into the realm of Schrodinger's "cat" being both alive and dead until an "observer" inspects the cat. I think this result may favor the "decoherence" interpretation of QM, and goes against the "transactional" interpretation favored by (among others) Gribbin.
Alternatively, there's always the reassuring possibility that mathematics is a less trustworthy guide to reality than commonly thought...
Update 5/26/2007: It turns out that in 2004 I posted on a fascinating discussion about how reality can be emergently structured that seems to fit very well with this experiment. I need to find more along the lines of that 2004 post!
Wednesday, April 25, 2007
CV is doing a tutorial on gravitational waves
The difficult childhood of gravitational waves | Cosmic Variance:I'm looking forward with bated breath to the next installment ...
...It might sounds strange that, given an equation describing their existence, gravitational-waves could nonetheless be questioned by large numbers of physicists. However, general relativity can be tricky, and it’s not always straightforward to understand what it’s trying to tell us. In this particular case, the question was whether or not gravitational waves were a gauge artifact. It can sometimes get confusing as to whether an effect is truly physical, or is just a byproduct of the coordinate system one has chosen. For example, look at the latitute/longitude coordinate system on the Earth. This system gets weird at the poles, where suddenly the longitude is no longer well defined (there are an infinite number of valid longitudinal coordinates for the same point). The North and South poles are somehow special, and if all you had were the coordinates, you might be afraid to take a walk there. Who knows what lurks at the singularities?! Needless to say, the problem is with the coordinates, and not with the poles themselves...
Microsoft morphs into General Motors: my OneCare account termination story
That was then. Now I still fear Microsoft will resurrect itself, but Gen Y thinks of them as harmless incompetents. My latest experience is pushing me closer to the Gen Y camp. Here's what happened when I tried to kill my Windows Live OneCare account (866-663-2273, but listen for the option number, they permute it ..):
Gordon's Tech: Microsoft OneCare dies: XP hangs by a threadOnce upon a time General Motors bestrode the American economy, an unassailable behemoth. It took them decades to fall, but by the 1960s they'd been rotted by easy money. Toyota entered.
.... Update 4/21/07: It's one thing to uninstall OneCare, another to kill the OneCare account. The account auto-renews forever. You can't change this online, you have to phone Microsoft to cancel. I tried this tonight. The phone rang a bit, then came a voice .. "Microsoft is closed". Click...
Update 4/22/07: OneCare support has the world's most obnoxious hold music. They alternative up-tempo elevator music with two repetitive sales pitches spoken in a cheerfully grating tone. I got to listen to a lot of that today. After a half-hour I went to lunch, when I returned the line had gone dead. So the wait time was probably 40 minutes. I'll try again tomorrow. ...
Update 4/24/07: Waited 30 minutes on hold. Called back and pushed 9,9,9. Got a support-referral person. They suggested I try option 2 for tech support. Got someone there. They said hours for the account services are 5am-10pm M-F PST and 5am-5pm PST Sat/Sun. They also suggested calling Microsoft's Money-Back-Guarantee line at 888-673-8624. They put through to another tech support number. They said I can't stop the account renewal process without support giving me an "ASIS" number. They transferred me to fee-based technical support where I listened to hold music. Then I gave up...
Update 4/25/07: I ignore the "get an ASIS number first" advice and and call the billing number again at 8:45am PT. Got through immediately -- but that was a false alarm. I'd hit option 3 twice, and errant key presses bring up a human router. She laughs maniacally when I mention OneCare and sends me back to the accounts line. I decide to wait 10 minutes. After seven minutes of the insanely irritating hold music and repetitive marketing patter I decide Microsoft owes me a copy of Macintosh Office 2007 and I contemplate piratical acts. At minute eight the phone picks up. I'm asked why I want to dump OneCare. "Because it has caused far more damage to my system than any virus I'm likely to see". There are no further questions, and to my disgruntled surprise I get a prorated credit of $32. End of story, except, of course, for a post to Gordon's Notes.
Microsoft went from nothing to the greatest corporation in world history in about 15 years. If the trend continues they'll collapse even faster, though their massive cash flows will keep them standing no matter how bad they smell.
Gen Y, I gather, fears Google ...
Update 7/8/07: I've since been thinking of Microsoft as a monstrous brain-eating zombie, though both Photosynth and Windows Live Writer suggest the Zombie can still keep some brains on the shelf. It's my wife, however, who pointed out that American under Bush has followed the same progression as Microsoft and General Motors. Very powerful, very dangerous, but no longer meaningful -- simply a big slowly dying Zombie.
Also, I posted an aside about "Microsoft on crack" in August of 2006, I think that was after the Windows Live Cam debacle.
Tuesday, April 24, 2007
Life in Guantanamo
The Tralfamadorians and the transactional interpretation of quantum mechanics
Kurt Vonnegut | Obituary - Economist.comThe Tralfamadorian position, I've read, is taken seriously (or at least semi-seriously) by some physicists. Many would say the 'transactional interpretation' of QM is consistent with a severely predestined universe, so that indeed all moments would aways exist, from start to end, and never be changeable in the slightest [2]. I imagine a vast celestial record player that could move back and forth, playing music backwards and forwards ...
... “Slaughterhouse-Five”, published in 1969 against the backdrop of racial unrest and the Vietnam war, propelled him from science-fiction writer (a label he abhorred) to literary icon. The novel caught the brooding, anti-establishment mood of the times and became an instant bestseller. Its signature hook, “So it goes”, which followed every death, was adopted as a mantra by opponents of the war.The main character, Billy Pilgrim, is kidnapped by small green aliens called Tralfamadorians, who teach him the true nature of time: that all moments in the past, present and future exist always, and that death is just an unpleasant moment, neither an end nor a beginning. When Billy is shot bringing this message to the world, he does not mind. He knew he would die like this; he has seen it all before. “Farewell, hello, farewell, hello” are his last words...
Anyway, it's been a long time since I read Slaughterhouse-five, and now that I'm ancient it's probably time to take a break from Quantum Mechanics and reread it ...
[1] One interesting hit, however, led to me subscribe to Backwards City ...
[2] Gribbin 1994: "At first sight, it might seem as if everything is fixed by these communications between the past and the future.... we are back with the image of a frozen universe ... in which neither time nor space has any meaning, and everything that ever was, or ever will be, just is.". Gribbin tries to wriggle out of this interpretation - unconvincingly.
Update: 15 things Vonnegut said well
Update 5/13/07: found a quote to affirm my recollection of the pre-deterministic aspects of the transactional interpretation.
Update 5/21/07: I continue to return to the theme of fate, though I don't want to belabor it with repeated posts. I'll sneak in some updates instead ...
- Newtonian physics implied that if one knew the position and velocity of every particle in existence, then one would know all events. Oddly enough, I think I first read of this in a 1930s era science fiction novel. I assume this was a discussion topic for philosophers during the long span of Newtonian physics.
OneThe standard interpretation time slicing inherent ingeneralspecial relativity is that there exists for each event a perspective from which the event is occurring in the past. Simple induction would then say all events are thus rigidly pre-determined. Of course we know special relativity is incomplete, so perhaps this is of academic interest. [jf 6/11/07: I wrote "general relativity" originally, but the meme comes from special relativity. For all I know general relativity lessens this rigidity. Einstein, at one point in his life, apparently firmly believed that all events, from the beginning to the end of time, were absolutely fixed, which gives a different spin to his famous comments about God and dice. To Einstein not only did God not play dice with the universe, the universe didn't "play" at all -- it simply was. Given the time that Vonnegut was writing, he was probably presenting a version of predestination derived from special relativity.]- The predetermination qualities of the transactional interpretation of QM arise from the future-past interactions (rather similar to time slicing in general relativity), but one could interpret non-locality (correlation of non-connected states) as arising not from "action at a distance" but merely as a side-effect of predetermination.
Of course, if splogs echo Brad rather than, say, David Broder, does that make them not entirely evil?
On the matter of pre-determination, the most obvious objection is how does a story that we perceive as approximately "internally consistent" manage to spontaneously manifest itself all at once? This pushes the anthropic principle to an extreme of extremes (in infinite time an infinite number of chance assemblies produce one that seems to be self-consistent). If one doesn't buy the "universe as a tv show" vision then one also rejects both special relativity and the transactional interpretation of quantum mechanics. Special relativity is known to be an incomplete approximation, so that's not too hard to reject. Transactional QM seems to be recently falling to the "decoherence" model in which reality is constructed and deconstructed dynamically*, so we may be back to a universe that's not pre-determined, but at the price of being in a universe in which reality itself is emergent, ephemeral and perhaps mutable*.
* For the benefit of those who don't read my stuff routinely, I'm not a physicist and I don't even personally know any theoretical physicists. I'm merely channeling the more respectable books written about the philosophical interpretations of modern physics.
Update 7/24/07: Newsweek makes the same connection. Do you suppose they got it from here ...?
Asthma rise and the hygiene hypothesis: evidence from Helicobacter
Resistance: Bacterium Linked to Ulcers May Lower Risk of Asthma - New York Times:Asthma, peanut allergies, atopic eczema ... there's a lot of that around. Getting a dog might help. That reminds me, whatever happened to studies suggesting intestinal worm infections help prevent and even treat ulcerative colitis?
...According to the article, which appears in the journal Archives of Internal Medicine, H. pylori acquisition in industrialized countries has been diminishing with each succeeding generation for at least the past 60 years.
“Helicobacter was once ubiquitous,” said Dr. Martin J. Blaser, a co-author of the article and the chairman of the department of medicine at New York University. “We provide evidence that there is a relationship between the decrease in helicobacter prevalence and the increase in childhood asthma.”
The researchers noted that their observations were consistent with the “hygiene hypothesis,” which suggests that childhood infections, particularly infections of the gut, help diminish or prevent allergies and asthma.
Calvinist theology: from Garrison Keillor
The chosen president | Garrison KeilorI didn't know about the L and the P. What a merciless, cruel faith. That's a God to fear ...
...Calvinism, as all of you Calvinists know, is based on five points of doctrine, which spell out the word 'TULIP' -- total depravity (everybody is sinful), unconditional election (God chooses who'll be saved, it's not up to you), limited atonement (Jesus didn't die for everybody, just for the chosen), irresistible grace (if God chooses you, you're saved, you can't resist) and perseverance of the saints (once saved, always saved, no matter what you do).
Myelin disorders underlie schizophrenia?
White Matter Matters in Schizophrenia: Scientific AmericanSince there are animal models for schizophrenia I'm sure the researchers have already tested drugs developed to enhance myelin production and preservation. Those papers should be out shortly ...
Scientists have suspected for more than two decades that schizophrenia is linked to defects in the brain's white matter. They could not tell, however, whether changes in the information-transmitting region of the brain detected by brain scans or autopsies were the cause or the symptoms of the illness.
A new study not only clarifies the association but also links it to genes previously tied to the debilitating mental disorder and chemical changes believed to occur in the schizophrenic brain. "[The report] provides evidence that alterations in myelin [the lipid layers that sheath and insulate nerve fibers and are the main constituent of white matter] can cause defects in neurons and the central nervous system in general that are related to neuropsychiatric disease," says the study's senior author Gabriel Corfas, a professor of neurology at Harvard Medical School's Children's Hospital Boston.
Corfas's team studied mice in which they blocked the erbB4 receptor, in oligodendrocytes, which make up the myelin sheath over a neuron's communication hub. The erbB4 receptors receive a growth factor called neuregulin 1, which is necessary for proper brain development. Genes expressed in oligodendrocytes—such as the one that codes for neuregulin 1—have previously been linked to schizophrenia, bipolar disorder, depression and obsessive-compulsive disorder....
...Corfas says that the new findings indicate that screening children with noticeable cognitive and social defects for increased white matter or changes in its organization could lead to earlier diagnosis of schizophrenia. In addition, he says the results indicate that therapies designed to treat other white matter disorders such as multiple sclerosis could be useful in treating schizophrenia and other neuropsychiatric disorders.