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Wednesday, Dec 30, 2009
 
Evolutionists censor movie again
The LA Times reports:
L.A.'s California Science Center will start the new year defending itself in court for canceling a documentary film attacking Charles Darwin's theory of evolution.

A lawsuit alleges that the state-owned center improperly bowed to pressure from the Smithsonian Institution, as well as e-mailed complaints from USC professors and others. ... On Oct. 5, the science center, one of 165 national affiliates of the Smithsonian that enjoy special access to loans from its massive collection, received an alert -- and a complaint -- from Harold Closter, director of the Smithsonian's affiliates program. Closter gave the science center the head's-up about a news release that had been issued not by the AFA but by the Discovery Institute, a Seattle-based think tank that promotes intelligent design and whose researchers are featured in "Darwin's Dilemma." ...

The AFA's suit, filed Oct. 14, contends that the contract issue was a "false pretext" and ... The AFA says that it should not have been held responsible for a release that it didn't issue itself.

The Discovery Institute replies here.

As I understand it, the AFA (whoever they are) paid to rent a public movie theater in LA. The movie is critical of Darwinism, and features some DI scholars. DI issued a press release that might have mischaracterized another govt agency. Evolutionists pressured the govt agency controlling the movie theater to cancel the showing.

I don't know anything about the movie, but even if it is as fictional as a Hollywood movie, it is hard to see any justification for censorship.

The evolutionists really hate the DI. I get that. They are like medieval inquisitors going after agents of the devil. Even if the DI is entirely wrong in all their opinions, it is no threat to anyone. Those who try to censor the DI only expose themselves as unreasonable.


Tuesday, Dec 29, 2009
 
Einstein and the anti-relativity cranks
In the October 2006 Cosmos magazine article, Was Einstein a fake?, John Farrell writes:
In his book Cranks, Quarks and the Cosmos, science writer and physicist Jeremy Bernstein points out that one of the criteria that always defines crank 'science' is its lack of correspondence with the body of scientific knowledge that has gone before it.

"I would insist that any proposal for a radically new theory in physics, or in any other science, contain a clear explanation of why the precedent science worked," he writes. Einstein did this, as the first page of his paper on special relativity, "On the Electrodynamics of Moving Bodies", illustrates perfectly. [p.18]

In contrast, "the crank," Bernstein writes, "is a scientific solipsist who lives in his own little world. He has no understanding nor appreciation of the scientific matrix in which his work is embedded ... In my dealings with cranks, I have discovered that this kind of discussion is of no interest to them." [p.20]

Here is that 1905 Einstein article, and he doesn't explain the precedent science at all. He mentions "Maxwell's electrodynamics" and "motion of the earth", but he failed to mention the Lorentz transformations that started in about 1887, the Lorentz aether theory which started in 1892, the Michelson-Morley experiment of 1887, and experiments detecting the relativistic mass of an electron.

Even in later life, Einstein denied that he even knew about Poincare's work and only admitted to knowing about one of Lorentz's papers on Lorentz transformations. He said, "The Michelson-Morley experiment had no role in the foundation of the theory." and "..the theory of relativity was not founded to explain its outcome at all." See Michael Polanyi's book.

By Bernstein's definition, Einstein was a crank, and not a good example for proposing new theories.

I am wondering why Einstein get praised for something that he did so terribly. He never showed an appreciation for what Poincare and others did, and in his later life he was the worst example of a "scientific solipsist" who was frequently announcing crackpot theories that showed no relation to the work of others.

Bernstein says:

As one might imagine, the comprehension and acceptance of Einstein's early work broke down along generational lines. Physicists -- at least the good ones -- of about Einstein's age understood almost immediately the importance of at least some of what he had done. [p.25]
Here are the ages in 1905 of those who are credited with contributing to the theory of special relativity: Einstein 26, Lorentz 52, Minkowski 41, Poincare 51, Planck 47, Kaufmann 44, Bucherer 42, Laue 26, Lewis 30. As you can see, they were not that young.

Bernstein says that Einstein got his first of many honorary degrees in 1909! [p.24] Those decisions are made by committees of old people, so it was not just the young who understood and accepted relativity.

Bernstein's main point is to say that he thinks that it is remarkable that the journal editors accepted Einstein's 1905 papers, when they were so bold and original, and from an unknown physicist. I say that there is a simple explanation -- the papers were not so bold and original. I am sure that the editors were familiar with Lorentz aether theory, and may have even heard Poincare's lectures on relativity.


Monday, Dec 28, 2009
 
The strangest man
From a book review of a recent biography of Paul Dirac:
One of the more interesting themes to run through this book is the contrast of two ways of doing physics, which might be called “bottom-up” and “top-down.” In the former, one gathers data by experiment, then looks for a mathematical theory that describes the data. In the latter, one contrives beautiful mathematical theories, then looks to see if nature conforms. Dirac was very much in the “top-down” camp. His confidence in his theories derived exclusively from their mathematical elegance.
Maybe this explains why he was so unproductive past age 30. Just like Einstein.
Farmelo writes: “[W]hat is most remarkable about the story of antimatter is that human beings first understood and perceived it not through sight, smell, taste and touch, but through purely theoretical reasoning inside Dirac's head.”
This is a little exaggerated. Dirac published a theory of electrons and protons in 1929. In 1931 he realized the particles had to have the same mass, so he said that it was maybe a theory of electrons and some new particle. The anti-electron was observed in 1932. Other antimatter came much later, and was not predicted from Dirac's theory.
The same might be said about Einstein's theory of general relativity, which was conceived in his head before any experiment indicated its necessity, and today's string theory, which is awaiting empirical verification. In the end, of course, observation is the ultimate test of any theory.
No, string theory is not awaiting empirical verification. There is nothing to verify because it does not make any testable predictions. The general relativity story is a little more complicated, and I will write about that later.

Here is proof that experiment suggested the necessity of somthing like general relativity. This is from Weinberg's reply to his article trashing paradigm shift theory:

From the eighteenth century on there were astronomers who speculated about possible departures from the Newtonian theory of gravitation. Take a look at the article on the planet Mercury in the eleventh edition of the Encyclopedia Britannica, written by the noted astronomer Simon Newcomb before the advent of Einstein's General Relativity. You will find Newcomb speculating that Newton's inverse square law of gravitation may be only approximate.
For decades, Mercury's orbit was the main quantitative evidence for general relativity. There was also eclipse evidence, but it was inaccurate.

Sunday, Dec 27, 2009
 
CDC advisors still biased towards vaccines
The NY Times reports:
WASHINGTON — A new report finds that the Centers for Disease Control and Prevention did a poor job of screening medical experts for financial conflicts when it hired them to advise the agency on vaccine safety, officials said Thursday.

Most of the experts who served on advisory panels in 2007 to evaluate vaccines for flu and cervical cancer had potential conflicts that were never resolved, the report said. Some were legally barred from considering the issues but did so anyway.

In the report, expected to be released Friday, Daniel R. Levinson, the inspector general of the Department of Health and Human Services, found that the centers failed nearly every time to ensure that the experts adequately filled out forms confirming they were not being paid by companies with an interest in their decisions.

The report found that 64 percent of the advisers had potential conflicts of interest that were never identified or were left unresolved by the centers.

This is an old story, and Congress has even had hearing about it. The CDC's response is that they cannot find anyone to recommend the vaccines, except for those on the drug company payroll. They are in the business of promoting vaccines, not objectively evaluating them.

Some of these vaccines could be worthwhile, even if they are promoted by greedy drug companies. But you cannot trust a CDC recommendation. CDC panel experts have sometimes said that they were voting to recommend a vaccine in order to force govt funding for it.


Saturday, Dec 26, 2009
 
Perfect Rigor
A reader asks me about the recent book, Perfect Rigor: A Genius and the Mathematical Breakthrough of the Century. The title seems to come from Poincare's (long) 1905 relativity paper:
If the inertia of matter is exclusively of electromagnetic origin, as generally admitted in the wake of Kaufmann’s experiment, and all forces are of electromagnetic origin (apart from this constant pressure that I just mentioned), the postulate of relativity may be established with perfect rigor. This is what I show by a very simple calculation based on the principle of least action.

But that is not all. In the article cited above, Lorentz judged it necessary to extend his hypothesis in such a way that the postulate remains valid in case there are forces of non-electromagnetic origin. According to Lorentz, all forces are affected by the Lorentz transformation (and consequently by a translation) in the same way as electromagnetic forces.

It was important to examine this hypothesis closely, and in particular to ascertain the modifications we would have to apply to the laws of gravitation. We find first of all that it requires us to assume that gravitational

A lot of people assume that Perelman turned down the $1M prize, but it hasn't been offered yet, AFAIK. I don't know why not. The rules say:
Before consideration, a proposed solution must be published in a refereed mathematics publication of worldwide repute (or such other form as the SAB shall determine qualifies), and it must also have general acceptance in the mathematics community two years after.
This has been clearly satisfied. It has now been 3.5 years since such publication, and since general acceptance.

I haven't seen the book, but it seems consist of a lot of gossip, innuendo, and amateur psychoanalysis about how Perelman is crazy. It does not attempt to explain any of the math alluded to in the title. It is a biography of Perelman, but the author did not interview him.

This is the latest example of a book about a mathematician that portrays him as crazy without reporting what he has to say or what he really accomplished. Another recent example is The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom. I think that these books are offensive.


Thursday, Dec 24, 2009
 
Current Nobel physics prize went to wrong guys
There is a controversy about the recent Nobel physics prize:
In the 1960s there were four men who worked together at Bell Labs in New Jersey: Willard Boyle, George Smith, Eugene Gordon and Mike Tompsett. In 2009, Smith and Boyle were awarded the Nobel prize.

Boyle and Smith were lauded for their creation of

"... the first successful imaging technology using a digital sensor, a CCD (Charge-Coupled Device). The CCD technology makes use of the photoelectric effect, as theorized by Albert Einstein and for which he was awarded the 1921 year's Nobel Prize. By this effect, light is transformed into electric signals. The challenge when designing an image sensor was to gather and read out the signals in a large number of image points, pixels, in a short time. The CCD is the digital camera's electronic eye. It revolutionized photography, as light could now be captured electronically instead of on film.
79 year old Eugene Gordon said that Tompsett's patent was for the CCD, and that Smith and Boyle had patented a charge-coupled device shift register, which had nothing to do with imaging.
I don't know who did the more important work, but the prize went for inventiong the first successful imaging technology using a digital sensor, a CCD (Charge-Coupled Device), but the recipients did not do that. You can read Boyle-Smith Patent No. 3858232 for a CCD that does not mention imaging at all, and Tompsett Patent No. 4085456 Here is another story about Michael Francis Tompsett not getting credit.

Wednesday, Dec 23, 2009
 
Who created the standard model for high-energy physics?
Our best theory of physics is the standard model of elementary particles. It combines electromagnetism, weak, and strong forces into a geometric quantum gauge theory, and became accepted in the 1970s. Who is the Einstein credited for this theory?

Sheldon Lee Glashow said this (pdf) in a recent CERN talk:

Why did it take until 1967 for Steve Weinberg (and Abdus Salam, a year later) to use the Higgs mechanism to explain the breaking of electroweak gauge symmetry? And why was this work ignored until the suspected renormalizability of the theory was established? (There were just two citations to Weinberg’s paper prior to 1971, but over 7000 afterward!) ...

When we visited MIT to explain our work to Weinberg, he was amiable but showed little interest. At the time, we ourselves were blissfully unaware of his 1967 electroweak paper and Steve himself seemed to have forgotten about it.

The next crucial event took place at the Amsterdam Conference in 1971, where Gerard ’tHooft announced his proof of the renormalizability of the electroweak model with spontaneous symmetry breaking provided by the Higgs mechanism.

Weinberg's 1972 general relativity textbook said:
However, I believe that the geometrical approach has driven a wedge between general relativity and the theory of elementary particles. As long as it could be hoped, as Einstein did hope, that matter would eventually be understood in geometrical terms, it made sense to give Riemannian geometry a primary role in describing the theory of gravitation. But now the passage of time has taught us not to expect that the strong, weak, and electromagnetic interactions can be understood in geometrical terms, and that too great an emphasis on geometry can only obscure the deep connections between gravitation and the rest of physics.
Glashow, Weinberg, and Salam got the Nobel Physics Prize in 1979, and 'tHooft got it in 1999.

It appears to me that 'tHooft make the big breakthru. He proved that the nonlinear gauge theories were consistent at a time when the other experts had given up on them. He did the hard work while others made lucky guesses. And yet 'tHooft's prize came 20 years after the others were recognized.

Weinberg's 1967 paper was disregarded by others and even himself, and he even implies in 1972 that his whole approach was wrong. What saved him was not new experimental data, but someone proving a mathematical theorem. That theorem turned a lucky guess equation into a consistent theory. Experimental confirmation came later in the 1970s.

I think that there is something seriously wrong with the way that science is credited. Why is Weinberg so much more famous than 'tHooft? Actually, I am surprised that 'tHooft won a Nobel prize at all. His prize is one of the few prizes that have gone for theoretical work.

The Nobel committee prefers experimental work, and that is fine with me, but Weinberg is not an experimentalist. Maybe they thought that 'tHooft's work was too mathematical, and that Weinberg's was easier to understand. But it was 'tHooft's work that showed that nonlinear gauge theories could be turned into a consistent quantum theory, and that paved the way for the current theories of both the weak and strong interactions.

Salam also got the prize for independently saying the same thing that Weinberg did. When two people do the same thing independently, it is a sign that maybe the ideas were in the air and the work was not so original.

Update: Here is Weinberg's account (pdf).


Monday, Dec 21, 2009
 
Great ideas from old scientists
John Derbyshire writes that we should Trust Science, altho he is not sure about the warmists. He says that only young scientist lead scientific revolutions:
There have been scientific revolutions aplenty, and there will surely be more. Galileo, Kepler, Newton, Lavoisier, Faraday, Darwin, Pasteur, Planck, Einstein, Hubble, and Wegener are not revered for their defense of a consensus. To overthrow a consensus, or force major changes on it, is the dream of every young scientist. Older scientists may settle for tenure, rank, political patronage, and a quiet life, but there will always be younger ones ready to fight from the contrarian corner.
His examples are unconvincing. I looked the ages of these guys when they first published something great that went against conventional wisdom. Here is what I got:

Darwin 50, Galileo 68, Hubble 42, Kepler 38, Lavoisier 35, Newton 44, Pasteur 44, Planck 42, Wegener 35.

I wasn't sure what age to put for Faraday. He did a lot of brilliant and cutting-edge experimental work, but I am not sure it took any guts to publish any of it. Perhaps his most radical and ultimately useful idea was his lines of force, which he proposed in a publication at age 54.

I skipped Einstein because I don't think he ever published any great works. Instead Poincare published his first version of special relativity at age 46 in 1900.

Einstein was 26 in 1905 when he published his first important papers. Apparently the Einstein myth is so powerful that it fools an otherwise intelligent writer like Derbyshire. Apparently he thinks that Einstein revolutionized science as a young man, and so all the other great science must have been similarly done by young men also.

That is why it is so important to get the Einstein story right. Somehow the Einstein myth has not only given people a distorted idea about what relativity is all about, but it has also given a distorted idea about how all of science works.


Sunday, Dec 20, 2009
 
Bodanis on Poincare
The historian David Bodanis wrote the book E=mc2: A Biography of the Worlds Most Famous Equation. The book is really a biography of Einstein, as it does not even mention the work done on the equation before and after Einstein's short 1905 paper on it.

He has some nonsense about Poincare:

In time a few scientists did begin to hear of his work, and then jealousy set in. Henri Poincaré was one of the glories of Third Republic France, and, along with David Hilbert in Germany, one of the greatest mathematicians in the world. As a young man Poincaré had written up the first ideas behind what later became chaos theory; as a student, the story goes, he'd once seen an elderly woman on a street corner knitting, and then, thinking about the geometry of her knitting needles as he walked along the street, he'd hurried back and told her that there was another way she could have done it: he'd independently come up with purling.

By now, though, he was in his fifties, and although he could still get some fresh ideas, he increasingly didn't have the energy to develop them. Or maybe it was more than that. Middle aged scientists often say that the problem isn't a lack of memory, or the ability to think quickly. It's more a fearfulness at stepping into the unknown. For Poincaré had once had the chance of coming close to what Einstein was doing.

In 1904 he'd been in the large group of disoriented European intellectuals invited to the World's Fair being held in St. Louis. (Max Weber, the German sociologist, was also there, and he was so startled by the raw energy he saw in America he described Chicago as being "like a man whose skin has been peeled off" that it helped jolt him out of a depression he'd been suffering for years.) At the fair, Poincaré had actually given a lecture on what he'd labeled a "theory of relativity," but that name is misleading for it only skirted around the edges of what Einstein would soon achieve. Possibly if Poincaré had been younger he could have pushed it through to come up with the full results Einstein reached the next year, including the striking equation. But after that lecture, and then the exhausting schedule his St. Louis hosts had for him, the elderly mathematician let it slide. The fact that so many French scientists had turned away from Lavoisier's hands on approach and instead insisted on a sterile over abstraction only made it harder for Poincaré to be immersed in practical physics.

By 1906, realizing that this young man in Switzerland had opened up an immense field, Poincaré reacted with the coldest of sulks. Instead of looking closer at this equation, which he could have considered a stepchild, and bringing it in to his Paris colleagues for further development, he kept a severe distance; never speaking of it; seldom mentioning Einstein's name. ... [p.78-79]

The few researchers around 1905 who had uncovered a small part of what he later deduced had no chance of matching him. Poincaré got closer than almost anyone else, but when it came to breaking our usual assumptions about time's flow or the nature of simultaneity, he backed off, unable to consider the consequences of such a new view.

Why was Einstein so much more successful? It's tempting to say it was just a matter of being brighter than everyone else. But several of Einstein's Bern friends were highly intelligent, while someone like Poincaré would have been off the scale on any IQ test. ... [p.85]

This is ridiculous. Poincare did not back off after 1904. The next year he published a 50-page paper on relativity that introduced spacetime and the Lorentz group. It was bolder, more thorough, and more advanced than what Einstein wrote.

It is true that Poincare barely mentioned Einstein. Einstein probably never wrote anything that was of use to Poincare. Poincare did write a letter of recommendation once for Einstein. That would be the place to look if you suspect Poincare of jealousy.


Friday, Dec 18, 2009
 
Isaacson on Poincare
Walter Isaacson wrote the biggest-selling Einstein book, Einstein: His Life and Universe, in 2007. He idolizes Einstein far out of proportion, of course.

I looked at what the book says about Poincare.

Einstein, who was still not yet enamored of math, at one point described Minkowski's work as "superfluous learnedness" and joked, "Since the mathematicians have grabbed hold of the theory of relativity, I myself no longer understand it." But he in fact came to admire Minkowski's handiwork and wrote a section about it in his popular 1916 book on relativity. [p.133]
He is talking about the idea of combining space and time into a four-dimensional spacetime. It is credited to Minkowski in 1908 but is actually due to Poincare in 1905. It does not just get a section in Einstein's book; most of the book depends on it.

What this is saying is that Poincare published the essence of special relativity in 1905, and Einstein still did not understand it in 1908.

Once again, it's worth asking why Einstein discovered a new theory and his contemporaries did not. Both Lorentz and Poincaré had already come up with many of the components of Einstein's theory. Poincaré even questioned the absolute nature of time.

But neither Lorentz nor Poincaré made the full leap: that there is no need to posit an ether, that there is no absolute rest, that time is relative based on an observer's motion, and so is space.

This is just a lie. Poincare explicitly says all of those things several years before Einstein.
Poincaré never made the connection between the relativity of simultaneity and the relativity of time, and he "drew back when on the brink” of understanding the full ramifications of his ideas about local time. Why did he hesitate? Despite his interesting insights, he was too much of a traditionalist in physics to display the rebellious streak ingrained in the unknown patent examiner," "When he came to the decisive step, his nerve failed him and he clung to old habits of thought and familiar ideas of space and time," Banesh Hoffmann said of Poincaré.
Poincare explicitly made those connections in 1900, 5 years before Einstein. There is no "full leap" or "decisive step" that Poincare failed to make.
Even more surprising, and revealing, is the fact that Lorentz and Poincaré never were able to make Einstein's leap even after they read his paper. Lorentz still clung to the existence of the ether ...

For his part, Poincaré seems never to have fully understood Einstein's breakthrough. Even in 1909, he was still insisting that relativity theory required a third postulate, which was that "a body in motion suffers a deformation in the direction in which it was displaced." In fact, the contraction of rods is not, as Einstein showed, some separate hypothesis involving a real deformation, but rather the consequence of accepting Einstein's theory of relativity. [p.134-135]

This is really wacky. Relativity textbooks today often admit that Einstein's two postulates are insufficient, and a third postulate is needed. This is evidence that Poincare understood it better, not worse.

Isaacson has only a shallow understanding of relativity, and he relies on quotes of the opinions of others to badmouth Poincare. His strongest quote is this unsource quote from the mathematical physicist Freeman Dyson:

The essential difference between Poincaré and Einstein was that Poincaré was by temperament conservative and Einstein was by temperament revolutionary. When Poincaré looked for a new theory of electromagnetism, he tried to preserve as much as he could of the old. He loved the ether and continued to believe in it, even when his own theory showed that it was unobservable. His version of relativity theory was a patchwork quilt. The new idea of local time, depending on the motion of the observer, was patched onto the old framework of absolute space and time defined by a rigid and immovable ether. Einstein, on the other hand, saw the old framework as cumbersome and unnecessary and was delighted to be rid of it. His version of the theory was simpler and more elegant. There was no absolute space and time and there was no ether. All the complicated explanations of electric and magnetic forces as elastic stresses in the ether could be swept into the dustbin of history, together with the famous old professors who still believed in them.
Note that Dyson is not claiming that Poincare said anything that was incorrect, inadequate, or at odds with observation. Dyson criticizes Poincare's temperament, attitude, and terminology. His comments are consistent with the view that Poincare invented the whole of special relativity before Einstein, and then Einstein found a better way of explaining it to physicists.

I doubt that Dyson ever even read Poincare. Poincare never advocated absolute space or elastic stresses in the ether or any of that stuff. Dyson is just repeating how 20th century physicists make fun of 19th century physicicsts. I would take his opinion of Poincare more seriously if there were some indication that he actually read Poincare.

Dyson probably would have gotten a Nobel prize in Physics for his work on quantum electrodynamics, if he had been considered a physicist instead of a mathematician. Being a mathematician, he was subject to the prejudices that physicists have against mathematicians. So it is funny to see him buying into similar prejudice against Poincare.

This is the same Dyson who said all the fuss about global warming is grossly exaggerated, and that Einstein had no technical skill as a mathematician.


Thursday, Dec 17, 2009
 
Einstein was not peer reviewed
Here is an example of Einstein's arrogance:
How many of Einstein’s 300 plus papers were peer reviewed? According to the physicist and historian of science Daniel Kennefick, it may well be that only a single paper of Einstein’s was ever subject to peer review. That was a paper about gravitational waves, jointly authored with Nathan Rosen, and submitted to the journal Physical Review in 1936. The Physical Review had at that time recently introduced a peer review system. It wasn’t always used, but when the editor wanted a second opinion on a submission, he would send it out for review. The Einstein-Rosen paper was sent out for review, and came back with a (correct, as it turned out) negative report. Einstein’s indignant reply to the editor is amusing to modern scientific sensibilities, and suggests someone quite unfamiliar with peer review:
Dear Sir,

We (Mr. Rosen and I) had sent you our manuscript for publication and had not authorized you to show it to specialists before it is printed. I see no reason to address the in any case erroneous comments of your anonymous expert. On the basis of this incident I prefer to publish the paper elsewhere.

Respectfully,

P.S. Mr. Rosen, who has left for the Soviet Union, has authorized me to represent him in this matter.

As it turns out, the referee was completely right, and Einstein was wrong. Einstein was claiming to have proved that gravity waves do not exist. He later resubmitted the paper else, but changed his conclusion to saying that gravity waves exist after all. I am sure he didn't credit that ten-page referee report.

For an even more indignant letter telling off academic referees, see the Roy F. Baumeister letter.


Wednesday, Dec 16, 2009
 
Why people are gullible
Half Sigma blog writes:
Humans have a pretty powerful herding instinct. The Gaians know this, which is why they are trying so hard to promote the idea that there’s a “consensus,” because they know that the perception of consensus will sway people to their side. After all, 99% of the people who believe in global warming believe because of social reasons and not because they’ve done their own independent assessment of the facts. For women, the herding instinct is even more powerful than it is for men. Men can be loners, but women are never loners.

The reason why ad hominen arguments are used is because they are effective at swaying opinions, and their effectiveness lies in the herding instinct. People want to believe what the in-group believes, and not what the weirdos or the evil people believe.

Without brave men like Galileo Galilei or Martin Luther or Charles Darwin to challenge the status quo when they know that the status quo is wrong, there would be no advancement of society. We’d still be in the dark ages with all thought controlled by the Catholic Church.

He sure picked three lousy examples.

Luther attacked the Catholic Churrch, but it was mainly to promote a more literal interpretation of the Bible and to argue certain theological points, such as gaining salvation by faith alone. Whether this was a great "advancement of society" is a matter of opinion. It was Luther, not the Catholic Church, who said that the Bible requires geocentrism.

For examples of great advances, it would be better to cite great scientific advances or great inventions. But then it is hard to find an example of the Catholic Church in opposition.


Tuesday, Dec 15, 2009
 
AP gives opinion on emails
The AP reports:
LONDON — E-mails stolen from climate scientists show they stonewalled skeptics and discussed hiding data — but the messages don't support claims that the science of global warming was faked, according to an exhaustive review by The Associated Press.

The 1,073 e-mails examined by the AP show that scientists harbored private doubts, however slight and fleeting, even as they told the world they were certain about climate change. However, the exchanges don't undercut the vast body of evidence showing the world is warming because of man-made greenhouse gas emissions.

Are we supposed to accept the opinion of five AP journalists over that of 1000s of scientists? The AP statement shows that they do not understand the issues.

I am already convinced that man-made greenhouse gas emissions are increasing in the atmosphere, and are trapping infrared radiation in the form of heat. The warming issues have to do with how great is the effect, whether there is positive feedback, whether it is making the world better or worse, whether we are headed toward a catastrophe, and what might be done about it.

Frankel saw "no evidence of falsification or fabrication of data, although concerns could be raised about some instances of very 'generous interpretations.' "

The e-mails were stolen from the computer network server of the climate research unit at the University of East Anglia in southeast England, an influential source of climate science, and were posted online last month.

The AP studied all the e-mails for context, with five reporters reading and re-reading them — about 1 million words in total.

These five reporters did not look at any data. They just looked at emails.

We don't know for sure that the emails were "stolen". The term "leaked" is more accurate. Maybe they were lawfully released to comply with a FOIA request.

The more important leak was the computer codes that showed how the raw data was manipulated. The reporters did not look at that.

Paul Kotta, a leftist writer for a top-secret govt nuclear weapons labs and part-time mail-order premium green tea seller has written this letter:

So, climate change deniers, let me get this straight: The same scientific community that has made this country prosperous and strong with innovations like the microcircuitry and telecommunications that power your blogs, the aeronautical advancements that whisk you to tea party rallies and the medical technologies that prolong your life (assuming your insurer covers the procedure) is now scheming to perpetrate an enormous hoax to ruin the American economy?

Such a broad-based, coordinated deception would be unprecedented in science’s history — but is quite common outside of science. A perfect example is the propaganda machine that has convinced you that, in this one case, science is plotting against us while the oil, coal and other polluting industries have the nation’s long-term interests at heart.

The scientists who made this country great never destroyed raw data and asked us to believe manipulated data. Well, maybe they did that at the nuclear weapons lab, but not for the technologies he mentions.

Saturday, Dec 12, 2009
 
The Black Hole War
String theorist and Stanford professor Leonard Susskind has a new book titled, The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics. It is 470 pages about a seemingly trivial philosophical difference. He justifies it at the beginning with:
The Black Hole War was a genuine scientific controversy nothing like the pseudodebates over intelligent design, or the existence of global warming. Those phony arguments, cooked up by political manipulators to confuse a naive public, don't reflect any real scientific differences of opinion. By contrast, the split over black holes was very real. Eminent theoretical physicists could not agree on which principles of physics to trust and which to give up. Should they follow Hawking, with his conservative views of space time, or 't Hooft and myself, with our conservative views of Quantum Mechanics? Every point of view seemed to lead only to paradox and contradiction. Either space time the stage on which the laws of nature play out could not be what we thought it was, or the venerable principles of entropy and information were wrong. Millions of years of cognitive evolution, and a couple of hundred years of physics experience, once again had fooled us, and we found ourselves in need of new mental wiring.

The Black Hole War is a celebration of the human mind and its remarkable ability to discover the laws of nature. It is an explanation of a world far more remote to our senses than Quantum Mechanics and relativity. Quantum gravity deals with objects a hundred billion billion times smaller than a proton. We have never directly experienced such small things, and we probably never will, but human ingenuity has allowed us to deduce their existence, and surprisingly, the portals into that world are objects of huge mass and size: black holes. [p.9-10]

The black hole war is nothing like the global warming debate because the latter has immediate testable predictions and public policy consequences. The climate data will soon tell us who is right and who is wrong.

Intelligent design is less clear-cut, as some hypotheses are testable and some are not. Susskind wrote his own 2005 book on The Cosmic Landscape: String Theory and the Illusion of Intelligent Design, where he made his own peculiar arguments for intelligent design.

But the black hole war is not going to be decided by any observation or other objective standard. It is only a question about the opinions that may be adopted by the "eminent theoretical physicists", whoever they are. Susskind sounds like a theologian arguing about which god to pray to, not a scientist.

He admits that we "probably never will" have any data to decide these issues, and he celebrates the ability of the human to quibble about such esoteric issues anyway.

An Amazon reviewer writes:

If we accept the argument that something that a falling observer (someone who cannot return nor communicate with the rest of the world) can observe is considered as a valid scientific observation, we then lose our ability to criticize people for believing that the dead go to Heaven. The dead person (one who cannot return nor communicate with the rest of the world) observes Heaven. We scientists must be very careful about our scientific reasoning, and not give others the opportunity to twist it to make it sound as if we support religion, as is, unfortunately, often the case.
I think that Susskind abandoned scientific reasoning long ago.

Friday, Dec 11, 2009
 
Hawking on Einstein
Astrophysicist Stephen Hawking gave a lecture at Caius College in May 1992 that was published in Black Holes and Baby Universes and Other Essays. He said:
The people who actually make the advances in theoretical physics don't think in the categories that the philosophers and historians of science subsequently invent for them. I am sure that Einstein, Heisenberg, and Dirac didn't worry about whether they were realists or instrumentalists. They were simply concerned that the existing theories didn't fit together. In theoretical physics, the search for logical self consistency has always been more important in making advances than experimental results. Otherwise elegant and beautiful theories have been rejected because they don't agree with observation, but I don't know of any major theory that has been advanced just on the basis of experiment. The theory always came first, put forward from the desire to have an elegant and consistent mathematical model. The theory then makes predictions, which can then be tested by observation. if the observations agree with the predictions, that doesn't prove the theory; but the theory survives to make further predictions, which again are tested against observation. If the observations don't agree with the predictions, one abandons the theory. [p.42]
No major theory from experiment? What is he talking about? All the major physics theories I know were based on experiment.

He goes on with his only example, relativity:

Or rather, that is what is supposed to happen. In practice, people are very reluctant to give up a theory in which they have invested a lot of time and effort. They usually start by questioning the accuracy of the observations. If that fails, they try to modify the theory in an ad hoc manner. Eventually the theory becomes a creaking and ugly edifice. Then someone suggests a new theory, in which all the awkward observations are explained in an elegant and natural manner. An example of this was the Michelson Morley experiment, performed in 1887, which showed that the speed of light was always the same, no matter how the source or the observer was moving. This seemed ridiculous. Surely someone moving toward the light ought to measure it traveling at a higher speed than someone moving in the same direction as the light; yet the experiment showed that both observers would measure exactly the same speed. For the next eighteen years people like Hendrik Lorentz and George Fitzgerald tried to accommodate this observation within accepted ideas of space and time. They introduced ad hoc postulates, such as proposing that objects got shorter when they moved at high speeds. The entire framework of physics became clumsy and ugly. Then in 1905 Einstein suggested a much more attractive viewpoint, in which time was not regarded as completely separate and on its own. Instead it was combined with space in a four dimensional object called spacetime. Einstein was driven to this idea not so much by the experimental results as by the desire to make two parts of the theory fit together in a consistent whole. The two parts were the laws that govern the electric and magnetic fields, and the laws that govern the motion of bodies.

I don't think Einstein, or anyone else in 1905, realized how simple and elegant the new theory of relativity was. It completely revolutionized our notions of space and time. [p.43]

No, this is quite wrong. Einstein did not combine time and space into a four dimensional object in 1905. He did not suggest any more attractive viewpoint than what Poincare had already presented. I think Poincare understood relativity in 1905, but not Einstein.

It is true that Einstein was not so concerned with experimental results, but that is only because he was just writing an exposition of the theory that Lorentz and Poincare created, and they were directly inspired by the Michelson Morley experiment.

I know that Hawking knew about Poincare's contributions to special relativity, because he wrote about them in his 1988 bestselling book, A Brief History of Time.

Hawking does not mention Poincare in this essay because it would destroy his argument. Poincare actually was very explicitly concerned with those philosophical categories and with those puzzling experiments.

Hawking's view is probably typical of theoretical physicists today, both in terms of drawing the wrong lessons from the relativity story and in believing in ignoring experiment. Hawking's own favorite research topic is the black hole information paradox, where there is no possibility of any experimental evidence. This attitude is ruining physics.


Thursday, Dec 10, 2009
 
There is no empty space
This blog explains the modern aether. If you think that the vacuum is empty space, read this.
It is the view of modern physics that there is no such thing as truly empty space. When I first heard this, I thought that the person saying it was some kind of crackpot. Didn’t we move past the aether theory in the 19th century? But apparently it is the honest belief of most professional physicists that what we call empty space, or “vacuum”, is really some kind of infinite, space-filling “fabric” upon which ripples can be created that carry force from one object to another. This is the idea of the quantum field.
Some people say that Einstein was a great genius because abolished the aether, and taught that light propagates thru empty space. Einstein did believe that from 1905 to 1916, but it was disproved in the 1930s. All modern theories of light require an aether.

Tuesday, Dec 08, 2009
 
String theory is not even wrong
The leading criticism of string theory is Not Even Wrong, a 2006 book and blog by Peter Woit. His Chapter 14 starts:
Is Superstring Theory Science?

No matter how things turn out, the story of superstring theory is an episode with no real parallel in the history of modern physical science. More than twenty years of intensive research by thousands of the best scientists in the world producing tens of thousands of scientific papers has not led to a single testable experimental prediction of the theory. This unprecedented situation leads one to ask whether one can really describe superstring theory research as scientific research in the field of physics. This question tends to take on two different forms. One form of the question that many physicists ask is whether superstring theory should not perhaps be described as mathematics rather than physics. A second form of the question asks whether the theory is a science at all.

Since I spend most of my time in a mathematics department, it's very clear to me how my mathematician colleagues would answer the question whether superstring theory is mathematics. They would uniformly say, "Certainly not!" Mathematicians see the defining activity of their discipline to be the making of precise statements of theorems about abstract mathematical entities and the construction of rigorous proofs of these theorems. The fact that superstring theory research refers to speculative physical entities is not really a problem, since mathematicians are masters of abstraction, and can easily change any precise theoretical framework into one expressed in the language of abstract mathematics. The problem is that superstring theory is not really a theory, but rather a set of hopes that a theory exists. To a mathematician, a set of hopes that a theory exists, hopes that come purely out of physical motivations, is definitely not mathematics at all. Just as in physics, such a set of hopes can in principle be used as motivation for making a precise set of conjectures about what is true, but until the conceptual framework reaches the point of one's being able to do this, it is not clear how one can really use it.

On the other hand, many physicists who don't work on superstring theory often characterize it as being mathematics. In the majority of cases, this is meant as a negative characterization, since many physicists share the attitude Gell Mann once held that abstract mathematics is some form of self abuse. Superstring theory is to a large degree thought of by mainstream physicists as mathematics and by mainstream mathematicians as physics, with each group convinced that it makes no sense within their frame of reference but presumably does within someone else's.

As this was a direct attack on the dominant subfield of theoretical physics, you would expect a serious academic rebuttal to have been published. There has been just All Strung Out? by Joseph Polchinski, an unpublished review Aaron Bergman, and some incoherent rants by Lubos Motl. Polchinski is a famous string theorist, and he also reviews The Trouble with Physics by Lee Smolin. They have some technical gripes with these books, but cannot refute the arguments that string theory is unscientific. Some other reviews were in the Economist, New Yorker, SciAm, and this blog. Other string theorists have ignored these books, or just made ad hominem attacks against the authors.

None of these articles refute Woit's main claims.

Bergman writes:

It is worthwhile at this point to provide a brief overview of what string theory is. As alluded to above, the biggest issue bedeviling fundamental theoretical physics is the incompatibility of quantum mechanics and gravity. Such a unification is called a theory of quantum gravity. The problem, however, is that this incompatibility has proven to be almost completely impenetrable to experiment. This is fairly unique in the history of physics. In this field, there have been almost no unexpected experimental results coming for three decades. ...

Such a situation is not entirely without precedence, however. At the turn of the twentieth century, Einstein was presented with the incompatibility of Newton’s theory of gravitation and his newly developed theory of special relativity. Almost without experimental input, and with a little help from mathematicians, Einstein was able to reconcile these two theories into his theory of general relativity, a profound new understanding of the nature of space and time.

The hope then is that we could, as a field, be like Einstein and solve our current conundrum by thought alone.

No, this is really wrong. The history of physics is filled with examples of theoretical conundrums that could not be experimentally resolved. Examples in past centuries include the theory that matter is made of atoms, the theory that the Earth moves, the question of what could be burning within the Sun, etc. Many of these questions must have seemed hopeless difficult.

What is unique about string theory is not the difficulty with experiment, but the broad adoption of a theory that can never be tested.

The analogy to Einstein is bogus. The first papers on black holes, deflection of starlight, precession of Mercury's orbit, and gravity waves were all written before Einstein ever wrote anything on gravity. The development of general relativity was directly concerned with explaining these things. It was never anything like string theory.

Bergman goes on:

It is true, as Dr. Woit states in this chapter, that there really is no such thing as ‘string theory’. It is, rather, a collection of partial theories and calculational techniques bound by physical intuition and conjecture. The amazing and beautiful thing, for those of us who study it, is that this skein is remarkably robust. Calculations that have the possibility of destroying this structure invariably turn out to reinforce it. One cannot help believe that, while we may not know what it is, there is a theory out there waiting for us. It is in this way that string theory is a labor of hope. ...

It is not worth spending much time on whether or not string theory is ‘science’. String theory is a hope to do science ...

He seems to be conceding Woit's point that string theory is not science, but arguing that it is a consistent mathematical structure. Bergman seems to be one of those physicists that Woit describes. He admits that it is not physics but argues that it is mathematics.

The trouble with Bergman's argument is that all mathematical structures are consistent. The argument is vacuous. Only a physicist would make such a silly argument.

Time magazine said in 2006:

That lack of specificity hasn't slowed down the string folks. Maybe, they've argued, there really are an infinite number of universes--an idea that's currently in vogue among some astronomers as well--and some version of the theory describes each of them. That means any prediction, however outlandish, has a chance of being valid for at least one universe, and no prediction, however sensible, might be valid for all of them.

That sort of reasoning drives critics up the wall. It was bad enough, they say, when string theorists treated nonbelievers as though they were a little slow-witted. Now, it seems, at least some superstring advocates are ready to abandon the essential definition of science itself on the basis that string theory is too important to be hampered by old-fashioned notions of experimental proof.

And it is that absence of proof that is perhaps most damning. ...

"It's fine to propose speculative ideas," says Woit, "but if they can't be tested, they're not science." To borrow the withering dismissal coined by the great physicist Wolfgang Pauli, they don't even rise to the level of being wrong. That, says Sean Carroll of the University of Chicago, who has worked on strings, is unfortunate. "I wish string theorists would take the goal of connecting to experiment more seriously," he says. "It's true that nobody has any good idea of how to test string theory, but who's to say someone won't wake up tomorrow morning and think of one? The reason so many people keep working on it is that, whatever its flaws, the theory is still more promising than any other approach we have."

No, no one is going to wake up tomorrow with an idea for testing whether anything is possible in an alternate universe. The theory is just too wacky. There is no test for alternate universes.

The idea that string theory is the only game in town is really wrong also. It is not. Even if it were, that is no justification. I wonder whether astrologers and Freudian dream interpreters ever used such silly justifications.


Sunday, Dec 06, 2009
 
Warmists are doubling down
The British mag Nature editorializes:
The theft highlights the harassment that denialists inflict on some climate-change researchers. ...

The e-mail theft also highlights how difficult it can be for climate researchers to follow the canons of scientific openness, which require them to make public the data on which they base their conclusions.

No, it shows how easier compliance would be. All UEA CRU had to do was to allow public access to a server.

Of course following those scientific canons properly would have been to manage the data much better in the first place.

Another article in it quotes:

Science and science institutions should be transparent, but they are not a 24-hour help service for climate sceptics who lack fundamental scientific and technical skills. [Thomas Stocker, University of Berne]
This elitism is offensive. People spent two years asking for the data and data manipulation programs, and were stonewalled. It was a completely reasonable request. What we found was that those who managed the data and wrote the programs are the ones who lack the necessary skills. The work is extremely sloppy.
Given the overwhelming scientific evidence for climate change, we should deal less and less with climate sceptics. Otherwise we should also deal with folks who think Elvis Presley is still alive, that Earth is less than 6,000 years old and that we cannot possibly have descended from monkeys. [Eric Rignot, University of California, Irvine]
Another elitist and dishonest approach. Everyone agrees that there is solid evidence for climate change. The climate has been changing for millions of years, and will continue to change for millions of more years.

This statement is like saying that we should ignore anyone who is skeptical about a manned mission to Mars because there is overwhelming evidence that the Earth is not flat, and people who believe in a flat Earth are like folks who think that Elvis is still alive. It is a nonsensical straw man attack.

The more I hear warmists say stupid stuff like this, the more I want to disbelieve their policy recommendations.

SciAm mag has its own anti-skeptic rant in Seven Answers to Climate Contrarian Nonsense.


Saturday, Dec 05, 2009
 
Darrigol on Einstein
Olivier Darrigol wrote a 2005 paper (pdf) on why Einstein should be credited with special relativity over Poincare. His article is pretty good, as he looks at what Poincare did in detail. Darrigol summarizes Poincare:
To sum up, in 1905/6 Poincaré obtained a version of the theory of relativity based on the principle of relativity and the Lorentz group. He believed this symmetry should apply to all forces in nature. He exploited it to derive the dynamics of the electron on a specific model and to suggest a modification of the law of gravitation. He nevertheless maintained the ether as the medium in which light truly propagated at the constant velocity c and clocks indicated the true time. He regarded the quantities measured in moving frames as only apparent, although the principle of relativity forbade any observational distinction between a moving frame and the ether frame. He understood the compatibility of the Lorentz transformations of coordinates with the optical synchronization of clocks and the invariance of the apparent velocity of light, but hesitated on the physical significance of the Lorentz contraction and never discussed the dilation of time.
It may sound as if he is saying that Poincare's theory was different from Einstein's, but elsewhere he says:
both theories are internally consistent and have the same empirical predictions (for the electrodynamics of moving bodies).2

[Footnote] The empirical equivalence of the two theories simply results from the fact that any valid reasoning of Einstein's theory can be translated into a valid reasoning of Poincaré's theory by arbitrarily calling the time, space, and fields measured in one given frame the true ones, and calling all other determinations apparent.

In other words, the theories are identical except for some minor terminological differences.

Darrigol seems to be criticizing Poincare for thinking that relativistic changes to space and time were "apparent", and possibly not the real changes that Einstein recognized. But elsewhere Darrigol says of Poincare:

There is no doubt, however, that he regarded the transformed fields and coordinates as the ones measured by moving observers.
So Poincare correctly used "apparent" to mean what the observer would measure.

Darrigol criticism of Poincare's use of the aether is a little stranger. He is referring to this in the previous paragraph:

Some commentators have speculated that he meant a revision of the concept of time, in Einstein's manner. This is not very likely, because the context of Poincaré's suggestion was length measurement instead of time measurement, and also because he ignored Einstein's point of view to the end of his life. More likely he was alluding to a suggestion he had earlier made at the Saint-Louis conference: "that the ether is modified when it moves relative to the medium which penetrates it."
Here is the context, from Poincare's St. Louis speech:
Thus in place of supposing that bodies in motion undergo a contraction in the sense of the motion, and that this contraction is the same whatever be the nature of these bodies and the forces to which they are otherwise submitted, could we not make an hypothesis more simple and more natural?

We might imagine, for example, that it is the ether which is modified when it is in relative motion in reference to the material medium which it penetrates, that when it is thus modified, it no longer transmits perturbations with the same velocity in every direction. It might transmit more rapidly those which are propagated parallel to the medium, whether in the same sense or in the opposite sense, and less rapidly those which are propagated perpendicularly. The wave surfaces would no longer be spheres, but ellipsoids, and we could dispense with that extraordinary contraction of all bodies. I cite that only as an example, ...

As you can see, the aether quote is just some hypothetical argument that Poincare is rejecting.

Poincare's papers are more equivocal than Einstein's. Poincare discusses alternate hypotheses, and how experiments might prove him wrong. Einstein doesn't bother, and just gives an explanation of the Lorentz-Poincare theory. This doesn't make Einstein's papers better; it just means that Poincare was looking at the bigger picture.


Friday, Dec 04, 2009
 
We are evolving smaller brains
Anthropologist Peter Frost writes:
We know the brain has been evolving in human populations quite recently," said paleoanthropologist John Hawks at the University of Wisconsin at Madison.

Surprisingly, based on skull measurements, the human brain appears to have been shrinking over the last 5,000 or so years.

"When it comes to recent evolutionary changes, we currently maybe have the least specific details with regard the brain, but we do know from archaeological data that pretty much everywhere we can measure - Europe, China, South Africa, Australia - that brains have shrunk about 150 cubic centimeters, off a mean of about 1,350. That's roughly 10 percent," Hawks said.

"As to why is it shrinking, perhaps in big societies, as opposed to hunter-gatherer lifestyles, we can rely on other people for more things, can specialize our behavior to a greater extent, and maybe not need our brains as much," he added. (source)

It’s usually assumed that humans have steadily increased in intellectual capacity. But what if this trend reversed with the advent of civilization? As societies grow more complex, perhaps the average human has not had to know so much. He or she can ‘delegate’ tasks (not that such delegation is always voluntary). Perhaps civilization has made us dumber, not smarter. ...

I’m increasingly convinced that extreme social stratification—i.e., the creation of a small class of intellectuals and a much larger helot class—is inimical to true scientific progress. The intellectuals are too few in number, and too dependent on the system, to make any real contribution.

He also writes:
Since the mid-20th century, ‘skin bleaching’ has become more and more common among dark-skinned populations. It involves lightening skin color by means of topical preparations that contain hydroquinone, cortisone, or mercury.

Thursday, Dec 03, 2009
 
Texas schools revise standards
The Texas Education Agency Social Studies TEKS pages has some draft recommendations for Historical Figures by Grade Level (pdf). They are dropping Copernicus, Galileo, Freud, and Einstein, and they are adding Phyllis Schlafly!

I am glad to see that someone is reading my blog. The scientific contributions of Copernicus, Galileo, and Einstein are vastly overrated, and I don't know why they would be mentioned in a Social Studies class anyway, except maybe to make some dubious point about how stupid other people were.


Tuesday, Dec 01, 2009
 
The big climate issue is positive feedback
MIT meteorology professor Richard Lindzen writes:
The potential (and only the potential) for alarm enters with the issue of climate sensitivity—which refers to the change that a doubling of CO2 will produce in GATA. It is generally accepted that a doubling of CO2 will only produce a change of about two degrees Fahrenheit if all else is held constant. This is unlikely to be much to worry about.

Yet current climate models predict much higher sensitivities. They do so because in these models, the main greenhouse substances (water vapor and clouds) act to amplify anything that CO2 does. This is referred to as positive feedback.

So the warmist argument goes like this. Science proves that CO2 causes Earth warming, via the greenhouse effect. Burning fossil fuels has increased the CO2 in the atmosphere. The is a scientific consensus that much of the warming of the last 50 years is attributable to CO2. The models predict that continued emissions could have catastrophic consequences in the 21th century.

As Lindzen explains, a weak link in the argument is that the models assume positive feedback, and there is little evidence for that.

I'd like to see the positive feedback quantified. Suppose that an increase in CO2 causes an x-degree temperature increase based on the physics of infrared absorption, and a y-degree actual increase when secondary effects are included. Then I would say that the feedback is +10% if y is +10% more than x, and -10% if y is -10% less than x.

What is the feedback? Is there a consensus that the feedback is in some particular range? Maybe Al Gore, the IPCC, and the UEA CRU have a good answer to this, but based on Lindzen, I doubt it.

Positive feedback would be dangerous because it would mean that the Earth's climate is unstable. A small change could be magnified into a big change. It would be like standing a pencil on its end. As it starts to topple over, it gets more unbalanced, and topples more rapidly.

The long term history of the Earth (over millions of years) is that CO2 has had many ups and downs. This suggests negative feedback. Once CO2 gets out of balance, something or some combination of forces brings the CO2 back into balance. So the Earth would presumably correct itself after many 1000s of years. But it is possible that there is a positive feedback for the first few 100 years before the negative feedback kicks in.

I don't even know what the feedback factors are, but feedback estimation seems to be the biggest scientific issue. I would like to see more debate on it.