Global Temperature, Global Warming?

What is global warming? Most people would answer this seemingly simple question with something like the following (see the article at wikipedia.org):

Global warming is the observed increase in the average temperature of the Earth’s near-surface air and oceans in recent decades and its projected continuation. [...]

One would think that all scientist agree on this definition. However, actually they don’t.

Some scientist would say that it does not even make sense. The June 2007 issue of the Journal of Non-equilibrium Thermodynamics includes a paper of Christopher Essex (U. of Western Ontario), Ross McKitrick (U. of Guelph) and Bjarne Andresen (Niels Bohr Institute), with the interesting title:

Does a Global Temperature Exist? [PDF]

In this paper it is argued that the concept of a “global temperature” is thermodynamically as well as mathematically meaningless. First of all, you cannot just add local temperatures on the Earth and then take the average to define a single “global” temperature of the Earth. Secondly, the average is not canonically defined. For example, taking a box of air with temperature 0 degrees and an identical one with temperature 100 degrees would lead to an arithmetic average of 50 degrees (add the two numbers and divide by two). However, the geometric average in this case, obtained by multiplying the two numbers (in degree Kelvin) and taking the square root is 46 degrees. Thus claims of distaster – or not – maybe a consequence of the averaging method used.

So, what is Global Warming? Can it be defined in a sound way, both from a physics and mathematics viewpoint?

Eli Rabett over at Rabett Run thinks that this paper is “a bowl of steaming crap”; I guess Lubos Motl thinks otherwise.

Update: The climate-friends at RealClimate.org thinks that this paper is irrelevant.

Fogh, Lies and Videotapes?

Our Prime Minister Anders Fogh Rasmussen does not fancy a certain documentary film which was shown on Danish national television in December 2006.

And you can understand why. At least if you remember, that Denmark is at war in Iraq as well as in Afghanistan.

“The secret war” (Danish: “Den Hemmelige Krig”) is about the fact that during the war in Afghanistan in 2002, Denmark handed over prisoners to the US soldiers (at least on one occation — the 18th of March, 2002) even though USA would no longer respect the Geneva-convention, and possibly that the Danish Government, led by Fogh Rasmussen, did not reveal this to the parliament.

A memo [PDF] by Donald Rumsfeld, 19th of january, 2002, states that

[...] Al Qaeda and Taliban individuals under the control of the Department of Defence are not entitled to prisoner of war status for purposes of the Geneva Conventions of 1949.

This was known publically soon thereafter. On the 28th of January, 2002 in the New York Times:

Vice Pres Dick Cheney and Defense Sec Donald H Rumsfeld say war captives in Afghanistan and Guantanamo Bay, Cuba, will not be designated as prisoners of war, regardless of what decision administration makes on Sec of State Colin Powell’s request for review of how Geneva Convention on captives’ rights might apply; [...] Cheney says convention does not apply to captives because they are not conventional soldiers, but terrorists operating outside internationally accepted norms;

In this way, the movie rightly questions the basis for Denmarks participation in the so-called “war against terror” in Afghanistan.

Fogh Rasmussen flatly rejects an independent investigation of the events in Afghanistan in early 2002, and as to whether the Geneva conventions has been violated. On the other hand he ask for an investigation as to whether the Danish national television, DR, made any factual mistakes in the movie.

Double standards, anyone?

State of the Union 2007

Last night, President Bush delivered his 2007 State Of The Union address.

After last years State of the Union Address, Lubos Motl thought that Bush was a genius (or rather, that he was “shining”); this year Lubos uprightly noted that “Bush had to drink some water”.

And this is basically how interesting President Bush’s talk was.

At any rate, I found the following statements worth emphasizing:

[...] Some in this chamber are new to the House and Senate — and I congratulate the Democratic majority. Congress has changed, but our responsibilities have not. Each of us is guided by our own convictions — and to these we must stay faithful. Yet we are all held to the same standards, and called to serve the same good purposes: To extend this nation’s prosperity … to spend the people’s money wisely … to solve problems, not leave them to future generations … to guard America against all evil, and to keep faith with those we have sent forth to defend us.

First, we must balance the federal budget. We can do so without raising taxes. What we need to do is impose spending discipline in Washington, D.C. We set a goal of cutting the deficit in half by 2009 — and met that goal three years ahead of schedule. Now let us take the next step. In the coming weeks, I will submit a budget that eliminates the federal deficit within the next five years. [...]

A future of hope and opportunity requires that all our citizens have affordable and available health care. When it comes to health care, government has an obligation to care for the elderly, the disabled and poor children. [...]

Tonight, I propose two new initiatives to help more Americans afford their own insurance. First, I propose a standard tax deduction for health insurance that will be like the standard tax deduction for dependents. Families with health insurance will pay no income or payroll taxes on $15,000 of their income. Single Americans with health insurance will pay no income or payroll taxes on $7,500 of their income. [...]

[...] Extending hope and opportunity depends on a stable supply of energy that keeps America’s economy running and America’s environment clean. For too long, our nation has been dependent on foreign oil. And this dependence leaves us more vulnerable to hostile regimes, and to terrorists who could cause huge disruptions of oil shipments … raise the price of oil … and do great harm to our economy.

It is in our vital interest to diversify America’s energy supply, and the way forward is through technology. We must continue changing the way America generates electric power by even greater use of clean coal technology … solar and wind energy … and clean, safe nuclear power. We need to press on with battery research for plug-in and hybrid vehicles, and expand the use of clean diesel vehicles and biodiesel fuel. We must continue investing in new methods of producing ethanol — using everything from wood chips, to grasses to agricultural wastes.

[...] Let us build on the work we have done and reduce gasoline usage in the United States by 20 percent in the next 10 years — thereby cutting our total imports by the equivalent of three-quarters of all the oil we now import from the Middle East.

To reach this goal, we must increase the supply of alternative fuels by setting a mandatory fuels standard to require 35 billion gallons of renewable and alternative fuels in 2017 — this is nearly five times the current target. At the same time, we need to reform and modernize fuel economy standards for cars the way we did for light trucks — and conserve up to 8 1/2 billion more gallons of gasoline by 2017.

[...] America is on the verge of technological breakthroughs that will enable us to live our lives less dependent on oil. These technologies will help us become better stewards of the environment — and they will help us to confront the serious challenge of global climate change.

[...] In the sixth year since our nation was attacked, I wish I could report to you that the dangers have ended. They have not. And so it remains the policy of this government to use every lawful and proper tool of intelligence, diplomacy, law enforcement, and military action to do our duty, to find these enemies, and to protect the American people.

[...] In order to make progress toward this goal, the Iraqi government must stop the sectarian violence in its capital. But the Iraqis are not yet ready to do this on their own. So we are deploying reinforcements of more than 20,000 additional soldiers and Marines to Iraq.

[...] My fellow citizens, our military commanders and I have carefully weighed the options. We discussed every possible approach. In the end, I chose this course of action because it provides the best chance of success. Many in this chamber understand that America must not fail in Iraq — because you understand that the consequences of failure would be grievous and far reaching.

[...] Our country is pursuing a new strategy in Iraq, and I ask you to give it a chance to work. And I ask you to support our troops in the field — and those on their way.

[...]American foreign policy is more than a matter of war and diplomacy. Our work in the world is also based on a timeless truth: To whom much is given, much is required.

Not the worst speech by President Bush — I must admit — maybe even better than the one in 2006, which, to say the least, is not much. But again, a speech of a very lonely president who is trying to reach out to skeptical Democrats.

The full text of the Presidents speech can be found here; official transcript from the White House — including applauses — can be found here.

For further discussion, dig into the excellent Chicago Tribune blog, The Swamp.

Fermi’s Paradox and Galaxy Probes

The Fermi paradox (1950) can be formulated as follows

If there are extraterrestrial civilizations out there, then where are they?

In a recent paper, Rasmus Bjork of the Niels Bohr Institute argues that finding other life in the Galaxy by using space probes, and possibly solving the paradox, might take extremely long time. A time which is comparable to the age of the universe. More precisely, he estimates that with 8 probes each having 8 subprobes around 4% of the Galaxy can be explored in 9.6 billion years.

So, if we sometimes feel lonely in the Universe it is because Aliens still haven’t had the time to visit us…

See also the discussion at Mangan’s Miscellany.

“Subway Superman”

Wesley Autrey, a construction worker who rescued a student from Massachusetts from an oncoming subway train has become a national hero in the US. And his reaction?

“I’m still saying I’m not a hero … ’cause I believe all New Yorkers should get into that type of mode,” he said on CBS’ “The Early Show” on Thursday. “You should do the right thing.”

Yes,

“You should do the right thing”.

And you surely did

Tagged (by right-wing strings)

I was just recently tagged by Lubos Motl; after some thought, I happily did as instructed:

“1. Grab the book closest to you.
2. Open to page 123, go down to the fifth sentence.
3. Post the text of the next 3 sentences on your blog.
4. Name the book and the author.
5. Tag three people.”

And the outcome?

In light of this, it can be said that most significant for the fate of the Jews and for our understanding of the character of Germans’ attitudes towards Jews is that the misgivings about certain eliminationist measures that did exist among some Germans cannot, by and large, rightly be interpreted as having been expressions of principled disapproval of the eliminationist project and especially of the beliefs that gave birth to it. The principal exception to this is to be found among those Germans who, for various reasons, gave aid to the approximately ten thousand German Jews who tried to escape deportation by hiding. The isolation of these Germans and of others who stood by their Jewish spouses indicates how exceptional they were among the larger German populace.

These sentences were taken from the book Hitler’s Willing Executioners: Ordinary Germans and the Holocaust by Daniel J. Goldhagen.

Finally, I tagged Clifford V. Johnson, “Lost clown” (who is angry for a reason — or two), and Michael Nielsen. What a silly game. But, hey, it is christmas…

Merry christmas and happy holidays from Denmark (where xmas effectively has been scrapped due to global warming. Proof: Winter in Copenhagen in pictures, 2005, compared to 2006.)

Update: The picture from 2006 show some spoiled young people trying to clean up after certain riots in Copenhagen.

Deconstructing Strings?

“Deconstruction” is a method of critical analysis of philosophical and literary language that emphasizes the internal workings of language and conceptual systems, the relational quality of meaning, and the assumptions implicit in forms of expression.

Todays most fascinating paper is without doubt the one by Bert Schroer entitled:

String theory deconstructed (a detailed critique of the content of ST from an advanced QFT viewpoint)

In this paper Bert (BS) supposedly gives “a detailed and comprehensive critique of claims and methods of string theory from an advanced quantum field theoretical viewpoint.” BS starts out by listing nine claims of string theory “which afterwards will be shown to be fundamentally flawed”. These nine claims are:

1 ) The Kaluza-Klein argument can be used in QFT (or ST) to encode compactified spatial coordinates into inner symmetries
2 ) In ST supersymmetry is spontaneously broken
3 ) Holography is a construct which needs quantum gravity as a prerequisite
4 ) The Maldacena conjecture is about a AdS—CFT holography
5 ) The counting zero mode degree of freedom estimate about the cosmological
constant is consistent with the principle of local covariance
6 ) String theory solves the “information paradox”
7 ) Strings are quantum objects with a localization in spacetime which is
string- instead of point-like
8 ) It has been shown that ST contains QFT in the limit of low energies.
9) The S-matrix of ST has the properties of a particle physics S-matrix

For one thing, BS does not like KK compactifications (claim #1), since “I recently red that already Pauli had shown that this is impossible, but there was no reference given.” And concerning claim 3), BS states that “I think that anybody who knows the framework of particle physics (say beyond the level of recent QFT texts which where written by string theorists) would agree that holography from d+1 to d dimension and its possible inversion cannot be anything else than a radical change of the spatial encoding of a specified algebraic substrate; using this word for anything else would be a misuse and lead to misunderstandings.” This seems to debunk the idea that holography should be related to quantum gravity.

But BS’s arguments against “the Maldacena conjecture” are even stronger. For example, he says that “I do not know any competent quantum field theorist who does not accept Rehren’s work as the correct formulation of AdS—CFT holography (Hollands, Wald, Brunetti, Fredenhagen, Verch, Buchholz, …)”. It is – at least to me – unclear what the …’s stand for here; but even more staggering are BS’s adventures into advanced psychoanalysis: “For psychologically understandable reasons it was this metaphoric QG connection which attracted the attention of string theorists (QG is the raison d’etre for string theory) and which led Maldacena to formulate a conjecture involving a vague idea of supersymmetric string under the KK curling (with its even more vague idea of its QG content) on the dual AdS side in case one starts from a (supersymmetric) conformal field theory”.

For some reason also, quantum mechanics seems to be enough to understand black hole physics: “Of course one can use Bekenstein’s classical formula and equate it with this microscopically computed entropy to determine epsilon (I have not done this, but there can be no doubt that at this point the Planck length enters and determines the size of the vacuum polarization cloud). The calculations are in two papers [...]”.

With Maldacena (and … and ….) literally on his knees, an alternative resolution of the apparent clash between quantum mechanic and general relativity was put forward by Wald: “His proposed solution was the start of the modern theory of QFT in CST in which the Lagrangian formalism is abandoned in favor of the adoption of the dichotomy of AQFT between the algebraic structure of QFT and the admissible states on such algebras.”

Numerous other advanced arguments seem to kill the claims 5) and 6) above. And for 7) I learned, that: “The localized algebras are monades with very different properties from algebras one meets in QM. There can be no doubt that the understanding of their positioning in a common Hilbert space will be an important step on the long way towards QG.”

But of course the “monad” (or, in biological terms, flagella) point of view also call into question whether string theory contains quantum field theory in its low-energy limit (8): “The message from this last case is that metaphoric arguments (e.g. looking at functional representations without actually doing the functional integrals) may turn out to lead to wrong results. Take for example the case of 2+1 dimensional QFT which have braid-group statistics. If the spin is anyonic (i.e. not semi-integer) the statistics is plektonic and the upholding of the spin-statistics theorem in such a case prevents the nonrelativistic limit to be a (second quantized) QM; it remains a nonrelativistic QFT. Only if one relinquishes the plektonic commutation relations, but preserves the anyonic spin one finds Wilczek’s anyons in the form of quantum mechanical Aharonov-Bohm dyons [...]”, and then “The message from this illustration is that a theory can only be asymptotically (e.g. for long distances) contained in a more fundamental one if their structures harmonize.”

But the flagella (monads) also kill the S-matrix arguments 9): “A much more detailed correspondence of Leibniz’s image of reality in terms of indivisible monades to the conceptual structure of particle physics is provided by the algebraic setting of QFT (AQFT). If one identifies Leibniz’s monades with copies of the unique hyperfinite type III_1 factor algebras then it can be shown that any QFT permits a faithful encoding into the relative positions of a finite number of monades”.

At this point I started thinking: is this all a joke? Was I being fooled? Staring a the screen I was wondering whether or not I had really been fooled. On the one hand, if I wasn’t fooled, then this paper was serious, hence I was fooled by my understanding of physics. But if I was fooled, then I did get what I expected from BS, so in what sense was I fooled?.

Then suddenly I realized, that I had seen this text before, but just in another (isomorphic) disguise. It was the famous “Sokal hoax”, a hoax paper published by physicist Alan D. Sokal in 1994, entitled “Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity”. (Sokal’s hoax served a public purpose, that of attracting attention to what Sokal saw as a decline of standards of rigor in the academic community; for this reason, Sokal’s text was “liberally salted with nonsense”). For example, quoting from Sokal:

“In mathematical terms, Derrida’s observation relates to the invariance of the Einstein field equation [...] under nonlinear space-time diffeomorphisms (self-mappings of the space-time manifold which are infinitely differentiable but not necessarily analytic). The key point is that this invariance group “acts transitively”: this means that any space-time point, if it exists at all, can be transformed into any other. In this way the infinite-dimensional invariance group erodes the distinction between observer and observed; the [pi] of Euclid and the G of Newton, formerly thought to be constant and universal, are now perceived in their ineluctable historicity; and the putative observer becomes fatally de-centered, disconnected from any epistemic link to a space-time point that can no longer be defined by geometry alone.

and

“It is still too soon to say whether string theory, the space-time weave or morphogenetic fields will be confirmed in the laboratory: the experiments are not easy to perform. But it is intriguing that all three theories have similar conceptual characteristics: strong nonlinearity, subjective space-time, inexorable flux, and a stress on the topology of interconnectedness.”

.

So, was I fooled or not?