## Thursday, January 29, 2009

### Water is blue ... because water is blue

 Pacific Ocean near Santa Barbara, California

One of the most appealing aspects of the ocean is the colour of the water, ranging from a greyish green to deep blue.

But wait a minute: When I pour water in a glass, it is a clear, transparent liquid. So, what is the cause of the blue colour of the sea? Is it the reflection of the blue sky, perhaps?

The answer is simple, and perhaps surprising: Water is blue, because water is blue.

### Blue Oceans,

Actually, water is quite a transparent liquid, but not perfectly transparent. All substances to a certain degree absorb light, and as a consequence, the intensity of a beam of light spreading through matter drops exponentially with distance, as described by the so-called Beer-Lambert law. Pure water appears transparent because it takes a distance of the order of metres to reduce by half the intensity of light passing through it. And, what is most important for the apparent colour of water, the absorption depends on the wavelength of light, hence colour.

The blue curve in the following figure shows the so-called absorption spectrum of pure water (data via Optical Absorption of Water by by Scott Prahl).

The absorption spectrum gives, on the vertical axis, the so-called absorption coefficient as a function of the wavelength of light (as measured outside of the medium). The area marked in yellow corresponds to the range of visible light, reaching from deep blue (at a wavelength of about 380 nanometer) to red (at a wavelength of about 760 nanometer). At the left of the visible spectrum lies the ultraviolet, and at the right, where the absorption curve is climbing and going through several bumps, the infrared.

The absorption coefficient is the inverse of the distance along which the intensity of light drops by a factor of e = 2.718..., and is measured in "inverse centimetre". Hence, an absorption coefficient of a = 10−2 cm−1 means that it takes a distance of d = 1/a = 10² cm = 1 m for the intensity of light to drop by one e-folding.

Now, as we can see, the absorption coefficient is very different at the red end of the visible spectrum than at the blue end. The absorption coefficient is plotted in the figure on a logarithmic scale, and indeed, absorption is about one hundred times stronger at the red end of the visible spectrum than at the minimum of the curve, which at a wavelength just below 500 nanometer still lies in the range of blue.

But this, of course, explains the intrinsic colour of water: when light passes through large amounts of water, its red component is absorbed the strongest, and the blue component the least - and hence, pure water appears to be blue.

### ... Vibrations,

Actually, the strong increase of the absorption coefficient of water towards the infrared not only causes the blue colour of the ocean. It is also intimately linked to the molecular structure of water.

Molecules of water consist of two hydrogen atoms bonded to one oxygen atom in a kinked shape. Water molecules are not completely rigid, but they can vibrate in different ways. The most important ways of shaking, or "vibrational modes", are a symmetric stretching, called ν1, a symmetric bending, called ν2, and an asymmetric stretching, called ν3:

As with any oscillatory system, vibrations are possible not just for these three modes, but also for higher harmonics - that is, overtones - and for combinations of different modes of oscillation. Indeed, bumps in the absorption curve of water can be identified with a combination of all three modes ("ν1+ ν23"), with a combination of the first overtone of mode 1 and mode 3 ("2ν13"), and with a combination of the second overtone of mode 1 and mode 3 ("3ν13"). For the higher harmonics 2ν1 and 3ν1, the frequency of oscillation is higher, and hence, absorption occurs at shorter wavelengths.

### ... Heavy Water,

There is, interestingly, a very clever way to check experimentally this explanation of the blue colour of water by the vibration of its molecules: Just look at heavy water instead of normal water!

In heavy water, D2O, the hydrogen atoms contain deuterons instead of protons, and hence have double the mass of "normal" hydrogen atoms. The electromagnetic forces bonding the hydrogen to the oxygen, however, are the same for heavy water and normal water. But this means that the frequencies of the different vibration modes of the molecule shift to lower values. It's the same phenomenon as when different masses are fixed to a spring: the higher the mass, the lower the frequency of oscillation.

As a consequence, one could expect the excitation of vibrations for the molecules of heavy water happens at lower frequencies than for normal water, hence at longer wavelengths. The increase of the absorption coefficient towards longer wavelengths could be expected to set in further in the infrared, barely touching the visible spectrum. And this is exactly what happens!

The following figure shows a measurement of the absorption spectra of normal and of heavy water, taken from WHY IS WATER BLUE? by Charles L. Braun and Sergei N. Smirnov, reproduced from J. Chem. Edu. 70(8) (1993) 612. The scale of the figures is linear, and the curves to the left are just scaled-up for a better visibility of the shape of the spectrum.

One can see that the bump corresponding to the mode 2ν13 is shifted form a wavelength of about 1,000 nm in normal water to about 1,300 nm in heavy water. There is an analogous shift towards longer wavelengths in all other features, and as result, the absorption spectrum of heavy water in the visible spectrum is nearly flat.

But this means that there are no marked differences in the absorption of light of different colours by heavy water. Thus, heavy water, different from normal water, should be colourless. And indeed, as shown in this photo by Braun and Smirnov, this is really the case!

 While a long tube filled with normal water (left) looks blue due to the absorption of the red component of the visible spectrum, the tube filled with heavy water is colourless (from WHY IS WATER BLUE? by Charles L. Braun and Sergei N. Smirnov).

### ... and Real Oceans

Beautiful physics is hidden below the blue surface of the ocean. But when I tried to inform me a bit about all this, I've also learned that whole books have been written on the topic, and that "the complexity of sea water as a substance means that its optical properties are essentially different from those of pure water. Sea water contains numerous dissolved mineral salts and organic substances, suspensions of solid organic and inorganic particles, including various live microorganisms, and also gas bubbles and oil droplets. Many of these components [..] absorb or scatter photons." (Light Absorption in Sea Water by Bogdan Woźniak and Jerzy Dera, page 5).

Here is a comparison of the absorption spectra of samples of water taken from different places around the globe (Light Absorption in Sea Water, page 6).

Curve 5, which resembles most the absorption spectrum of water we have seen above, has been measured in a sample taken from the Tonga Trench in the Pacific Ocean, at a depth of 10,000 m. And curve 8, the uppermost flat one, has been measured in surface water from the Gulf of Riga in the Baltic Sea.

From the shape of this spectrum, I would guess the sea near Riga looks more grey than blue.

Edit: The first version of the post falsely claimed that a microwave oven heats up food by setting into vibration the molecules of water. That's not correct: Microwaves, with frequencies in the range between 0.3 GHz and 300 GHz, corresponding to wavelengths from 1 mm to 1 m, have not enough energy to excite the vibrational modes of the water molecule. What the electromagnetic field of microwave frequencies does is to shake the water molecules by grappling them by their electrical dipole moments, and to set them in rotation. A detailed explanation can be found on Martin Chaplins unique site, Water Structure and Science", under Water and Microwaves.

Actually, the wavelength of microwaves is about a factor of 1000 longer than in the infrared and far infrared region where the vibrational absorption bands can be found. The vibrational bands in the infrared, though, make water vapour a strong greenhouse gas.

Thanks to all our readers who have pointed out the mistake to me, especially CIP and Jay!

Tags: , ,

## Tuesday, January 27, 2009

### This and That

Something to look at:

## Sunday, January 25, 2009

### Change You Can Believe In

“We will restore science to its rightful place.”
~Barack Obama, Inauguration Speech

I have a complaint.

It is impossible these days to live in North America and not be optimistic about the changes the new President of the United States will hopefully initiate, especially for science. These are not easy times for somebody who has pessimism as substantial ingredients in her bloodstream. Psychologists call it “preventive pessimism.” It's essential for my survival. And every time somebody mocks me about it I point out the world needs pessimists. There's too few of us. And we're constantly afraid we'll die out.

Currently your local blogging pessimist is wondering what the heck “restoring science to its rightful place” means. Where is the “rightful place” of science? Who decides that? And how is science supposed to get there? Most people seem to assume the statement is an announcement of financial support towards governmental funding bodies. The optimist is excited. The pessimist points out money alone isn't sufficient, it also matters how it is used. And there are problems one just can't solve with money.

I have written many times on the problems with the present academic system, for example here and here. The central point is, as far as the internal organization is concerned, that the individual incentive structure of the academic system does not presently result in a desirable macro behavior - that would be an efficient use of time, human and financial resources. Instead, the present system rewards behavior that does not necessarily have anything to do with good scientific research. The reasons for this are most importantly:

• The use of simplified measures for scientific success that, once institutionalized, turn into goals researchers pursue for their own sake (like a high number of publications or citations).

• Career obstacles for those who want to change their field of research which creates incentives to stick with a topic even if returns diminish and other areas lack personnel.

• Neglecting to pay attention to sociological effects in large and growing communities which can result in severe misjudgement of promises, hypes, fashion trends, and bubbles of nothing.

This is how far the internal organization is concerned.

Being a scientist is not an easy task. It requires ignoring personal preferences, likes and dislikes and to just focus on the evidence. It is a process that can very easily be skewed by any sort of external pressure, may that be financial pressure, peer pressure or time pressure. Regarding the external organization one further has to worry that public pressure negatively affects researchers objectivity.

The academic “ivory tower” allowed research to flourish in an environment free from such pressures. This protection has now mostly crumbled away, which goes on the expenses of scientific integrity. This is what needs to be restored. It's not that researchers are not aware their interests are being affected, and they don't notice they have to waste time with playing silly games to remain in the market. It's that the problem is a system failure that disables its own repair because spending time on that repair also would be against the individual interest.

Restoring Science

“We will increase support for high-risk, high-payoff research portfolios at our science agencies.”
~Barack Obama, Sciencedebate 2008

Sounds good, doesn't it? (Or at least it did before we learned that some high-risk, high-payoff folks wrecked our financial system.) But what does that mean? Who decides how much risk is good for science? Will we get central planning? Will somebody compute it?

I think all such prescriptions are temporary fixes, and will eventually cause new problems. Today you might call for more risk-taking, tomorrow you'll be complaining about too much risk-taking. The only way to address these questions is to allow the system to self-optimize. That means in particular, give scientists enough freedom to chose which path they think leads to progress - within the constraints given by the overall direction the society set. Just trust these scientists. Their individual goal is knowledge discovery, and if you just let them follow these goals that will get you exactly what you want - progress.

In more detail:
1. Scientific progress is a long-term project. Running it with people on short-term contracts creates an internal disagreement between individual interest and the long-term goals, especially when combined with high competitive pressure. Scientists will be forced to focus on projects that fit into a short time frame, and they will have to watch out for letters of recommendation necessary for their next job search.

To solve the problem, create decent middle-class-jobs for scientists. These don't have to be high-profile jobs, but they shouldn't be crappy short-term contracts either. People who chose academia aren't there because they want to become rich. They are there because they love science. Just give them a sensible job, one in which they can continue if they do well, one in which they can pursue long-term projects and don't have to be concerned about shifts in the public opinion or the approval of their peers.

In short: stop the trend of exporting more and more research to postdocs on 2 year contracts.

2. Avoid that researchers can get stuck in a field and make sure they can change into a different one without too large personal drawbacks. Unless one makes sure this is the case one will create groups of people who self-support their own work and colleagues working on similar projects to increase their own career chances.

To solve the problem, don't require extensive prior experience in a very narrow field of expertise to obtain funding. Instead, look at the applicant's ability to carry out research projects in general. Further, support people who want to learn the basics of a new field, and give them a grace period in which they will likely not be highly productive.

3. Appropriately reward community services - they keep science healthy. That might be eg peer review, public outreach or writing review articles - even if no original research. All these are activities we need, but they are currently underappreciated.

4. Restore autonomy of researchers and research institutions. Reduce financial dependence and personal dependence of researchers. That means in particular, don't require researchers to get in grants to obtain tenure - it exports power to funding agencies. Don't assign researchers to supervisors or specific topics unless absolutely necessary. Instead, promote independence to support originality.

5. Especially in basic research, don't require scientists to plan ahead for several years, this is completely off reality. A five year plan for a research project can become redundant within the first month. A common practice is thus to file in proposals about projects that are already finished or almost finished because then one can write what funding agencies like to hear: lots of details already with results. That's one of the games people have learned to play.

How to solve the problem: orient proposal requirements on the reality of the research field, and fund researchers who have demonstrated the ability to carry out research projects without asking for detailed plans. Have a little faith and don't overplan.

The balance between high-risk and conservative research, and between specialization and interdisciplinarity will vary from field to field, and from one decade to the next. Just make sure the system is able to accommodate these changing needs and can achieve a dynamical balance.

Bottomline
“Science is the only news. When you scan through a newspaper or magazine, all the human interest stuff is the same old he-said-she-said, the politics and economics the same sorry cyclic dramas, the fashions a pathetic illusion of newness, and even the technology is predictable if you know the science. Human nature doesn’t change much; science does, and the change accrues, altering the world irreversibly.”
~Stewart Brand

If you want change you can believe in, free scientific research from the constraints of an outdated academic system.

## Saturday, January 24, 2009

### Conservative solutions to the black hole information problem

Exclusively for the readers of this blog, an executive summary of my recent paper:
Conservative solutions to the black hole information problem
By Sabine Hossenfelder and Lee Smolin
arXiv: 0901.3156,

which provides a classification of solution attempts to the black hole information loss problem. As a warm-up, I recommend you read my post on the Black Hole Information Loss Paradox. You will notice that in this earlier post the basic argument of the paper is already outlined. The paper just makes the definitions more precise, and discusses the options one has to solve the problem based on how radical departures from semi-classical gravity they require. Not to mention that the paper has a lot of nice figures. We have made some effort to make the paper understandable for a broad audience, so don't be shy and download the full thing.

The Core of the Problem: The Singularity

The essence of the argument is the following: A singularity is something you don't want to cross your path. Why? Because infinities are dangerous. They crunch and destroy things, they literally set an end to existence, and in doing so they are indifferent as to what exactly crossed their way. A singularity is always singular. Infinity is always infinity. As such, crossing a singularity is an irreversible process. The problem is that once an initial state ended up being singular, you can't figure out what it looked like originally.

The problem with black hole information is that evolution is not unitary if you believe that the initial state of the black hole gets converted mostly into thermal radiation to excellent precision. Non-unitarity is generally considered an unappealing property because it is in conflict with quantum mechanics and can cause all kinds of nasty side-effects you don't want. But an evolution that is not reversible cannot be unitary. Reversibility is not a sufficient, but a necessary condition for unitarity. However, since irreversibility is a characteristic of the presence of singularities, first thing you want to allow for a unitary evolution is to remove the singularity. Classically, this singularity is unavoidable. But we know that close to the singularity the curvature gets very strong (into the Planckian regime) and classical General Relativity (GR) is no longer valid. It should be replaced by a more fundamental theory that can be expected to remove the singularity, though the details are not well understood today.

The paper offers a generalization of the classical singularities in GR that can be used for spacetimes that might have quantum gravitational regions. Throughout the paper we have tried not to make any specific assumptions about the unknown fundamental theory. The problem with the classical definition of geodesic completeness is that the notion of a geodesic, which relies on the presence of a metric, might not make sense any longer in the presence of strong quantum gravitational effects. The definition we are suggesting is motivated by the classical definition, and is then what I outlined above: a space-time is non-singular if evolution is time-reversible. It then follows trivially that a singular space-time generically suffers from information loss. Thus, a black hole space-time without information loss can not be singular in the so defined sense. If you want to understand what happens to the black hole information, first thing you should do is thus to get rid of the singularity.

It is honestly a mystery to me why some people are so obsessed with the black hole horizon, believing that the horizon is the problem. The horizon is not where information gets destroyed. It is merely some surface where the information becomes irretrievable from the outside. Not to mention that the horizon can be at arbitrarily small background curvature. One thus shouldn't expect any quantum gravitational effects to be relevant at the horizon, and no reason to seek a solution there.

Removing the singularity removes an obstacle to unitary evolution, but it doesn't explain how information survives. In the paper we discuss the possibilities one has if one just accepts that quantum gravitational effects are negligible until the very endstate of the evaporation. These solutions we have dubbed “conservative” . Everything else that requires non-locality on horizon scales or quantum gravitational effects in the weak curvature regime and so on, we have called “radical”.

The conservative solutions can be classified into three cases. In all of them it is assumed the singularity is removed by quantum gravitational effects:

1. The information is released in the final Planck phase, in which case there never is a real event horizon (in the paper, that's option 3).

2. The information survives in a baby universe that disconnects from our universe ( option 4A).

3. The information survives in a permanent, massive remnant (option 4B).

Most importantly, conservative solutions imply that the endstate of black hole evaporation - when the black hole has about Planck mass and Planck size - carries a (potentially arbitrarily large) amount of information. The reason is simply that, if one accepts that the semi-classical approximation holds, Hawking radiation does not carry any information (except its temperature). Thus, the information has to remain inside. We thus have an endstate that must be able to store a large amount of information, even though it has a small surface area. This speaks in particular for the surface-interpretation of the black hole entropy. Objects with these properties are known to be possible in General Relativity, we have discussed such “bags of gold” and “monsters” in a recent post.

The three above mentioned possible cases have been discussed for some while in the literature until some time in the mid 90s. There are some objections to all of them that we address in the paper. All in all, though valid objections, they are not terribly convincing. It is thus puzzling to some extend why there hasn't been more effort invested in what seem to be the most straightforward outcomes of black hole evaporation. Unfortunately, I have had many times the impression these conservative solutions were abandoned prematurely for the sake of creating more fanciful radical solutions, for not say, absurd speculations.

A note on the definition of singularities we are using: If one had a fundamental theory to describe spacetime in the regions with strong quantum graviational effects, one could consider other notions of singular spacetimes, for example by using divergence of operators describing the background curvature or likewise. Then there arises the question how this definition would coincide with the one we have been using. One could imagine cases where they do not. Eg, the information of fields propagating in the background might not be sensitive to a curvature singularity, or the singularity itself could encode information.

Bottomline

The sane thing to do is to stick with conservative options until we are sure it's a no-go. That requires in particular understanding the properties of Planck-sized quantum graviational objects with high entropy.

## Friday, January 23, 2009

### Interna

We currently have an interesting workshop at Perimeter Institute ongoing on

As things are, a speaker dropped out unexpectedly tomorrow morning (well, Waterloo in January does not make for a particularly attractive travel destination). And since I just finished a paper on the black hole information loss problem, one of the workshop organizers had the idea I could fill in the slot. I really tried but couldn't say "No". So now I am wondering what I will be talking about tomorrow morning. Meanwhile, I wish you all a happy weekend, and share with you the nicest Obamisms I have come across this week

And I recommend Joshua's interesting post What does it mean to be a digital President?

## Tuesday, January 20, 2009

### This and That

Instead of substantial original writing, here are some links I came across over the weekend that you might also find interesting:

• Back last summer, we had mentioned a report in Science by James Evans, Electronic Publication and the Narrowing of Science and Scholarship (doi: 10.1126/science.1150473). The paper said that as more and more scientific journals became available online, the articles referenced tended to be more recent, fewer journals and articles were cited, and more of those citations were to fewer journals and articles. This result seemed a bit surprising to Bee and me.

Now, the Science issue of 2 January 2009 prints a few letters in reaction to this paper (unfortunately, subscription required), and comments by James Evans.

For example, K. Brad Wray suggests that we may find that scientists' narrower focus on the literature is a good sign, as in science, relatively few papers affect subsequent scholarship, and scientists may be spending less time reading literature that is extraneous to their research.

Yves Gingras, Vincent Larivière and Éric Archambault question the result as such, claiming that the conclusions are not warranted by Evans's data. Based on their own analysis (arXiv:0809.5250v1), they argue that Evens' conclusions reflect a transient phenomenon related to recent access to online publications which they know from disciplines in which online access has been available the longest (such as nuclear physics and astrophysics), and that researchers are increasingly relying on older science, and citations are increasingly dispersed across a larger proportion of papers and journals.

Christopher S. Von Bartheld and Shaun P. Collin point out that current citation indices do not distinguish the purposes of citations, which may serve as confirmation, refutation, background, technical details, or another role, and that expanding the range of papers known to authors [via online access], a more complete grasp of current literature helps them to select more appropriate citations. Taking this into account, they argue, trends toward fewer citations may be a positive development.

• In Physics Today, correspondence by readers is freely available online. In the January issue, Robert A. Putnam makes the interesting observation that the observed strength of fluctuations in the Cosmic Microwave Background of about 1:100000 corresponds to pressure fluctuations in air, commonly noted as sound, in a crowded room, hence the cocktail party at the beginning of the universe.

The same issue contains, also freely available, an article about AdS/CFT by Igor R. Klebanov and Juan M. Maldacena, Solving quantum field theories via curved spacetimes.

• The January 2009 issue of Review of Modern Physics has articles about the The Physics of Maxwell's demon and information by Koji Maruyama, Franco Nori, Vlatko Vedral (doi: 10.1103/RevModPhys.81.1, arXiv:0707.3400), and on The electronic properties of graphene, by A. H. Castro Neto, F. Guinea, N. M. R. Peres, K. S. Novoselov and A. K. Geim (doi: 10.1103/RevModPhys.81.109, arXiv:0709.1163). Graphene is the chicken-wire single atom layer modification of carbon, where electrons behave as massless Dirac particles and show all kinds of cool stuff, for example the Klein paradox.

Now, I'll need a few more weekends to read these two papers...

## Sunday, January 18, 2009

### How to Fix The World

My flight back from Brazil to Canada last week unfortunately had a connection in Washington. Even though transit only, I had to queue at US immigration for two hours to have my fingerprints taken and to get an I-94, just to hand it in behind the next door. It didn't help there were two officers for about 500 people. By the time I had located my bag and dropped it onto the next conveyor belt my onward flight had left. Needless to say, I had then to go through security one more time, throw away the water and Coke to buy new one at the airport in Washington. That, ladies and gentlemen, is the actual reason behind the totally nonsensical liquid ban: to force travellers to buy a Coke for \$4,20. And what btw happens to the gallons of soft-drinks homeland security collects every day in the land of the free and the home of Coca Cola?

Either way, I went to customer service and got myself on standby for the next flight to Toronto. And while I was hoping somebody misses his flight at noon, I was walking up and down the hallway in what must be the dullest terminal in the world. The newsstands were offering an abundance of Obama fan products, T-shirts, baseball caps, mugs, pins, pens, keyrings, you ought to be prepared for inauguration day! Obama was grinning down from literally every newspaper. Having time to kill, I bought the Newsweek Special Edition “How to Fix The World - A Guide for the Next President.” It is a collection of advises from "bold innovators from different fields” and is a very mixed bag.

Many of the contributors advocate the need to global politics and multi-lateralism. Kishore Mahburani, dean of the Lee Kuan Yew School of Public Policy at the National University of Singapore, for example writes

“While Americans like to show off their toughness by mocking multi-lateralism, strategic thinking shows that the United States is well served by strengthening, not undermining international cooperation. Fortunately, the economic meltdown may have finally changed Americans' views on this question.”

Sergey Lavrov, foreign minister of Russia, writes “Russia and the United States must work together in a multipolar world,” and Larry Diamond, a senior fellow at the Hoover Institution and professor of Sociology and Political Science at Stanford University, addresses the need to promote democracy both in and outside the USA:

“The new president should keep in mind the power of example. Washington can't promote democracy abroad if it erodes at home.”

Several contributions are about the US relations to India, China and Russia, some offer advice on the war in Iraq and Afganistan, and how to deal with Iran. Gideon Rose, managing editor of the journal Foreign Affairs, asks for “adult supervision” of foreign politics, praising the “disciplined intelligence” of Obama's campaign and his “respect for professionalism”. Ayaan Hirsi Ali writes on the importance of promoting women's' rights in the Middle East, though she remains vague on how so.

Joseph Stiglitz, Nobel laureate in economics and professor at Columbia University, calls upon “more global and more robust oversight” of financial markets:

“What we need now is a global financial regulatory body to help monitor and gauge systemic risk. If financial rules are allowed to vary too widely from nation to nation, there is a risk of a race to the bottom - some nations will move toward a lore lax regulation to capture financial business at the expense of their competitors. The financial system will be weakened, with consequences that are now all too apparent.”

And he offers the following insight

“[W]e need to restrict the scope for conflicts of interest - whether among rating agencies being paid by those they are rating, or mortgage companies owning the companies that appraise the properties on which they issue mortgages.”

Robert Zoellick, president of the World Bank, asks for “A New Kind of Globalisation” and uses many fashionable words to say little:

"The architecture designed to deal with global markets is creaking. To deal with all this, we need a new multilateralism, one that suits the times. It should be a flexible network, not a fixed system - a network that maximizes the strengths of interconnecting actors, public and private.”

He then asks for a “steering group” to "tackle the reform of financial systems” but he remains vague on the how and what. I'd hope Obama has advisers that have more useful things to say.

Pascal Lamy, director-general of the WTO, advocates that the new president should “reignite Americans' belief in free markets”. He is concerned since “a survey conducted in 2008 found that only 53 percent of Americans think trade is good for their country.” Well, I think one should consider the reason for this might not be their lacking belief in free markets, but rather their lacking belief there is intelligent life outside their country. He goes on to reason “And while trade does create both winners and losers, Harvard professor Robert Z. Lawrence argued convincingly in a 2008 study that the stagnation of middle- and working-class wages is largely attributable to the larger share of the profits that has gone into the hands of the superrich.” If anybody could tell me why this is an argument either pro or con regulation, I don't get it.

Luiz Inacio Lula Da Silva, president of Brazil is very clear and uninhibited to the point:

“We [in Brazil] are ready to do our part [to develop a better system of international economic governance], and our economy is better prepared than most to confront the crisis. We have said no to macroeconomic adventurism. Inflation is under control and we are growing steadily. We have plenty of foreign reserves and owe nothing to the International Monetary Fund [...] Since I took office in 2003, more than 10 million Brazilans have joined the workforce. Some 20 millions have risen out of absolute poverty [..] Above all, we are redistributing our income and reducing social inequality [...]

This is not the time for protectionism, but for progressive action born of generosity and solidarity that will forge collective answers to 21st century challenges.”

But let's come to the more fun part. Sameer Reddy, a freelance writer based in Berlin, points out that “the United States has a serious public-relations problem” because “if you ask citizens of other countries to paint a portrait of the average American tourist, it would look something like this: a loud, chubby sightseer wearing a fanny pack, baseball cap, printed T-shirt, jean short and sneakers.” But “the election of president Obama - with his youthful, cleancut good looks,” he writes “offers a valuable opportunity for a national top-to-toe makeover”. He then continues to advocate that simplicity, not sloppiness, “is Americas true stylistic heritage” and that “when Obama takes office Jan 20, Americans will, with luck, create their own new New Look, modeled after his elegantly simple and straightforward wardrobe and manner. And women everywhere will be watching carefully as the new First Lady, Michelle, tries to find the elusive balance not only between work and family but between practical and stylish dressing”.

I would only want to add that Americans might profit if they'd pay more attention to what their politicians do than how they look.

And what advice would you give?

## Saturday, January 17, 2009

### No "ama"s yet

If you weren't yet convinced that Califoria is a bit... different, you might be thrilled to hear of “Sarah's Smash Shack.” Located in San Diego, the Smash Shack is the place to go if you want to break something into pieces. You can bring your stuff or buy something at location, and you can bring your iPod along to smash with an appropriate background music. Groups get a discount.

Sarah and her staff also provide pens since apparently people like to write names or messages on plates before throwing them on the next wall. Asked what people do write on these plates, Sarah replies
“What we see runs the whole gamut from a simple drawing, to a single word or name, to a mantra, to a soliloquy. We find a few 'uck's and 'it's on the plate fragments, as well as quite a few political 'W's. We haven't found any 'ama's yet.”
[Source: Psychology Today 02/2009]

## Friday, January 16, 2009

Hi Folks: Due to a spam attack that has lasted for several hours now comments are currently disabled. Sorry about that. I will try to change settings in the afternoon to see whether the storm has passed by.

Update 3pm: Turning comments back on...

## Thursday, January 15, 2009

### Monsters

These days, everybody is talking about entropy. In fact, there is so much talk about entropy I am waiting for a Hollywood starlet to name her daughter after it. To help that case, today a contribution about the entropy of black holes.

To begin with let us recall what entropy is. It's a measure for the number of micro-states compatible with a given macro-state. The macro-state could for example be given by one billion particles with a total energy E in a bag of size V. You then have plenty of possibilities to place the particles in the bag and to assign a velocity to them. Each of these possibilities is a micro-state. The entropy then is the logarithm of that number. Don't worry if you don't know what a logarithm is, it's not so relevant for the following. The one thing you should know about the total entropy of a system is that it can't decrease in time. That's the second law of thermodynamics.

It is generally believed that black holes carry entropy. The need for that isn't hard to understand: if you throw something into a black hole, its entropy shouldn't just vanish since this would violate the second law. So an entropy must be assigned to the black hole. More precisely, the entropy is proportional to the surface area of the black holes, since this can be shown to be a quantity which only increases if black holes join, and this is also in agreement with the entropy one derives for a black hole from Hawking radiation. So, black holes have an entropy. But what does that mean? What are the microstates of the black hole? Or where are they? And why doesn't the entropy depend on what was thrown into the black hole?

While virtually nobody in his right mind doubts black hole have an entropy, the interpretation of that entropy is less clear. There are two camps: On the one side those who believe the black hole entropy counts indeed the number of micro-states inside the black hole. I guess you will find most string theorists on this side, since this point of view is supported by their approach. On the other side are those who believe the black hole entropy counts the number of states that can interact with the surrounding. And since the defining feature of black holes is that the interior is causally disconnected from the exterior, these are thus the states that are assigned to the horizon itself. These both interpretations of the black hole entropy are known as the volume- and surface-interpretations respectively. You find a discussion of these both points of view in Ted Jacobson's paper "On the nature of black hole entropy" [gr-qc/9908031] and in the trialogue "Black hole entropy: inside or out?" [hep-th/0501103].

A recent contribution to this issue comes from Steve Hsu and David Reeb in their paper

Steve is a neighbor here on blogspot over at Information Processing. In their paper Steve and David examine the question how much matter one can stuff into a volume bounded by a given surface, and how much entropy this matter can carry. In flat space-time the relation between the volume of an area and its surface is trivial, it's just Euclidean geometry. But not so if space-time is strongly curved!

To see this, consider the often made analogy of a curved space to a rubber sheet. Draw a circle on it. That's your surface. But it's a rubber sheet, meaning you can deform the sheet inside the circle arbitrarily. You could for example form it to a bag and stuff a lot of gold into it.

This pictorial terminology is sadly not my invention: these kind of solutions have been known to be possible in General Relativity for a long time, and have been dubbed “bags of gold” by Wheeler already in the early 70s. Their defining property is that they have a potentially arbitrarily large interior volume, but a small surface area.

Steve and David in their paper now construct a weird kind of solution they dub “monsters,” which exemplifies what one can do with these bags. To understand what a monster is, consider some stuff (eg coins of gold) dispersed in space-time, such that the background is to good approximation flat. Now pick up these coins and put them closely together - so close that they almost, but not entirely, form a black hole. What you achieve in this way is that you get a strong gravitational field and a deviation of the volume-surface relation from flat space. That process of picking up and redistributing the coins should not be thought of as a process that is actually dynamically happening, but just as a way to create the initial conditions*. If you create these initial conditions carefully you can achieve most importantly two things:
1. You can get the asymptotic mass a far away observer would measure (ADM mass) to be arbitrarily small, no matter how many coins you have had. The reason for this is that the strong gravitational field contributes with a negative binding energy.

2. You can similarly get an arbitrarily large entropy inside a sphere with fixed surface area, think of the coins as the particles forming a particular micro-state. The reason is that the volume can get arbitrarily large, and you can stuff all the coins in, even though the surface area and the asymptotic mass might remain small.

The authors also show in their paper that if you create the monster state and let it evolve in time, it inevitably forms a black hole. Since it can have been arbitrarily close to being a black hole, it is plausible to expect that almost all of this entropy goes into the black hole. If the volume interpretation of the black hole entropy was correct, this would be in conflict with it. Weirder than that, the monster solution must have come out of a white hole in the past. This solution is thus very similar to an expanding and re-collapsing closed FRW universe embedded in empty space.

Despite these monster solutions existing in GR, there remains the question however whether they do exist in reality, since they are somewhat pathological and constructed. Though it might be possible to argue these states will never be formed from any sensible initial condition, in a quantum theory the situation is more tricky since everything that can happen does happen - even though it might be very improbable. That means the monsters could be spontaneously formed through tunneling processes. That might however in practice not happen even once during the lifetime of the universe.

Steve was visiting PI in November and gave a very clear talk about the monsters, that is recommendable if you want to know more details. You can find it at PIRSA 08110026 and the slides are here.

* You shouldn't take the picture too literally though, much like in the often used example with the marble on the rubber-sheet it is slightly misleading as there isn't actually something "on" the spacetime (the sheet) that extends into an additional dimension.

## Monday, January 12, 2009

### Jeffrey Sachs makes a Case for Bigger Government

Jeffrey Sachs is an interesting figure in the world of economics. Besides doctoring around on the economies of Bolivia and Russia, he is responsible for the “Sachs Plan” that has been imposed on Poland in 1990. He basically pushed a young and insecure democratic government into extreme measures of deregulation and privatization, in an example of economic “Shock therapy”. It is hard to say exactly how that could happen to a government that had essentially directly emerged out of a labor union and was as far left as can be, but he seems to have assured the struggling country would obtain substantial financial support from the IMF, which then however was never provided.

After his plan was put into place basically overnight, food prices soared, unemployment rose sharply resulting in strikes and demonstrations all over the country by a population who felt betrayed. In the first two years, Poland saw 30% reduction in industrial production. People were eventually sufficiently fed up with the experiment and the government had to cut back on its plans. Today, Poland is doing economically reasonably well, I am tempted to say despite not because of Sachs' help. Poland's unemployment rate though is still the highest in the European Union. What is most dramatic indicator of the change that Poland had to swallow: from 1989 to 2003 the number of Poles who lived below the poverty line increased from 15% to 59% [1]. I am far from being a supporter of communism and think the transition was a good development, but it could have been done in a better way, more sustainable and less painful.

I was thus pleasantly surprised that Jeffrey Sachs' recent book “Common Wealth” is a very reasonable and moderate account on economic and political development that assigns a place to government and is respectful towards other culture's preferences towards regulation and social welfare. It is nowhere close to free-market radicalism or advocating the need for shock therapy. Jeffrey Sachs has an essay in the current issue of Time Magazine (Jan 19 2009 p. 34-6) titled “The Case for Bigger Government” which reflects this respect towards the role of government even stronger. He writes:

“Even as our economy worsened, many Americans consoled themselves with the belief that at lest we were better off than people in other rich nations. No more. When you compare the U.S. with Canada, Western Europe and Japan, the news is sobering. Our child-poverty and infant mortality rates are the highest, our life expectancy is the lowers, our budget deficit as a share of gross domestic product (GDP) is the highest, and our 15-year-olds rank among the lowest on tests of math and science [...]”

One could add that in the USA “The national direct estimates of the percentages of adults lacking Basic Prose Literacy Skills are 14.5 percent for the 2003 National Assessment of Adult Literacy.” In other words, about one out of seven Americans can't read. Sachs continues:
“A pressing example: our mostly private health system, at \$8,000 per American, is twice the cost of Europe's mostly public system, yet with worse outcome. And nearly 50 million Americans lack health insurance [...]

As our budget choices were getting tougher in the 1970s, Europe faced similar dilemmas and took a different course. While Americans rejected new taxes and new domestic programs, Europeans elected governments that introduced higher taxation, many value-added taxes, to cover the rising costs of health care, education, infrastructure, poverty relief and international-development aid. Ultimately, the Europeans restrained excessive growth in the welfare state in order to maintain global competitiveness and rebalance their economies and succeeded in sustaining the public-private partnerships and welfare-state benefits.

The European strategy, with levels of taxation and government spending roughly 8% to 10% of GDP higher than in the U.S., has many successes to show for it: less costly and more reliable healthcare, the elimination of hard-core poverty, solid educational achievements, and social services that ensure better care for children and more flexibility for mothers and the elderly.”

He finishes by pointing out there won't be one solution for everybody but that different countries will prefer different balances, depending on their social, cultural and historical context:
“The U.S. will not mimic Europe for many reasons - size, diversity, tradition and, of course, vested interests - but we an learn from Europe. Most important, we can see how government can be a partner of the private sector, not an enemy. The time has arrived to restore national prosperity and security with a smartly rebalanced partnership between the public and private sectors.”

I would then hope that similarly the Europeans acknowledge they can learn from the USA, to begin with how to mobilize their citizens to politically participate and to identify with the Union.

[1] Numbers: Naomi Klein, “The Shock Doctrine”, p. 230 and references therein.

## Sunday, January 11, 2009

### Photos from Brazil

Some photos from our trip to Brazil, just so you know how we've spend our time (taking photos of each other obviously). Click to enlarge.

Paraty:

Copacabana:

Near Ubatuba:

Some more photos on Flickr.

## Saturday, January 10, 2009

### Backreaction meets Theorema Egregrium

On our trip along the coast from Rio towards Sao Paulo, we had a brief stopover to say hello to Christine from Theorema Egregrium. The below photo confirms once again that I always look stupid on photos, so please excuse the expression on my face.

From left to right: me, my husband, Christine, her husband. The photo was taken by her lovely son, Pedro. (Click to enlarge, and see Christine's post on the event).

## Thursday, January 08, 2009

### Book Review: “The God Delusion” by Richard Dawkins

The God Delusion
By Richard Dawkins
Houghton Mifflin (September 18, 2006)
On Amazon.com

I didn’t intend to write a review on Dawkins’ book for religion is without doubt one of – if not the – most discussed topics of today’s human culture, and given that the book is two years old already I am sure some thousand people have already said what there is to say. However, since we have on this blog repeatedly touched the issue of unquestioned belief and its troublesome relation to knowledge discovery (and Phil and Rae Ann encouraged me to), I thought the book would make for a good opportunity to discuss some questions regarding science and religion. I am offline while writing this, and I didn't read anybody else’s review, so apologies in case I’m repetitive.

The God Delusion

Richard Dawkins’ book is a passionate argument against religious believes. In ten chapters, he presents the most commonly raised points in favor of religion, for the existence of a God, and in favor of tolerating both, for then to meticulously debunk them and expose their fallacies. His writing style is very clear while being entertaining, though he gets occasionally somewhat polemic. In many cases he anticipates objections a believer would raise and deals with them right away, which makes it very easy to follow his line of thought. The book tells that Dawkins has plenty of experience with arguing about this topic, and he draws from a huge reservoir of anecdotes. His main message is that atheists should voice their opinions more openly, not back up, and not quietly tolerate religion for it can be harmful.

Dawkins’ starts with explaining in the first two chapters in which way he refers to God: A “superhuman, supernatural intelligence who deliberately designed and created the universe and everything in it, including us.” He refers to the existence of such as the “God Hypothesis”. His central argument against the God Hypothesis it is that a God with these abilities necessarily must be more complex than anything it allegedly created, therefore its own existence is enormously improbably, not to mention implausible: It begs the question who created God. This then turns the argument God is in some way a ‘simple’ explanation ad absurdum. Unsurprisingly for the time the book was written, Dawkins spends some time in defeating Creationists’ arguments, pointing out with a multitude of examples that the claims for Creationism stem in all instances from a lacking understanding of how Natural Selection results in complexity: by small gradual changes for which we have plenty of evidence.

Dawkins also makes a brief excursion into fundamental physics, asking for the origin of our universe and the laws of physics. He seems to regard the anthropic principle as a plausible explanation for why our universe is the way it is, but even more he seems to like Lee Smolin’s idea of Cosmological Natural Selection which goes very well with Dawkins’ affection for Natural Natural Selection. (See here for my Thoughts on the Anthropic Principle, and here for some comments on CNS.)

A recurring theme in the book is the evidence that higher education goes along with an increase of atheism, signaling the conflict of reason with unquestioned acceptance of inconsistent belief systems. He presents several survey results from different countries to make the point, and in the first chapters he also works with quotations of many well-known scientists. Though the circle of people I know is hardly representative, this confirms my personal impression. Dawkins’ argues that science and religion is mutually incompatible for the heart of science is examining the evidence and building understanding from it, whereas the main virtue of religion is believing without any evidence.

Dawkins spends a chapter on the plausible roots of religion, suggesting that the susceptibility of the human mind for religion is a by-effect of our brain’s evolution. Most notably he points out the vulnerability of children’s minds to indoctrination, a side-effect of evolutionary advantageous trust in adult’s knowledge, that allows religios ideas to be reproduced and passed on over the generations:

“More than any other species, we survive by the accumulated experience of previous generations, and that experience needs to be passed on to children for their protection and well-being. Theoretically, children might learn from personal experience not to go too near a cliff edge, not to eat untried red berries, not to swim in crocodile infested waters. But, to say the least, there will be a selective advantage to child brains that possess the rule of thumb: believe, without question, whatever your grown-ups tell you. Obey your parents; obey the tribal elders, especially when they adopt a solemn, minatory tone. Trust your elders without question. This is a generally valuable rule for a child. But […] it can go wrong.”

He also comments on the idea that religious traditions and convictions that our brains are most receptive for survive as memes in our civilizations. That addresses the survival of religious cults. As far as their origin is concerned, he suggests that the human mind has a predispostion to assign intentions to inanimate objects and to create explanatory narratives.

In chapter seven he dissects the Bible to demonstrate how inconsistent it is and how cruel its stories are, rendering it an unsuitable source to derive ones morals from. In chapter eight, he argues that religion is a global source of political conflict and cause of suffering. In chapter nine he explains in which sense religion is a cause also of personal suffering for many religions ensure loyalty by threatening with punishment in the case of acting against its rules, which can result in psychological trauma.

He ends with marveling at the enrichment to ones’ life when one understands part of how the world works, a step of insight that only science can provide, whereas religious believes demand the suppression of our curiosity and humans’ natural desire to understand.

Richard Dawkins spends some time addressing the argument that religions offer comfort and inspiration, making the case that both come at the price of suppressing the own mind’s curiosity and shutting off its questions. What he does not address at all however is the sociological role that many churches play in our cultures.

Leaving aside the fact that churches have something to do with religions, they are basically large groups that offer its members a sense of belonging and acceptance. They offer a place to turn to in case of trouble, and they have traditions that strengthen the feeling of being part of something. If you move into a new country and don’t know anybody, you look for the next church with the right symbol on its door and find a community where you know the rules of the game. In most countries, major churches play a vital role for the social system, they take care of the sick and the poor, they offer advice and counseling, not to mention places to meet likeminded people. Dawkins does not comment on this beneficial sociological side at all which I find very disappointing.

Some years ago I was at a physics conference and was sharing a table with nine other people, from several European countries, and from North and South America. I can’t quite recall how the topic came up but upon try it turned out all of us knew the Pater Noster by heart, though everybody in his native language and though most of us were not attending church. It found it astonishing to realize we shared this common knowledge though it had nothing to do with the reason of us meeting in the first place.

And that brings me to why, in its current form, religion will continue to dominate over science. Because scientists don’t have traditions, because science is all about competition and not about belonging, because you are not accepted simply by declaring your willingness of being part, because we don’t take care of our group members, because we offer no advice in hard times and no guidance for those in trouble. Because the scientific enterprise as it is today does not take care of these most human needs. And as long as we don’t make the scientific enterprise a more welcoming place, people will continue instead to turn to religion for comfort and a place of belonging.

Maybe, and only maybe, the Web2.0 is a step into the right direction. One of the roles that blogs play is without doubt one of mutual support, advice, and counseling.

Another point I found disappointing about Dawkins’ book is that his elaborations for the biggest part focuses on the Bible. I would have thought for a book on religion, he should have made more effort to present contradictions or murky moral values from other world religions as well.

I entirely agree with Dawkins’ assessment that the main reason why religions survive is that parents and preachers indoctrinate children. If you have grown up being told there is a God who watches over you, it is hard to part with it later in life. It is not coincidentally in most cases people carry on with the religion of their families, it is hardly a conscious choice of a grown-up. Whether or not somebody thinks God should play a role in his or her life is a personal decision, but it should be up for them when they are old enough to understand what they are chosing among. Dawkins however remains unfortunately very vague on how to address the problem for I see no way it will ever be possible or even desirable to dictate parents how to raise their kids. The only way I can see a change could happen is what he refers to as “consciousness raising.” As far as I am concerned, the worst thing about religion seems to me that it is such a waste of people’s time and interferes with their ability to understand and enjoy life.

I also don't share Dawkins’ sense that religion and science is mutually incompatible. It is some aspects of religious teachings that are incompatible, for - as I said earlier - science is the very antithesis of a belief system, you'd better call it a “doubt system”. There are also many aspects of presently established religions that are outdated and incompatible with scientific knowledge today. However, since I don't think we will know just everything there is to know any time soon, believing will remain part of human culture very possibly forever. The realm of believing however changes with time, and this has been and is reason for tension. Given the success and relevance of scientific research, almost all traditional religions are presently in a pretty much indefensible position and I expect they will become mostly redundant in the soon future (except for the incorrigible fundamentalists that will remain). What we will likely see instead is the spread of religions that are up to date with scientific progress and constrain belief to where it doesn't interfere with science, possibly finding new niches that science itself has only brought into our attention.

And finally, just to give you the context from which I am writing: I am a heathen, and according to Dawkins further a “sexed up atheist”. I insist on the “sexed up”.

Bottomline

The book is a recommendable read and it is very well written, entertaining though somewhat polemic. “The God Delusion” is basically a handbook for the atheist. It arms the reader with arguments for the people with the leaflets who want to talk about the existence of God. If this was an Amazon review, I’d give four stars.

## Wednesday, January 07, 2009

### Britain from Above

Two particularly nice pieces of data visualization. Enjoy!

## Monday, January 05, 2009

### Guestpost: Dan Falk on the Nature of Time

[I met Dan Falk early last year at the SciBar Camp in Toronto, and later again at PI's multiverse conference. As most science writers I've met, he brings a cheerful interest in whatever the so-called edge of research currently discusses that is impossible to maintain if you happen to dance on that edge. He has written two books, neither of which I read, but I have occasionally come across his articles in the Globe and Mail which are always a pleasure.]

What better time than the start of a new year to reflect on the nature of time. (Thanks, Sabine, for letting me post here on this subject!)

Today’s atomic clocks can measure time to within a fraction of a billionth of a second per day – so well, in fact, that they reveal the irregularities in the earth’s rotation. As a result, we have to insert a “leap second” into the day every few years, as we did recently on the evening of Dec. 31 – a subject I discussed in an essay in the Toronto Star.

The technology that allows for this ultra-fine dissecting of time is indeed impressive. Yet our science – and perhaps our philosophy – may have some catching up to do. Indeed, one can legitimately ask: What is it, exactly, that these clocks are measuring?

I’ve given a lot of thought to this question of the last few years, as it lies at the heart of my latest book, In Search of Time: Journeys along a Curious Dimension (McClelland & Stewart, 2008).

Physics – perhaps surprisingly – has less to say on the subject than we might expect. Einstein’s relativity tells us all about the rates at which clocks tick: We know that a clock whizzing by at high speed will be seen to tick more slowly than one that appears to be stationary; that a clock in a strong gravitational field will tick more slowly than one on the surface of the earth.

Yet Einstein’s equations do not distinguish past from present or present from future. Just as with Newtonian physics, they say nothing of time’s “flow,” its relentless passage. Indeed, physics considers all moments to be alike, with space and time laid out in a vast, static “block.”

But this is not how we experience time: We seem to inhabit a single moment, a fleeting “now.” The explanation for this, it seems, may lie not in physics but in psychology or philosophy; indeed, many thinkers suspect that time’s alleged flow – this “moving now” – may be little more than an illusion, a trick of the mind.

Einstein once spoke of this dilemma. His friend, the philosopher Rudolf Carnap, recalls Einstein admitting that “the experience of the Now worried him seriously.” The experience of the Now, Einstein told him, “means something special for man, something essentially different from the past and future, but that this important difference does not and cannot occur within physics.”

And so the question remains, where does this difference occur? Why do we feel that time passes? Perhaps it will take an intellect even greater than Einstein’s to illuminate the mystery of time’s apparent flow.

Related posts:

## Saturday, January 03, 2009

### This and That

Stefan and I, we are still enjoying Rio, so here are just some things to read I came across recently:

• The Edge Annual Question 2009: What will change Everything? with answers from all the usual suspects: Carlo Rovelli tries to face that his dreams might not come true and he won't witness any great breakthroughs in theoretical physics at all. Lisa Randall shows to be very down to earth and suggests that further increase in computing power will go along with progress in science. Alexander Vilenkin elaborates on the Doomsday Argument and our responsibility to become a space-colonizing species. (For an explanation why the Doomsday Argument is nonsense read this). Lee Smolin wants to liberate time and rethink the meaning of truth and reality - and amazingly enough manages to connect this line of thought to neoclassical economic theory. Max Tegmark fears an accidental nuclear war, Lawrence Krauss a deliberate one, and Garrett Lisi takes once again the meta-stance and suggests Changes in the Changers.

• The Globe and Mail collects the most absurd stories from the world of work 2008. Highlights: A Chicago public school teacher was pulled from the classroom after she taped a nine-year-old special education student to his chair because he wouldn't sit down. -- An Italian priest organized an online beauty contest for nuns in an effort to dispel the perception that they were all old, sad and dowdy. His bishop nixed the project.-- Two German police officers were mistaken for male strippers when they investigated a complaint about a noisy party. They were mobbed by drunken women urging them to rip their clothes off. -- The head of a German telesales company fired three non-smokers and announced he would hire only smokers in the future. Non-smokers, he said, are grumblers who don't socialize with their co-workers.

• Seed Magazine has an excellent article "The Scientist in 2008" by Steven Shapin: "Who are the scientists of today? Where do they work? What motivates them? As science increasingly shapes our cultural moment, the identity of its practitioners is also evolving." It is a highly recommendable read though I wish he would have drawn some conclusions from his argumentation. A sample: "The increasing alignment of science with commercial institutions carries a risk: the loss in the public mind of the idea of an independent scientific voice — not truth speaking to power but power shaping what counts as truth. [...] We're still a long way from the general "corruption" of science —  witness the moral outrage attending stories about commercial or political incursions into science. But if it came to pass that these associations count as normal, then the scientific voice would no longer sound independent. The material utility of science that is a substantial basis for its success would then undermine itself. To be a modern scientist is to be an employee, but the job must have a degree of autonomy or scientists will be of no use — to the institutions that engage their services or to the public."

• Spiegel Online has a very interesting article about France's plans to build the first nuclear fusion power plant. They also report: "A few weeks ago in Garching, physicists discovered another way to improve the fusion process. The discovery is so recent that the results have not been published. Using the ASDEX Upgrade reactor they found that adding nitrogen produces a sensational effect. Instead of being cooled off by contact with this impurity, the plasma grows hotter. "Just how this unexpected phenomenon comes about is something we don't really understand yet," Hasinger admitted. "Surprisingly, the addition of nitrogen seems to insulate the plasma better." The nitrogen enigma suggests how many unanswered questions remain."

And our comment feed still doesn't work, sorry.