Science

a onblur=”try {parent.deselectBloggerImageGracefully();} catch(e) {}” href=”http://4.bp.blogspot.com/_AWa1cp-Somo/SaR1uXl4KsI/AAAAAAAAAYU/zEKKGS1QNWo/s1600-h/8417311690_410485.gif”img style=”float:left; margin:0 50px 20px 0;cursor:pointer; cursor:hand;width: 200px; height: 187px;” src=”http://4.bp.blogspot.com/_AWa1cp-Somo/SaR1uXl4KsI/AAAAAAAAAYU/zEKKGS1QNWo/s200/8417311690_410485.gif” border=”0″ alt=”"id=”BLOGGER_PHOTO_ID_5306495700416604866″ //aA while ago, Bee wrote a post about a href=”http://backreaction.blogspot.com/2006_02_01_archive.html”Risky Black Holes/a. br /br /This seems to be a timeless topic #x2013; it could have been written today. It was three years ago, and it started this blog. br /br /Happy Birthday, Backreaction!br /brbr /nbsp;br /br /brdiv class=”blogger-post-footer”"You do not really understand something unless you can explain it to your grandmother.” ~ Albert Einsteinimg width=’1′ height=’1′ src=’http://res1.blogblog.com/tracker/22973357-7737220969885687540?l=backreaction.blogspot.com’//div

… the origin of the word “travel”?br /br /It goes back to the Old French word emtravail/em “suffering or painful effort, trouble” (12c.), from travailler “to toil, labor,” originally “to trouble, torture,” from Vulgar Latin emtripaliare/em “to torture,” from emtripalium/em (in Literary Latin emtrepalium/em) “instrument of torture.”br /br /Source: a href=”http://www.etymonline.com/”The Online Etymology Dictionary/abr /br /Yep.br /br /Next time you fly from the East- to the Westcoast, suffering from cheap airline coffee and dull movies, try to imagine you’d have taken the trip 200 years ago…br /hr /br /span style=”font-size:85%;”See also: Did you know…br /ullia href=”http://backreaction.blogspot.com/2007/12/did-you-know-vi.html”… that the Eskimos have 98 words for snow?/a/lilia href=”http://backreaction.blogspot.com/2007/10/did-you-know-v.html”… that the can opener was invented 48 years after invention of the can?/span/a/lilia href=”http://backreaction.blogspot.com/2007/05/did-you-know-iv.html”span style=”font-size:85%;”… the opposite of eloquent?/span/a/lilia href=”http://backreaction.blogspot.com/2006/12/did-you-know-iii.html”span style=”font-size:85%;”… why the toast is called toast?/span/a/lilia href=”http://backreaction.blogspot.com/2006/11/did-you-know-ii.html”span style=”font-size:85%;”… what the Baconian method is?/span/a/lilia href=”http://backreaction.blogspot.com/2006/11/did-you-know.html”span style=”font-size:85%;”… why Google is called Google?/span/li/ul/apppdiv class=”blogger-post-footer”"You do not really understand something unless you can explain it to your grandmother.” ~ Albert Einsteinimg width=’1′ height=’1′ src=’http://res1.blogblog.com/tracker/22973357-1842485430912788582?l=backreaction.blogspot.com’//div

a href=”http://blogs.epicindia.com/leapinthedark/The%20Shock%20Doctrine.jpg”img style=”FLOAT: right; MARGIN: 0px 0px 10px 10px; WIDTH: 164px; CURSOR: hand” alt=”" src=”http://blogs.epicindia.com/leapinthedark/The%20Shock%20Doctrine.jpg” border=”0″ //a strongspan style=”font-size:130%;”The Shock Doctrine - The Rise of Disaster Capitalism/span/strongbr /By Naomi Klein divMetropolitan Books (September 18, 2007) /divbr /br /In late 2007, I read an article in a href=”http://www.harpers.org/archive/2007/10/0081739″Harper’s Magazine, titled “Disaster Capitalism”/a which, well written, vividly argued, left an impression. I Googled for the author, Naomi Klein, and was lead to a href=”http://www.naomiklein.org/shock-doctrine”her website/a announcing the new book, on which the Harper’s article had offered a glimpse. I watched a href=”http://www.youtube.com/watch?v=cvG0gbvZ4tY”a truly appalling promotional video/a, and reminded myself that the author probably wasn’t responsible for the advertisements before ordering the book.br /br /span style=”font-size:130%;”uSummary/ubr //spanbr /In “The Shock Doctrine” Naomi Klein puts forward the thesis that worldwide and over decades shocks have been used to push through unpopular free market decisions, mostly privatization and deregulation, generally against the will of the people but always to the advantage of large corporations, the wealthy upper class, and corrupt governments. Shocks might be natural disasters, wars, terrorist attacks, or economic turmoils. The book is a collection of well researched and documented examples, from Bolivia over Chile, Poland, Iraq, China, the UK, Russia, again Iraq, Israel, South Africa, Sri Lanka, the Maldives to New Orleans.br /br /The book begins with drawing parallels to shock therapy in the 50s and 60s, the attempt to reset the human mind by whatever means into an infantile state, a “clean slate” on which there could be imprinted a new beginning. Klein reports how these insights were later used for purposes of torture all over the world.br /br /Throughout the book, Klein traces the actions of Milton Friedman, and his “Chicago Boys” who provided the ideological and allegedly scientific backup for operations in the course of which hundreds of thousands of people were murdered, died, or committed suicide. (a href=”http://backreaction.blogspot.com/2009/01/jeffrey-sachs-makes-case-for-bigger.html”Jeffrey Sachs /amakes an appearance in several instances.) If her claim of a shocked nation being a desirable state to perform unpopular free market reforms feels far fetched to you as it did to me, this is actually quite well documented in many instances, and a href=”http://en.wikipedia.org/wiki/Shock_therapy_(economics)”one doesn’t have to look very far/a to find this option was considered quite appropriate as means for what some considered progress.br /br /Over the decades, Naomi argues, the ideology spread, packed into the wrapper that a free market maximizes social welfare, filled with a creamy myth of tricke-down. Extreme measures were more easily put into place in tyrannies, but found their way into democratic systems as well, through cloak and dagger operations, through exerting economic pressure, or just by corruption, all in the midst of states of confusion and shock:br /br /blockquote“And that is how the crusade that Friedman began managed to survive the dreaded transition to democracy - not by its proponents persuading electorates of the wisdom of their world view, but by moving deftly from crisis to crisis, expertly exploiting the desperation of economic emergencies to push through policies that would tie the hands of fragile new democracies. Once the tactic was perfected, opportunities just seemed to multiply.”/blockquotebr /Particularly shocking for me has been to learn about the role of the International Monetary Fund (IMF) in these doings. In many cases, support has been tied to requests for privatization and deregulation, clearly interferences with nations’ autonomy and often with their political landscape.br /br /Naomi Klein traces traces the historical route to our present days, when a large and increasing sector of our global economy has specialized in disaster help and security, up to the point that devastating news actually score as good news on the stock market. Her account of which private companies made billions after billions with the war in Iraq and Hurricane Katrina, all with taxpayers’ money (resp. by increasing the government’s debt) is sobering, especially in the face of how incompetent these tasks were performed (or paid for but not performed at all).br /br /She finishes the book with examples of where shock has worn off, especially in South America were social democracy has put a halt to selling off countries and destroying communities, and established a new autonomy of these nations independent on the IMF. The main message I think she wants to get across is to be prepared for when a shock hits, for we can most easily be exploited when taken by surprise.br /br /span style=”font-size:130%;”uComments/u /spanbr /br /The book is an interesting read and an impressive collection of facts, quotations, and data. I can’t help however to find Klein’s account very single sided. As meticulously as she has collected evidence in favour of her thesis, I did not get the impression she has as carefully looked for evidence against her thesis. I feel like her narrative is compelling in its simplicity and has certainly some truth to it, but lacks many qualifiers.br /br /Most importantly, her arguments are directly and by name targeted at recommendations out of the pocketbook of neoclassical economics. But what she actually is criticising is not a free market or the drawbacks of particular regulations, but corporatism and corruption (not to mention torture). In fact, in the introduction she writes:br /blockquote“A more accurate term for a system that erases the boundaries between Big Government and Big Business is not liberal, conservative or capitalist but corporatist. Its main characteristics are huge transfers of public wealth to private hands, often accompanied by exploding debt, an ever widening chasm between the dazzling rich and the disposable poor, and an aggressive nationalism that justifies bottomless spending on security. For those inside the bubble of extreme wealth created by such an arrangement, there can be no more profitable way to organize a society.”/blockquotebr /She then however fails to explain why privatization and deregulation must necessarily be tied to these circumstances she is bemoaning, and thus why her constant stabbing at Friedman and the Chicago School. Instead of providing an argument on why this connection would be, she just offers example after example. I don’t find this very insightful, as I would have wanted to know what could have been done better and why.br /br /The book was recently turned into a documentary by directors Michael Winterbottom and Matt Whitecross, a href=”http://www.spiegel.de/international/zeitgeist/0,1518,607234,00.html”who make an effort pointing out it is not a conspiracy theory/a. Indeed, it is not. There is no sense in which Klein raises the impression these events were deliberately planned. Instead, the picture she paints is one in which ideological convictions have gone awry and people in power neglected to pay attention to reality - or just did not live up to their expectations. As she writes repeatedly, there is no way in which the human mind or a country can be cleaned of its history and provide the perfect platform to build on it from scratch a flawless utopia. This strive for perfection is an illusion, and one in whose pursuit comes suffering. To add my own perspective on that, it is less a conspiracy and more a system failure. Most importantly, the system fails to correct its own problems since those who hold the power have no incentives to do so.br /br /Besides this, the book is nicely written and reads very well. It is however very repetitive, and fuzzy in articulating the main claims and conclusions. As far as I am concerned, I would have been fine with the first 100 pages and then a collection of facts and data. I really don’t need to be told the story of the evil Friedmanians fifty times. And for my taste, she gives way too much room to the history of shock therapy treatment and its applications for torture. I don’t even doubt that these concepts were picked up by economists. Such cross-fertilization between different fields is interesting (the concept of a ‘landscape’ being picked up by physicists is a similar example), but I didn’t want to buy a book on torture or electroshock treatments and would have appreciated less details on that matter.br /br /All together, if this was an amazon review, I’d give three points. ppbr //pdiv class=”blogger-post-footer”"You do not really understand something unless you can explain it to your grandmother.” ~ Albert Einsteinimg width=’1′ height=’1′ src=’http://res1.blogblog.com/tracker/22973357-6148184124867053272?l=backreaction.blogspot.com’//div

Yesterday we had a very nice colloquium by Ramesh Narayan from Harvardbr /br /ulEvidence for the Black Hole Event Horizonbr /br /span style=”font-size:85%;”Abstract: Astronomers have discovered many candidate black holes in the universe and have studied their properties in ever-increasing detail. Over the last decade, a few groups have developed observational tests for the presence of event horizons in candidate black holes. The talk will discuss one of these tests, which indicates that the supermassive black hole at the center of our Galaxy must have a horizon./span /ulbr /You can find the recording at PIRSA: a href=”http://pirsa.org/09020024/”09020024/a.br /br /Black hole formation is a prediction of General Relativity (GR). We know that stars that have masses more than a few times the solar mass can not, once their nuclear power is burned out, stabilize at a finite radius and the gravitational pressure of their own mass will cause them to completely collapse. In this process, the density of the object increases, and the gravitational force on the surface gets stronger. If the gravitational force on the surface gets so strong not even light can escape, we call this surface an event horizon. It is the characteristic feature of black holes. Classically, nothing can ever leave the region behind the event horizon.br /br /Since the early 90s, evidence has mounted for astrophysical black holes. These come in two rough categories: solar size black holes, with masses of a few times the mass of our sun that form directly from collapse of stars, and the so-called supermassive black holes, with masses about a million to a billion times the solar mass, that form through accretion in densely populated areas, mostly in the center of galaxies.br /br /The cheap way to label an object a black hole is to measure its mass (eg from the motions of nearby stars) and its radius (eg by determining the source area of its emission). For a black hole, we know the relation between both, iR/i = 2 iGM/i, where emG/em is the gravitational constant, emR/em is the radius, and emM/em is the mass. The radius of a black hole of about solar mass would be roughly 3 km, and that of a supermassive black hole is then consequently some million to billion kms. If one has data that allows to estimate mass and radius, if there is too much mass in an observed region of spacetime, one can conclude it has to be a black hole. (Keep in mind this is astrophysics, so observables typically have large errorbars and it takes some effort to pin down conclusions.)br /br /This is however somewhat unsatisfactory. What one would really like to know is whether the object does have an event horizon, which is the defining feature of a black hole. The question is then, what observables can help us to determine whether we are dealing with a compact object that has a surface, or with an object that has an event horizon?br /br /First let me emphasize that compact objects of the masses we are concerned with here that have a radius close by but not quite the radius of a black hole are not possible in GR. These objects can’t be stabilized. But if one modifies GR, one can get away with this. People have looked into such modifications but these are not very convincing options. The reason is simple: To avoid collapse, one needs a mechanism to stabilize matter at a density that allows the matter to just not form a black hole. That is, one needs a deviation from the standard theory at densities of about emM/em/emR/emsup3/sup, and inserting the black hole radius this goes as ~ 1/iM/isup2/sup. This means, the more massive the black hole is, the smaller is the density at which you need deviations from the standard theory.br /br /And this density can be arbitrarily small. It can be as small as densities we deal with every day. Take a supermassive black hole with 10sup9/sup times the mass of the sun, which has a radius of about 10sup9/supkm. This gives a density of about 10sup39/supkg per 10sup27/supkmsup3/sup, or 1 kg per dmsup3/sup, which is about the density of water. Not exactly a very extreme condition, and one that we have quite some experience with. From Einstein’s field equations we further know the density scales like the background curvature. This means if you want to generally avoid the formation of black holes, you need modifications of GR in the arbitrarily small curvature regime. In this regime, the theory is extremely well tested, and we have not seen any deviations whatsoever.br /br /But still, one would like to have observational evidence for the presence of the horizon (after all, it could be a naked singularity, no?). The key to this is to compare the emissions of an object that does have a surface with that of an object that does not have a surface. Astrophysical black holes accrete matter, and that matter heats up, which leads to emissions. When the accreted matter hits the surface this also leads to emissions, that can - in the case of astrophysical black holes - be violent nuclear explosions. An object with an event horizon on the other hand will not have contributions to the emitted radiation from the surface. Both will thus differ in their luminosity, which is observable.br /br /In his talk, Narayan summarized the observations of the luminosity of both solar mass black holes in our galaxy, and for a href=”http://en.wikipedia.org/wiki/Sagittarius_A*”Sgr A*, the supermassive black hole in the center of our galaxy/a. In both cases, the observed emission is much smaller than would be expected if the object had a surface, and thus clear evidence for the presence of an event horizon.br /br /Related: a href=”http://diracseashore.wordpress.com/2009/02/19/black-holes-as-frozen-stars/”Coincidentally, Moshe just today wrote a nice post on Frozen Stars./adiv class=”blogger-post-footer”"You do not really understand something unless you can explain it to your grandmother.” ~ Albert Einsteinimg width=’1′ height=’1′ src=’http://res1.blogblog.com/tracker/22973357-1812154162033652130?l=backreaction.blogspot.com’//div

a onblur=”try {parent.deselectBloggerImageGracefully();} catch(e) {}” href=”http://portal.unesco.org/culture/en/ev.php-URL_ID=38831″img id=”BLOGGER_PHOTO_ID_5305365965257215538″ style=”FLOAT: right; MARGIN: 0px 0px 10px 10px; WIDTH: 226px; CURSOR: hand; HEIGHT: 320px” alt=”" src=”http://1.bp.blogspot.com/_6yQy29edf4Q/SaByPIKajjI/AAAAAAAAADo/GB5WjzHcjek/s320/PosterIMLD2009.jpg” border=”0″ //aToday is the “a href=”http://portal.unesco.org/culture/en/ev.php-URL_ID=38724″International Mother Language Day/a”, which has been iproclaimed by the General Conference of UNESCO … to promote linguistic and cultural diversity and multilingualism/i. You may be aware of the issue from our recent post a href=”http://backreaction.blogspot.com/2009/02/what-is-world-coming-to.html”emWhat is the world coming to?/em/a.br /br /German radio added drama this morning a href=”http://www.wdr.de/themen/kultur/1/tag_der_muttersprache/2009/koelsch_090221.jhtml”by reporting/a that some German dialects such as Kölsch, Bairisch (Bavarian), and Letzeburgisch are in danger of extinction - a bit of an exaggeration, as you can check out on the “a href=”http://www.unesco.org/culture/ich/index.php?pg=00206″UNESCO Interactive Atlas of the World’s Languages in Danger/a” which lists eg Bavarian as merely “unsafe” (and let me tell you, if you don’t know Bavarian, it is definitely unsafe to use it).br /br /Anyway, our blog works quite well because we and you, dear readers and commenters, can communicate without major accidents in one common language, English (or so we hope). But this is not our native tongue, and maybe it isn’t yours either.br /br /Looking at the visitors statistics (see below) of Backreaction, it seems that more than 75% of all readers come from English-speaking countries - but this actually just reflects the “language settings” of the visiting web browsers. It doesn’t say necessarily much about the mother language of the real people using these browsers (Bee eg has her settings on US-English).br /br /a onblur=”try {parent.deselectBloggerImageGracefully();} catch(e) {}” href=”http://1.bp.blogspot.com/_6yQy29edf4Q/SaB3MmNwEWI/AAAAAAAAAEA/5QNJwOEzU1s/s1600-h/langcc.jpg”img id=”BLOGGER_PHOTO_ID_5305371419342803298″ style=”DISPLAY: block; MARGIN: 0px auto 10px; WIDTH: 400px; CURSOR: hand; HEIGHT: 227px; TEXT-ALIGN: center” alt=”" src=”http://1.bp.blogspot.com/_6yQy29edf4Q/SaB3MmNwEWI/AAAAAAAAAEA/5QNJwOEzU1s/s400/langcc.jpg” border=”0″ //abr /a onblur=”try {parent.deselectBloggerImageGracefully();} catch(e) {}” href=”http://3.bp.blogspot.com/_6yQy29edf4Q/SaB3idEH0QI/AAAAAAAAAEI/2sjscr1cTW4/s1600-h/languages.jpg”img id=”BLOGGER_PHOTO_ID_5305371794843619586″ style=”DISPLAY: block; MARGIN: 0px auto 10px; WIDTH: 320px; CURSOR: hand; HEIGHT: 254px; TEXT-ALIGN: center” alt=”" src=”http://3.bp.blogspot.com/_6yQy29edf4Q/SaB3idEH0QI/AAAAAAAAAEI/2sjscr1cTW4/s320/languages.jpg” border=”0″ //abr /br /So, to celebrate International Mother Language Day and to learn more about the background and diversity of our readers, we invite you to leave in the comments a few greetings in your actual mother tongue - and maybe you can add what language it actually is :-)br /blockquoteWillkommen bei “Backreaction” am Internationalen Tag der Muttersprache! Das ist heute die Gelegenheit, hier ein paar freundliche Worte in Eurer Muttersprache zu hinterlassen. Wir freuen uns auf Eure Kommentare!/blockquotebr /(Don’t understand German? Try the a href=”http://translate.google.com/translate?prev=hphl=enu=http%3A%2F%2Fbackreaction.blogspot.com%2F2009%2F02%2Finternational-mother-language-day.htmlsl=detl=en”translation by Google/a!)div class=”blogger-post-footer”"You do not really understand something unless you can explain it to your grandmother.” ~ Albert Einsteinimg width=’1′ height=’1′ src=’http://res1.blogblog.com/tracker/22973357-5993800011746878357?l=backreaction.blogspot.com’//div