- UID
- 604786
- 在线时间
- 小时
- 注册时间
- 2011-2-11
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
速度
For Now, the Eurozone and the Markets Pooh-pooh the Downgrades. But the Long-Term Looms
计时一
Modestly positive trading on European stock markets Monday morning appeared to confirm what euro zone leaders had predicted for weeks: that the decision Friday by Standard & Poor’s to cut the credit rating of nine European economies had been so fully expected by investors that it was destined to be greeted as old news when it actually happened. Yet if the supposedly ho-hum downgrade didn’t provoke a plunge across European bourses, it’s because markets were already well aware of the deeper, far longer-term concerns S& cited in announcing its move–and that the market was overlooking those for now to act on shorter-term outlooks. It probably means that worst difficulties probably await member governments in the weeks and months to come.
Probably the largest of those tests will be creating what markets and analysts demand most from the euro zone: true integration of the 17-member club into the united body it has long claimed it is. As my colleague Michael Schuman notes in his story today, “until the leaders of Europe find a way to share sacrifices and allocate losses, the debt crisis will continue to spiral downwards.” Only in that way, Michael stresses, can mutually binding policies and reforms—including sticks of deficit and debt reduction and carrots like competition and growth stimulus—be applied to what’s now a too radically diverse economic patchwork of strengths and weaknesses. Indeed, as the S& downgrade both highlights and accentuates, the euro right now is a lot like a locomotive pulling a string of first-, second-, third- and fourth-class three cars advancing at different speeds and lurching in divergent directions—and which could cause the entire train to derail if they aren’t brought quickly into greater alignment.
——284
计时二
Perhaps fittingly, European leaders responded to Friday’s S& downgrade with contrasting degrees of consternation. Though French officials had long said that retaining France’s triple-A rating was virtually a life-and-death matter, their comments over the weekend echoed the more recent phlegmatic change of tone. Several French cabinet members noted, for example, that the AA+ note Paris now shares with the U.S. is the next best thing to the lost top mark—and a drop in status that hasn’t led to the American government’s borrowing costs rising significantly. Some German officials reacted sternly by urging euro partners to pick up the pace of cost-cutting and reform, while others went the other way by joining European Union authorities in darkly questioning S&’s motives and bone fides to intervene as it did–and urging the EU to establish rating agencies of its own (and in so doing raising questions about the motives and bone fides of creating such outfits from the outset).
Similarly defensive and angry voices were heard elsewhere in Europe—some wondering why S& cut France’s rating when rival Moody’s decided Monday to stand pat with its AAA grade. Others questioned how S& could possibly downgrade French debt while preserving the UK’s triple-A rating. Some critics and pundits lashed out at S& with the claim that agencies and their ratings—which failed to see most of the major crises, market melt-downs, or bankruptcies of the past 10 years coming—simply don’t matter, and should be ignored. (This isn’t one of those, but is interesting on the topic of whether downgrades matter.)
——360
计时三
Though S&’s decision Friday was in many ways debatable (as have been its actions or failure to act in the past), it can also be said to formalize something that already existed within the euro zone: a hierarchical ranking of supposed equals. The cuts left only Finland, Luxembourg, the Netherlands and Germany with triple-A status (with the first three of those on negative watch), while France, Belgium, Austria and Estonia were all assigned to a second tier of relatively stable yet nevertheless subaltern grades. Below them come somewhat risky Italy, Malta, Slovenia, Spain, Slovakia and Ireland, followed by the junk domain of Portugal, Cyprus, and Greece. Whether that will result in an immediate and significant increase in debt financing costs for most demoted nations—i.e., above the rising rates that some like France were already being forced to pay on new bonds ahead of the downgrade—remains to be seen. Initial impact on looming French debt issues suggests that, if a spike comes, it won’t be immediate. However, the risk of that eventually transpiring is significant, especially as euro zone governments seek to raise over $40 billion in new loans from markets in 2012 as they roll over $1 trillion of debt–much of it in the first half of the year.
And that’s only one example of how a bite to one part of the euro zone often causes teeth marks to appear elsewhere in it. As dangerously stalled negotiations between Greece and creditor banks indicates, difficulties experienced in a weak section of the euro neighborhood will eventually be felt in even the stronger sections. For example, as the only euro heavyweight with all its force intact, Germany–with France downgraded–is having to weigh-in even harder to get a deal cut between Athens and its creditors—knowing the risk of a technical (or actual) Greek default could blow the single currency apart (and along with it, billions in German funds already pumped in to keep Athens propped up). Meanwhile, in the wake of the S& downgrade Berlin has also resigned itself to inject even more German money into the European Financial Stability Facility to compensate for what markets will now view as less stable funding pledged by downgraded partners.
——371
计时四
Germany shouldn’t expect gratitude for its efforts. To the contrary, many euro countries that have applied drastic austerity measures imposed by Berlin in exchange for bail-out money are openly complaining that the German obsession with cost-cutting utterly forgets the equally important funding of economic growth—a lack of attention that’s speeding the march of many euro economies into recession. As such, some commentators—including Michael Shuman in his story today–warn the German emphasis on debt reduction without attention to growth stimulus is actually worsening Europe’s wider economic situation.
That kind of criticism of Germany’s leadership in the crisis is bound to grow as economic activity slows further, market demands on new bond issues push financing costs to downgraded states ever higher, and looming national elections cause incumbent leaders to look for scapegoats abroad to blame their troubles on. The atmosphere in Europe won’t grow any happier, either, when (not if) officials elsewhere in recessionary euro nations offer their own form of schadenfreude at Germany’s export-driven economy grinding to a halt as consumer spending in its largest clients—i.e., other euro countries—dries up.
That scenario is exactly the opposite of what investors are looking for. Yes, they want debt and spending brought under control; but they also want clear signs of cohesive, intelligent, and efficient planning and policies applied across the entire euro zone as a means of creating a terrain conducive to significant and sustained economic growth. (The dirty secret is, markets don’t even care that much about sovereign debt levels so long as growth—and with it income states can generate from it—remains robust, and with it the profit outlook for companies and investors.) That requires a leveling of the euro zone economic, fiscal and labor playing field across the board in a way that both reflects and enhances true unity between members.
——307
S&’s decision Friday is a reflection that such unity doesn’t exist. Now it’s up to euro zone states themselves to decide whether that humbling serves as an excuse for why their common currency effort failed, or spurs them towards the sweeping measures required to save it.
计时五
War with Iran: A Conflict Obama Hopes to Avoid May Be Imposed on Him
It’s unlikely that President Barack Obama intends to go to the polls in November with the United States engaged in a hot war with Iran, but there is a growing danger that events could conspire to make the decision for him. The Wall Street Journal reported Friday that ”U.S. defense leaders are increasingly concerned that Israel is preparing to take military action against Iran, over U.S. objections, and have stepped up contingency planning to safeguard U.S. facilities in the region in case of a conflict.” Besides planning for the contingency of being dragged into a war started by Israel, the Journal reported that Administration officials from President Obama on down have urged their Israeli counterparts to refrain from unilateral military action. The Israeli response, says the paper, has been “non-committal.” Indeed, Joint Chiefs of Staff chairman Gen. Martin Dempsey is due to visit Israel on Thursday with the purpose, according to Israeli reports, of ascertaining Israel’s intentions.
The Iranians would likely hold the U.S. accountable for any Israeli military action, and any retaliation against U.S. assets (or even attacks on Israel) might prompt the U.S. to escalate the confrontation in order to disable Iran’s military capability — and perhaps strike at its nuclear program in the process. Israel’s leaders would certainly prefer the U.S. to do the job, because its capacity to sustain an air assault on Iran is far greater than Israel’s is. But Israeli leaders have long warned that should Washington fail to stop Iran’s nuclear progress, they might be compelled to take military action alone. Israeli media outlets reported Sunday that a massive joint exercise between the Israeli and U.S. military to simulate countering an Iranian missile attack on Israel will be postponed by Washington, in order to ease the dangerous level of tension that has built up with Tehran in recent weeks.
——306
越障
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity.[1] It is a contender for a theory of everything (TOE), a self-contained mathematical model that describes all fundamental forces and forms of matter.
String theory posits that the electrons and quarks within an atom are not 0-dimensional objects, but rather 1-dimensional oscillating lines ("strings"). The earliest string model, the bosonic string, incorporated only bosons, although this view developed to the superstring theory, which posits that a connection (a "supersymmetry") exists between bosons and fermions. String theories also require the existence of several extra, unobservable dimensions to the universe, in addition to the four known spacetime dimensions.
The theory has its origins in an effort to understand the strong force, the dual resonance model (1969). Subsequent to this, five different superstring theories were developed that incorporated fermions and possessed other properties necessary for a theory of everything. Since the mid-1990s, in particular due to insights from dualities shown to relate the five theories, an eleven-dimensional theory called M-theory is believed to encompass all of the previously-distinct superstring theories.
Many theoretical physicists (e.g., Stephen Hawking, Witten, Maldacena and Susskind) believe that string theory is a step toward the correct fundamental description of nature. This is because string theory allows for the consistent combination of quantum field theory and general relativity, agrees with general insights in quantum gravity (such as the holographic principle and Black hole thermodynamics), and because it has passed many non-trivial checks of its internal consistency.[2][3][4][5][unreliable source?] According to Hawking in particular, "M-theory is the only candidate for a complete theory of the universe."[6] Nevertheless, other physicists (e.g. Feynman and Glashow) have criticized string theory for not providing novel experimental predictions at accessible energy scales.[7][8]
Overview
String theory posits that the electrons and quarks within an atom are not 0-dimensional objects, but made up of 1-dimensional strings. These strings can oscillate, giving the observed particles their flavor, charge, mass and spin. Among the modes of oscillation of the string is a massless, spin-two state -- a graviton. The existence of this graviton state and the fact that the equations describing string theory include Einstein's equations for general relativity mean that string theory is a quantum theory of gravity. Since string theory is widely believed[9] to be mathematically consistent, many hope that it fully describes our universe, making it a theory of everything. String theory is known to contain configurations that describe all the observed fundamental forces and matter but with a zero cosmological constant and some new fields.[10] Other configurations have different values of the cosmological constant, and are metastable but long-lived. This leads many to believe that there is at least one metastable solution that is quantitatively identical with the standard model, with a small cosmological constant, containing dark matter and a plausible mechanism for cosmic inflation. It is not yet known whether string theory has such a solution, nor how much freedom the theory allows to choose the details.
String theories also include objects other than strings, called branes. The word brane, derived from "membrane", refers to a variety of interrelated objects, such as D-branes, black p-branes and Neveu–Schwarz 5-branes. These are extended objects that are charged sources for differential form generalizations of the vector potential electromagnetic field. These objects are related to one another by a variety of dualities. Black hole-like black p-branes are identified with D-branes, which are endpoints for strings, and this identification is called Gauge-gravity duality. Research on this equivalence has led to new insights on quantum chromodynamics, the fundamental theory of the strong nuclear force.[11][12][13][14] The strings make closed loops unless they encounter D-branes, where they can open up into 1-dimensional lines. The endpoints of the string cannot break off the D-brane, but they can slide around on it.
The full theory does not yet have a satisfactory definition in all circumstances, since the scattering of strings is most straightforwardly defined by a perturbation theory. The complete quantum mechanics of high dimensional branes is not easily defined, and the behavior of string theory in cosmological settings (time-dependent backgrounds) is not fully worked out. It is also not clear as to whether there is any principle by which string theory selects its vacuum state, the spacetime configuration that determines the properties of our universe (see string theory landscape).
Basic properties
String theory can be formulated in terms of an action principle, either the Nambu-Goto action or the Polyakov action, which describe how strings propagate through space and time. In the absence of external interactions, string dynamics are governed by tension and kinetic energy, which combine to produce oscillations. The quantum mechanics of strings implies these oscillations exist in discrete vibrational modes, the spectrum of the theory.
On distance scales larger than the string radius, each oscillation mode behaves as a different species of particle, with its mass, spin and charge determined by the string's dynamics. Splitting and recombination of strings correspond to particle emission and absorption, giving rise to the interactions between particles. An analogy for strings' modes of vibration is a guitar string's production of multiple but distinct musical notes. In the analogy, different notes correspond to different particles. One difference is the guitar string exists in 3 dimensions, so that there are only two dimensions transverse to the string. Fundamental strings exist in 9 dimensions and the strings can vibrate in any direction, meaning that the spectrum of vibrational modes is much richer.
String theory includes both open strings, which have two distinct endpoints, and closed strings making a complete loop. The two types of string behave in slightly different ways, yielding two different spectra. For example, in most string theories one of the closed string modes is the graviton, and one of the open string modes is the photon. Because the two ends of an open string can always meet and connect, forming a closed string, there are no string theories without closed strings.
The earliest string model, the bosonic string, incorporated only bosonic degrees of freedom. This model describes, in low enough energies, a quantum gravity theory, which also includes (if open strings are incorporated as well) gauge fields such as the photon (or, in more general terms, any gauge theory). However, this model has problems. What is most significant is that the theory has a fundamental instability, believed to result in the decay (at least partially) of spacetime itself. In addition, as the name implies, the spectrum of particles contains only bosons, particles which, like the photon, obey particular rules of behavior. In broad terms, bosons are the constituents of radiation, but not of matter, which is made of fermions. Investigating how a string theory may include fermions in its spectrum led to the invention of supersymmetry, a mathematical relation between bosons and fermions. String theories that include fermionic vibrations are now known as superstring theories; several different kinds have been described, but all are now thought to be different limits of M-theory.
Some qualitative properties of quantum strings can be understood in a fairly simple fashion. For example, quantum strings have tension, much like regular strings made of twine; this tension is considered a fundamental parameter of the theory. The tension of a quantum string is closely related to its size. Consider a closed loop of string, left to move through space without external forces. Its tension will tend to contract it into a smaller and smaller loop. Classical intuition suggests that it might shrink to a single point, but this would violate Heisenberg's uncertainty principle. The characteristic size of the string loop will be a balance between the tension force, acting to make it small, and the uncertainty effect, which keeps it "stretched". As a consequence, the minimum size of a string is related to the string tension. |
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2012-1-17 22:12:31
收藏
收藏
