PLato said,"Look to the perfection of the heavens for truth," while Aristotle said "look around you at what is, if you would know the truth" To Remember: Eskesthai
After almost a century of observations, the ultra-high energy sky has finally displayed an anisotropic distribution. A significant correlation between the arrival directions of ultra-high cosmic rays measured by the Pierre Auger Observatory and the distribution of nearby active galactic nuclei signals the dawn of particle astronomy. These historic results have important implications to both astrophysics and particle physics.
It is known that geometry assumes, as things given, both the notion of space and the first principles of constructions in space. She gives definitions of them which are merely nominal, while the true determinations appear in the form of axioms. The relation of these assumptions remains consequently in darkness; we neither perceive whether and how far their connection is necessary, nor a priori, whether it is possible.
From Euclid to Legendre (to name the most famous of modern reforming geometers) this darkness was cleared up neither by mathematicians nor by such philosophers as concerned themselves with it. The reason of this is doubtless that the general notion of multiply extended magnitudes (in which space-magnitudes are included) remained entirely unworked. I have in the first place, therefore, set myself the task of constructing the notion of a multiply extended magnitude out of general notions of magnitude. It will follow from this that a multiply extended magnitude is capable of different measure-relations, and consequently that space is only a particular case of a triply extended magnitude. But hence flows as a necessary consequence that the propositions of geometry cannot be derived from general notions of magnitude, but that the properties which distinguish space from other conceivable triply extended magnitudes are only to be deduced from experience. Thus arises the problem, to discover the simplest matters of fact from which the measure-relations of space may be determined; a problem which from the nature of the case is not completely determinate, since there may be several systems of matters of fact which suffice to determine the measure-relations of space - the most important system for our present purpose being that which Euclid has laid down as a foundation. These matters of fact are - like all matters of fact - not necessary, but only of empirical certainty; they are hypotheses. We may therefore investigate their probability, which within the limits of observation is of course very great, and inquire about the justice of their extension beyond the limits of observation, on the side both of the infinitely great and of the infinitely small.
Zurich, 14 October 1913
Highly esteemed colleague,
a simple theoretical consideration makes it plausible to assume that light rays will experience a deviation in a gravitational field.
[Grav. field] [Light ray]
At the rim of the Sun, this deflection should amount to 0.84" and decrease as 1/R (R = [strike]Sonnenradius[/strike] distance from the centre of the Sun).
[Earth] [Sun]
Thus, it would be of utter interest to know up to which proximity to the Sun bright fixed stars can be seen using the strongest magnification in plain daylight (without eclipse).
Bending light around a massive object from a distant source. The orange arrows show the apparent position of the background source. The white arrows show the path of the light from the true position of the source.The fact that this does not happen when gravitational lensing applies is due to the distinction between the straight lines imagined by Euclidean intuition and the geodesics of space-time. In fact, just as distances and lengths in special relativity can be defined in terms of the motion of electromagnetic radiation in a vacuum, so can the notion of a straight geodesic in general relativity.
I attach special importance to the view of geometry which I have just set forth, because without it I should have been unable to formulate the theory of relativity. ... In a system of reference rotating relatively to an inert system, the laws of disposition of rigid bodies do not correspond to the rules of Euclidean geometry on account of the Lorentz contraction; thus if we admit non-inert systems we must abandon Euclidean geometry. ... If we deny the relation between the body of axiomatic Euclidean geometry and the practically-rigid body of reality, we readily arrive at the following view, which was entertained by that acute and profound thinker, H. Poincare:--Euclidean geometry is distinguished above all other imaginable axiomatic geometries by its simplicity. Now since axiomatic geometry by itself contains no assertions as to the reality which can be experienced, but can do so only in combination with physical laws, it should be possible and reasonable ... to retain Euclidean geometry. For if contradictions between theory and experience manifest themselves, we should rather decide to change physical laws than to change axiomatic Euclidean geometry. If we deny the relation between the practically-rigid body and geometry, we shall indeed not easily free ourselves from the convention that Euclidean geometry is to be retained as the simplest. (33-4)
I want to understand what makes the world tick. Einstein said he wanted to know what was on God's mind when he made the world. I don't think he was a religious man, but I know what he means.Lenny Susskind
Pierre de Fermat IPA: [pjɛːʁ dəfɛʁ'ma] (August 17, 1601 – January 12, 1665)"A gambler's dispute in 1654 led to the creation of a mathematical theory of probability by two famous French mathematicians, Blaise Pascal and Pierre de Fermat. Antoine Gombaud, Chevalier de Méré, a French nobleman with an interest in gaming and gambling questions, called Pascal's attention to an apparent contradiction concerning a popular dice game. The game consisted in throwing a pair of dice 24 times; the problem was to decide whether or not to bet even money on the occurrence of at least one "double six" during the 24 throws. A seemingly well-established gambling rule led de Méré to believe that betting on a double six in 24 throws would be profitable, but his own calculations indicated just the opposite.
Using the laser altimeter, MESSENGER will verify the presence of a liquid outer core in Mercury by measuring the planet's libration. Libration is the slow 88-day wobble of the planet around its rotational axis.
More recently, Earth-based radar observations of Mercury have also determined that at least a portion of the large metal core is still liquid to this day! Having at least a partially molten core means that a very small but detectable variation in the spin-rate of Mercury has a larger amplitude because of decoupling between the solid mantle and liquid core. Knowing that the core has not completely solidified, even as Mercury has cooled over billions of years since its formation, places important constraints on the thermal history, evolution, and core composition of the planet.
This MESSENGER image was taken from a distance of about 18,000 kilometers (11,000 miles) from the surface of Mercury, at 20:03 UTC, about 58 minutes after the closest approach point of the flyby. The region shown is about 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image.
But the truth is, the Earth's topography is highly variable with mountains, valleys, plains, and deep ocean trenches. As a consequence of this variable topography, the density of Earth's surface varies. These fluctuations in density cause slight variations in the gravity field, which, remarkably, GRACE can detect from space. 
Fig. 1. Story line showing the principle of least action sandwiched between relativity and quantum mechanics See A call to actionIt could be the weirdest and most embarrassing prediction in the history of cosmology, if not science.
If true, it would mean that you yourself reading this article are more likely to be some momentary fluctuation in a field of matter and energy out in space than a person with a real past born through billions of years of evolution in an orderly star-spangled cosmos. Your memories and the world you think you see around you are illusions.
Source: Sean Carroll, California Institute of TechnologyIn equilibrium, the entropy of the system cannot increase (because it is already at a maximum) and it cannot decrease (because that would violate the second law of thermodynamics). The only changes allowed are those in which the entropy remains constant.
Jules Henri Poincare (1854-1912)The scientist does not study nature because it is useful. He studies it because he delights in it, and he delights in it because it is beautiful.
Since we are assuming at this juncture the point of view of the mathematician, we must give to this concept all the precision that it requires, even if it becomes necessary to use mathematical language. We should then say that the body of laws is equivalent to a system of differential equations which link the speed of variations of the different elements of the universe to the present values of these elements.
Such a system involves, as we know, an infinite number of solutions, But if we take the initial values of all the elements, that is,their values at the instant t =(which would correspond in ordinary language to the "present"), the solution is completely determined, so that we can calculate the values of all the elements at any period
whatever, whether we suppose />0, which corresponds to the "future," or whether we suppose t<0, which corresponds to the "past." What is important to remember is that the manner of inferring the past from the present does not differ from that of inferring the future from the present.
Even among supportive publishers, there is a fear that the transition to open access could be rough, and might even put them out of business.
Illustration by Sandbox StudioForget about paying for journal subscriptions. If a new proposal takes hold, particle physics journals would get their funding from labs, libraries, and agencies that sponsor research, and readers could peruse them for free.
The Open Access (OA) tenets of granting unrestricted access to the results of publicly-funded research are in contrast with current models of scientific publishing, where access is restricted to journal customers. At the same time, subscription costs increase and add considerable strain on libraries, forced to cancel an increasing number of journals subscriptions. This situation is particularly acute in fields like High-Energy Physics (HEP), where pre-prints describing scientific results are timely available online. There is a growing concern within the academic community that the future of high-quality journals, and the peer-review system they administer, is at risk.
To address this situation for HEP and, as an experiment, Science at large, a new model for OA publishing has emerged: SCOAP3 (Sponsoring Consortium for Open Access Publishing in Particle Physics). In this model, HEP funding agencies and libraries, which today purchase journal subscriptions to implicitly support the peer-review service, federate to explicitly cover its cost, while publishers make the electronic versions of their journals free to read. Authors are not directly charged to publish their articles OA.
SCOAP3 will, for the first time, link quality and price, stimulating competition and enabling considerable medium- and long-term savings. Today, most publishers quote a price in the range of 1’000–2’000 Euros per published article. On this basis, we estimate that the annual budget for the transition of HEP publishing to OA would amount to a maximum of 10 Million Euros/year, sensibly lower than the estimated global expenditure in subscription to HEP journals.
Each SCOAP3 partner will finance its contribution by canceling journal subscriptions. Each country will contribute according to its share of HEP publishing. The transition to OA will be facilitated by the fact that the large majority of HEP articles are published in just six peer-reviewed journals. Of course, the SCOAP3 model is open to any, present or future, high-quality HEP journal, aiming for a dynamic market with healthy competition and a broader choice.
HEP funding agencies and libraries are currently signing Expressions of Interest for the financial backing of the consortium. A tendering procedure will then take place. Provided that SCOAP3 funding partners are ready to engage in long-term commitments, many publishers are expected to be ready to enter into negotiations.
The example of SCOAP3 could be rapidly followed by other fields, directly related to HEP, such as nuclear physics or astro-particle physics, or similarly compact and organized with a reasonable number of journals.
For example, theory says that Higgs particles are matter particles, but in most respects the Higgs behaves more like a new force than like a particle. How can this be? In truth, the Higgs is neither matter nor force; the Higgs is just different.
A least-square fit to a number of precisely known data in electroweak physics using the Standard Model as theoretical framework and the Higgs mass as a free parameter yields an expectation value for the Higgs mass around the minimum of the parabola. [Source: Precision Electroweak Measurements and Constraints on the Standard Model by the LEP Collaborations and the LEP Electroweak Working Group, arXiv: 0712.0929v2, Figure 5.]See Backreaction for explanation. The Higgs Mass
At 9:07 AM, January 05, 2008, Anonymous a quantum diaries survivor said...
Hi Stefan,
I wish to pay a tribute to your nice post here and answer the question you pose about the counter-intuitive trend of discovery reach at the LHC versus Higgs mass (for a given integrated luminosity), waiting for Michael's posts on the Higgs.
The problem is that as the Higgs mass changes, the mixture of possible final states it decays into changes dramatically. So, while at 160 GeV the Higgs is best sought in its decay to a pair of real W bosons (which weigh 80 GeV each), and in that case backgrounds are small because the signature is very distinctive, at 115 GeV the Higgs mostly decays to a pair of b-quark jets. Seeing a bump in the jet-jet mass distribution is utterly out of the question because in that case backgrounds are HUGE. So one has to rely on very rare decays such as H->gamma gamma - which still is plagued by large backgrounds.
The Higgs search is not one, but ten different analyses, depending on the unknown parameter M_h. Each analysis has its own problems. The higher the Higgs mass, the smaller the number of produced events; but as M_h changes, the signature varies from invisible to highly distinctive. Above 180 GeV, a Higgs can be seen with no trouble in the ZZ final state, when four muons are a gold-plated signature. It is not by chance that CMS was originally conceived as a compact muon solenoid: muons are all you need, at high mass, for the Higgs.
Cheers,
T.
In a nutshell, what Karim showed was that each time a memory is used, it has to be restored as a new memory in order to be accessible later. The old memory is either not there or is inaccessible. In short, your memory about something is only as good as your last memory about it. Joseph LeDoux
This all has a purpose for me, in that what can be changed according to what our previous assessment was based upon “while remembering.” What it can do to help “readjust our views” based on what we first felt impressed upon us “in reflection?”
Neuroscientist, New York University; Author, The Synaptic SelfLike many scientists in the field of memory, I used to think that a memory is something stored in the brain and then accessed when used. Then, in 2000, a researcher in my lab, Karim Nader, did an experiment that convinced me, and many others, that our usual way of thinking was wrong. In a nutshell, what Karim showed was that each time a memory is used, it has to be restored as a new memory in order to be accessible later. The old memory is either not there or is inaccessible. In short, your memory about something is only as good as your last memory about it. This is why people who witness crimes testify about what they read in the paper rather than what they witnessed. Research on this topic, called reconsolidation, has become the basis of a possible treatment for post-traumatic stress disorder, drug addiction, and any other disorder that is based on learning.
"If it was a consistent effort on your part how would it be any different then remembering what happened yesterday? Depends on “what you want to remember?”
I still find “the change” intriguing and how it would change “current thinking?”
Psychology professor Karim Nader is helping sufferers of post-traumatic stress disorder lessen debilitating symptoms—and in some cases, regain a normal life.Owen Egan See also: The Trauma TamerIC: Why is this research so important?
Karim Nader: There are a lot of implications. All psychopathological disorders, such as PTSD, epilepsy, obsessive compulsive disorders, or addiction—all these things have to do with your brain getting rewired in a way that is malfunctioning. Theoretically, we may be able to treat a lot of these psychopathologies. If you could block the re-storage of the circuit that causes the obsessive compulsion, then you might be able to reset a person to a level where they aren’t so obsessive. Or perhaps you can reset the circuit that has undergone epilepsy repeatedly so that you can increase the threshold for seizures. And there is some killer data showing that it’s possible to block the reconsolidation of drug cravings.
The other reason why I think it is so striking is that it is so contrary to what has been the accepted view of memory for so long in the mainstream. My research caused everybody in the field to stop, turn around and go, “Whoa, where’d that come from?” Nobody’s really working on this issue, and the only reason I came up with this is because I wasn’t trained in memory. [Nader was originally researching fear.] It really caused a fundamental reconceptualization of a very basic and dogmatic field in neuroscience, which is very exciting. It is the first time in 100 years that people are starting to come up with new models of memory at the physiological level.
