Samstag, 15. Dezember 2018

Two styles of theorizing / Dirac:

From Eros to Gaia, 1992:

>To give to nonexperts a true impression of the Dirac style, it is best to use his own words. Here is Dirac, at the age of seventy, talking to a mixed audience at the University of Miami in Coral Gables. The title of his talk was “Basic Beliefs and Fundamental Research.”

There is one fairly obvious way of getting a new theory. Keep close to the experimental results, hear about all the latest information that the experimenters obtain, and then proceed to set up a theory to account for them. That is a more or less straightforward procedure and there are many physicists working on such lines, competing with one another, and it might develop somewhat into a rat-race. Of course it needs rather intelligent rats to take part in it. But I don’t want to speak about this method of procedure.

There is another way in which a theoretical physicist may work which is slower and more sedate and may lead to more profound results. It does not depend very closely on experimental work. This consists in having some basic beliefs and trying to incorporate them into one theory. Now why should one have basic beliefs? I don’t know that I can explain that. It’s just that one feels that nature is constructed in a certain way and one hangs onto the idea rather like one might hang onto a religious belief. One feels that things simply have to be on these lines and one must devise a mathematical theory for incorporating the basic belief.

These two styles of theorizing are well known in the history of science. Historians call the first style Baconian and the second Cartesian. Our young colleagues today, with less awareness of their place in history, are accustomed to call the two styles “bottom-up” and “top-down.” Dirac in his talk went on to explain how the very greatest theoretical physicists, in particular Newton and Einstein, worked from the top down, deducing laws of nature from fundamental beliefs rather than inducing laws from the results of experiment. Dirac himself is in modern times the supreme example of a top-down physicist. Here is what he says about himself:

"My own early work was very much influenced by Bohr orbits, and I had the basic belief that Bohr orbits would provide the clue to understanding atomic events. That was a mistaken belief.… I found out that my own basic belief was wrong and I had to go over to quite a new line of thinking. I had to have some more general basis for my work, and the only reliable basis I could think of, the only basis which was sufficiently general so as to secure me from making the same mistake again, was to set up a principle of mathematical beauty: to say that we don’t really know what the basic equations of physics are, but they have to have great mathematical beauty. We must insist on this, and that is the only feature of the equations that we can have confidence in and insist on.… How can one make beauty a fundamental test for the correctness of a physical theory? Well, it is quite clear that beauty does depend on one’s culture and upbringing for certain kinds of beauty, pictures, literature, poetry and so on.… But mathematical beauty is of rather a different kind. I should say perhaps it is of a completely different kind and transcends these personal factors. It is the same in all countries and at all periods of time.… Well, that is the essence of what I wanted to tell you. In fact one can feel so strongly about these things, that when an experimental result turns up which is not in agreement with one’s beliefs, one may perhaps make the prediction that the experimental result is wrong and that the experimenters will correct it after a while. Of course one must not be too obstinate over these matters, but still one must sometimes be bold."

Dirac was bold. His confidence in his own instinct for mathematical beauty led him in succession to three fundamental discoveries: first, the general abstract formulation of quantum mechanics; second, the correct quantum description of electromagnetic radiation processes; and third, the Dirac equation for the electron. In each case he was led not merely to a new physical law but to a new style of mathematical description of nature. And in each case the experiments proved him right, although, as he hints in the Coral Gables lecture, there were initially some contradictory experimental results which he was bold enough to ignore.

Dirac’s fundamental belief, the belief that the basic criterion for choosing a physical theory should be aesthetic, proved itself in his hands overwhelmingly successful. Nature agreed with his criterion. And this agreement between Nature’s and Dirac’s notions of beauty presents us with a new example of an old philosophical riddle. Why should Nature care about our feelings of beauty? Why should the electron prefer a beautiful equation to an ugly one? Why should the universe dance to Dirac’s tune? These are deep questions which neither scientists nor philosophers know how to answer. Dirac, by his style of discovery, has posed these questions more sharply than anyone else. More even than Newton and Einstein he used the criterion of beauty consciously and directly as a way of finding truth.<

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>In the history of science, from its beginnings to the present day, the Baconian and the Cartesian traditions have remained alive, Baconian science emphasizing empirical facts and details, Cartesian science emphasizing general ideas and principles. The healthy growth of science requires that both traditions be honored. Bacon without Descartes would reduce science to butterfly collecting; Descartes without Bacon would reduce science to pure mathematics.<

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>I have described the history of science as a dialogue between unifiers and diversifiers. Unifiers are following the tradition of Descartes, diversifiers are following the tradition of Bacon. Unifiers are trying to reduce the prodigality of nature to a few general laws and principles. Diversifiers are exploring the details of things and events in their infinite variety. Unifiers are in love with ideas and equations; diversifiers are in love with birds and butterflies. My friend and colleague, the physicist Chen Ning Yang, told me once that when he was a boy of six in China he looked up at the stars and asked what are the laws that make them move across the sky. But when I was a boy of six in England, I looked up at the stars and asked what are their names. Yang was interested in stars in general; I was interested in stars as individuals.<

Mittwoch, 12. Dezember 2018

Statusfrage:

"Wenn du es dir aussuchen könntest, würdest du dann gern in der Mitte der Gesellschaft, oder gern ganz, ganz oben stehen?"

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Ehe man die Frage beantwortet, ist es sicherlich spannend, Status erst einmal sehen zu lernen.

Sonntag, 9. Dezember 2018

Hubris:


"Hubris, Greek hybris, in ancient Athens, the intentional use of violence to humiliate or degrade. The word’s connotation changed over time, and hubris came to be defined as overweening presumption that leads a person to disregard the divinely fixed limits on human action in an ordered cosmos."

Narzissmus:

Wikipedia:

Der Psychiater und Neurowissenschaftler Raphael M. Bonelli kritisiert 2016 die theorielastige Narzissmusdiskussion des 20. Jahrhunderts und plädiert für ein naturwissenschaftliches Narzissmusverständnis unter Berücksichtigung empirischer Forschungsergebnisse. Für sein Modell des Narzissmus beruft er sich auf die neurobiologischen und genetischen Forschungen von Robert Cloninger, insbesondere die „drei Dimensionen des Charakters“ (Self-Directedness, Cooperativeness, Self-Transcendence). Narzissmus ist aus dieser Sicht gekennzeichnet durch den Dreischritt:

  • Selbstidealisierung – im Sinne eines überhöhten Selbstwertgefühls und einer überzogenen Selbsteinschätzung. Der Narzisst hat ein grandioses Verständnis der eigenen Wichtigkeit und glaubt von sich, „besonders“ und einzigartig zu sein.
  • Fremdabwertung – im Sinne einer Verachtung und aktiven Herabsetzung des anderen, das zu einer Kooperationsunfähigkeit führt. Der Narzisst zeigt deswegen eine Gier nach Bewunderung, legt ein Anspruchsdenken an den Tag, ist ausbeuterisch, unwillig zur Empathie, neidisch und arrogant.
  • Selbstimmanenz – als Gegensatz zur Selbsttranszendenz bei Victor Frankl und Robert Cloninger. Der Narzisst kann sich für kein höheres Ideal begeistern außer für sich selbst.

Samstag, 8. Dezember 2018

Kognitive Begabung:

"Eine Person ist 'intellektuell hochbegabt', wenn sie sich schnell und effektiv deklaratives und prozedurales Wissen aneignen kann, dieses Wissen in variierenden Situationen zur Lösung individuell neuer Probleme adäquat einsetzt, rasch aus den dabei gemachten Erfahrungen lernt und erkennt, auf welche neuen Situationen bzw. Problemstellungen die gewonnenen Erkenntnisse transferierbar sind (Generalisierung) und auf welche nicht (Differenzierung)."

Detlef Rost

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"Intelligentere haben im Vergleich zu weniger intelligenten Menschen in kumulativen Lernsequenzen unter vergleichbaren Zeit- und Instruktionsbedingungen mit einer gewissen Wahrscheinlichkeit in der Vergangenheit mehr und intelligenter organisiertes (tiefer verstandenes, vernetztes, multipel repräsentiertes und flexibel nutzbares) Wissen erworben. Diese bereichsspezifischen Vorkenntnisse erleichtern die darauf aufbauenden weiteren Lernprozesse."

Helmke & F. E. Weinert

Donnerstag, 6. Dezember 2018

Ein Vortrag als ein Gemisch von Bekanntem und Unbekanntem:

Damit ein Zuhörer von einem Vortrag besonders profitiert, muss der Vortrag für den Zuhörer eine sinnvolle Mischung an bekannten und  an unbekannten Elementen enthalten. 

Ein Thema wird manchmal erst dann interessant, wenn wir ein gewisses Anfangsinvestment an Zeit, Gedanken und Aufmerksamkeit erbracht haben. Von da an findet sich in den relevanten Texten zum Thema ausreichend Bekanntes, sodass wir diese mit Gewinn lesen können.

Mittwoch, 5. Dezember 2018

>I’ve created 365 Dilbert comics a year for 19 years. I remembered all of them for about the first four years. Now it is impossible. So I sit there for a few minutes rummaging through my memories and finding nothing but spider webs. At this point I will digress and give you my untested theory about creativity:

Creativity is highly correlated to poor memory.

For me, ideas stream through my head at a frantic pace. I feel like a bear trying to grab a salmon. If my paw misses its target, that salmon is gone for good. I don’t dwell on it. I just lunge for the next salmon. I think people who have fewer thoughts per hour have time to let them settle in and form memories. It’s just a theory.<

Scott Adams