All but one: the Greek world. Already in the classical era, the Greeks saw the Earth as a stone floating in space without falling (figure 1b). Beneath the Earth, there was neither more earth without limit, nor turtles, nor columns, but rather the same sky that we see over our heads. How did the Greeks manage to understand so early that the Earth is suspended in the void and that the Heavens continue under our feet? Who understood this and how?
The man who made this enormous leap in understanding the world is the main character in this story : ‘ Avačiμavôpoc , Anaximander , who lived twenty – six centuries ago in Miletus, a Greek city on the coast of what is now Turkey. This discovery alone would make Anaximander one of the intellectual giants of the ages. But Anaximander’s legacy is still greater. He paved the way for physics, geography, meteorology, and biology. Even more important than these contributions , he set in motion the process of rethinking our worldview – a search for knowledge based on the rejection of any obvious – seeming “certainty,” which is one of the main roots of scientific thinking.
Anaximander: And the Birth of Science
by Carlo Rovelli
Over two millennia ago, the prescient insights of Anaximander paved the way for cosmology, physics, geography, meteorology, and biology, setting in motion a new way of seeing the world. His legacy includes the revolutionary ideas that the Earth floats in a void, that animals evolved, that the world can be understood in natural rather than supernatural terms, and that universal laws govern all phenomena. He introduced a new mode of rational thinking with an openness to uncertainty and the progress of knowledge.
In this elegant work, the renowned theoretical physicist Carlo Rovelli brings to light the importance of Anaximander’s overlooked influence on modern science. He examines Anaximander not from the point of view of a historian or as an expert in Greek philosophy, but as a scientist interested in the deep nature of scientific thinking, which Rovelli locates in the critical and rebellious ability to reimagine the world again and again. Anaximander celebrates the radical lack of certainty that defines the scientific quest for knowledge.
(Google translate)
1 つを除くすべて: ギリシャの世界。 すでに古典時代に、ギリシャ人は地球を、落下することなく空間に浮いている石と見なしていました (図 1b)。 地球の下には、際限のない地球もカメも柱もありませんでしたが、私たちが頭上に見ているのと同じ空がありました. ギリシア人は、地球が空虚に浮遊し、天が私たちの足元に続いていることを、どのようにして早くから理解できたのでしょうか? 誰が、どのようにこれを理解したのでしょうか?
世界を理解する上でこの大きな飛躍を遂げた男が、この物語の主人公です。’Avačiμavôpoc、アナクシマンドロスは、現在のトルコの海岸にあるギリシャの都市ミレトスに 26 世紀前に住んでいました。 この発見だけでも、アナクシマンダーは時代を超えた知的巨人の 1 人になるでしょう。 しかし、アナクシマンダーの遺産はまだ大きいです。 彼は物理学、地理学、気象学、生物学への道を開きました。 これらの貢献よりもさらに重要なことに、彼は私たちの世界観を再考するプロセスを開始しました。これは、科学的思考の主要なルーツの 1 つである、明白に見える「確実性」の拒絶に基づく知識の探求です。
Carlo Rovelli
The Order of Time
時間は存在しない
http://www.kushima.org/?p=65321
**
Carlo Rovelli
Reality is Not What it Seems: The Journey to Quantum Gravity
世界は「関係」でできている: 美しくも過激な量子論
http://www.kushima.org/?p=67306
Carlo Rovelli
Wikipedia
Carlo Rovelli (born May 3, 1956) is an Italian theoretical physicist and writer who has worked in Italy, the United States and, since 2000, in France.[3] He is also currently a Distinguished Visiting Research Chair at the Perimeter Institute,[4] and core member of the Rotman Institute of Philosophy of Western University.[5]
He works mainly in the field of quantum gravity and is a founder of loop quantum gravity theory. He has also worked in the history and philosophy of science. He collaborates with several Italian newspapers, including the cultural supplements of the Corriere della Sera, Il Sole 24 Ore and La Repubblica.
His popular science book, Seven Brief Lessons on Physics, was originally published in Italian in 2014. It has been translated into 41 languages[6] and has sold over a million copies worldwide.[7] In 2019, he was included by Foreign Policy magazine in a list of 100 most influential global thinkers.[8]
Life and career
Carlo Rovelli was born in Verona, Italy, on 3 May 1956. He attended the Liceo Classico Scipione Maffei in Verona. In the 1970s, he participated in the student political movements in Italian universities. He was involved with the free political radio stations Radio Alice in Bologna and Radio Anguana in Verona, which he helped found.[9] In conjunction with his political activity, he was charged, but later released, for crimes of opinion related to the book Fatti Nostri, which he co-authored with Enrico Palandri, Maurizio Torrealta, and Claudio Piersanti.[10]
Rovelli has credited his use of LSD at this time with sparking his interest in theoretical physics, saying of his experience: “it was an extraordinarily strong experience that touched me also intellectually… Among the strange phenomena was the sense of time stopping. Things were happening in my mind but the clock was not going ahead; the flow of time was not passing any more… And I thought: ‘Well, it’s a chemical that is changing things in my brain. But how do I know that the usual perception is right, and this is wrong? If these two ways of perceiving are so different, what does it mean that one is the correct one?”[11]
In 1981, Rovelli graduated with a BS/MS in physics from the University of Bologna, and in 1986 he obtained his PhD at the University of Padova, Italy. Rovelli refused military service, which was compulsory in Italy at the time, and was therefore briefly detained in 1977.[12] He held postdoctoral positions at the University of Rome, the International School for Advanced Studies in Trieste, and Yale University. Rovelli was on the faculty of the University of Pittsburgh from 1990 to 2000,[13] where he was also affiliated with the Department of History and Philosophy of Science. Since 2000 he has been a professor at the Centre de Physique Théorique de Luminy of Aix-Marseille University in France.[14]
Main contributions
Loop quantum gravity
In 1988, Rovelli, Lee Smolin and Abhay Ashtekar introduced a theory of quantum gravity called loop quantum gravity. In 1995, Rovelli and Smolin obtained a basis of states of quantum gravity, labelled by Penrose‘s spin networks, and using this basis they were able to show that the theory predicts that area and volume are quantized. This result indicates the existence of a discrete structure of space on a very small scale. In 1997, Rovelli and Michael Reisenberger introduced a “sum over surfaces” formulation of the theory, which has since evolved into the currently covariant “spinfoam” version of loop quantum gravity. In 2008, in collaboration with Jonathan Engle and Roberto Pereira, he has introduced the spin foam vertex amplitude which is the basis of the current definition of the loop quantum gravity covariant dynamics. Loop theory is today considered a candidate for a quantum theory of gravity. It finds applications in quantum cosmology, spinfoam cosmology and quantum black hole physics.
Physics without time
In his 2004 book, Quantum Gravity, Rovelli developed a formulation of classical and quantum mechanics that does not make explicit reference to the notion of time. The first step towards a theory of quantum gravity without a time variable is described by Wheeler–DeWitt equation. The timeless formalism is used to describe the world in the regimes where the quantum properties of the gravitational field cannot be disregarded. This is because the quantum fluctuation of spacetime itself makes the notion of time unsuitable for writing physical laws in the conventional form of evolution laws in time.
This position led him to face the following problem: if time is not part of the fundamental theory of the world, then how does time emerge? In 1993, in collaboration with Alain Connes, Rovelli proposed a solution to this problem called the thermal time hypothesis. According to this hypothesis, time emerges only in a thermodynamic or statistical context. If this is correct, the flow of time is not fundamental, deriving from the incompleteness of knowledge. Similar conclusions had been reached earlier in the context of nonequilibrium statistical mechanics, in particular in the work of Robert Zwanzig, and in Caldeira-Leggett models used in quantum dissipation.[15][16]
Relational quantum mechanics
In 1994, Rovelli introduced the relational interpretation of quantum mechanics, based on the idea that the quantum state of a system must always be interpreted relative to another physical system (like the “velocity of an object” is always relative to another object, in classical mechanics). The idea has been developed and analyzed in particular by Bas van Fraassen[17] and by Michel Bitbol. Among other important consequences, it provides a solution of the EPR paradox that does not violate locality.[18]
Rovelli has expressed the main idea of relational quantum mechanics in the popular book Helgoland.
Relative information
Rovelli won the second prize in the 2013 FQXi contest “It From Bit or Bit From It?” for his essay about “relative information”. His paper, Relative Information at the Foundation of Physics, discusses how “Shannon’s notion of relative information between two physical systems can function as [a] foundation for statistical mechanics and quantum mechanics, without referring to subjectivism or idealism…[This approach can] represent a key missing element in the foundation of the naturalistic picture of the world.”[19] In 2017, Rovelli elaborated further upon the subject of relative information, writing that:
History and philosophy of science
Carlo Rovelli, Rome 2015
Rovelli has written a book on the Greek philosopher Anaximander, published in France, Italy, US[21] and Brazil. The book analyses the main aspects of scientific thinking and articulates Rovelli’s views on science. Anaximander is presented in the book as a main initiator of scientific thinking.
For Rovelli, science is a continuous process of exploring novel possible views of the world;[22] this happens via a “learned rebellion”, which always builds and relies on previous knowledge but at the same time continuously questions aspects of this received knowledge.[23] The foundation of science, therefore, is not certainty but the very opposite, a radical uncertainty about our own knowledge, or equivalently, an acute awareness of the extent of our ignorance.[23]
Religious views
Rovelli defines himself “serenely atheist”.[24] He discussed his religious views in several articles and in his book on Anaximander. He argues that the conflict between rational/scientific thinking and structured religion may find periods of truce (“there is no contradiction between solving Maxwell’s equations and believing that God created Heaven and Earth”),[25] but it is ultimately unsolvable because (most) religions demand the acceptance of some unquestionable truths while scientific thinking is based on the continuous questioning of any truth. Thus, for Rovelli, the source of the conflict is not the pretense of science to give answers – the universe, for Rovelli is full of mystery and a source of awe and emotions – but, on the contrary, the source of the conflict is the acceptance of our ignorance at the foundation of science, which clashes with religions’ pretense to be depositories of certain knowledge.[25]
Main awards
Popular culture
Books and articles
Rovelli has written more than 200 scientific articles published in international journals. He has published two monographs on loop quantum gravity and several popular science books. His book, Seven Brief Lessons on Physics, has been translated into 41 languages.
Scientific books
ISBN 0-521-83733-2
Popular books