Daily Archives: July 7, 2022

Carbon-based nanomaterials such as carbon nanotubes (CNTs), fullerenes, and graphene receive a great deal of attention today due to their unique physical properties. A new study explores the potential of hybrid nanostructures and introduces a new porous graphene CNT hybrid structure with remarkable thermal and mechanical properties.

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The study shows how the remarkable characteristics of novel graphene CNT hybrid structures could be modified by slightly changing the inherent geometric arrangement of CNTs and graphene, plus various filler agents.

The ability to accurately control thermal conductivity and mechanical strength in the graphene CNT hybrid structures make them a potentially suitable candidate for various application areas, especially in advanced aerospace manufacturing where weight and strength are critical.

Carbon nanostructures and hybrids of multiple carbon nanostructures have been examined recently as potential candidates for numerous sensing, photovoltaic, antibacterial, energy storage, fuel cell, and environmental improvement applications.

The most prominent carbon-based nanostructures in the research appear to be CNTs, graphene, and fullerene. These structures exhibit unique thermal, mechanical, electronic, and biological properties due to their extremely small size.

Structures that measure in the sub-nanometer range behave according to the peculiar laws of quantum physics, and so they can be used to exploit nonintuitive phenomena such as quantum tunneling, quantum superposition, and quantum entanglement.

CNTs are tubes made out of carbon and that measure only a few nanometers across in diameter. CNTs display notable electrical conductivity, and some are semiconductor materials.

CNTs also have great tensile strength and thermal conductivity due to their nanostructure, and the strength of covalent bonds formed between carbon atoms.

CNTs are potentially valuable materials for electronics, optics, and composite materials, where they may replace carbon fibers in the next few years. Nanotechnology and materials science also use CNTs in research.

Graphene is a carbon allotrope that is shaped into a single layer of carbon atoms arranged in a two-dimensional lattice structure composed of hexagonal shapes. Graphene was first isolated in a series of groundbreaking experiments byUniversity of Manchester, UK, scientists Andrew Geim and Konstantin Novoselov in 2004, earning them the Nobel Prize for Physics in 2010.

In the few decades since then, graphene has become a useful nanomaterial with exceptionally high tensile strength, transparency, and electrical conductivity leading to numerous and varied applications in electronics, sensing, and other advanced technologies.

A fullerene is another carbon allotrope that has been known for some time. Its molecule consists of carbon atoms that are connected by single and double bonds to form a mesh, which can be closed or partially closed. The mesh is fused with rings of five, six, or seven atoms.

Fullerene molecules can be hollow spheres, ellipsoids, tubes, or a number of other shapes and sizes. Graphene could be considered an extreme member of the fullerene family, although it is considered a member of its own material class.

As well as a great deal of research invested into understanding and characterizing these carbon nanostructures in isolation, scientists are also exploring the properties of hybrid nanostructures that combine two or more nanostructure elements into one material.

For example, foam materials have adjustable properties that make them suitable for practical applications like sandwich structure design, biocompatibility design, and high strength and low weight structure design.

Carbon-based nanofoams have been utilized in medicine as well, examining bone injuries as well as acting as the base for replacement bone tissue.

Carbon-based cellular structures are produced both with chemical vapor deposition (CVD) and solution processing. Spark plasma sintering (SPS) methods are also implemented for using graphene for biological and medical applications.

As a result, scientists have been looking at ways to make three-dimensional carbon foams structurally stable. Research suggests that stable junctions between different types of structures (CNTs, fullerene, and graphene) need to be formed for this material to be stable enough for extensive application.

New research from mechanical engineers at Turkeys Istanbul Technical University introduces a new hybrid nanostructure formed through chemical bonding.

The porous graphene CNT structures were made by organizing graphene around CNTs in nanoribbons. The different geometrical arrangement of graphene nanoribbon layers around CNTs (square, hexagon, and diamond patterns) led to different physical properties being observed in the material, suggesting that this geometric rearrangement could be used to fine-tune the new structure.

The study was published in the journal Physica E: Low-dimensional Systems and Nanostructures in 2022.

Researchers found that the structures with fullerenes inserted, for example, exhibited significant compressive stability and strength without sacrificing tensile strength. The geometric arrangement of carbon nanostructures also had a significant effect on their thermal properties.

Researchers said that these new hybrid nanostructures present important advantages, especially for the aerospace industry. Nanoarchitectures with these hybrid structures may also be utilized in hydrogen storage and nanoelectronics.

Belkin, A., A. Hubler, and A. Bezryadin (2015). Self-Assembled Wiggling Nano-Structures and the Principle of Maximum Entropy Production. Scientific Reports. doi.org/10.1038/srep08323

Degirmenci, U., and M. Kirca (2022). Carbon-based nano lattice hybrid structures: Mechanical and thermal properties. Physica E: Low-dimensional Systems and Nanostructures. doi.org/10.1016/j.physe.2022.115392

Geim, A.K. (2009). Graphene: Status and Prospects. Science. /doi.org/10.1126/science.1158877

Geim, A.K., and K.S. Novoselov (2007). The rise of graphene. Nature Materials. doi.org/10.1038/nmat1849

Monthioux, M., and V.L. Kuznetsov (2006). Who should be given the credit for the discovery of carbon nanotubes? Carbon. doi.org/10.1016/j.carbon.2006.03.019

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Notable Thermal and Mechanical Properties of New Hybrid Nanostructures - AZoM

Physics is upheld by two pillars: the physics of relativity and quantum mechanics. Relativity, which was first proposed by Albert Einstein. It explains the universe on its largest scales, such as gravity and the speed of light. Quantum mechanics is the very opposite, being the science of the smallest scales, such as atoms and subatomic particles. Together, relativity and quantum mechanics can explain the very large and the very small. However, despite both upholding all of what we know about physics, relativity and quantum mechanics dont work well together. In fact, scientists have been unable to combine the two theories into a single, unified theory of everything.

Relativity and quantum mechanics are like a dog and a cat constantly fighting, unable to find any compromise. It may not seem overly important to combine the two pillars of physics into one. After all, separately, relativity and quantum mechanics can explain most of the universe. However, having two separate laws that govern the universe has its problems.

For example, imagine there were two types of streets, and the type defines the rules of driving. Some streets have either one type or the other, so the rules are pretty simple. However, other streets fit the definition of both types, so which driving rules apply to them? Like having two completely different rules of the road, the inability to combine quantum mechanics and relativity creates chaos when trying to understand our universe. Interestingly, there are some potential theories out there that combine the two pillars of physics, the most famous of which is string theory.

According to string theory, if you were to look inside any fundamental particle, such as an electron, you would find a tiny vibrating string of energy. When the string vibrates, the energy it generates creates a particle such as an electron. In string theory, fundamental particles can be thought of as energy vibrations. Furthermore, string theory predicts the existence of eleven dimensions. The reason we dont see these dimensions in our everyday lives is because theyre simply too small to detect. However, the extra dimensions play a vital role. The configuration of the dimensions determines how a string vibrates, and hence what particle is made. The strings vibrate in eleven dimensions, and the frequency at which the string vibrates is dependent upon how the string is oriented within the eleven dimensions. Different frequencies of vibrations generate different particles.

The reason why string theory is a potential theory of everything is because it predicts that all forms of matter are made up of strings, and thus everything is really made up of the same stuff. Whether its the gravitational force or the electromagnetic force, all of it relates back to vibrating strings. It should be noted, however, that no evidence has been found to support string theory. None of its predictions have been verified through either experiment or observation. As of yet, its more of a mathematical theory rather than one of physics.

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What Is String Theory? - Worldatlas.com

Q. Can you give some examples from the book of the lessons that a catastrophe can teach about the future, and about how to live and face death?

A. Jack and I have spent our lives reading, teaching, and writing about religion, philosophy, and art. In our conversation in the book, we explore the lessons of two major themesdeath and friendshipthat great writers and artists of the past can offer us today.

Suffering life-threatening disease is a humbling experience that reminds you how fragile life is. Acknowledging this vulnerability and accepting deaths inevitability can be liberating, and it opens you to empathetic relationships with other people.

Genuine friendship is a rare gift. Isolation and solitude are not the sameisolation separates, solitude connects. Though often alone and separated by a continent during those long months, our epistolary conversation deepened our friendship.

Q. Do things seem less bleak now than they didwhile you were working on the book?

A. Though we knew the pandemic would be devastating, we never anticipated that many millions of people globally would contract the disease, and over one million would die in the U.S. This virus is smart and adapts to human intervention faster than humans adapt to it. We started writing about a biological virus, but quickly realized that the body politic and global media are also infected with deadly viruses. The different strains of these viruses are co-evolving at an accelerating rate. Given the political paralysis in this country, and the growing instability of the global financial and political situation, things are so much worse now that it is hard to be hopeful. Hopelessness, however, is a luxury we cannot afford.

Q. What have you read lately that you would recommend, and why?

A. Suzanne Simards Finding the Mother Tree: Discovering the Wisdom of the Forest is a well-researched book about plant intelligence that makes you rethink the relationship between human beings and the natural world.

Lee Smolin, Time Reborn: From the Crisis in Physics to the Future of the Universe. A provocative reinterpretation of the most fundamental dimension of life.

Matt Haig, The Midnight Library. An inventive novel of regrets framed in terms of quantum physics and multiple worlds theory.

Q. What's on your night stand now?

A. Since I tend to read all day every day, I dont keep books on my night stand, but the books beside my desk are: Carlo Rovelli, Reality Is Not What It Seems: The Journey to Quantum Gravity; David Kaiser, How the Hippies Saved Physics; and a novel, Olga Ravns The Employees.

Q. What do you read when you're working on a book, and what kind of reading do you avoid while writing?

A. After months, sometimes years, of reading, I will suddenly see the book; its a strange experience. At that point, a book more or less writes itself. When in this zone, I read nothing else because reading more can break my rhythm and make me lose the thread.

Q. Any interesting summer plans?

A. I live in the Berkshire Mountains of Massachusetts. This summer I am looking forward to a welcome relief from COVID summersmy children and grandchildren will be returning home. In addition, I have created a philosophical sculpture garden, which requires lots of work. I am beginning the design of a new sculpture.

Q. You're hosting a dinner party. Which three academics or scholars, dead or alive, would you invite, and why?

A. If I could time travel, I would return to Jena in Germany on New Years Eve 1803, and throw a dinner party for Immanuel Kant, Johann Wolfgang von Goethe, Friedrich Schiller, Friedrich Schelling, Caroline Schelling, Friedrich Schleiermacher, Friedrich Holderlin, Alexander von Humboldt, the Schlegel brothers, Dorothea von Schlegel, and, above all, G.W.F. Hegel.

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Two Professors Embarked on an Extended Conversation During the Pandemic - Columbia University

An excerpt from Chomsky and Moros new book The Secrets of Words.

By: Noam Chomsky and Andrea Moro

In their new book The Secrets of Words, influential linguist Noam Chomsky and his longtime colleague Andrea Moro have a wide-ranging conversation, touching on such topics as language and linguistics, the history of science, and the relation between language and the brain. Moro draws Chomsky out on todays misplaced euphoria about artificial intelligence (Chomsky sees lots of hype and propaganda coming from Silicon Valley), the study of the brain (Chomsky points out that findings from brain studies in the 1950s never made it into that eras psychology), and language acquisition by children. Chomsky in turn invites Moro to describe his own experiments, which proved that there exist impossible languages for the brain, languages that show surprising properties and reveal unexpected secrets of the human mind.

Chomsky once said, It is important to learn to be surprised by simple facts an expression of yours that has represented a fundamental turning point in my own personal life, says Moro. This is something of a theme in The Secrets of Words. Another theme, explored in the excerpt from the book featured below, is that not everything can be known; there may be permanent mysteries, about language and other matters.

Andrea Moro: There is something you wrote, back when you gave the Managua Lectures, and actually you rephrased it in a very articulated fashion in the talk you gave at the Vatican. It is an expression of yours that has represented a fundamental turning point in my own personal life, but also I am sure for all the students who heard it. You once said: It is important to learn to be surprised by simple facts. Considering it carefully and analyzing it word by word, this sentence contains at least four different foci, so to speak: first, it makes note of the importance of the thought expressed (it is important); second, it refers to a learning process, an effort rather than to a personal inherited talent (to learn), and by doing so it emphasizes the importance of the responsibility to teach; third, it refers to the sense of wonder and curiosity as the very engine of discovery, and to an awareness of the complexity of the world that is, an observation that goes back to Plato and the origin of philosophy (to be surprised); finally, fourth, arguably the most striking and innovative observation, it states that simple facts make a difference (by simple facts).

The sudden awareness of something that calls for an explanation, once the fog of habit has lifted, seems to be the real stuff revolutions sparkles are made of: from Newtons legendary falling apple to Einsteins elevator, from Plancks black body problem to Mendels pea plants, the real force comes from asking questions about what all of a sudden doesnt seem to be obvious. Of course, it could be that one is exposed to a certain fact by chance, but, as Pasteur once put it, In the fields of observation chance favors only the prepared mind, and this is why we need to learn how to be surprised.

Actually, certain simple facts can be visible to the minds eye rather than to our direct vision. Owen Gingerich once made me realize how Galileo reached the conclusion that all bodies fall to the Earth at the same speed even if they have different weight, besides the obvious restrictions due to their shape: Galileo never amused himself by throwing objects from the Tower of Pisa. Instead, he reflected that if a heavy object fell faster than a light one, then when the two objects are tied together we would face a paradox: The lighter object should slow down the heavier one, but together they should fall faster since their total weight is greater than that of the heavier object on its own. Galileo, surprised by this simple mental fact, came to the fundamental conclusion that the only possibility is that these two objects had to fall at the same speed and then, generalizing it, that all objects fall at the same speed (disregarding friction with the air due to their shape). And this without having to climb the tower other than to enjoy the panorama.

The sudden awareness of something that calls for an explanation, once the fog of habit has lifted, seems to be the real stuff revolutions sparkles are made of.

And the second thing I would like to highlight from your synthesis: At a certain point you said that it is impossible to build a machine that talks. Obviously, I cannot but agree, but theres one important thing that I want to emphasize: There is a fundamental distinction between simulating and comprehending the functioning (of a brain but also of any other organ or capacity). It is, of course, very useful to have tools, which we can interact with by speaking, but it is certainly clear that those simulations cannot be used to understand what really goes on in the brain of a child when they grow and acquire their grammar. Of course, we can always stretch words so that they become felicitous to mean something different from what they used to mean. This reminds me of the answer Alan Turing gave to those who repeatedly asked him if one day machines could think. We can read his own words and substitute think with talk, which I think leaves the essence of Turings idea valid:

I propose to consider the question, Can machines think? This should begin with definitions of the meaning of the terms machine and think. The definitions might be framed so as to reflect so far as possible the normal use of the words, but this attitude is dangerous. If the meaning of the words machine and think are to be found by examining how they are commonly used it is difficult to escape the conclusion that the meaning and the answer to the question, Can machines think? is to be sought in a statistical survey such as a Gallup poll. But this is absurd. . . . The original question, Can machines think? I believe to be too meaningless to deserve discussion. Nevertheless I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking without expecting to be contradicted.

There is one question I would like to ask you. The way that you have depicted the relationship between chemistry and physics in the history of science allows us to reflect on the relationship between linguistics and neuroscience. My personal view, which doesnt count, obviously [laughs], and which is why I want to ask you, is that linguistics cannot be, must not be ancillary to what we currently know about our brain; but if anything, we have to change and grow toward, perhaps, a unification provided that we dare to use the term mystery in the way that you used it. In other words, it is not out of the question that humans may never end up understanding creativity in language, namely the capacity to express a verbal thought independently of ones physical environment. Indeed, it could well be that we must just stop short of the boundaries of Babel, that is, the limits of variation that may affect human languages as given independently of experience. Equivalently, one could consider the boundaries of Babel as the infants stem mind, or stem brain, that is, the potentiality to acquire any language within a certain amount of time since birth. The discovery of this amazing link between language structure and the brain is so revolutionary that it can be expressed by reversing the 2,000-year-old traditional perspective and arriving at the surprising conclusion that its flesh that became logos, not vice versa. I would like you to comment a little on this.

Noam Chomsky: Im kind of a minority. The two of us are a minority. [Moro laughs.] There may indeed be a mystery. Lets take a look at, say, rats, or some other organism. You can train a rat to run pretty complicated mazes. Youre never going to train a rat to run a prime number maze a maze that says, turn right at every prime number. The reason is that the rat just doesnt have that concept. And theres no way to give it that concept. Its out of the conceptual range of the rat. Thats true of every organism. Why shouldnt it be true of us? I mean, are we some kind of angels? Why shouldnt we have the same basic nature as other organisms? In fact, its very hard to think how we cannot be like them. Take our physical capacities. I mean, take our capacity to run 100 meters. We have that capacity because we cannot fly. The ability to do something entails the lack of ability to do something else. I mean, we have the ability because we are somehow constructed so that we can do it. But that same design thats enabling us to do one thing is preventing us from doing something else. Thats true of every domain of existence. Why shouldnt it be true of cognition? Were capable of developing humans, not me humans are capable of developing, say, advanced quantum theory, based on certain properties of their mind, and those very same properties may be preventing them from doing something else. In fact, I think we have examples of this; plausible examples. Take the crucial moment in science when scientists abandoned the hope for getting to an intelligible world. That was discussed at the time.

It is not out of the question that humans may never end up understanding creativity in language.

David Hume, a great philosopher, in his History of England he wrote a huge history of England theres a chapter devoted to Isaac Newton, a full chapter. He describes Newton as, you know, the greatest mind that ever existed, and so on and so forth. He said Newtons great achievement was to draw the veil away from some of the mysteries of nature namely, his theory of universal gravitation and so on but to leave other mysteries hidden in ways we will never understand. Referring to: Whats the world like? Well never understand it. He left that as a permanent mystery. Well, as far as we know, he was right.

And there are other perhaps permanent mysteries. So, for example, Descartes, and others, when they were considering that mind is separate from body notice that that theory fell apart because the theory of body was wrong; but the theory of mind may well have been right. But one of the things that they were concerned with was voluntary action. You decide to lift your finger. Nobody knows how that is possible; to this day we havent a clue. The scientists who work on voluntary motion one of them is Emilio Bizzi, hes one of MITs great scientists, one of the leading scientists who works on voluntary motion he and his associate Robert Ajemian recently wrote a state-of-the-art article for the journal of the American Academy of Arts and Sciences in which they describe what has been discovered about voluntary motion. They say theyll put the outcome fancifully. Its as if were coming to understand the puppet and the strings, but we know nothing about the puppeteer. That remains as much a mystery as it has been since classical Greece. Not an inch of progress; nothing. Well, maybe thats another permanent mystery.

There are a lot of arguments saying, Oh, it cant be true. Everythings deterministic, and so on. All sorts of claims. Nobody truly believes it, including those who present reasons (two thermostats might be hooked up to interact, but they dont take the trouble to work out reasons). Science doesnt tell us anything about it. Science tells us it doesnt fall within science, as currently understood. Science deals with things that are determined or random. That was understood in the 17th century. Its still true today. You have a science of events that are random, of things that are determined; you have no science of voluntary action. Just as you have no science of the creativity of language. Similar thing. Are they permanent mysteries? Could be. Could be that its just something that well never comprehend.

Something similar might hold for some aspects of consciousness. What does it mean for me to look at the background that I see here and see something red? Whats my feeling of red? You can describe what the sensory organs are doing, whats going on in the brain, but it doesnt capture the essence of seeing something red. Will we ever capture it? Maybe not. Its just something thats beyond our cognitive capacities. But that shouldnt really surprise us; we are organic creatures. Its a possibility.

So maybe the best that we can do is what science did after Newton: Construct intelligible theories. Try to construct the best theory we can about consciousness or voluntary action or the creative use of language, or whatever were talking about. The miracle that so amazed Galileo and Arnauld and still amazes me, I cant understand it how can we, with a few symbols, convey to others the inner workings of our mind? Thats something to really be surprised about, and puzzled by. And we have some grasp of it, but not a lot.

When I started working on the history of linguistics which had been totally forgotten; nobody knew about it I discovered all sorts of things. One of the things I came across was Wilhelm von Humboldts very interesting work. One part of it that has since become famous is his statement that language makes infinite use of finite means. Its often thought that we have answered that question with Turing computability and generative grammar, but we havent. He was talking about infinite use, not the generative capacity. Yes, we can understand the generation of the expressions that we use, but we dont understand how we use them. Why do we decide to say this and not something else? In our normal interactions, why do we convey the inner workings of our minds to others in a particular way? Nobody understands that. So, the infinite use of language remains a mystery, as it always has. Humboldts aphorism is constantly quoted, but the depth of the problem it formulates is not always recognized.

Noam Chomsky is Institute Professor and Professor of Linguistics Emeritus at MIT and Laureate Professor in the Department of Linguistics at the University of Arizona, where he is also the Agnese Nelms Haury Chair in the Agnese Nelms Haury Program in Environment and Social Justice. He is the author of many influential books on linguistics, including Aspects of the Theory of Syntax and The Minimalist Program.

Andrea Moro is Professor of General Linguistics at the Institute for Advanced Study (IUSS) in Pavia, Italy. He is the author of Impossible Languages, The Boundaries of Babel, A Brief History of the Verb To Be, and other books.

Chomsky and Moro are co-authors of The Secrets of Words, from which this article is excerpted.

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Noam Chomsky and Andrea Moro on the Limits of Our Comprehension - The MIT Press Reader