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Posts Tagged ‘Physics

“The Universe is under no obligation to make sense to you”*…

 

bubble

Uppsala University researchers have devised a new model for the Universe – one that may solve the enigma of dark energy. Their new article, published in Physical Review Letters, proposes a new structural concept, including dark energy, for a universe that rides on an expanding bubble in an additional dimension.

We have known for the past 20 years that the Universe is expanding at an ever accelerating rate. The explanation is the “dark energy” that permeates it throughout, pushing it to expand. Understanding the nature of this dark energy is one of the paramount enigmas of fundamental physics.

It has long been hoped that string theory will provide the answer. According to string theory, all matter consists of tiny, vibrating “stringlike” entities. The theory also requires there to be more spatial dimensions than the three that are already part of everyday knowledge. For 15 years, there have been models in string theory that have been thought to give rise to dark energy. However, these have come in for increasingly harsh criticism, and several researchers are now asserting that none of the models proposed to date are workable.

In their article, the scientists propose a new model with dark energy and our Universe riding on an expanding bubble in an extra dimension. The whole Universe is accommodated on the edge of this expanding bubble. All existing matter in the Universe corresponds to the ends of strings that extend out into the extra dimension. The researchers also show that expanding bubbles of this kind can come into existence within the framework of string theory. It is conceivable that there are more bubbles than ours, corresponding to other universes.

The Uppsala scientists’ model provides a new, different picture of the creation and future fate of the Universe, while it may also pave the way for methods of testing string theory…

Via AAAS Eureka Alerts

(For a different emerging new theory– that may or may not be contradictory– see “Our universe has antimatter partner on the other side of the Big Bang.”)

* Neil deGrasse Tyson

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As we fumble with the fundamentals, we might send carefully-deduced birthday greetings to Richard Bevan Braithwaite; he was born on this date in 1900.  A Cambridge philosopher who specialized in the philosophy of science, he focused on the logical features common to all sciences.  Braithwaite was concerned with the impact of science on our beliefs about the world and the appropriate responses to that impact.  He was especially interested in probability (and its applications in decision theory and games theory) and in the statistical sciences.  He was president of the Aristotelian Society from 1946 to 1947, and was a Fellow of the British Academy.

It was Braithwaite’s poker that Ludwig Wittgenstein reportedly brandished at Karl Popper during their confrontation at a Moral Sciences Club meeting in Braithwaite’s rooms in King’s. The implement subsequently disappeared. (See here.)

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Written by LW

January 15, 2019 at 1:01 am

“I see the beard and cloak, but I don’t yet see a philosopher”*…

 

beards

Victorian taste-maker Thomas Gowing:

The Beard, combining beauty with utility, was intended to impart manly grace and free finish to the male face. To its picturesqueness, Poets and Painters, the most competent judges, have borne universal testimony. It is indeed impossible to view a series of bearded portraits, however indifferently executed, without feeling that they possess dignity, gravity, freedom, vigor, and completeness; while in looking on a row of razored faces, however illustrious the originals, or skillful the artists, a sense of artificial conventional bareness is experienced…

More from Gowing’s masterwork, The Philosophy of Beards, at “The argument we need for the universal wearing of beards.”

* Aulus Gellius

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As we let ’em grow, we might send carefully-calculated birthday greetings to Vladimir Andreevich Steklov; he was born on this date in 1864.  An important Russian mathematician and physicist, he made important contributions to set theory, hydrodynamics, and the theory of elasticity, and wrote widely on the history of science.  But he is probably best remembered as the honored namesake of the Russian Institute of Physics and Mathematics (for which he was the original petitioner); its math department is now known as the Steklov Institute of Mathematics.

220px-steklov source

 

Written by LW

January 9, 2019 at 1:01 am

“Humanize your talk, and speak to be understood”*…

 

violet_personified

Personification is weird…yet entirely natural. It’s the odd practice of pretending things are people. When we personify, we apply human attributes to inanimate objects, to nature, to animals, or to abstract concepts, sometimes complete with dramatic stories about their social roles, emotions and intentions. We can observe this linguistically through features like unexpected pronoun use or certain animate verbs and adjectives that are usually only applied to people. A common example is how ships and other vessels traditionally have a feminine gender in English (even if the ship happens to be a “man-of-war“)… There’s a strange empathy in words like “she is alone” applied to an object that can’t possibly have a sense of loneliness. This isn’t the artifice of poetry, but everyday language. On the face of it, the concept of personification seems pretty crazy, the stuff of fantasy and magical thinking…

You might think, like many a respectable scientist, that it has no place in our earth logic, because not only is it not real, it is objectively false (and therefore unscientific), since inanimate objects do not have feelings or intentions (and if animals do, we can’t possibly know for sure). Yet personification is not only wildly popular in language use (even if we don’t always notice it), it’s a fascinating psychological phenomenon that reveals a lot about social cognition and how we might understand the world…

How the way we talk about the things around us both shapes and reflects our understanding of the world: “Personification Is Your Friend: The Language of Inanimate Objects.”

* Moliere

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As we muse on anthropomorphic metaphor and meaning, we might recall that today’s a relative-ly good day for it, as it was on this date in 1900 that German physicist Max Planck presented and published his study of the effect of radiation on a “black-body” substance (introducing what we’ve come to know as the Planck Postulate), and the quantum theory of modern physics– and for that matter, Twentieth Century modernity– were born.

Planck study demonstrated that in certain situations energy exhibits the characteristics of physical matter– something unthinkable at the time– and suggested that energy exists in discrete packets, which he called “quanta”… thus laying the foundation on which he, Einstein, Bohr, Schrodinger, Dirac, and others built our modern understanding.

220px-Max_Planck_1933Max Planck

 

Written by LW

December 14, 2018 at 1:01 am

“As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.”*…

 

quantum computing

Quantum computing is all the rage. It seems like hardly a day goes by without some news outlet describing the extraordinary things this technology promises. Most commentators forget, or just gloss over, the fact that people have been working on quantum computing for decades—and without any practical results to show for it.

We’ve been told that quantum computers could “provide breakthroughs in many disciplines, including materials and drug discovery, the optimization of complex manmade systems, and artificial intelligence.” We’ve been assured that quantum computers will “forever alter our economic, industrial, academic, and societal landscape.” We’ve even been told that “the encryption that protects the world’s most sensitive data may soon be broken” by quantum computers. It has gotten to the point where many researchers in various fields of physics feel obliged to justify whatever work they are doing by claiming that it has some relevance to quantum computing.

Meanwhile, government research agencies, academic departments (many of them funded by government agencies), and corporate laboratories are spending billions of dollars a year developing quantum computers. On Wall Street, Morgan Stanley and other financial giants expect quantum computing to mature soon and are keen to figure out how this technology can help them.

It’s become something of a self-perpetuating arms race, with many organizations seemingly staying in the race if only to avoid being left behind. Some of the world’s top technical talent, at places like Google, IBM, and Microsoft, are working hard, and with lavish resources in state-of-the-art laboratories, to realize their vision of a quantum-computing future.

In light of all this, it’s natural to wonder: When will useful quantum computers be constructed? The most optimistic experts estimate it will take 5 to 10 years. More cautious ones predict 20 to 30 years. (Similar predictions have been voiced, by the way, for the last 20 years.) I belong to a tiny minority that answers, “Not in the foreseeable future.” Having spent decades conducting research in quantum and condensed-matter physics, I’ve developed my very pessimistic view. It’s based on an understanding of the gargantuan technical challenges that would have to be overcome to ever make quantum computing work…

Michel Dyakonov makes “The Case Against Quantum Computing.”

* Albert Einstein

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As we feel the need for speed, we might recall that it was on this date in 1942 that a team of scientists led by Enrico Fermi, working inside an enormous tent on a squash court under the stands of the University of Chicago’s Stagg Field, achieved the first controlled nuclear fission chain reaction… laying the foundation for the atomic bomb and later, nuclear power generation.

“…the Italian Navigator has just landed in the New World…”
– Coded telephone message confirming first self-sustaining nuclear chain reaction, December 2, 1942.

Illustration depicting the scene on Dec. 2, 1942 (Photo copyright of Chicago Historical Society)

source

Indeed, exactly 15 years later, on this date in 1957, the world’s first full-scale atomic electric power plant devoted exclusively to peacetime uses, the Shippingport Atomic Power Station, reached criticality; the first power was produced 16 days later, after engineers integrated the generator into the distribution grid of Duquesne Light Company.

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Written by LW

December 2, 2018 at 1:01 am

“A measurement is not an absolute thing, but only relates one entity to another”*…

 

kilogram

 

Until now, [the mass of the kilogram] has been defined by the granddaddy of all kilos: a golf ball-sized metal cylinder locked in a vault in France [a replica of which is pictured above]. For more than a century, it has been the one true kilogram upon which all others were based…

Made of a corrosion-resistant alloy of 90 percent platinum and 10 percent iridium , the international prototype kilo has rarely seen the light of day. Yet its role has been crucial, as the foundation for the globally accepted system for measuring mass upon which things like international trade depend.

Three different keys, kept in separate locations, are required to unlock the vault where the Grand K and six official copies — collectively known as ‘‘the heir and the spares’’ — are entombed together under glass bell-jars at the International Bureau of Weights and Measures, in Sevres on the western outskirts of Paris.

Founded by 17 nations in 1875 and known by its French initials, the BIPM is the guardian of the seven main units humanity uses to measure its world : the meter for length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the mole for the amount of a substance and the candela for luminous intensity.

Of the seven, the kilo is the last still based on a physical artifact, the Grand K. The meter, for example, used to be a meter-long metal bar but is now defined as the length that light travels in a vacuum in 1/299,792,458th of a second…

The metal kilo is being replaced by a definition based on Planck’s constant, which is part of one of the most celebrated equations in physics but also devilishly difficult to explain . Suffice to say that the update should, in time, spare nations the need to occasionally send their kilos back to Sevres for calibration against the Grand K. Scientists instead should be able to accurately calculate an exact kilo, without having to measure one precious lump of metal against another…

More of this weighty story at “The kilogram is changing. Weight, what?

* H.T. Pledge, Science since 1500

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As we muse on measurement, we might send well-calibrated birthday greetings to August Kundt; he was born on this date in 1839.  An astronomer-turned-physicist, he developed a method to measure the velocity of sound in gases and solids using a closed glass tube (now known as a Kundt’s Tube).

AugustKundt source

We might also spare a thought for another physicist, Niels Bohr; he died on this date in 1962.  A Danish physicist and philosopher, Bohr was the first to apply quantum theory to the problem of atomic and molecular structure, creating the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete, and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another– a model the underlying principles of which remain valid.  And he developed the principle of complementarity: that items could be separately analyzed in terms of contradictory properties, e.g., particles behaving as a wave or a stream. His foundational contributions to understanding atomic structure and quantum theory won him the Nobel Prize in Physics in 1922.

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“The information revolution came without an instruction manual”*…

 

Machines

In my graduate seminar we’ve recently been thinking a bit about machines. Given that our focus has been on the 19th Century, attention has been directed toward ergodic machines (from the root ergon meaning work). Ergodic machines are machines that run on heat and energy. Such machines are essentially mechanical in nature. They deal with basic physical mechanics like levers and pulleys, and questions of mass, weight, and counter-balance. Ergodic machines adhere to the laws of motion and inertia, the conservation of energy, and the laws of thermodynamics governing heat, pressure, and energy…

Still, ergodic machines do not account for all machines. Informatic machines, those devices dominating contemporary life, have in many ways taken over from their 19th-century counterparts. Informatic machines have physical bodies, of course, and they frequently require electricity or other forms of power to operate. However the essence of the informatic machine is not found in motion, unrest, heat, or energy. The essence of the informatic machine is found in form, not energy or presence. From the perspective of philosophy, computers are therefore quite classical, even conservative. They follow that most basic law of Western idealism, that the formal determines the physical

The anti-computer has yet to be invented. But traces of it are found everywhere. Even Bitcoin, that most miserable invention, relies on an anti-computational infrastructure. In order to mine coins, one must expend energy. Hence these twenty-first-century machines are yoked to a nineteenth-century mandate: burn fuel to release value. Bitcoin may run on a computer but it is anti-computational at heart. Bitcoin only works because it is grounded in an anti-computer (energy). It is thus a digital machine made subsidiary to an analog foundation, a twenty-first-century future tied to a nineteenth-century past.

The encryption algorithms at the heart of Bitcoin are anti-computational as well. Cryptography deploys form as a weapon against form. Such is the magic of encryption. Encryption is a kind of structure that makes life difficult for other competing structures. Encryption does not promote frictionlessness, on the contrary it produces full and complete friction at all levels. Not the quotidian friction of everyday life, but a radical friction frustrating all expression. What used to be a marginal activity practiced by hackers — cracking password hashes — is now the basis of an entire infrastructure. Earn a buck by cracking hashes using “brute force.” Turn your computer into an anti-computer.

A friend of Marshall McLuhan’s, Father John Culkin, SJ, a Professor of Communication at Fordham University, observed that “we shape our tools and then our tools shape us” (though the quote is often attributed to McLuhan, who may in fact have inspired it).   Alexander R. Galloway ponders the tools that dominate our lives these days: “Anti-Computer.”

* “The central paradox of the machines that have made our lives so much brighter, quicker, longer and healthier is that they cannot teach us how to make the best use of them; the information revolution came without an instruction manual”  — Pico Iyer

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As we muse on machines, we might spare a thought for James Clerk Maxwell; he died on this date in 1879.  a mathematician and and physicist, his work in uniting electricity, magnetism, and light– that’s to say, formulating the classical theory of electromagnetic radiation— is considered the “second great unification in physics” (after the first, realized by Isaac Newton), and laid the foundation for modern physics, starting the search for radio waves and paving the way for such fields as special relativity and quantum mechanics.  In the millennium poll – a survey of the 100 most prominent physicists at the turn of the 21st century – Maxwell was voted the third greatest physicist of all time, behind only Newton and Einstein.

225px-James_Clerk_Maxwell source

 

Written by LW

November 5, 2018 at 2:01 am

“If you think this Universe is bad, you should see some of the others”*…

 

copernicus

FIRST OF FOUR?: The first Copernican revolution moved the Earth out of the center of the solar system. The second recognized that there are many planets in our galaxy, and the third that there are many galaxies in the observable universe. Proving that our universe is one among many would represent a fourth Copernican revolution.

 

A challenge for 21st-century physics is to answer two questions. First, are there many “big bangs” rather than just one? Second—and this is even more interesting—if there are many, are they all governed by the same physics?

If we’re in a multiverse, it would imply a fourth and grandest Copernican revolution; we’ve had the Copernican revolution itself, then the realization that there are billions of planetary systems in our galaxy; then that there are billions of galaxies in our observable universe. But now that’s not all. The entire panorama that astronomers can observe could be a tiny part of the aftermath of “our” big bang, which is itself just one bang among a perhaps infinite ensemble.

At first sight, the concept of parallel universes might seem too arcane to have any practical impact. But it may (in one of its variants) actually offer the prospect of an entirely new kind of computer: the quantum computer, which can transcend the limits of even the fastest digital processor by, in effect, sharing the computational burden among a near infinity of parallel universes…

Cambridge physicist and Astronomer Royal Martin Rees suspects that our universe is one island in an archipelago: “The Fourth Copernican Revolution.”

* Philip K. Dick

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As we find our place, we might recall that it was on this date in 1884 that 41 delegates from 25 nations, meeting in Washington, DC for the International Meridian Conference, adopted Greenwich as the universal meridian.  They also established that all longitude would be calculated both east and west from this meridian up to 180°.

PrimeMeridianThm source

 

Written by LW

October 13, 2018 at 1:01 am

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