Archive for the ‘Physics’ Category

Lockheed-Martin and compact fusion – a long way away but more credible than the E-Cat cold-fusion hype

October 21, 2014

Andrea Rossi and his E-Cat cold fusion claims still smell like a fraud. It has been hyped for over 4 years now with little to show. I am somewhat surprised that there are still a few gullible academics and journalists around who keep the circus going.

The Lockheed-Martin development of a compact fusion reactor has a long way to go but I find it much more credible. I could consider betting some money on the compact fusion reactor but would not touch the E-Cat with a very, very, long barge pole.

Th availability of a fusion reactor of any kind would revolutionise the availability of electrical energy but always subject to cost. Mere availability would not be enough to cause a paradigm shift. The availability of gas (natural gas, shale gas and gas from methane hydrates) now extends to about 1,000 years. The use of gas turbine combined-cycle power plants, which have a 2 year construction period, will provide the cost benchmark for electricity production. Where fusion might place in the power generation mix will depend on its operating cost but the level to which it may penetrate will depend on the capital cost and the construction time.

A compact reactor as envisaged by Lockheed- Martin however would be a game changer not only for electricity generation but also for desalination, electrical vehicles and even space travel. The beauty of “compact” if achieved is that it “automatically” leads to low-cost and modular construction.

The probablity of success in the time-frame envisagesd is still low. It is a high risk development and it will not be cheap. But the potential reward is immense.

Some of the characteristics of their high-beta, compact reactor are:

  • The device is cylindrical and 2×2×4 meters in size.
  • The magnetic field increases the farther out that the plasma goes, which pushes the plasma back in.
  • It also has very few open field lines (very few paths for the plasma to leak out; uses a cylinder, not a Tokamak ring).
  • Very good arch curvature of the field lines.
  • The system has a beta of about 1.
  • This system uses deuterium and tritium.
  • The system heats the plasma using radio waves.

L-M Press Release: 

PALMDALE, Calif., Oct. 15, 2014 – The Lockheed Martin [NYSE: LMT] Skunk Works® team is working on a new compact fusion reactor (CFR) that can be developed and deployed in as little as ten years. Currently, there are several patents pending that cover their approach.

While fusion itself is not new, the Skunk Works has built on more than 60 years of fusion research and investment to develop an approach that offers a significant reduction in size compared to mainstream efforts.

“Our compact fusion concept combines several alternative magnetic confinement approaches, taking the best parts of each, and offers a 90 percent size reduction over previous concepts,” said Tom McGuire, compact fusion lead for the Skunk Works’ Revolutionary Technology Programs. “The smaller size will allow us to design, build and test the CFR in less than a year.”

After completing several of these design-build-test cycles, the team anticipates being able to produce a prototype in five years. As they gain confidence and progress technically with each experiment, they will also be searching for partners to help further the technology.

 

Physics Nobel goes blue

October 7, 2014

LEDsuperbright.com

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2014 to

Isamu Akasaki
Meijo University, Nagoya, Japan and Nagoya University, Japan

Hiroshi Amano
Nagoya University, Japan

and

Shuji Nakamura
University of California, Santa Barbara, CA, USA

“for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources”

PRESS RELEASE

Gravitation could just as well be called “magical attraction”

October 1, 2014

We don’t know how the four fundamental forces of nature are communicated. We explain the actions at a distance they give rise to by defining new words. We might as well just use the word “magic”.

We may like to think of ourselves as being very modern, very scientific, very rational without having – or needing – any recourse to mystical powers. Yet there is much where we don’t know what we don’t know. We use the forces  of gravitation and magnetism and can even calculate their magnitude but are no closer to knowing why they exist and how they are communicated. We have theories as to why they exist and how they work but these theories require that we define new, abstract/imaginary concepts of space-time and curvature of space. Gravitation fields and electromagnetic fields cause motion at a distance but where we don’t know how the forces bringing about such motion are communicated. We have no idea why gravity fields apparently propagate at (or, some say, greater than) the speed of light. We invent particles with magical properties but without any real understanding why such magical properties may exist. But our invocation of curvature  in space or virtual photons or up-quarks or down-quarks is no different to the ancients invoking magic and communicated through the aether. The rubber sheet analogy for curved spacetime is flawed in that it only works because gravity magic already exists and keeps the bodies attached to the top of the stretched rubber sheet.

Wherever we have forces acting at a distance we can just as well use the word “magic” instead of any of the other words we imagine. Inventing a massless graviton is merely invoking magic. We could just as well refer to gravitation as attraction magic and electromagnetic interaction as electromagic. And all the various magics are just natural.

For example, here is the Wikipedia entry for Gravitation where the words gravitation, gravity and other fundamental forces have been replaced by “magic” or “magical forces”.

Attraction magic is a natural phenomenon by which all physical bodies attract each other. Magical attraction gives weight to physical objects and causes them to fall toward the ground when dropped.

In modern physics, attraction magic is most accurately described by the general theory of relativity (proposed by Einstein) which describes attraction magic as a consequence of the curvature of spacetime. For most situations magical attraction is well approximated by Newton’s law of universal attraction magic, which postulates that the magical attraction force of two bodies of mass is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

In pursuit of a theory of everything, the merging of general relativity and quantum mechanics (or quantum field theory) into a more general theory of quantum magical attraction has become an area of active research. It is hypothesised that the magical attraction force is mediated by a massless spin-2 particle called the graviton, and that magical attraction would have separated from the electromagic force during the grand unification epoch.

Magical attraction is the weakest of the four fundamental magic forces of nature. The attraction magical force is approximately 10−38  times the strength of the strong magic force (i.e., magical attraction is 38 orders of magnitude weaker), 10−36  times the strength of the electromagical force, and 10−29  times the strength of the weak magic force. As a consequence, magical attraction has a negligible influence on the behavior of sub-atomic particles, and plays no role in determining the internal properties of everyday matter. On the other hand, magical attraction is the dominant force at the macroscopic scale, that is the cause of the formation, shape, and trajectory (orbit) of astronomical bodies, including those of asteroids, comets, planets, stars, and galaxies. It is responsible for causing the Earth and the other planets to orbit the Sun; for causing the Moon to orbit the Earth; for the formation of tides; for natural convection, by which fluid flow occurs under the influence of a density gradient and magical attraction; for heating the interiors of forming stars and planets to very high temperatures; for solar system, galaxy, stellar formation and evolution; and for various other phenomena observed on Earth and throughout the universe. This is the case for several reasons: magical attraction is the only force acting on all particles with mass; it has an infinite range; it is always attractive and never repulsive; and it cannot be absorbed, transformed, or shielded against. Even though electromagic is far stronger than magical attraction, electromagic is not relevant to astronomical objects, since such bodies have an equal number of protons and electrons that cancel out (i.e., a net electromagic charge of zero).

Sounds fine and sufficiently unintelligible/magical to me.

Physics still contains a lot of magic.

No black holes, no Big Bang would leave the universe without a beginning

September 30, 2014

There is now a mathematical proof that black holes cannot exist. Event horizons and singularities then also cannot exist. Without singularities being possible there could have been no Big Bang. And without a Big Bang, the “age” of the universe has no meaning. Where does that leave time? and space-time?

(And without a Big Bang I will have to revisit my view of stasis since my own little speculation is that while time periods – Δt – can be conceived of, time itself – t- is nothing other than an axis of change connecting states of stasis.)

Black Hole star eater – National Geographic

If the mathematics holds up then not only science but also science fiction will have to look for new concepts of space and space-time and pathways to different universes and worm-holes and warp-speeds.

PhysOrg: … By merging two seemingly conflicting theories, Laura Mersini-Houghton, a physics professor at UNC-Chapel Hill in the College of Arts and Sciences, has proven, mathematically, that can never come into being in the first place. The work not only forces scientists to reimagine the fabric of space-time, but also rethink the origins of the universe. ……

The reason black holes are so bizarre is that it pits two fundamental theories of the universe against each other. Einstein’s theory of gravity predicts the formation of black holes but a fundamental law of quantum theory states that no information from the universe can ever disappear. Efforts to combine these two theories lead to mathematical nonsense, and became known as the information loss paradox.

In 1974, Stephen Hawking used quantum mechanics to show that black holes emit radiation. Since then, scientists have detected fingerprints in the cosmos that are consistent with this radiation, identifying an ever-increasing list of the universe’s black holes.

But now Mersini-Houghton describes an entirely new scenario. She and Hawking both agree that as a star collapses under its own gravity, it produces Hawking radiation. However, in her new work, Mersini-Houghton shows that by giving off this radiation, the star also sheds mass. So much so that as it shrinks it no longer has the density to become a black hole.

Before a black hole can form, the dying star swells one last time and then explodes. A singularity never forms and neither does an . The take home message of her work is clear: there is no such thing as a black hole.

….. Many physicists and astronomers believe that our originated from a singularity that began expanding with the Big Bang. However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened.

The blackest of them all..

August 5, 2014

Vantablack (from Vertically Aligned Nano Tube Array) absorbs upto 99.965% of all radiation it receives and is now the blackest material known. It is blacker than NASA’s “super-black” (99%) and, I suppose, will be the start of ultra-black.

The uncoated part of this foil remains three-dimensional but the coated part reflects virtually no light and appears flat.

Piece of foil partially coated with Vantablack

Vantablack is manufactured by Surrey Nano Systems and is already in production.

The Engineer: Vantablack, a so-called ‘super black’ coating from Surrey Nanosystems, combines exceptionally low mass, thermal stability and an ability to absorb 99.96 per cent of incident radiation. Consequently, the coating is suited to applications including apertures, baffles, cold shields and Micro Electro Mechanical Systems (MEMS)–type optical sensors.

The material also overcomes limitations encountered in the manufacture of super-black carbon nanotube-based materials, where high temperatures precluded direct application to sensitive electronics or materials with relatively low melting points. This, along with poor adhesion, prevented their application to space and airborne instrumentation.

There is no established blackness scale. Black paint reflects almost 10% of incident light. Newly laid asphalt reflects 2 – 5% depending upon surface composition. Carbon black (polycrystalline carbon resulting from incomplete combustion) reflects only 1% of incident light. Though we take blackness to be the absence of reflection of radiation, material may reflect radiation at a different wave-length to the incident radiation. All light photons that are absorbed must eventually become heat and all bodies will radiate heat (infra-red) dependent upon only their surface temperature. In physics, a black body is theoretical and absorbs all incident electromagnetic radiation, at all wavelengths and all angles of incidence. In practice such a body can’t exist.

NASA SuperblackNASA engineers have produced a material that absorbs on average more than 99 percent of the ultraviolet, visible, infrared, and far-infrared light that hits it — a development that promises to open new frontiers in space technology. …… 

The nanotech-based coating is a thin layer of multi-walled carbon nanotubes, tiny hollow tubes made of pure carbon about 10,000 times thinner than a strand of human hair. They are positioned vertically on various substrate materials much like a shag rug. The team has grown the nanotubes on silicon, silicon nitride, titanium, and stainless steel, materials commonly used in space-based scientific instruments. (To grow carbon nanotubes, Goddard technologist Stephanie Getty applies a catalyst layer of iron to an underlayer on silicon, titanium, and other materials. She then heats the material in an oven to about 1,382 degrees Fahrenheit. While heating, the material is bathed in carbon-containing feedstock gas.)

The tests indicate that the nanotube material is especially useful for a variety of spaceflight applications where observing in multiple wavelength bands is important to scientific discovery. One such application is stray-light suppression. The tiny gaps between the tubes collect and trap background light to prevent it from reflecting off surfaces and interfering with the light that scientists actually want to measure. Because only a small fraction of light reflects off the coating, the human eye and sensitive detectors see the material as black.

In particular, the team found that the material absorbs 99.5 percent of the light in the ultraviolet and visible, dipping to 98 percent in the longer or far-infrared bands. “The advantage over other materials is that our material is from 10 to 100 times more absorbent, depending on the specific wavelength band,” Hagopian said.

Currently, instrument developers apply black paint to baffles and other components to help prevent stray light from ricocheting off surfaces. However, black paints absorb only 90 percent of the light that strikes it. The effect of multiple bounces makes the coating’s overall advantage even larger, potentially resulting in hundreds of times less stray light.

In addition, black paints do not remain black when exposed to cryogenic temperatures. They take on a shiny, slightly silver quality, said Goddard scientist Ed Wollack, who is evaluating the carbon-nanotube material for use as a calibrator on far-infrared-sensing instruments that must operate in super-cold conditions to gather faint far-infrared signals emanating from objects in the very distant universe. If these instruments are not cold, thermal heat generated by the instrument and observatory, will swamp the faint infrared they are designed to collect.

 

 

Mystical threes and magic scaling number of the Efimov State

June 3, 2014

The number three has long been attributed with mystical and divine properties.

trinityTime and Life itself is a matter of threes. Birth, life and death. The past, the present and the future. Third time lucky. Three wishes. The Holy Trinity. Three daughters. The Good, the Bad and the Ugly. The three primary colours. A Troika. Brahma,Vishnu, Shiva. The Creator, the Preserver, the Destroyer. Three monkeys. Three wise men. Three Kings.

Three has its place in Physics as well. Pascal’s triangle and the Golden Number and the Fibonacci series. A theoretical prediction that fundamental particles in sets of three give rise to stable arrangements of infinitely scaleable, nesting sets has now been shown to be real – the Efimov State.

WiredMore than 40 years after a Soviet nuclear physicist proposed an outlandish theory that trios of particles can arrange themselves in an infinite nesting-doll configuration, experimentalists have reported strong evidence that this bizarre state of matter is real. 

n 1970, Vitaly Efimov was manipulating the equations of quantum mechanics in an attempt to calculate the behavior of sets of three particles, such as the protons and neutrons that populate atomic nuclei, when he discovered a law that pertained not only to nuclear ingredients but also, under the right conditions, to any trio of particles in nature.

While most forces act between pairs, such as the north and south poles of a magnet or a planet and its sun, Efimov identified an effect that requires three components to spring into action. Together, the components form a state of matter similar to Borromean rings, an ancient symbol of three interconnected circles in which no two are directly linked. The so-called Efimov “trimer” could consist of a trio of protons, a triatomic molecule or any other set of three particles, as long as their properties were tuned to the right values. And in a surprising flourish, this hypothetical state of matter exhibited an unheard-of feature: the ability to range in size from practically infinitesimal to infinite. 

Efimov had shown that when three particles come together, a special confluence of their forces creates the Borromean rings effect: Though one is not enough, the effects of two particles can conspire to bind a third. The nesting-doll feature — called discrete scale invariance — arose from a symmetry in the equation describing the forces between three particles. If the particles satisfied the equation when spaced a certain distance apart, then the same particles spaced 22.7 times farther apart were also a solution. This number, called a “scaling factor,” emerged from the mathematics as inexplicably as pi, the ratio between a circle’s circumference and diameter.

Now it seems 3 different research teams have shown the existence of Efimov nesting.

“With just one example, it’s very difficult to tell if it’s a Russian nesting doll,” said Cheng Chin, a professor of physics at the University of Chicago who was part of Grimm’s group in 2006. The ultimate proof would be an observation of consecutive Efimov trimers, each enlarged by a factor of 22.7. “That initiated a new race” to prove the theory, Chin said. 

Eight years later, the competition to observe a series of Efimov states has ended in a photo finish. “What you see is three groups, in three different countries, reporting these multiple Efimov states all within about one month,” said Chin, who led one of the groups. “It’s totally amazing.”

Read the article.

Related: Physicists Prove Surprising Rule of Threes

Universe may be getting more massive rather than expanding

May 25, 2014

Not being Sheldon Cooper I have difficulty with the theory of an Expanding Universe. A finite Universe expanding into an infinite nothingness would be bad enough. But an infinite. ever-expanding Universe becomes incomprehensible. This expansion apparently consists of the scale of space itself expanding, such that galaxies are moving away from each other but where – for some other incomprehensible reasons – this does not apply at less than galactic scale (and certainly not at the scale of the puny earth or our human bodies)!

Skyserver: …. other physicists and mathematicians working on Einstein’s theory of gravity discovered the equations had some solutions that described an expanding universe. In these solutions, the light coming from distant objects would be redshifted as it traveled through the expanding universe. The redshift would increase with increasing distance to the object. ……

When he (Hubble) plotted redshift against relative distance, he found that the redshift of distant galaxies increased as a linear function of their distance. The only explanation for this observation is that the universe was expanding.

Once scientists understood that the universe was expanding, they immediately realized that it would have been smaller in the past. At some point in the past, the entire universe would have been a single point. This point, later called the big bang, was the beginning of the universe as we understand it today.

But now a new paper suggests that the red shift may be due to the Universe increasing in mass rather than expanding.  The Big Bang singularity – says the paper – turns out to be a consequence of choosing “a singular set of field coordinates”But the paper has still to run the gauntlet of peer review.

C. Wetterich, A Universe without expansion, arXiv:1303.6878  arxiv.org/abs/1303.6878/

Abstract
We discuss a cosmological model where the universe shrinks rather than expands during the radiation and matter dominated periods. Instead, the Planck mass and all particle masses grow exponentially, with the size of atoms shrinking correspondingly. Only dimensionless ratios as the distance between galaxies divided by the atom radius are observable. Then the cosmological increase of this ratio can also be attributed to shrinking atoms. We present a simple model where the masses of particles arise from a scalar “cosmon” field, similar to the Higgs scalar. The potential of the cosmon is responsible for inflation and the present dark energy. Our model is compatible with all present observations. While the value of the cosmon field increases, the curvature scalar is almost constant during all cosmological epochs. Cosmology has no big bang singularity. There exist other, equivalent choices of field variables for which the universe shows the usual expansion or is static during the radiation or matter dominated epochs. For those “field coordinates“ the big bang is singular. Thus the big bang singularity turns out to be related to a singular choice of field coordinates.

Just as an expanding Universe -in reverse – leads to a Big Bang where some pre-existing mass “explodes” from a zero size, a Universe getting more massive – in reverse – must lead to a an initial mass-less state. Just about as incomprehensible as the Expanding Universe.

Nature: 

But, as Wetterich points out, the characteristic light emitted by atoms is also governed by the masses of the atoms’ elementary particles, and in particular of their electrons. If an atom were to grow in mass, the photons it emits would become more energetic. Because higher energies correspond to higher frequencies, the emission and absorption frequencies would move towards the blue part of the spectrum. Conversely, if the particles were to become lighter, the frequencies would become redshifted.

Because the speed of light is finite, when we look at distant galaxies we are looking backwards in time — seeing them as they would have been when they emitted the light that we observe. If all masses were once lower, and had been constantly increasing, the colours of old galaxies would look redshifted in comparison to current frequencies, and the amount of redshift would be proportionate to their distances from Earth. Thus, the redshift would make galaxies seem to be receding even if they were not.

Work through the maths in this alternative interpretation of redshift, and all of cosmology looks very different. The Universe still expands rapidly during a short-lived period known as inflation. But prior to inflation, according to Wetterich, the Big Bang no longer contains a ‘singularity’ where the density of the Universe would be infinite. Instead, the Big Bang stretches out in the past over an essentially infinite period of time. And the current cosmos could be static, or even beginning to contract.

Cosmology uses real mathematics and is – of course – much more respected than astrology. However the modern invocation of dark energy and dark matter by physicists and cosmologists is quite as magical as the invocation of the aether or of various elixirs by alchemists. In fact even gravity – though calculable and predictable – is just another “magical” term with no proper explanation.

Half of Newton’s papers were on religion, 10% on alchemy and only 30% on science and math

May 16, 2014

Unlike Alfred Nobel who I posted about recently, Isaac Newton left no will when he died in 1727. But he left behind him a mass of papers estimated to run to about 10 million words. But most of the notes he left behind dealt with religious subjects and alchemy and his views were not just politically incorrect but potentially embarrassing if not dangerous to his heirs.

Wired has interviewed Sarah Dry who has just published her book on The Newton Papers.

WiredHe wrote a forensic analysis of the Bible in an effort to decode divine prophecies. He held unorthodox religious views, rejecting the doctrine of the Holy Trinity. After his death, Newton’s heir, John Conduitt, the husband of his half-niece Catherine Barton, feared that one of the fathers of the Enlightenment would be revealed as an obsessive heretic. And so for hundreds of years few people saw his work. It was only in the 1960s that some of Newton’s papers were widely published.

Now of course The Newton Project is putting all of his papers online and they have so far transcribed about 6.4 million words:

The Newton Project is a non-profit organization dedicated to publishing in full an online edition of all of Sir Isaac Newton’s (1642–1727) writings — whether they were printed or not. The edition presents a full (diplomatic) rendition featuring all the amendments Newton made to his own texts or a more readable (normalised) version. We also make available translations of his most important Latin religious texts.

Although Newton is best known for his theory of universal gravitation and discovery of calculus, his interests were much broader than is usually appreciated. In addition to his celebrated scientific and mathematical writings, Newton also wrote many alchemical and religious texts.

Sarah Dry traces the history of the Newton papers and how they languished over the years. It was not perhaps by conspiracy but there was some clear apprehension that sorting and cataloguing them would be embarrassing because there was so much of a “heretical” nature:

Sarah Dry in WiredThere’s roughly 10 million words that Newton left. Around half of the writing is religious, and there are about 1 million words on alchemical material, most of which is copies of other people’s stuff. There are about 1 million words related to his work as Master of the Mint. And then roughly 3 million related to science and math.

…… one of the messages of the book is that getting too involved in the papers can be hazardous to your health. One of the first editors of the papers said an older man should take up the task, because he’d have less to lose than a younger man.

This is highly technical stuff. The alchemical stuff is technical, the scientific stuff is technical, the religious stuff is technical. I was more interested in the papers and the characters that worked on them. One person was David Brewster, who wrote a biography of Newton during the Victorian Era. He fought long and hard to resuscitate Newton’s reputation. But he was also one of these Victorians that had to tell the truth. So when he published his biography [in 1855], it included much of the heresy and alchemy, despite the fact that Brewster was a good orthodox Protestant.

…. When the papers came to Cambridge in the late 1800s, they were unsorted and chaotic. And the two men given to sorting them were John Couch Adams and George Stokes. Adams was the co-discoverer of Neptune. He famously never wrote anything down. And Stokes was just as great a physicist, but he wrote everything down. He in fact wrote 10,000 letters. So these two guys get the papers, and then they sit on them for 16 years; they basically procrastinate.

When actually confronted with Newton’s paper, they were horrified and dismayed. Here was this great scientific hero. But he also wrote about alchemy and even more about religious matters. Newton spent a long time writing a lot of unfinished treatises. Sometimes he would produce six or seven copies of the same thing. And I think it was disappointing to see your intellectual father copying this stuff over and over. So the way Adams and Stokes dealt with it was to say that, “His power of writing a beautiful hand was evidently a snare to him.” Basically, they said he didn’t like this stuff, he just liked his own writing.

There’s also Grace Babson, who created the largest collection of Newton objects and papers in America. She was married to a man who got rich predicting the crash of 1929. And Roger Babson [her husband] based his market research on Newtonian principles, using the idea that for every action there is an equal an opposite reaction. The market goes up so it must come down. Interestingly, he thought of gravity as an evil scourge.

Clearly people felt that tarnishing Newton’s image was a heresy in itself and they felt that publicising his stranger writings could do such damage to their icon. But the time since his death is critical here. Newton’s image  is now immune to such damage. I think that no matter how weird his views may have been about the Bible and prophecies and the occult and alchemy, they cannot – now – detract from his work on maths and physics and motion.

But his catalogers have a point. If one part of his work had been  debunked or ridiculed soon after his death, it could have damaged his reputation and even the credibility of his work in Physics and Maths. It is common practice now – as it was common practice then – for detractors to attack an opponent’s views on one subject obliquely, by denigrating his views or work in some other field. Wrong thinking in one field – by association – becomes wrong thinking in all fields.

It may have been different if they had TV in those days. For if Newton had lived in today’s world it could well be that his eminence in Physics and Maths  would have made him an instant TV pundit on all subjects. We would be suffering the pain of listening him to expound on his other weird and wonderful ideas. As we all must endure when we have to listen to actors pontificating about environmental science or psychiatrists excusing errant behaviour or politicians pretending they understand economics!!

A multiverse model of the Universe from 800 years ago

May 6, 2014

Bishop Robert Grosseteste, detail of a window on the South transept Westernmost. St Paul’s Parish Church, Morton, Near Gainsborough. 1896

Robert Grosseteste (ca. 1168–1253), Bishop of Lincoln from 1235 to 1253, was one of the most prominent and remarkable figures in thirteenth-century English intellectual life. His views on light and matter were some 800 years in advance of his time.

If a single leitmotif runs through Grosseteste’s works, it is that of light. The notion of light occupies a prominent place in Grosseteste’s commentaries on the Bible, in his account of sense perception and the relation of body and soul, in his illuminationist theory of knowledge, in his account of the origin and nature of the physical world, and, of course, in his writings on optics. 

 

His treatise De Luce (meaning “Concerning Light”), written in 1225, describes a Universe created via a Big Bang-like explosion of light before forming into a series of nine celestial spheres.

Past Horizons:

The Ordered Universe Project, which brings together physicists, psychologists, cosmologists, Latin experts and medieval historians, has been studying the texts of Robert Grosseteste, one-time Bishop of Lincoln. The team created a fresh Latin translation, aided by other experts with knowledge of the medieval mindset and its context, before applying modern mathematical and computational techniques to Grosseteste’s equations. ….

Dr Giles Gasper, the Ordered Universe Project’s Principal Investigator and Associate Director of Durham University’s Institute of Medieval and Early Modern Studies, said: “De Luce is the earliest known attempt to describe the Universe using a coherent set of physical laws, centuries before Sir Isaac Newton.

“It proposes that the same physics of light and matter, which explain the solidity of ordinary objects, could be applied to the cosmos as a whole. In doing so it also suggests, although this was probably not apparent to Grosseteste at the time, a series of ordered universes reminiscent of the modern “multiverse” concept.

“Grosseteste’s calculations are very consistent and precise. Had he had access to modern calculus and computing methods, he surely would have used them, so that is what the team has done.”

Richard G. Bower, Tom C. B. McLeish, Brian K. Tanner, Hannah E. Smithson , Cecilia Panti, Neil Lewis, Giles E. M. Gasper, A Medieval Multiverse: Mathematical Modelling of the 13th Century Universe of Robert Grosseteste, Royal Society Journal, Proceedings of the Royal Society A, arXiv:1403.0769

Abstract: In his treatise on light, written in about 1225, Robert Grosseteste describes a cosmological model in which the Universe is created in a big-bang like explosion and subsequent condensation. He postulates that the fundamental coupling of light and matter gives rises to the material body of the entire cosmos. Expansion is arrested when matter reaches a minimum density and subsequent emission of light from the outer region leads to compression and rarefaction of the inner bodily mass so as to create nine celestial spheres, with an imperfect residual core. In this paper we reformulate the Latin description in terms of a modern mathematical model. The equations which describe the coupling of light and matter are solved numerically, subject to initial conditions and critical criteria consistent with the text. Formation of a universe with a non-infinite number of perfected spheres is extremely sensitive to the initial conditions, the intensity of the light and the transparency of these spheres. In this “medieval multiverse”, only a small range of opacity and initial density profiles lead to a stable universe with nine perfected spheres. As in current cosmological thinking, the existence of Grosseteste’s universe relies on a very special combination of fundamental parameters.

Seventeen equations that changed the world

March 20, 2014

I just came across this summarising Ian Stewart’s book on 17 Equations That Changed The World at Business Insider: 

seventeen equations

seventeen equations

I have used all of these up to Equation 12. I have never used the equations on Relativity or Schrodinger’s equation or those on Chaos or Information theory or the Black-Scholes Equation. But, I wouldn’t disagree with Equations 12 – 17, but considering the amount of time I spent applying it at University and during my working life I would have liked to see Bernoulli’s Equation on the list:

Bernoulli's Equation

where:

v\, is the fluid flow speed at a point on a streamline,
g\, is the acceleration due to gravity,
z\, is the elevation of the point above a reference plane, with the positive z-direction pointing upward – so in the direction opposite to the gravitational acceleration,
p\, is the pressure at the chosen point, and
\rho\, is the density of the fluid at all points in the fluid.

Follow

Get every new post delivered to your Inbox.

Join 652 other followers