Posts Tagged ‘Physics’

Magic is to physics as Heineken is to the human body

September 10, 2015

Magic already fills all the spaces that physics cannot reach.

Take spacetime (you can just as well call it the mellifluous aether which carries gravitational waves from the sun to the distant reaches of the solar system where other beers cannot reach).

The stretched rubber-sheet analogy to explain spacetime and gravity is just that – an analogy. And not a very good one as xkcd has so well illustrated.

spacetime magic — by xkcd

“Spacetime” is a label for any mathematical model which combines space and time into a continuum. It is just a model. But why that model should apply is magic.

Spacetime is just an imagined structure of the universe and is imbued with mathematically-defined properties such that “spacetime is distorted by the mass of bodies which exist within it and these distortions, in turn, affect the motion of those masses”. A somewhat circular argument which does not explain the “why” or the “how” beyond “it must be so, because it is so”.

Spacetime does not explain the existence of gravity. It merely shifts the need for magic to explain magical attraction (labelled gravity) to another place where physics cannot reach. In a universe where motion is not independent of time, and where the very duration of time can vary as a consequence of motion, even the magnitude of the 3 physical dimensions become variables subject to the observer and his motion. Not to mention that mass can be energy and some of both can be dark. Neither mass nor energy nor momentum can any longer be conserved, because phantom dark energy can be called upon and injected into the equations whenever it is needed to explain the unexplainable. And to have a “phantom” class of undetectable, unobservable dark energy which is doubly undetectable, does seem to go over the top. Rather than just put dark energy and dark matter, and even phantom dark energy into the category of magic, intrepid physicists have invented new classes of  unknown, unobservable, undetectable, sub-atomic particles. Some have charm and some have spin. Some have properties which are as yet undefined but will be sufficient to the explanation required to be constructed. Why not just call them “magic particles”?

Physics no longer goes for the parsimonious explanation. Big Physics seems nowadays to be based on introducing complexities wherever possible rather than looking for the least complicated explanation which is sufficient to the explanation. For every ultimate, fundamental particle that is “found”, but found wanting, two further magic particles have to be invoked.

Of course, there is a Grand Unified Theory which explains electromagnetic, weak, and strong interactions and naturally there is a Theory of Everything which even explains gravity. It is quite simple and sufficient to the purpose. It is called Magic and it occupies all the spaces that Physics cannot reach.

It is time for a Heineken. Now if I could only remember the right spell and the right incantation to go with it, ………

 

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Physics came first and then came chemistry and later biology

August 19, 2015

I generally take it that there are only 3 basic sciences, physics, chemistry and biology. I take logic to be the philosophical framework and the background for the observation of the universe. Mathematics is then not a science but a language by which the observations of the universe can be addressed. All other sciences are combinations or derivatives of the three basic sciences. Geology, astronomy, cosmology, psychology, sociology, archaeology, and all the rest derive from the basic three.

I was listening to a report today about some Japanese researchers  who generated protein building blocks by recreating impacts by comets containing water, amino acids and silicate. Some of the amino acids linked together to form peptides (chained molecules). Recurring lengths of peptide chains form proteins and that leads to life. What interested me though was the element of time.

Clearly “chemistry” had to exist before “biology” came into existence. Chemistry therefore not only comes first and “higher” in the hierarchy of the existence of things but is also a necessary, but insufficient, requirement for “biology” to exist. Chemistry plus some “spark” led to biology. In that case the basic sciences are reduced to two since biology derives from chemistry. I cannot conceive of biology preceding chemistry. The elements and atoms and molecules of chemistry had to exist before the “spark” of something brough biology into existence.

chemical reactions (chemistry) + “spark of life”(physics?) = biology

By the same token, does physics precede chemistry? I think it must. Without the universe existing (physics) and all the elements existing within it (which is also physics) and without all the forces acting upon the elements (still physics), there would be no chemistry to exist. Or perhaps the Big Bang was physics and the creation of the elements itself was chemistry? But considering that nuclear reactions (fusion or fission) and the creation of new elements are usually considered physics, it would seem that the existence of physics preceded the existence of chemistry. The mere existence of elements would be insufficient to set in motion reactions between the elements. Some other forces are necessary for that (though some of these forces are even necessary for the existence of the elements). Perhaps physics gives the fundamental particles (whatever they are) and then chemistry begins with the formation of elements? Whether chemistry starts with elements or with the fundamental particles, physics not only must rank higher as a science, it must have come first. Particles must first exist before they can react with each other.

Particles (physics) + forces (physics) = chemistry.

In any event, and by whatever route I follow, physics preceded chemistry, and physics must exist first for chemistry to come into being. That makes chemistry a derivative of physics as biology is a derivative of chemistry.

We are left with just one fundamental science – physics.

by elfbrazil wikipedia

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.

An infinite and timeless universe measured with an accuracy of 1%!

January 10, 2014

A new paper has been capturing some headlines. It is all completely beyond me and while the Abstract – written presumably in English – may be perfectly intelligible for an astronomer or a physicist, it is totally incomprehensible for me. But some of the quotations in the accompanying press release – which were picked up and reported widely in the mainstream media (here and here for example) – sounded strangely illogical.

from the Press Release

  • Today the Baryon Oscillation Spectroscopic Survey (BOSS) Collaboration announced that BOSS has measured the scale of the universe to an accuracy of one percent.
  • “One-percent accuracy in the scale of the universe is the most precise such measurement ever made,” says BOSS’s principal investigator, David Schlegel, a member of the Physics Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). 
  • … the BOSS results suggest that dark energy is a cosmological constant whose strength does not vary in space or time. 
  • …. the BOSS analysis “also provides one of the best-ever determinations of the curvature of space. The answer is, it’s not curved much.”
  • “One of the reasons we care is that a flat universe has implications for whether the universe is infinite,” says Schlegel.
  • … “That means – while we can’t say with certainty that it will never come to an end – it’s likely the universe extends forever in space and will go on forever in time. Our results are consistent with an infinite universe.”
  • … By 380,000 years after the big bang, however, the temperature of the expanding mixture had cooled enough for light to escape, suffusing the newly transparent universe with intense radiation, which in the 13.4 billion years since has continued to cool to today’s faint but pervasive cosmic microwave background.
  • … BOSS collaborator Beth Reid of Berkeley Lab translates the two-dimensional sky coordinates of galaxies, plus their redshifts, into 3-D maps of the density of galaxies in space. “It’s from fluctuations in the density of galaxies in the volume we’re looking at that we extract the BAO standard ruler,” she says.
  • …. The universe’s expansion history has been measured with unprecedented accuracy during the very stretch of ancient time, over six billion years in the past, when expansion had stopped slowing and acceleration began. …

At this point I gave up.

My knowledge of physics and astronomy is sadly lacking and I cannot be reconciled to a universe which is

  • an expanding universe, where
  • the expansion is accelerating, and where
  • the university is infinite, and
  • timeless, and 
  • has been “measured” to an accuracy of 1%

1% of an infinite universe ought to be infinity in my boggled mind!  Is the “ruler” expanding as well? And did time exist before the Big Bang? And if the universe is “timeless”, is time just an artificial construct? And can infinity expand without having a larger infinity?

Oh well! I’m afraid I cannot picture this universe – but I am only an engineer.

Lauren Anderson et al, The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 10 and 11 galaxy samplesMonthly Notices of the Royal Astronomical Society, 2014.

Abstract: We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). Our results come from the Data Release 11 (DR11) sample, containing nearly one million galaxies and covering approximately 8500 square degrees and the redshift range 0.2the baryon acoustic oscillation (BAO) feature. The acoustic features are detected at a significance of over 7σ in both the correlation function and power spectrum. Fitting for the position of the acoustic features measures the distance relative to the sound horizon at the drag epoch, rd, which has a value of rd,fid=149.28Mpc in our fiducial cosmology. We find DV=(1264±25Mpc)(rd/rd,fid) at z=0.32 and DV=(2056±20Mpc)(rd/rd,fid) at z=0.57. At 1.0 per cent, this latter measure is the most precise distance constraint ever obtained from a galaxy survey. Separating the clustering along and transverse to the line-of-sight yields measurements at z=0.57 of DA=(1421±20Mpc)(rd/rd,fid) and H=(96.8±3.4km/s/Mpc)(rd,fid/rd). Our measurements of the distance scale are in good agreement with previous BAO measurements and with the predictions from cosmic microwave background data for a spatially flat cold dark matter model with a cosmological constant.

Cats and physics

January 1, 2014

It’s pretty obvious which kitten is going to grow up to be a physicist.

 

It’s only a matter of time and evolution.

From Luboš Motl’s The Reference Frame

Wang versus Wen at the Chinese Academy of Sciences

October 23, 2013

The Chinese Academy of Sciences (CAS), formerly known as Academia Sinica, is the national academy for the natural sciences of the People’s Republic of China. Collectively known as the “Two Academies”  along with the Chinese Academy of Engineering, it is an institution of the State Council of China, functioning as the national scientific thinktank and academic governing body, providing advisory and appraisal services on issues stemming from the national economy, social development, and science and technology progress. It is headquartered in Beijing, with branch institutes all over mainland China. It has also created hundreds of commercial enterprises, with Lenovo being one of the most famous.

Sun tzu

Being selected as  a full member of the Academy is the most sought after position for a Chinese scientist. Selection takes place every two years and this year there are 391 “candidates” and probably no more than 5 – 10% will be selected. At the end of 2008, there were 692 CAS members, including 40 female members and 51 foreign members. So roughly one in 2 million Chinese gets to be a member of the Academy.

Politicking and lobbying are not unknown in the selection of new members. This can be quite cut-throat and vicious as is quite normal in academic rivalry. In this particular case Physics Professors Wang and Wen were competing for a place. Wang – in a master-stroke worthy of Sun Tzu – accused Wen of academic misconduct with regard to a paper published in Nature Communications. Each fired off their ammunition on their blog posts. Three co-authors claimed – or were persuaded to claim – that their names had wrongly been included on the paper by Wen. This effectively killed Wen’s chances. While Wang had won the battle he may have lost the war. The Academy was not amused. Wang had rocked the boat too much. And in the latest development Wang  has now withdrawn – or has been persuaded to withdraw – his candidature. It could be some time before he is allowed to be a candidate again.

South China Morning Post:

A prominent physics professor at Nanjing University, Wang Mu, 51, announced on his blog on Monday his intention to withdraw from this year’s selection race for new members of the Chinese Academy of Sciences (CAS), a title only given to leading scientists and academic authorities in China.

His decision has shocked many in Chinese academic circles. To many, the reason behind it is even more shocking. Wang has withdrawn from the race so he can investigate another candidate, his colleague, 49-year-old physics professor Wen Hai Hu, for alleged academic fraud.

On September 15, Wang informed the Division of Mathematics and Physics of the Chinese Academy of Sciences that in May Wen had published a fraudulent research paper in Nature Communications, a journal focusing on advancements in the field of physical, biological and chemical science.

According to Wang, three co-authors of the published paper didn’t participate in any of the experiments or analysis mentioned in it, and they had never seen the article before it was published. Wang said that in July this year the editorial department of Nature Communications had received a request from the three co-authors to remove their names from the paper. …..

….. While many were disappointed by Wang’s decision, some questioned his motive, which provoked further discussion on whether the CAS member system should be abolished.

“As far as I know, it is a close race between them. To Wang, Wen has become an obstacle on his path to promotion. The fact that Wang bypassed the university and reported to CAS directly has killed Wen’s hopes of becoming a member of CAS. The last thing CAS wants is to see a dirty fight,” a commenter posted on sciencenet.cn.

On October 13, the Ministry of Education of China ordered Nanjing University to investigate the scandal. And the Chinese Academy of Sciences also formed a team to conduct an independent investigation.

UPDATE!

The paper in question seems to be this one:

Influence of microstructure on superconductivity in KxFe2−ySe2 and evidence for a new parent phase K2Fe7Se8, Xiaxin Ding, Delong Fang, Zhenyu Wang, Huan Yang, Jianzhong Liu, Qiang Deng, Guobin Ma,Chong Meng, Yuhui Hu & Hai-Hu Wen, Nature Communications 4, Article number: 1897 (2013) doi:10.1038/ncomms2913

 If the news story is correct Hai-Hu Wen is the senior author and 3 of the 9 other co-authors are the ones who have apparently written to the Editor complaining that their names have “been used in vain”!!

Physics Nobel today – Higgs? but (hopefully) not CERN! Update – awarded to François Englert and Peter W. Higgs

October 8, 2013

UPDATE 2!

There is more speculation doing the rounds as to why the awards were delayed by one hour.

There are some suggestions that this time was used to kill the ridiculous notion of having CERN – the organisation – as the third award winner! If that was the reason then it was time well spent!

The deliberations of the awards committee will not be released for 50 years.

=============================================

UPDATE!

The Physics Nobel award has been awarded to François Englert and Peter W. Higgs

NO CERN thankfully.

=============================================

  • 106 Nobel Prizes in Physics have been awarded between 1901-2012.
  • 47 Physics Prizes have been given to one Laureate only.
  • women have been awarded the Physics Prize so far.
  • person, John Bardeen, has been awarded the Physics Prize twice.
  • 25 years was the age of the youngest Physics Laureate ever, Lawrence Bragg, when he was awarded the 1915 Physics Prize together with his father.
  • 55 is the average age of the Physics Laureates the year they were awarded the prize.

==============================================

The speculation this morning on Swedish Radio is that the Higgs Boson will be recognised. There was some speculation that Higgs himself could lose out but that CERN – as an organisation – could be a winner. I hope not. The Radio commentators all seem to have the impression that the Higgs particle was discovered by CERN last year. But my understanding is that nothing was actually found. Something – not inconsistent with a Higgs particle – was indicated and the Higgs particle was “tentatively confirmed to exist on 14 March 2013” (though “tentative” and “confirmation” is a contradiction in terms).

In any event, I think the Nobel should stick to individuals and not go the way of the discredited Peace Prize and name an organisation like CERN. Professor Higgs would be acceptable even though it would be preferable to wait – but not CERN.

We shall see. (The announcement is due in about 3 hours).

Thomson Reuters predictions:

PHYSICS

François Englert and Peter W. Higgs
For their prediction of the Brout-Englert-Higgs boson

Hideo Hosono
For his discovery of iron-based superconductors

Geoffrey W. Marcy and Michel Mayor and Didier Queloz
For their discoveries of extrasolar planets

Fluid jets and fishbones

August 9, 2013

Just a few examples from a striking gallery of pictures by  John W. M. Bush (MIT Mathematics)

Colliding jets and the patterns that ensue.

Fishbone john bush

Fishbone john bush

fluids john bush

colliding jets john bush

We examine the form of the free surface flows resulting from the collision of equal jets at an oblique angle. Glycerol-water solutions with viscosities of 15-50 cS were pumped at flow rates of 10-40 cc/s through circular outlets with diameter 2 mm. … At low flow rates, the resulting stream takes the form of a steady fluid chain, a succession of mutually orthogonal fluid links, each comprised of a thin oval sheet bound by relatively thick fluid rims. The influence of viscosity serves to decrease the size of successive links, and the chain ultimately coalesces into a cylindrical stream. As the flow rate is increased, waves are excited on the sheet, and the fluid rims become unstable.  The rim appears blurred to the naked eye; however, strobe illumination reveals a remarkably regular and striking flow instability. Droplets form from the sheet rims but remain attached to the fluid sheet by tendrils of fluid that thin and eventually break. The resulting flow takes the form of fluid fishbones, with the fluid sheet being the fish head and the tendrils its bones. Increasing the flow rate serves to broaden the fishbones.  In the wake of the fluid fish, a regular array of drops obtains, the number and spacing of which is determined by the pinch-off of the fishbones. 

h/t Science is Beauty

 

Why averaging climate models is meaningless

June 14, 2013

This comment/ essay by rgbatduke on WUWT is well worth reading and digesting.

“this is a point that is stunningly ignored — there are a lot of different models out there, all supposedly built on top of physics, and yet no two of them give anywhere near the same results!”

A professional taking amateurs to task!

(Note! See also his follow-up comments here and here rgbatduke would seem to be Professor R G Brown of Duke University?)

rgbatduke says:

Saying that we need to wait for a certain interval in order to conclude that “the models are wrong” is dangerous and incorrect for two reasons. First — and this is a point that is stunningly ignored — there are a lot of different models out there, all supposedly built on top of physics, and yet no two of them give anywhere near the same results!

This is reflected in the graphs Monckton publishes above, where the AR5 trend line is the average over all of these models and in spite of the number of contributors the variance of the models is huge. It is also clearly evident if one publishes a “spaghetti graph” of the individual model projections (as Roy Spencer recently did in another thread) — it looks like the frayed end of a rope, not like a coherent spread around some physics supported result.

Note the implicit swindle in this graph — by forming a mean and standard deviation over model projections and then using the mean as a “most likely” projection and the variance as representative of the range of the error, one is treating the differences between the models as if they are uncorrelated random variates causing >deviation around a true mean!.

Say what?

This is such a horrendous abuse of statistics that it is difficult to know how to begin to address it. One simply wishes to bitch-slap whoever it was that assembled the graph and ensure that they never work or publish in the field of science or statistics ever again. One cannot generate an ensemble of independent and identically distributed models that have different code. One might, possibly, generate a single model that generates an ensemble of predictions by using uniform deviates (random numbers) to seed
“noise” (representing uncertainty) in the inputs.

What I’m trying to say is that the variance and mean of the “ensemble” of models is completely meaningless, statistically because the inputs do not possess the most basic properties required for a meaningful interpretation. They are not independent, their differences are not based on a random distribution of errors, there is no reason whatsoever to believe that the errors or differences are unbiased (given that the only way humans can generate unbiased anything is through the use of e.g. dice or other objectively random instruments).

(more…)

Physics Nobel today – update — awarded to Haroche and Wineland

October 9, 2012

UPDATE 2!

Well the rumours were wrong and the prize has been awarded to Serge Haroche of France and David Wineland of the US.

UPDATE: There is a rumour doing the rounds in Sweden this morning that the Physics prize will go to Alain Aspect of France and Anton Zeilinger of Austria.

============================================

There is still some speculation that the Physics Nobel to be announced today could go to Higgs and CERN scientists for the much-hyped,  “non-discovery” of the Higgs Boson but somehow I doubt it.

 Thomson Reuters proposes three possible winners:

1. Charles H. Bennett, Gilles Brassard and William K. Wootters

For their pioneering description of a protocol for quantum teleportation, which has since been  experimentally verified

2. Leigh T. Canham

For discovery of photoluminescence in porous silicon

 3.Stephen E. Harris and Lene V. Hau

For the experimental demonstration of electromagnetically induced transparency (Harris) and of  ‘slow light’ (Harris and Hau)

There is an outside chance that it may be awarded for work straddling Physics and Chemistry – in the world of  nano-particles perhaps.


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