Tuesday, November 30, 2010

A Disturbing E-mail re Garrett Lisi (Since Resolved by Lisi ... Read the Comments)

I got a very disturbing e-mail from "Anonymous" regarding Garrett Lisi's claim that he has had a paper published in a peer-reviewed Journal but that in fact no such paper has been published there.

I should very much like to have this resolved as I cannot locate the paper myself after half an hour of searching.

A link would be most appreciated, so that we can put this to rest and I can then delete this post. Here is the e-mail:

Fri, November 26, 2010 7:50:31 PM
[Multiplication by Infinity] New comment on Garrett Lisi in Real Time.
Add to Contacts

Anonymous has left a new comment on your post "Garrett Lisi in Real Time":

Peter Woit is deleting requests for Garrett Lisi to provide a full reference for the paper he claims he published in a peer-reviewed journal. I can find no such paper.

"Dear Peter,

If you do not believe me, please search Garrett's claimed article for yourself:

And you will find: "Your search - Garrett Lisi - did not match any articles published in J Phys A Math Theor 43."

"Your search - Lisi - did not match any articles published in J Phys A Math Theor.""

You can see more here, where Peter deleted a ton of my posts for asking simple questions: http://www.math.columbia.edu/~woit/wordpress/?p=3292&cpage=2#comment-70663

Yes--at Peter Woit's blog, Garrett claims that a peer-reviewed paper exists.

When commenters questioned its reality, Peter Woit snapped: "
Peter Woit says: November 26, 2010 at 12:06 pm

I’ve had to delete repeated anonymous comments by someone who couldn’t be bothered to either look things up for himself or read Garrett’s previous response to the same question:

At Peter Woit's blog, Garret writes, "
No, but it’s wrong. The paper with Lee and Simone lays out 90% of the theory, and was published in J. Phys. A: Math. Theor. 43 (2010). Lee and I tend to just put papers on the arxiv, but Simone thought it would be good to put it in a journal. There was no problem getting it published."

But then we go to Garrett's wikipedia page which he is known to self-edit, and there is no mention of any such paper.

There is no mention of any paper with Simone, nor the J. Phys. A: Math. Theor. 43 (2010).


Why is there no mention of the supposed journal paper that was peer-reviewed which Lisi states he coauthored? Is Lisi lying about the existence of such a peer-reviewed paper?

In addition, there is no mention of Simone on the page.

Thursday, November 25, 2010

List of unsolved problems in physics

This is a list of some of the major unsolved problems in physics. Some of these problems are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are experimental, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.


Theoretical problems

The following problems are either fundamental theoretical problems, or theoretical ideas which lack experimental evidence and are in search of one, or both, as most of them are. Some of these problems are strongly interrelated. For example, extra dimensions or supersymmetry may solve the hierarchy problem. It is thought that a full theory of quantum gravity should be capable of answering most of these problems (other than the Island of stability problem).

Quantum gravity, cosmology, and general relativity

Vacuum catastrophe
Why does the predicted mass of the quantum vacuum have little effect on the expansion of the universe?
Quantum gravity
How can quantum mechanics and general relativity be realized as a fully consistent quantum field theory?[1] Is spacetime fundamentally continuous or discrete? Would a consistent theory involve a force mediated by a hypothetical graviton, or be a product of a discrete structure of spacetime itself (as in loop quantum gravity)? Are there deviations from the predictions of general relativity at very small or very large scales or in other extreme circumstances that flow from a quantum gravity theory?
Black holes, black hole information paradox, and black hole radiation
Do black holes produce thermal radiation, as expected on theoretical grounds? Does this radiation contain information about their inner structure, as suggested by Gauge-gravity duality, or not, as implied by Hawking's original calculation? If not, and black holes can evaporate away, what happens to the information stored in them (quantum mechanics does not provide for the destruction of information)? Or does the radiation stop at some point leaving black hole remnants? Is there another way to probe their internal structure somehow, if such a structure even exists?
Extra dimensions
Does nature have more than four spacetime dimensions? If so, what is their size? Are dimensions a fundamental property of the universe or an emergent result of other physical laws? Can we experimentally "see" evidence of higher spatial dimensions?
Cosmic inflation
Is the theory of cosmic inflation correct, and if so, what are the details of this epoch? What is the hypothetical inflaton field giving rise to inflation? If inflation happened at one point, is it self-sustaining through inflation of quantum-mechanical fluctuations, and thus ongoing in some impossibly distant place?
Are there physical reasons to expect other universes that are fundamentally non-observable? For instance: Are there quantum mechanical "alternative histories" or "many worlds"? Are there "other" universes with physical laws resulting from alternate ways of breaking the apparent symmetries of physical forces at high energies, possibly incredibly far away due to cosmic inflation? Is the use of the anthropic principle to resolve global cosmological dilemmas justified?
The cosmic censorship hypothesis and the chronology protection conjecture
Can singularities not hidden behind an event horizon, known as "naked singularities", arise from realistic initial conditions, or is it possible to prove some version of the "cosmic censorship hypothesis" of Roger Penrose which proposes that this is impossible?[2] Similarly, will the closed timelike curves which arise in some solutions to the equations of general relativity (and which imply the possibility of backwards time travel) be ruled out by a theory of quantum gravity which unites general relativity with quantum mechanics, as suggested by the "chronology protection conjecture" of Stephen Hawking?
Arrow of time
What do the phenomena that differ going forward and backwards in time tell us about the nature of time? How does time differ from space? Why are CP violations observed in certain weak force decays, but not elsewhere? Are CP violations somehow a product of the Second Law of Thermodynamics, or are they a separate arrow of time? Are there exceptions to the principle of causality? Is there a single possible past?
Are there non-local phenomena in quantum physics? If they exist, are non-local phenomena limited to transfers of information, or can energy and matter also move in a non-local way? Under what circumstances are non-local phenomena observed? What does the existence or absence of non-local phenomena imply about the fundamental structure of spacetime? How does this relate to quantum entanglement? How does this elucidate the proper interpretation of the fundamental nature of quantum physics?
Future of the universe
Is the universe heading towards a Big Freeze, a Big Rip, a Big Crunch or a Big Bounce? Is our universe part of an infinitely recurring cyclic model?

High energy physics/Particle physics

Higgs mechanism
Does the Higgs particle exist? What are the implications if it does not? Is there only one of them?
Hierarchy problem
Why is gravity such a weak force? It becomes strong for particles only at the Planck scale, around 1019 GeV, much above the electroweak scale (100 GeV, the energy scale dominating physics at low energies). Why are these scales so different from each other? What prevents quantities at the electroweak scale, such as the Higgs boson mass, from getting quantum corrections on the order of the Planck scale? Is the solution supersymmetry, extra dimensions, or just anthropic fine-tuning?
Magnetic monopoles
Do particles that carry "magnetic charge" exist? The existence of some types of magnetic monopoles would explain charge quantization.[citation needed]
Proton decay and unification
How do we unify the three different quantum mechanical fundamental interactions of quantum field theory? As the lightest baryon, are protons absolutely stable? If not, then what is the proton's half-life?
Is spacetime supersymmetry realized in nature? If so, what is the mechanism of supersymmetry breaking? Does supersymmetry stabilize the electroweak scale, preventing high quantum corrections? Does the lightest supersymmetric particle comprise dark matter?
Generations of matter
Are there more than three generations of quarks and leptons? Why are there generations at all? Is there a theory that can explain the masses of particular quarks and leptons in particular generations from first principles (a theory of Yukawa couplings)?
Fundamental symmetries and Neutrinos
What is the nature of the neutrinos, what are their masses, and how have they shaped the evolution of the universe? Why is there now more detectable matter than antimatter in the universe? What are the unseen forces that were present at the dawn of the universe but disappeared from view as the universe evolved?

Nuclear physics

Quantum chromodynamics
What are the phases of strongly interacting matter, and what roles do they play in the cosmos? What is the internal landscape of the nucleons? What does QCD predict for the properties of strongly interacting matter? What governs the transition of quarks and gluons into pions and nucleons? What is the role of gluons and gluon self-interactions in nucleons and nuclei? What determines the key features of QCD, and what is their relation to the nature of gravity and spacetime?
Nuclei and Nuclear astrophysics
What is the nature of the nuclear force that binds protons and neutrons into stable nuclei and rare isotopes? What is the origin of simple patterns in complex nuclei? What is the nature of neutron stars and dense nuclear matter? What is the origin of the elements in the cosmos? What are the nuclear reactions that drive stars and stellar explosions?
Island of stability
What is the heaviest possible stable or metastable nucleus?

Other problems

Quantum mechanics in the correspondence limit (sometimes called Quantum chaos)
Is there a preferred interpretation of quantum mechanics? How does the quantum description of reality, which includes elements such as the superposition of states and wavefunction collapse or quantum decoherence, give rise to the reality we perceive? Another way of stating this is the Measurement problem - what constitutes a "measurement" which causes the wave function to collapse into a definite state?
Physical information
Are there physical phenomena, such as black holes or wave function collapse, which irrevocably destroy information about their prior states?
Theory of everything
Is there a theory which explains the values of all fundamental physical constants?[3] Is there a theory which explains why the gauge groups of the standard model are as they are, why observed space-time has 3 + 1 dimensions, and why all laws of physics are as they are? Do "fundamental physical constants" vary over time? Are any of the particles in the standard model of particle physics actually composite particles too tightly bound to observe as such at current experimental energies? Are there fundamental particles that have not yet been observed and if so which ones are they and what are their properties? Are there unobserved fundamental forces implied by a theory that explains other unsolved problems in physics?

Empirical phenomena lacking clear scientific explanation

Cosmology and astronomy

Baryon asymmetry
Why is there far more matter than antimatter in the observable universe?
Cosmological constant problem
Why doesn't the zero-point energy of the vacuum cause a large cosmological constant? What cancels it out?
Dark energy
What is the cause of the observed accelerated expansion (deSitter phase) of the Universe? Why is the energy density of the dark energy component of the same magnitude as the density of matter at present when the two evolve quite differently over time; could it be simply that we are observing at exactly the right time? Is dark energy a pure cosmological constant, or are models of quintessence such as phantom energy applicable?
Dark matter
What is dark matter?[4] Is it related to supersymmetry? Do the phenomena attributed to dark matter point not to some form of matter but actually to an extension of gravity?
Entropy (arrow of time)
Why did the universe have such low entropy in the past, resulting in the distinction between past and future and the second law of thermodynamics?[5]
Horizon problem
Why is the distant universe so homogenous, when the Big Bang theory seems to predict measurable anisotropies of the night sky larger than those observed? Possible approaches to a solution are inflation and the variable speed of light hypothesis.
Ecliptic alignment of CMB anisotropy
Some large features of the microwave sky, at distances of over 13 billion light years, appear to be aligned with both the motion and orientation of the Solar System. Is this due to systematic errors in processing, contamination of results by local effects, or an unexplained violation of the Copernican principle?
Shape of the Universe
What is the 3-manifold of comoving space, i.e. of a comoving spatial section of the Universe, informally called the "shape" of the Universe? Neither the curvature nor the topology is presently known, though the curvature is known to be "close" to zero on observable scales. The cosmic inflation hypothesis suggests that the shape of the Universe may be unmeasurable, but since 2003, Jean-Pierre Luminet et al. and other groups have suggested that the shape of the Universe may be the Poincaré dodecahedral space. Is the shape unmeasurable, the Poincaré space, or another 3-manifold?

High energy physics/Particle physics

Electroweak symmetry breaking
What is the mechanism responsible for breaking the electroweak gauge symmetry, giving mass to the W and Z bosons? Is it the simple Higgs mechanism of the Standard Model,[6] or does nature make use of strong dynamics in breaking electroweak symmetry, as proposed by Technicolor?
Neutrino mass
What is the mechanism responsible for generating neutrino masses? Is the neutrino its own antiparticle? Or could it be an antiparticle that simply cannot join and annihilate with a normal particle because of its irregular state?
Inertial mass/gravitational mass ratio of elementary particles
According to the equivalence principle of general relativity, the ratio of inertial mass to gravitational mass of all elementary particles is unity. However, there is no experimental confirmation for many particles. In particular, we do not know what the weight of a macroscopic lump of antimatter of known mass would be.
Proton spin crisis
As initially measured by the European Muon Collaboration, the three main ("valence") quarks of the proton account for about 12% of its total spin. Can the gluons that bind the quarks together, as well as the "sea" of quark pairs that are continually being created and annihilating, properly account for the rest of it?
Quantum chromodynamics (QCD) in the non-perturbative regime
The equations of QCD remain unsolved at energy scales relevant for describing atomic nuclei, and, among others, mainly numerical approaches seem to begin to give answers at this limit. How does QCD give rise to the physics of nuclei and nuclear constituents?
Why has there never been measured a free quark or gluon, but only objects that are built out of them, like Mesons and Baryons? How does this phenomenon emerge from QCD?[citation needed]
Strong CP problem and axions
Why is the strong nuclear interaction invariant to parity and charge conjugation? Is Peccei-Quinn theory the solution to this problem?
Hypothetical particles
Which of the hypothetical particles predicted by supersymmetric theories and other fairly well-known theories actually occur in nature?

Astronomy and astrophysics

Accretion disc jets
Why do the accretion discs surrounding certain astronomical objects, such as the nuclei of active galaxies, emit relativistic jets along their polar axes? Why are there Quasi-Periodic Oscillations in many accretion discs? Why does the period of these oscillations scale as the inverse of the mass of the central object? Why are there sometimes overtones, and why do these appear at different frequency ratios in different objects?
Coronal heating problem
Why is the Sun's Corona (atmosphere layer) so much hotter than the Sun's surface? Why is the magnetic reconnection effect many orders of magnitude faster than predicted by standard models?
Gamma ray bursts
How do these short-duration high-intensity bursts originate?[7]
Supermassive black holes
What is the origin of the M-sigma relation between supermassive black hole mass and galaxy velocity dispersion?[8]
Observational anomalies
Hipparcos anomaly: What is the actual distance to the Pleiades?[citation needed]
Pioneer anomaly[4]: What causes the small additional sunward acceleration of the Pioneer spacecraft?[9][10]
Flyby anomaly: Why is the observed energy of satellites flying by earth different by a minute amount from the value predicted by theory?
Galaxy rotation problem: Is dark matter responsible for differences in observed and theoretical speed of stars revolving around the center of galaxies, or is it something else?
What is the exact mechanism by which an implosion of a dying star becomes an explosion?
Ultra-high-energy cosmic ray[4]
Why is it that some cosmic rays appear to possess energies that are impossibly high (the so called OMG particle), given that there are no sufficiently energetic cosmic ray sources near the Earth? Why is it that (apparently) some cosmic rays emitted by distant sources have energies above the Greisen-Zatsepin-Kuzmin limit?[11][12]
Pulsar Time Dilation
Why do the emissions from pulsars at great cosmological distances fail to exhibit the predicted time dilation properties?
Rotation rate of Saturn
Why does the magnetosphere of Saturn exhibit a (slowly changing) periodicity close to that at which the planet's clouds rotate? What is the true rotation rate of Saturn's deep interior? [13]

Condensed matter physics

Amorphous solids
What is the nature of the glass transition between a fluid or regular solid and a glassy phase? What are the physical processes giving rise to the general properties and the physics of glasses?[14][15]
Cold fusion
What is the explanation for the controversial reports of excess heat, radiation and transmutations?[4][16][17]
Cryogenic electron emission
Why does the electron emission in the absence of light increase as the temperature of a photomultiplier is decreased?[18][19]
High-temperature superconductors
What is the mechanism that causes certain materials to exhibit superconductivity at temperatures much higher than around 50 kelvin?[20]
What causes the emission of short bursts of light from imploding bubbles in a liquid when excited by sound?[21]
Is it possible to make a theoretical model to describe the statistics of a turbulent flow (in particular, its internal structures)?[22] Also, under what conditions do smooth solutions to the Navier-Stokes equations exist? This is probably the last unsolved problem in Classical or Newtonian Physics.

Biological problems approached with physics

These fields of research normally belong to biology, and traditionally were not included in physics but are included here because increasingly it is physicists who are researching them using methods and tools more popular in physics research than biology.[23][24]

Synaptic plasticity
It is necessary for computational and physical models of the brain, but what causes it, and what role does it play in higher-order processing outside the hippocampus and visual cortex?
Axon guidance
How do axons branching out from neurons find their targets? This process is crucial to nervous system development, allowing the building up of the brain.
Stochasticity and robustness to noise in gene expression
How do genes govern our body, withstanding different external pressures and internal stochasticity? Certain models exist for genetic processes, but we are far from understanding the whole picture, in particular in development where gene expression must be tightly regulated.
Quantitative study of the immune system
What are the quantitative properties of immune responses? What are the basic building blocks of immune system networks? What roles are played by stochasticity?

Problems solved in recent decades

Long-duration gamma ray bursts (2003)
Long-duration bursts are associated with the deaths of massive stars in a specific kind of supernova-like event commonly referred to as a collapsar.
Solar neutrino problem (2002)
Solved by a new understanding of neutrino physics, requiring a modification of the Standard Model of particle physics—specifically, neutrino oscillation.
Age Crisis (1990s)
The estimated age of the universe was around 3 to 8 billion years younger than estimates of the ages of the oldest stars in our galaxy. Better estimates for the distances to the stars and the addition of dark energy into the cosmological model reconciled the age estimates.
Quasars (1980s)
The nature of quasars was not understood for decades[25]. They are now accepted as a type of active galaxy where the enormous energy output results from matter falling into a massive black hole in the center of the galaxy[26].


  1. ^ Alan Sokal (July 22, 1996), Don't Pull the String Yet on Superstring Theory, New York Times, http://query.nytimes.com/gst/fullpage.html?res=9D0DE7DB1639F931A15754C0A960958260
  2. ^ Joshi, Pankaj S. (January 2009), "Do Naked Singularities Break the Rules of Physics?", Scientific American, http://www.sciam.com/article.cfm?id=naked-singularities
  3. ^ Open Questions, Particle Physics, item 12
  4. ^ a b c d 13 things that do not make sense newscientistspace, 19 March 2005, Michael Brooks
  5. ^ Open Questions item 4
  6. ^ Open Questions, Particle Physics, item 6
  7. ^ Open Questions, Cosmology and Astrophysics, item 11
  8. ^ Ferrarese, Laura; Merritt, David (2000), "A Fundamental Relation between Supermassive Black Holes and their Host Galaxies", The Astrophysical Journal 539: L9-L12, http://adsabs.harvard.edu/abs/2000ApJ...539L...9F
  9. ^ Open Questions, Particle Physics, item 13
  10. ^ newscientistspace item 8
  11. ^ Open Questions, Cosmology and Astrophysics, item 12
  12. ^ newscientistspace item 3
  13. ^ "Scientists Find That Saturn's Rotation Period is a Puzzle". NASA. June 28, 2004. http://www.nasa.gov/mission_pages/cassini/media/cassini-062804.html. Retrieved 2007-03-22.
  14. ^ Kenneth Chang (July 29, 2008), "The Nature of Glass Remains Anything but Clear", The New York Times, http://www.nytimes.com/2008/07/29/science/29glass.html
  15. ^ "The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition." P.W. Anderson (1995), "Through the Glass Lightly", Science 267: 1615
  16. ^ John R. Vacca (2004), The World's 20 Greatest Unsolved Problems, Prentice Hall, ISBN 9780131426436, http://books.google.com/books?id=ouMmAAAACAAJ
  17. ^ Feder, T.; John, O. (2004), Physics Today: 27, doi:10.1063/1.1881896, http://www.physicstoday.com/pt/vol-58/iss-1/PDF/vol58no1p31a.pdf
  18. ^ http://www.physorg.com/news187421719.html
  19. ^ doi:10.1209/0295-5075/89/58001
  20. ^ Open Questions, Condensed Matter and Nonlinear Dynamics, item 2
  21. ^ Proceedings: Mathematical, physical, and engineering sciences (Royal Society) 453, 1997, "An unsolved problem in modern physics concerns the phenomenon of sonoluminescence"
  22. ^ Open Questions, Condensed Matter and Nonlinear Dynamics
  23. ^ The Nobel Prizes in Physics 1901-2000
  24. ^ The Office of Science - What is Physics?
  25. ^ "The MKI and the discovery of Quasars". Jodrell Bank Observatory. http://www.jb.man.ac.uk/public/story/mk1quasars.html. Retrieved 2006-11-23.
  26. ^ Hubble Surveys the "Homes" of Quasars Hubblesite News Archive, 1996-35

External links

Grand Unified Theory - The Next Logical Step

Click here, then go to the southeast to the terra incognito, which nevertheless produces a heck of a lot of papers, most of them probably wrong. A shame, because some of them are on the right path, and the way seems obscured for all the noise.

Specifically, look at...

- Grand Unified Theory
- Quantum Gravity
- Theory of Everything (a combination of the 2 above)

These are the "darling" realms of Science Journalists everywhere, but we haven't a workable theory of any of them.

So let's back up.

What is Grand Unified Theory?

Well first, it's pretty damned important, that's what it is.

Second, if we ever get it (Sheldon Glashow and Howard Georgi et. al. gave it a good shot, but came up short), then it will be a unification of The Electroweak Theory, and Quantum Chromodynamics, and we know the gist of them.

We KNOW what Q-Chro and EW are. So why not put most of the theoretical efforts there?

I don't know why not, but I believe in first-things-first and not putting the cart before the horse. In fact I'm not even sure this is where the most effort isn't being put forth, since the QG and TOE people seem to speak louder than most.

Tuesday, November 23, 2010

Garrett Lisi in Real Time

Garrett Lisi in 10 Years:

Garrett Lisi is responding to criticism and his critics over at Peter Woit's Not Even Wrong weblog, which means we get a double-dose of Lisi this month, as his article with Harvard-educated physicist Jim Weatherall is featured prominently in this month's issue of Scientific American.

Click here for the Not Even Wrong post and discussion (84 replies so far).

Lisi's version of E8 Lie Algebra, as far as I can tell, is an attempt to build a background upon which, with further development, the fundamental particles that we know exist today, with their exact masses, charges, and chiral behavior for those particles that behave so, will emerge. It has not accomplished its goal as of yet, but it is early and needs more work, as Lisi himself has stated right from the beginning.

Click here for Garrett Lisi's Homepage

C;ick here for Lisi's Elementary Particle Explorer and have some fun in Physics for a change.

I personally as a lifelong professional student have no idea where this theory is going. If it goes the way of Epicycles as its critics claim it is, then so be it. A great day will then come when the theory is disproven, as disproofs aka "falsifications" are often as famous as proven theories, as Michelson-Morley and Stern-Gerlach attest.

But if true, we are at the dawn of a really good thing.

I wish to see more people explore this theory. Its recent interest into triality is particularly exciting to me personally. The number 3, I have always felt, occurs with a bit more regularity in nature than it should. Is there something there? It will always occur more than 4 and less than 2, its neighboring integers, but seems to express itself moreso than that which would nicely fit its place in a first quadrant hyperbola bar graph of integer occurrence, regardless.

We'll see. Mathematics is beyond exciting once its frontiers are studied, and its seemingly limitless applications to Physics seem beyond the surreal. It is truly a beautiful world and E8 symmetry is likewise lovely. So let it be written, so let it be done.

Which reminds me, the picture above is not of Lisi but of the great actor Yul Brynner in "The King and I." "Men of a certain age" such as myself know this, I just remind us that young people exist who never knew of him. Youth is noone's fault, but that doesn't mean it is nevertheless an affliction. Father Time has the cure, be patient, like we all have to be as we await the further development of Lisi-Lie E8.

For Edgers, everywhere:

The Hall of Science in Queens

Business on Saturday took me to Queens, following which my wife and I decided to take in The Hall of Science, built for the 1964-1965 New York World's Fair and operating ever since. I'd last visited in 1965 at the age of 9, so this was a real treat for me.

I must say that minus the IMAX, the operating budget must be one-fourth the budget for Jersey City's Liberty Science Center which is in spitting distance of The Statue of Liberty, yet it's 4 times better.

I was pleasantly reminded of that which I'd forgotten, that being The History Wall (of famous mathematicians) in the permanent Mathematics exhibit. I could have spent all day there!

From the HoS website:

History Wall

The History Wall spans the time from the 12th century (approximately the beginning of modern mathematics) to the explosive development of mathematics today. Many of the world's greatest creative mathematicians are depicted. Each is designated by a panel made up of a portrait, personal introductory notes and significant mathematical achievements. Surrounding the portraits and biography are panels and notations that illustrate the active influence on the mathematicians and the important accomplishments of the period. A computer kiosk deployed more recently brings the analysis of mathematics up to date and allows for the expansion into future generations.

Spherical Cow

Spherical cow

From Wikipedia, the free encyclopedia

Spherical cow is a metaphor for highly simplified scientific models of reality. The phrase comes from a joke about theoretical physicists:

A spherical cow jumps over the moon.

Milk production at a dairy farm was low so the farmer wrote to the local university, asking help from academia. A multidisciplinary team of professors was assembled, headed by a theoretical physicist, and two weeks of intensive on-site investigation took place. The scholars then returned to the university, notebooks crammed with data, where the task of writing the report was left to the team leader. Shortly thereafter the farmer received the write-up, and opened it to read on the first line: "Consider a spherical cow in vacuum. . . ."[1]

As with any mathematical joke, it is told in many variants.[2]

In Russian, a spherical horse in vacuum [3] [4] from a joke about predicting race results is well known and is widely used common parlance.

The point of the joke is that physicists will often reduce a problem to its simplest form in order to make calculations more feasible, even though such simplification may hinder the model's application to reality.


Popular culture

The joke is referred to by Leonard Hofstadter in the form of a "spherical chicken" in the American sitcom The Big Bang Theory ("The Cooper-Hofstadter Polarization").

It is used in the title of at least one book: Consider a Spherical Cow: A Course in Environmental Problem Solving by John Harte.[1]

Chris Morris makes a literal reference to Spherical Cows in his spoof documentary series Brass Eye.

See also


External links