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Flip Tanedo | USLHC | USA

View Blog | Read Bio

Meet the quarks

One of the most important experiments in the history of physics was the Rutherford experiment where “alpha particles” were shot at a sheet of gold foil. The way that the particles scattered off the foil was a tell-tale signature that atoms contained a dense nucleus of positive charge. This is one of the guiding principles of high-energy experiments:

If you smash things together at high enough energies, you probe the substructure of those particles.

When people say that the LHC is a machine colliding protons at 14 TeV, what they really mean is that it’s a quark/gluon collider since these are the subnuclear particles which make up protons. In this post we’ll begin a discussion about what these subatomic particles are and why they’re so different from any of the other particles we’ve met.

(Regina mentioned QCD in her last post—I think “subtracting the effects of QCD,” loosely phrased, is one of the ‘problems’ that both theorists and experimentalists often struggle with.)

This post is part of a series introducing the Standard Model through Feynman diagrams. An index of these entries can be found on the original post. In this post we’ll just go over the matter particles in QCD. (I’m experimenting with more frequent—but shorter—posts.)

A (partial) periodic table for QCD

The theory that describes quarks and gluons is called Quantum Chromodynamics, or QCD for short. QCD is a part of the Standard Model, but for this post we’ll focus on just QCD by itself. Quarks are the fermions—the matter particles—of the theory. There are six quarks, which come in three “families” (columns in the table below):

The quarks have cute names: the up, down, charm, strange, top, and bottom. Historically the t and b quarks have also been called “truth” and “beauty,” but—for reasons I don’t quite understand—those names have fallen out of use, thus sparing what would have been an endless parade of puns in academic paper titles.

The top row (u,c,t) is composed of particles with +2/3 electric charge while the bottom row is composed of particles of -1/3 charge. These are funny values since we’re used to protons and electrons with charges +1 and -1 respectively. On the one hand this is a historical effect: if we measured the quark charges first we would have said that

  • the down quark has charge -1
  • the up quark has charge +2
  • the electron has charge -3
  • and the proton has charge +3

It’s just a definition of how much is one “unit” of charge. However, the fact that the quark and lepton charges have these particular ratios is a numerical curiosity, since it is suggestive (for reasons we won’t go into here) of something called grand unification. (It’s not really as “grand” as it sounds.)

One quark, two quark, red quark, blue quark?

I drew the above diagram very suggestively: there are actually three quarks for each letter above. We name these quarks according to colors: thus we can have a red up quark, a blue up quark, and a green up quark, and similarly with each of the five quarks. Let me stress that actual quarks are not actually “colored” in the conventional sense! These are just names that physicists use.

The ‘colors’ are really a kind of “chromodynamic” charge. What does this mean? Recall in QED (usual electromagnetism) that the electron’s electric charge means that it can couple to photons. In other words, you can draw Feynman diagrams where photons and electrons interact. This is precisely what we did in my first post on the subject. In QED we just had two kinds of charge: positive and negative. When you bring a positive and negative charge together, they become neutral. In QCD we generalize this notion by having three kinds of charge, and bringing all three charges together gives you something neutral. (Weird!)

The naming of different kinds of quarks according to colors is actually very clever and is based on the way that colored light mixes. In particular, we know that equal parts of red + green + blue = white. We interpret “white” as “color neutral,” meaning having no “color charge.”

There’s a second way to get something color neutral: you can add something of one color with it’s “anti-color.” (You can formalize these in color theory, but this would take us a bit off course.) For example, the “anti-color” of red is cyan. So we could have red + “anti-red” (cyan) = color neutral.

If we don’t see them, are quarks real?

The point of all of these “color mixing” analogies is that [at low energies], QCD is a strongly coupled force. In fact, we often just call it the strong force. It’s responsible for holding together protons and neutrons. In fact, QCD is so strong that it forces all “color-charged” states to find each other and become color neutral. We’ll get into some details about this in follow up posts when we introduce the QCD force particles, the gluons. For now, you should believe (with a hint of scientific skepticism) that there is no such thing as a “free quark.” Nobody has ever picked up a quark and examined it to determine its properties. As far as you, me, the LHC, and everyone else is concerned, quarks are always tied up in bound states.

There are two kinds of bound states:

  • Bound states of 3 quarks: these are called baryons. You already know two: the proton and the neutron. The proton is a combination (uud) while the neutron is a combination (ddu). For homework, check that the electric charges add up to be +1 and 0. Because these have to be color neutral, we know that the quark colors have to sum according to red + green + blue.
  • Bound states of a quark and an anti-quark: these are called mesons. These are color-neutral because you have a color + it’s anti-color. The lightest mesons are called pions and are composed of up and down quarks. For example, the π+ meson looks something like (u anti-d).  (Check to make sure you agree that it has +1 electric charge.)

Collectively these bound states are called hadrons. In the real world (i.e. in our particle detectors) we only see hadrons because any free quarks automatically get paired up with either anti-quarks or two other quarks. (Where do these quarks come from? We’ll discuss that soon!)

This seems to lead to an almost philosophical question: if quarks are always tied up in hadrons, how do we know they really exist?

A neat historical fact: Murray Gell-Mann and Yuval Ne’eman, progenitors of the quark model, originally proposed quarks as a mathematical tool to understand the properties of hadrons; largely because we’d found lots of hadrons, but no isolated quarks. For a period in the 60s people would do calculations with quarks as abstract objects with no physical relevance.

Why we believe that quarks are real

This seems to lead to an almost philosophical question: if quarks are always tied up in hadrons, how do we know they really exist? Fortunately, we are physicists, not philosophers. Just as Rutherford first probed the structure of the atomic nucleus by smashing high energy alpha particles (which were themselves nuclei), the deep inelastic scattering experiments at the Stanford Linear Accelerator Center (joint with MIT and Caltech) in the 60s collided electrons into liquid hydrogen/deuterium targets and revealed the quark substructure of the proton.

A discussion of deep inelastic scattering could easily span several blog posts by itself. (Indeed, it could span several weeks in a graduate quantum field theory course!) I hope to get back to this in the future, since it was truly one of the important discoveries of the second half of the twentieth century. To whet your appetites, I’ll only draw the Feynman diagram for the process:

This is unlabeled, but by now you should see what’s going on. The particle on top is the electron that interacts with the proton, which is drawn as the three quark lines on the bottom left. The circle (technically called a “blob” in the literature) represents some QCD interactions between the three quarks (holding them together). The electron interacts with a quark through some kind of force particle, the wiggly line. For simplicity you can assume that it is a photon (for homework, think about what is different if it’s a W). We’ve drawn the quark that interacts as the isolated line coming out of the blob.

This quark is somewhat special because it’s the particle that the electron recoils against. This means that it gets a big kick in energy, which can knock it out of the proton. As I mentioned above, this quark is now “free” — but not for long! It has to hadronize into more complicated QCD objects, mesons or baryons. The spectrum of outgoing particles gives clues about what actually happened inside the diagram.

We’ve just glossed over the surface of this diagram: there is a lot of very deep (no pun intended) physics involved here. (These sorts of processes are also a notorious pain in the you-know-where to calculate the first time one meets them in graduate courses.)

(By the way: the typical interactions of interest at the LHC are similar to the diagram above, only with two protons interacting!)

A hint of group theory and unification

I would be negligent not to mention some of the symmetry of the matter content of the Standard Model. Let’s take a look at all of the fermions that we’ve met so far:

There are all sorts of fantastic patterns that one can glean from things that we’ve learned in these blog posts alone!

The top two rows are quarks (each with three different colors), while the bottom two rows are leptons. Each row has a different electric charge. Each column carries the same properties, except that each successive column is heavier than the previous one. We learned that the W boson mediates decays between the columns, and since heavy things decay into lighter things, most of our universe is made up of exclusively the first column.

There are other patterns we can see. For example:

  • When we first met QED, we only needed one type of particle, say the electron. We knew that electrons and anti-electrons (positrons) could interact with a photon.
  • When we met the weak force (the W boson), we needed to introduce another type or particle: the neutrino. An electron and an anti-neutrino could interact with a W boson.
  • Now we’ve met the strong force, QCD. In our next post we’ll meet the force particle, the gluon. What I’ve already told you, though, is that there are three kinds of particles that interact with QCD: red, green, and blue. In order to form something neutral, you need all three color charges to cancel.

There’s a very deep mathematical reason why we get this one-two-three kind of counting: it comes from the underlying “gauge symmetry” of the Standard Model. The mathematical field of group theory is (a rough definition) the study of how symmetries can manifest themselves. Each type of force in the Standard Model is associated with a particular “symmetry group.” Without knowing what these names mean, it should not surprise you if I told you that the symmetry group of the Standard Model is: U(1) SU(2) SU(3). There’s that one-two-three counting!

It turns out that this is also very suggestive of grand unification. The main thrust of the idea is that all three forces actually fit together in a nice way into a single force which is represented by a single “symmetry group,” say, SU(5). In such a scheme, each column in the “periodic table” above can actually be “derived” from the mathematical properties of the GUT (grand unified theory) group. So in the same way that QCD told us we needed three colors, the GUT group would tell us that matter must come in sets composed of quarks with three colors, a charged lepton, and a neutrino; all together!

By the way, while they sound similar, don’t confuse “grand unified theories” with a “theory of everything.” The former are theories of particle physics, while the latter try to unify particle physics with gravity (e.g. string theory). Grand unified theories are actually fairly mundane and I think most physicists suspect that whatever completes the Standard Model should somehow eventually unify (though there has been no direct experimental evidence yet). “Theories of everything” are far more speculative by comparison.

Where we’ll go from here?

I seem to have failed in my attempt to write shorter blog posts, but this has been a quick intro to QCD. Hopefully I can write up a few more posts describing gluons, confinement, and hadrons.

For all of you LHC fans out there: QCD is really important. (For all of you LHC scientists out there, you already know that the correct phrase is, “QCD is really annoying.”) When we say that SLAC/Brookhaven discovered the charm quark or that Fermilab discovered the top quark, nobody actually bottled up a quark and presented it to the Nobel Prize committee. Our detectors see hadrons, and the properties of particular processes like deep inelastic scattering allow us to learn somewhat indirectly about the substructure of these hadrons to learn about the existence of quarks. This, in general, is really, really, really hard—both experimentally and theoretically.

Thanks everyone,
Flip, US LHC Blogs

(By the way, if there are particle physics topics that people want to hear about, feel free to leave suggestions in the comments of the blog. I can’t promise that I’ll be able to discuss all of them, but I do appreciate feedback and suggestions. Don’t worry, I’ll get to the Higgs boson eventually… first I want to discuss the particles that we have discovered!)

  • AlexP

    What does the prime of q’ mean in the Feynman diagrams of top quark production ?

    In most cases, it seems q stands for an up or charm, and q’ for the corresponding down or strange, but then some “t-channel tqb” diagrams, eg at http://www-d0.fnal.gov/Run2Physics/top/singletop_observation/, would not conserve electric charge.

    Great blog BTW – have read the whole series.

  • Hi Alex — thanks! What a great page, too—I’ll probably end up borrowing some of their figures (with proper referencing, of course!) for future posts. I think D0 has slightly nicer plots and public pages than CDF… though I should be careful saying that since most of the experimentalists I talk to have ties to CDF. 🙂

    As to you question, I assume that you are referring to diagrams like this (from the same page):

    Here the prime just means “a different quark.” The reason for this is that we know that the W connects quarks of different charge: so in that diagram the q’ has to be a charge +2/3 quark and q has to be a charge -1/3 quark in order to satisfy conservation of electric charge. (The W carries +1 unit of charge from the qq’ fermion line down to the bt fermion line.)

    This is more or less what you said, I think—though I may have the q and q’ mixed up.

    In this particular diagram, the gluon is the really energetic guy… so probably the q’ is most likely an up quark and the q is a down quark (for most reactions).

    I guess another point is that the people doing the analysis don’t necessarily care what q and q’ are. In the detector they’re just going to show up as jets where (especially for the light quarks) it is hard to identify the original scattering quark.

    [I suspect that you probably know a lot of this if you’re already reading the D0 physics pages!]

    Thanks for the great comment,

  • josh222

    Hi Flip,
    you wrote:

    “The quarks have cute names: the up, down, charm, strange, top, and bottom. Historically the t and b quarks have also been called “truth” and “beauty,” but—for reasons I don’t quite understand—those names have fallen out of use, thus sparing what would have been an endless parade of puns in academic paper titles.”

    Maybe you you laughed too soon 🙂

    Do you know why they call it “atoms”?

  • Stephen Brooks

    The other name for that LHCb particle is the slightly ridiculous “bottomonium” 🙂

  • Tim

    “top” and “bottom” are not immune to puns. Before the top was discovered, some theorists were obsessed with “topless models”, and there was an extensive “search for naked bottoms …”

  • Haha, good observations everyone.

    Josh—I never realized that “LHCb” was short for “Large Hadron Collider beauty experiment.” Though I admit that sounds better than “LHCb” which conjures up the image of a “b-team”… e.g. is LHCb supposed to be the junior varsity version of the LHC? 🙂

    “Atom” comes, I believe, from Greek for indivisible. A poor name in retrospect, but I think the idea of indivisible constituent particles was a big step philosophically. I won’t begrudge Democritus for not knowing about subatomic structure! 🙂

    Stephen — indeed! It is common to name quark–anti-quark mesons made up of the same heavy flavor as quark-onium where “quark” is replaced by the flavor. For example, bottomonium and charmonium are both mesons which friends of mine have worked on.

    … if they discover a fourth generation of quarks I hope they name one of them the panda. That way we can talk about panda-monium.

    Tim — thanks for pointing these out to me! I’ll have to recycle those jokes in my own talks in the future. 🙂

    Thanks for the comments everyone!

  • josh222

    Sorry, my question was not really clear.
    Of course I know what the word “atom” means and where it comes from.

    On the site I linked to it reads:
    “6 September 2010: Beautiful atoms”
    “The LHCb has observed beautiful atoms. The atoms are bound states of the beauty quark and anti-beauty quark.”

    Why do they call a quark/anti-quark particle “atom”,
    has it anything in common with atoms (besides the mass)?

  • josh222

    There was some unintended pun with the LHC in some media
    some time ago:

    I found a hint on some interesting event related to
    promotion/recruitment of young scientists in:

    The press release from CERN with the links to the web-cast
    in 4 different languages can be found here:

  • Frank1728

    (1) By putting the lepton families and the quark families in columns as in your last diagram, the implication seems to be that a fundamental reason exists for the electron family to be closely related to the up/down family, the muon family to the charm/strange family, etc. Is there such a physics reason for this implication?

    (2) Although the number of lepton families with “light” neutrinos is limited to 3, no such limit exists for the number of quark families, although there seems to be a cosmology conjecture that there may be 15 fundamental particles max. Thus, there is room for another 2 or 3 quarks to add to the 12 fundamental particles in your last diagram. If another quark family of 2 quark is discovered (two quarks to satisfy GIM), how might you then display the columns of lepton and quark families?

    (3) Thanks to you and the other bloggers for some very interesting physics summaries and for relating some of your real-life experiences in the research projects.

  • Hi Josh — ah, I now understand your question about the phrase “atom” by LHCb.

    The analogy of B mesons to atom is actually pretty good, but you are absolutely correct to be skeptical about taking the analogy to seriously.

    The analogy is accurate in the following respect: just like an atom (Hydrogen in particular), a B meson is a quantum mechanical bound state between a heavy fermion (the [anti] b quark) and a light fermion (a d or s for the neutral B mesons). In this respect one can think of the b quark as a “nucleus” and the light quark as “electrons” that are bound to it by some central potential. This time the potential is QCD rather than QED.

    Mesons with one heavy and one light quark are interesting in this respect since the kind of models (or ‘effective theories’) that people use to describe them often do mirror the quantum mechanics of the Hydrogen atom.


  • Hi Frank! Good questions, they basically are addressing the structure of unification.

    I think the short answer is: there’s no clear cut answer. 🙂 There are many models for unification, and I only gave a picture of the simplest types.

    You’re absolutely right that it’s not strictly necessary that the up and down quarks should be paired with the electron and electron neutrino. The reason why people arrange the particles according to mass based on how we understand the Higgs mechanism that gives masses to the fermions in the Standard Model.

    I wish I could give a good intuitive reason for why the number of quarks and leptons have to be the same, but there’s a technical reason called anomaly cancellation. In some sense the Standard Model is quantum mechanically inconsistent if we don’t have the same number of quarks and leptons. The theoretical structure of the model ends up demanding that certain numbers have to sum to zero, and these numbers are related to the charges of the quarks and leptons under the various forces. It turns out that the way charges are assigned requires that the “columns” of matter particles are complete, i.e. they each contain an up-type quark, a down-type quark, a charged lepton, and a neutrino.

    (There might be other places, maybe Wikipedia, which explain anomaly cancellation in an intuitive way. I think the PBS “Elegant Universe” documentary had a very awkward example that probably didn’t convey the main point.)

    As far as the Standard Model is concerned, anomaly cancellation is required by self-consistency. One of the appeals of grand unified models is that they provide some explanation for this structure.

    Thanks for your kind words about our blog!

    Best wishes,

  • josh222

    Thanks for the explanation Flip!

    Now I know where I have seen the diagram on the right
    of the first plot before. It really looks like some
    electronic band structure.

    The last time I have seen this was at the famous
    “Britney Spears’ Guide to Semiconductor Physics”

  • Frank1728

    Thanks for your comments about anomaly cancellation requirements in response to my questions about the lepton family and quark family relationships.

    I read some of the online articles about the triangle anomaly and others. There exists a fascinating post by John Baez asking about weak hypercharge and anomaly cancellation requirements at


    which, about 2/3 the way down the long page of comments with other mathematicians and physicists (March 29, 2009), points out that 2 solutions to the anomaly cancellation hypercharge equations exist:

    (1) the solution normally chosen by the Standard Model in which all left-handed fermions and all left-handed antifermions have non-zero hypercharge, and

    (2) only the left-handed anti-quarks have non-zero hypercharge.

    The first solution, the normal Standard Model solution, leads to the necessity of having both a lepton family and a quark family in each “generation”, but without specifying which lepton family goes with which quark family.

    The second solution means that the “generation” can have simply a quark family alone (or a lepton family alone) and still satisfy the triangle anomaly cancellation, etc.

    I wonder why this second solution has been ignored in the discussions. With it, one can have a 4th quark family without a 4th lepton family, for example. As several people have pointed out, the existence of this 4th quark family would resolve the baryon asymmetry problem in the Universe.

  • Alexander Thoor

    Hi Flip and the others, what a great blog, thank you 🙂
    Now to my question:
    If there is more than one collision per crossing in the detectors, how can it tell which particle came from what collision? Or how is that not important to know if it cant tell?

    Best Regards

  • Hi…

    Nice…Quark explaination Flip ^_^ it is very interesting for me to know this information after I read Christine Nattrass post, anyway I have a few question…

    1.What Type Of Quark LHC Analyze ? (Is It Mesons ?)

    2.Is It Quark Really Looks Like Liquid Or Because Of Gluon It Looks Like Liquid ?

    3.If Its Liquid Isn’t QGP Vaporate In The Air ???

    For…me QGP concept can be describe like Cloud concept so only thats I wanna know for now ^_^


  • Hi Fujimia! My apologies, I think some of our correspondence might suffer a bit from translation, but I’ll do my best to answer and feel free to follow up with more questions.

    1. This will be the subject of my next post! ^_~ Unfortunately I’m not so much of an expert, perhaps one of the other bloggers can also say some things. When very high energy quarks/gluons are produced, they hadronize into mesons and baryons. I’ll explain more later, but in fact the very high energy quarks/gluons turn into a *spray* of many hadrons (mostly mesons). We call this a hadronic “jet.” It is these jets of hadrons that we observe in our detectors, particularly in the so-called hadronic calorimeter. Small and light mesons will also sometimes make their way all the way to the outer parts of the detector, I’ll introduce a few of these in my future post.

    2/3. Unfortunately I don’t quite understand the questions here. Quarks and gluons are particles, just like any other particle. I think you are referring to the quark gluon plasma (QGP)… this is a rather different kind of phenomenon that unfortunately I am not such an expert on. (Christine is an expert, however—perhaps she can shed some light on this!)

    I can give a very rough picture of the difference. The “high Pt” (high momentum; in particular high transverse momentum for experts) interactions at the LHC that will be looking for things like the Higgs and new particles look at the scenario where individual quarks and/or gluons interact and produce new, heavy particles. This is a *pointlike* interaction where all the energy is concentrated in the quark/gluon interaction. In quark-gluon plasma experiments, the idea is to collide very dense nuclei and to produce not a pointlike interaction, but a small volume that with high energy. ((This is a very rough explanation!)) By doing so we can hope to study the collective behavior of quarks/gluons at high temperatures, not just the individual interactions of quarks and gluons.

    Unfortunately I cannot at the moment think of a good analogy for the quark gluon plasma as this is now a bit far from my expertise and I don’t want to say misleading things! 🙂

    Thanks for the questions!

  • QCD deserves central focus, since the elucidation of quarks, gluons, and strings should lead to Plank scale models for atoms and waves. Research progress depends on the data density of the atomic topological function used to analyze the structural details of electrons, waves, energy, and force fields. Recent advancements in quantum science have produced the picoyoctometric, 3D, interactive video atomic model imaging function, in terms of chronons and spacons for exact, quantized, relativistic animation. This format returns clear numerical data for a full spectrum of variables. The atom’s RQT (relative quantum topological) data point imaging function is built by combination of the relativistic Einstein-Lorenz transform functions for time, mass, and energy with the workon quantized electromagnetic wave equations for frequency and wavelength.

    The atom labeled psi (Z) pulsates at the frequency {Nhu=e/h} by cycles of {e=m(c^2)} transformation of nuclear surface mass to forcons with joule values, followed by nuclear force absorption. This radiation process is limited only by spacetime boundaries of {Gravity-Time}, where gravity is the force binding space to psi, forming the GT integral atomic wavefunction. The expression is defined as the series expansion differential of nuclear output rates with quantum symmetry numbers assigned along the progression to give topology to the solutions.

    Next, the correlation function for the manifold of internal heat capacity energy particle 3D functions is extracted by rearranging the total internal momentum function to the photon gain rule and integrating it for GT limits. This produces a series of 26 topological waveparticle functions of the five classes; {+Positron, Workon, Thermon, -Electromagneton, Magnemedon}, each the 3D data image of a type of energy intermedon of the 5/2 kT J internal energy cloud, accounting for all of them.

    Those 26 energy data values intersect the sizes of the fundamental physical constants: h, h-bar, delta, nuclear magneton, beta magneton, k (series). They quantize atomic dynamics by acting as fulcrum particles. The result is the exact picoyoctometric, 3D, interactive video atomic model data point imaging function, responsive to software application keyboard input of virtual photon gain events by relativistic, quantized shifts of electron, force, and energy field states and positions. This system also gives a new equation for the magnetic flux variable B, which appears as a waveparticle of changeable frequency. Molecular modeling and chip design engineering application software developer features for programming flow are built-in.

    Images of the h-bar magnetic energy waveparticle of ~175 picoyoctometers are available online at http://www.symmecon.com with the complete RQT atomic modeling manual titled The Crystalon Door, copyright TXu1-266-788. TCD conforms to the unopposed motion of disclosure in U.S. District (NM) Court of 04/02/2001 titled The Solution to the Equation of Schrodinger.

  • Pingback: GUT exposure « Trauma Blog()

  • Alf Pretzell

    Main items against continued operation of LHC and related engines

    – a public discussion about the possible outcome of experiments and theory is missing for decades already

    – the safety assessment of this experiment does not describe the comparison with nature or counterarguments against the proposed risks with enough detail – the assessment is made by the people operating the engine and not by an independent board and not according to modern standards

    – a discussion even at very simple levels (momentum of the secondaries, safety of Lorentz transformation) was not possible with my colleagues – clarification could not be reached

    – this extremely abstract science is fully absurd if we consider the lack of knowledge in other fields (knowledge of self, infections, ecological problems) and limited cognitive power of us humans

    – enormous money and more important manpower is consumed by this project – in general science of matter is worth to be explored of course

    – this kind of “wild” pioneering without knowledge of self is possibly dangerous for us all – men, women, children – , not only in particle physics but as well in nanophysics, molecular engineering, genetics and so forth. This is known in principle but the controlling institutions like ITAS in Germany or the offices of the UN are giving general advice but are not active at the respective places according to my witness – LHC is a good example

    I appeal to all: scientists, citizens, officials -> control this very deficient situation immediately and make aware others. These words are rough for you experimenting people but they are true und I heard too much lies here on earth in this respect – discuss and adapt your doing. This is possible by downshifting and like I told you all already…

    Alf Pretzell

  • Alf Pretzell

    My efforts should be understood as an emergency call – I apologize for any unprofessional communication. I am quits with the participants concerning exchange of concepts and demands to the best of my knowledge.

    Institutions and scientists involved have been informed as well as the public.

  • Alf Pretzell

    Please bear in mind I acknowledge your research, the difficult task of theory building. Remember I am myself a scientist:



    Because I was not able to establish a stable environment apart from the Internet for discussing those problems I left this engagement. Find argumentation in a discussion with John Ellis from spring 2010 here


    UNESCO declares in http://unesdoc.unesco.org/images/0016/001600/160021e.pdf

    “Science ethics, articulating the basic values and ground rules of scientific research and its applications, especially in light of the growing risk of conflicts of interest (e.g., due to pressure to publish, commercialization or security constraints),and assessing the institutional mechanisms that define academic freedom and responsibility.”

    Don’t take it amiss, but for me those issues a are often less “ethics” but more just “collegium logicum”. Nevertheless they are difficult enough I feel I have to admonish you to occupy yourselves in this regard: “Il faut les tous …” We need all – not only you but you at CERN as well – to develop guidelines inside our complex techno-culture inside a complex world.

  • Alf Pretzell

    Particle Physics I admit is fair to provide me with this little speaker’s corner here inside your nets. That’s really very nice of you. Indeed up to now I didn’t “meet the quarks”… nevertheless in real world I debated with many particle and astrophysicists from 2008 till 2010 and had to learn CERN is seriously about this obviously too boisterous and – concerning the clever comparison with natural events – scarcely assessed research including MBHs or QGP.

    Santa Clara University explains Hans Jonas’ “The imperative of Responsibility” on http://www.scu.edu/ethics/practicing/focusareas/environmental_ethics/lesson8.html

    “Jonas argued that, formerly, humans were a part of nature. They understood themselves as integral to nature, and could not act so as to seriously disrupt their environment. The Enlightenment revolutions in science, technology and economics changed that way of thinking and our capacity to destroy the environment upon which society depends. We humans are now able to intervene in nature in ways not previously possible. A number of these technological interventions can cause irreversible harm to human health and the environment, and that this demands more sustained ethical reflection from every stakeholder, those who benefit and those who are harmed by these technologies.”

    Like mentioned above many of the implications following such an attitude inside our socio- and ecosphere I consider logical, rational, intellectual – briefly speaking: Tasks for YOU tough thinkers at CERN…!

  • Oscar

    Atom is from the Greek word for ‘uncutable’. We use it because the first suggestion of finite dub-structure came from a Greek philosopher who theorised that if you take something, cut it in half, cut it in half again and so on you would eventually reach something you cannot cut. He was kind of right – as far as we can tell you can’t ‘cut’ quarks – but what he was thinking about wasn’t actually atoms. The idea kind of faded for a while but (as I understand it) was brought back by chemists because chemistry made much more sense with atoms. And the test is history. Actually, all of it was my vague recollection of history but still.

  • Alf Pretzell

    “By the way, if there are particle physics topics that people want to hear about, feel free to leave suggestions in the comments of the blog”

    Santa Clara again concerning this topic urgently suggested here by me and known since more than 2000 years:

    “In Aristotle’s “Nicomachean Ethics,” phronesis is “the science of what is just, fine and good for a human being.” It requires skill in gathering knowledge and MAKING JUDGMENTS ABOUT IT.”

    …yes: Today’s colleagues from philosophy are able to help the CERN team as well. That would be really really very nice.

  • Alf Pretzell

    Rafaela Hillerbrand, Toby Ord and Anders Sandberg, colleagues from philosophy or ethics, help here in the Journal of Risk Research pointing to “… methodological challenges for risks at low probabilities and high stakes”:


  • Alf Pretzell

    [Editor’s note: This comment has been edited at the author’s request.]

    Only public intelligence, in principle bravely brought forward by CERN for example, can be acknowledged and corrected, but has to serve public safety and order. Even this, to, on the one hand, build protective intelligence publicly, to correct it, make it recognizable and, on the other hand, watertight against occult, deviant or naive incompetence and intelligence or severe dual-use, are complex tasks for us and no automatisms – soothingly we remember corrections, in most cases, are normal for a dynamic human society.

    I conclude experiences during commitment are shared by many social
    achievers. Though witness, originality, direct power and partly impartial judgement of helpful contributors are to be respected, unprofessional civic commitment, shall preferably be embedded by awake professional – trained by own commitment e.g. – support and inspection, official and legal frame, to
    care, which can be civil service’s excellence, duty and mastery, for check, composure and comfort, escort learning processes and to avoid
    overburdening and exclusion of frequently little experienced comitted forces,
    Because there are plenty of observations, contributions and needs in between civic notes on the public sector, like e.g. pot-holes, garbage, and party political or highly complex issues. This defence and structuring of the public nowadays is faced by clubs, NGOs, lectures, book publications or organized by the Internet: Concerning participation new framing and intrumentation structuring public perceptibility, controlled accessibility and participation, forging self-determined but obligatory links to the public administration, on the level of town councils e.g., but preserving own judgement, emphasizing procedures and practice by creation of incremental microactions, legitimizing, limiting, accrediting and culturally embedding free commitment e.g. within circle of friends, maybe by mutual support, meeting the level of experience, creatively rewarding it, e.g. by free use of public property, are comfortably possible. Inadequate as it might be to let socially relevant tasks be solved solely by an
    elite, officials or commercial interests, it can be likewise misleading to let this be done, too loosely, by lay labour without strong professional and official support, by the arts or by occult, secluded intelligence. But knowledge regarding participation, therefore, should be further activated, especially in the age of too technical Internet, because lay and ad hoc contributions from their part may
    irritate professional routines, wrong or partly wrong maybe, but finely tuned and, see the following section, sprightly embedded.

    Consider to support this idea at CERN, recover your intelligent and brillant teamwork by further developing the world wide web in terms of a reanalogization of digital routines. We can make use of existing routines for safety, privacy and possibility for surveillance, but in the context of recent debate about big data and NSA.