A mass of information

[Fred56]

Ahem.

This thread, "heated" though some may feel it may have become, has spawned at least one "child" thread process. In which there is much discussion of black holes and so on, how we can look at them and what information is available (from them to us).

There also has developed in that thread, (it seems to me) a perception that its parent has "diverged" from mainstream Physics. I say this is not true at all, we are discussing the nature of not just reality, but the reality of information, and believe me, it is most definitely connected. You need to remove your thermodynamically-designed classical spectacles for a bit.

[foodchain]

Ahem.

This thread, "heated" though some may feel it may have become, has spawned at least one "child" thread process. In which there is much discussion of black holes and so on, how we can look at them and what information is available (from them to us).

There also has developed in that thread, (it seems to me) a perception that its parent has "diverged" from mainstream Physics. I say this is not true at all, we are discussing the nature of not just reality, but the reality of information, and believe me, it is most definitely connected. You need to remove your thermodynamically-designed classical spectacles for a bit.

 

 

Something I have noticed is computer models using mathematics can develop all kinds of exotic environments in where strange stuff can occur. You seem to be one very interested in say physics for example. I have a rather stark question basically. Is the reality as put forward by physics more or less a quantitative mathematical model that represents only that. What I mean is you can understand what will occur via the math, but only to that extent. Also, if per say this is true, when we view say the universe through a physics model, is it safe to say then what I am really seeing is a mathematical model of the universe? Such as our current skills with math basically doing the whole QM observer thing on reality? Now I don’t put math at any different of a regard then language in general. It can be used to bias and of course can simply be wrong, or more or less human overall. What I am trying to ask is if physical models of the universe as produced by physics extend understanding past simply being a model that will predict based on math, and as such trying to think about energy as for what it really is, is not something such models really attempt to do at all. If this is true then what branch of science really attempts to explain what stuff is?

 

I think the question applies to information and its processing.

[Mr Skeptic]

...

There also has developed in that thread, (it seems to me) a perception that its parent has "diverged" from mainstream Physics. I say this is not true at all, we are discussing the nature of not just reality, but the reality of information, and believe me, it is most definitely connected. You need to remove your thermodynamically-designed classical spectacles for a bit.

 

What you don't seem to understand is that science doesn't give a damn about "reality". Science is about observable reality. If you say, for example, that gravity is caused by invisible pink unicorns according to Einstein's equations, science will say, "We don't care about the invisible pink unicorn; if we cannot observe a difference than we will just assume there is no invisible pink unicorn and keep just Einstein's equations. Cause it's simpler that way."

[Fred56]

Science is about observable reality.

Which, of course, everyone has an absolutely crystal-clear understanding of.

if we cannot observe a difference ...we will just assume there is no invisible pink unicorn

Natch.

 

Well, let's see if can "diverge any further" from the classical path...

 

"We adopt the view ...[that] information is the primary physical entity that possesses objective meaning. Bas[ed] on two postulates[:] ...(i) entanglement is a form of quantum information corresponding to internal energy, (ii) sending qubits corresponds to work, ...in the closed bipartite quantum communication systems the information is conserved. ...[A]lso [there is an]...entanglement-energy analogy in context of the Gibbs-Hemholtz-like equation connecting the entanglement of formation, distillable entanglement and bound entanglement. ...n the deterministic protocols of distillation the information is conserved." -Ryszard, Michal, and Pawel Horodecki 20 Jun 2000

 

Unless I'm mistaken, these guys are saying that sending "quantum information" is the equivalent of doing work... and that information, is like that other stuff, whatsaname, you know, energy...

[Mr Skeptic]

That is essentially correct. I think that information having energy is also why it cannot be transmitted faster than c.

[Fred56]

I am trying to ask ..if physical models of the universe as produced by physics extend understanding past simply being a model that will predict based on math, and as such trying to think about energy as for what it really is, is not something such models really attempt to do at all. If this is true then what branch of science really attempts to explain what stuff is?

 

There are literally thousands of mathematicians, physicists, philosophers, (and us in this forum), looking pretty hard at this. Our models seem to have done a fairly good job so far, but obviously our current views, still sort of stuck in the 19th century (to some extent), are possibly interfering somehow with the view we need.

I guess, one day when some future Einstein or Newton realises what it is we need to be "seeing", it will probably be considered something obvious, something we "should have been seeing" all along... something fairly obvious (about the universe) to anyone, if they just think about it...

 

A bit more "information mapping" has condensed into "real ideas" (I have thought of something):

 

The concept of information that not only has energy but a mass equivalent flies in the face of centuries of thinking, of presuming that we can interact with the world around us and observe the changes that “occur” in it, “receive” this information: some measurement, perhaps the circumference of some tree -and the result: “two full armspans and once to the elbow”, would then be stored, “weightlessly and masslessly”, in our consciousness, where it would remain until some later event required us to “access” it -(perhaps to “remember the location” of a large enough tree to build something), and this “remembering” -recalling from (some kind of) biochemical store, "information of use to us", is a cost in those terms, biochemical terms: molecules of ATP; proteins that fold and unfold as they “reconfigure”, reacting both chemically to “signal” molecules, and sometimes, less often, bursts of electrical activity occur (on the membranes of specialised cells within this processing and memory store).

 

All of which results in our conscious determination of the thing we measure and "receive information" from (both as photons, and as conceptual projections which, whilst receiving "photon information" (light), react electrically and biochemically to it. We believe that these mappings -ideas that “form” around such, or because of such, external sense stimuli (light, sound, etc.) are weightless, have no existence as real things except inside some space -a conscious or “unconscious” mind, which is part of the world around it, but appears to have its own internal universe of information.

 

Our brains project complex and intricate virtual models of reality on the world (of senses) and receive back the stimuli (information) needed to both find their way in the external and explore the internal space they themselves occupy...

 

“ ...then you'll see you're really only very small, and Life goes on within you and without you.” - George Harrison (sorry, couldn't resist)

 

There's also this:

The "potential information" of (quantum) superposition, cannot exist (have any mass or energy) until it is measured -unless this “virtuality” has some “virtually infinite” mass/energy equivalent.

 

There is actual "quantum information" and potential "quantum information”. The second becomes real only when we 'measure' its mass into existence.

 

The mass of photon “information” does not require us to project or measure anything, though it isn't free either, but the mass of “entanglement information” does, and it is extremely “unstable”, usually swamped by the “background noise” of thermodynamic, dispersive matter (which is also mass/energy). Also it doesn't "believe" in the existence of space. -D P LaTrobe-Easte 2007

[foodchain]

There are literally thousands of mathematicians, physicists, philosophers,

 

I just shortened the post so you would know I am still replying to you is all:doh:

 

Ok. Let me try again.

 

Here is a trick question, or at least I think its tricky. If you could move at the speed of a photon away from the universe as we know it, in terms of size. This is if you could do such, eventually the universe would become so small that you would not see it anymore. So in that, is distance really what is existing or the change brought about by acts of energy/information? Is it by energy that my environment has changed so much, or is it simply spatial distance that has changed so much?

 

What I am trying to get at is physics has taken all the natural phenomena of the universe, and put it through a human made thing, such as our thought of chiefly current mathematics. So when you take a physical model of the universe, to view the universe and everything in it, from a photon to an amoeba, what I am I really looking at in terms of that model? I mean the entire reality of a black hole as put forward currently is theoretically accepted on the basis that such models have produced success in being able to predict natural phenomena’s behavior. So the black hole for all intensive purposes in what? What does this mean for what a particle is, or a photon, or even the structure of an atom or even what an atom is?

 

I always thought physics was trying to determine the exact or absolute reality of nature, but I don’t really know if that’s what its about anymore, so I am confused. So the question again is really this one. Does physics try to figure out what energy is, or does it simply build mathematical models based on trying to predict the behavior of natural phenomena?

 

As for the rest, such and philosophy and everything else in-between. One of the reasons I am so interested in biology is I think we really need to be able to solve for life, I think its applies to so much really, such is how we think or even how we view to really anything that has to do with humans or and or life.

[fredrik]

I always thought physics was trying to determine the exact or absolute reality of nature, but I don’t really know if that’s what its about anymore, so I am confused. So the question again is really this one. Does physics try to figure out what energy is, or does it simply build mathematical models based on trying to predict the behavior of natural phenomena?

 

I'm not much into quotes in general, but here is one I like that applies.

 

"There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature."

-- Niels Bohr

 

I think this quote captures the essence that science isn't about finding forever lasting truths, it's about learning. And if you develop Bohrs statment with the interpretation that the implicit observer - "we" - is arbitrary and that every observer does not necessarily agree, then I think the statement is very modern and still applies.

 

Everything we "know" about nature, is acquired during our experience with it. So it seems very natural to think that the "process of inducing and selecting expectations" from real interactions is more to the fundamental point.

 

So if someone says that "we know what the electron has a certain mass" - I think the more fundamental part is to expose the exact process of, given our history, we are lead us to this "knowledge"? But analysing the logic of learning, we are at a more fundamental level IMO. Analysing that, should also yield us an estimate of the uncertainty in this knowledge.

 

This is how I like to interpret Bohrs quote.

 

/Fredrik

[Fred56]

One 'observation' that could be made about 'condensed' matter's and the photon's ability to be more than one wave function is that they are independent of one aspect of entropy (our measure of dispersal/distance), but not independent of another aspect, which results in its 'death'/decoherence.

The photon is the other side of the mass/energy relation, but can be 're-quantised' to divide into two copies. Mass cannot divide like photons (except when its moving, it can 'spread out' and seemingly travel every available path), but forms a sort of blob of a single quantum state at low temp. (its entropy has to be lowered), and single atoms can entangle various quantum states (spin polarisation, magnetic phase) with neighbours, but usually only when it is 'cold'.

What explains this (superposition is affected by the random, vibrational aspects of matter, but ignores the effect of this, which is the dispersal of the same matter)?

 

Reality is out the WINDOW --look, out there...

"What are the limits of human knowledge? Is the physical world shaped in some sense by our perception of it? Is there an element of randomness in the universe,or are all events predetermined?

 

Mandel,being inclined toward understatement,offers a more modest description of his mission."We are trying to understand the implications of quantum mechanics," he says,"The subject is very old,but we are still learning." Indeed,it has been nearly a century since Max Planck proposed that electromagnetic radiation comes in tidy bundles of energy called quanta.

 

Building on this seemingly tenuous supposition,scientists erected what is by far the most successful theory in the history of science.In addition to yielding theories for all the fundamental forces of nature except gravity,quantum mechanics has accounted for such disparate phenomena as the shining of stars and the order of the periodic table. From it have sprung technologies ranging from nuclear reactors to lasers.

 

Still,quantum theory has deeply disturbing implications. For one,it shattered traditional notions of causality. The elegant equation devised by Erwin Schrödinger in 1926 to describe the unfolding of quantum events offered not certainties,as Newtonian mechanics did,but only an undulating wave of possibilities. Werner Heisenberg's uncertainty principle then showed that our knowledge of nature is fundamentally limited - as soon as we grasp one part,another part slips through our fingers.

 

The founders of quantum physics wrestled with these issues. Albert Einstein, who in 1905 showed how Planck's electromagnetic quanta, now called photons,could explain the photoelectric effect (in which light striking metal induces an electric current), insisted later that a more detailed, wholly deterministic theory must underlie the vagaries of quantum mechanics.

 

Arguing that "God does not play dice," he designed imaginary, "thought" experiments to demonstrate the theory's "unreasonableness." Defenders of the theory such as Niels Bohr, armed with thought experiments of their own, asserted that Einstein's objections reflected an obsolete view of reality. "It is not the job of scientists," Bohr chided his friend, "to prescribe to God how He should run the world.

...

After Einstein introduced his theory of relativity, notes Jeffrey Bub, a philosopher at the University of Maryland, "we threw out the old Euclidean notion of space and time, and now we have a more generalised notion." Quantum theory may demand a similar revamping of our concepts of rationality and logic, Bub says.

 

Boolean logic, which is based on 'either-or' propositions, suffices for a world in which an atom goes either through one slit or the other, but not both slits. "Quantum mechanical logic is non-Boolean," he comments. " Once you understand that, it may make sense." Bub concedes, however, that none of the so-called quantum logic systems devised so far has proved very convincing.

 

A different kind of paradigm shift is envisioned by Wheeler.The most profound lesson of quantum mechanics, he remarks, is that physical phenomena are somehow defined by the questions we ask of them. " This is in some sense a participatory universe," he says. The basis of reality may not be the quantum, which despite its elusiveness is still a physical phenomenon, but the bit, the answer to a yes-or-no question,which is the fundamental currency of computing and communications. Wheeler calls his idea "the it from bit."

 

Following Wheeler's lead, various theorists are trying to recast quantum physics in terms of information theory,which was developed 44 years ago to maximise the amount of information transmitted over communications channels. Already these investigators have found that Heisenberg's uncertainty principle, wave-particle duality and nonlocality can be formulated more powerfully in the context of information theory, according to William K. Wootters of Williams College, a former Wheeler student who is pursuing the it-from-bit concept.

 

Meanwhile theorists at the surreal frontier of quantum theory are conjuring up thought experiments that could unveil the riddle in the enigma once and for all. David Deutsch of the University of Oxford thinks it should be possible, at least in principle, to build a "quantum computer," one that achieves superposition of states. Deutsch has shown that if different superposed states of the computer can work on separate parts of a problem at the same time, the computer may achieve a kind of quantum parallelism, solving certain problems more quickly than classical computers.

 

Taking this idea further, Albert - with just one of his minds - has conceived of a quantum computer capable of making certain measurements of itself and its environment. Such a "quantum automaton" would be capable of knowing more about itself than any outside observer could ever know-and even more than is ordinarily permitted by the uncertainty principle.The automaton could also serve as a kind of eyewitness of the quantum world, resolving questions about whether wave functions truly collapse, for example. Albert says he has no idea how actually to engineer such a machine, but his calculations show the Schrödinger equation allows such a possibility." -John Horgan

The second "Albert" is David Z. Albert, at Columbia University who is researching a many-worlds model.

 

So, some scientists have successfully applied the Informatics concept of information -or more specifically, what communication or measurement are -in thermodynamic terms, to formulate newer versions of the earlier quantum field theories.

 

Shannon's 'information entropy" -which should more properly be called (un)certainty, has a symmetry with our thermodynamic model of heat. Despite the perceived problems with equating the two (which are related to the observation that heat is physical and "information" isn't). Entropy, a measure or metric of disorder in some system, offers a level of uncertainty to any observer who wishes to measure it.

 

Information in fact reduces an observers uncertainty about a system and so reduces the informational entropy (it doesn't add to it, and the thermal or physical entropy doesn't change, just knowledge of it). Measuring the state S of a system (knowing the state, or having maximal available knowledge), reduces an observer's entropic state (of knowledge), and so because the system does not, after all consist of an "external" observed, and a separate, "internal" observer, but is rather a single complementary system, our model of communication and measurement is certainly not representable as an independently available 'set'. It costs something to lower the uncertainty -and this cost is the measurement of that same 'external' thing. In this sense they are reflections of each other, or are symmetrical equivalents.

 

The more information (the more content in any message) the more reduction (in uncertainty) occurs. Information has energy. The equations show this symmetry, so it must behave in an equivalent way...

 

Edit: anyone reading this might spot a glaring error in the last couple of paragraphs (hint: it has to do with measurement). Can you spot it?

 

"The Question is: What is The Question?" -John A. Wheeler

[Fred56]

The "glaring error" in the previous post is indeed about measurement, and the fact that information has mass/energy.

Previously, when talking about the observer/observed measurement paradigm, I said:

[T]he thermal or physical entropy doesn't change

This is true -energy is conserved. But there has to be an exchange between the two -the observer must "extract" information (photons or other energy) from a system, and this lowers the amount in the system.

 

Something like an open fire, for example, is radiating energy in all directions. An observer will only be able to measure some of this. Most of the 'measurable' energy is lost to the surroundings.

 

Modern instruments can help to measure certain aspects of a system, but such things only reduce the effort needed at the time of measurement (it takes energy to make an instrument). They can collect information for us, but this “short cut” is illusory. Energy must be “collected” (by the electrons in our eyes' pigment cells, for instance), and the observer processes this "information energy", which requires more energy. Storing a measurement (as memory) is not cost-free. The input which 'produces' -via our brain- a memory, is also only a small part of the relative energy an observer must use to do this.

 

In other words, to have "complete" information about some system, the observer would need to 'measure' all of the photons (and any other energy output), which would mean extracting all of it from the observed system. This is not practicable, the system would need to lose all its energy, and we do not usually measure more than a tiny fraction of the total available information. The system being measured doesn't need to transfer much energy to an observer for them to do this –we are generally aware of a campfire, say. We can stand near it and feel warm (measure the fire), without having to look at it, and so we don't need to receive much information to do this. If we get too close (measure too much information) there is usually a result from the information energy overload --we get singed or burned.

 

So there is a cost in physical energy --radiation, sound, etc.-- to the (observed) system being measured, and a cost to the (observer) system --in chemical and electrical energy-- doing the measuring.

 

The small amount of energy transferred to the observer (measured), projects to a potentially unbounded amount of information (except that we generally don't spend a lot of energy on any single observation). The observer uses (their own internal store of) energy to map the information impinging on their senses to a more stable form (than a fleeting “sample”).

 

There is also a transfer from the observer to the external system. This is the work required by the observer to measure it, which again, in terms of the systems energy, might be small (and so have only a small effect). If you go near a fire, your body will absorb heat (part of this is your measurement), but the act of walking to the fire to take this measurement (and the fact your body absorbs heat without measuring it) will have some effect on the fire itself --although this isn't really noticeable.

 

Small systems with small energies have only a possibility of observation, which explains why we can't see very well at extremely small scales, despite having built instruments which, because they need to transfer a measurable amount of energy to an observer, must collect sufficient energy themselves. Also it is much easier to perturb the system because of the work required to be able to measure it.

 

So the problem is building a sensitive enough instrument that can record a tiny amount (say a single photon) of energy. This is only possible if such a signal is amplified dramatically (using, say a photomultiplier) -because neurons in an eye require many hundreds, or thousands of photons before they trigger a single pulse. Such a sensitive instrument will generally take a lot of effort to design and build. We are forever at this remove from the world of fundamental mass/energy quanta.

[lakmilis]

ok didnt read everything, but yes Fred I also am in the school of time does not exist. (works as a dimension in a model though by all means).

 

About the information, sure, so we say information is energy or must be encoded within it. Then I would like to hear the ideas from the aspect principle,, was it called?

 

ANyway, the expriment showing a couple photon pair , regardless of distance become reciprocally polarized when one of the two is polarized.....

 

Since no third photon can make an infinite jump between them, as long as this experiment stands, none of your 'strong' arguments hold as well...don't be so sure you got a clue about it

 

My proposal for this or rather inquiry was looking into something similar as Kaluza-Klein did, albeit philosophically or empirically rather than rationally (i.e. using observation to make deductions and inductions, rather than deriving it from pure tensor fields , mathematically and then testing if it would fit the data).

 

i.e. using 5 dimensions instead of 4 to describe the reality.

 

 

Anyway, I left that very vague on purpose, don't want people to digress, but link the aspect principle or experiment with the arguments of the planck energy being the smallest or even the only* way of passing information. And saying the photon is the smallest energy packet..doesn't neutrinos which are smaller 'physically' , have smaller energy than a photon? do they not carry information as they are in their own respect an 'entity' or object rather?

 

lak

[Fred56]

Ah, hmm, yes. Well perhaps there is a need to really define what information and communication actually are. There are the messages (intelligent or sentient) observers get, and there are (conceptually) messages between non-sentient observers. An electron emitting a photon which is then absorbed by another electron is 'communicating' in a physical sense (and after all, it is this same process that gives us vision). So getting them confused can be downright, well, confusing. I think there is definitely a difference. The whole field of Information Theory is apparently "non-physical", as opposed to the physical information in some thermodynamic system. We already understand this, but seem to get confused about the distinction all the time. Maybe "physical" information should always be called such, and "information" should be the label we give to the stuff in our brains (then we need to show just how they are different).

BTW this "aspect principle" or experiment with photons, can you post a bit more about it?

Aspect is the guy's name, yes? I haven't really looked at this yet.

[Riogho]

Communication is:

 

The process by which one person stimulates meaning in the mind of another person through verbal and nonverbal messages.

 

Trust me, I had to know that Word-for-Word for a class...

[Fred56]

The process by which one person stimulates meaning in the mind of another person through verbal and nonverbal messages.

This is the "second kind", only possible between sentient beings. However this is not the only definition: the world communicates with us too (and with itself).

[Mr Skeptic]

Communication is:

 

The process by which one person stimulates meaning in the mind of another person through verbal and nonverbal messages.

 

Trust me, I had to know that Word-for-Word for a class...

 

Best get off the internet then, cause that's computers communicating with other computers!

[Riogho]

 

I'm just doing what she told me! I told her it was a stupid definition too

[Fred56]

Not sure what sort of intro to give this one:

Swapping entanglement

...[A]n important feature is that teleportation provides no information whatsoever about the state being teleported. This means that any quantum state can be teleported. In fact, the quantum state does not have to be well defined; indeed, it could even be entangled with another photon. This means that a Bell-state measurement of two of the photons - one each from two pairs of entangled photons - results in the remaining two photons becoming entangled, even though they have never interacted with each other in the past ... Alternatively, one can interpret this "entanglement swapping" as the teleportation of a completely undefined quantum state (see Bose et al.). In a recent experiment in Innsbruck, we have shown that the other two photons from the two pairs are clearly entangled.

-physicsworld.com

[hilstein]

Heres the beginning of the essay (the rest is above):

A hundred years ago, a young scientist was thinking about our current view of the universe, and decided there was something wrong with it. He spent several years reviewing the thinking and insights into the nature of reality introduced by the theories of James Clerk Maxwell. He developed or adapted his own mathematical symbology, and constructed a theory which would predict the expansion of the universe.

For all of human history, man has believed in the existence of both an external and measurable world, and external and measurable time and distance within it. This is coupled, or co-cepted, with the belief that this measurement is “free”, it comes at no cost to either the observer, or the thing observed. There is no perturbation of any system and, conceptually, all information is available. These ideas -of complete information and an external measurable “system” that can be viewed as separate, or isolated, without cost- were thought by many, especially at the close of the 19th century, to be the keys to unlock the secrets of the universe (unfinished)...

 

 

This is just the Newton's viewpoint of spacetime

 

I was trying to define the non-existence of it (time). It isn't that easy, but I don't think I say: "It doesn't exist" and then: "but it does exist".

I say it exists only as a concept. That's an "idea" btw.

(that last sentence is recursively "defined by itself" -work that one out?)

 

i have similar thought as yours。i think time originate from the movement of objects。

[Fred56]

Here's a bit of, information, about the way we got to where we are with current (i.e. "modern") thinking:

19th-20th Century (end of Victorian era)

1873 Maxwell's theory of E&M describes the propagation of light waves in a vacuum.

1874 George Stoney develops a theory of the electron and estimates its mass.

1895 Röntgen discovers x rays.

1898 Marie and Pierre Curie separate radioactive elements. Thompson measures the electron, and puts forth his "plum pudding" model of the atom -- the atom is a slightly positive sphere with small, raisin-like negative electrons inside.

1900 Planck suggests that radiation is quantized.

1905 Einstein proposes a quantum of light (the photon) which behaves like a particle. Einstein's other theories explained the equivalence of mass and energy, the particle-wave duality of photons, the equivalence principle, and special relativity.

1909 Geiger and Marsden, under the supervision of Rutherford, scatter alpha particles off a gold foil and observe large angles of scattering, suggesting that atoms have a small, dense, positively charged nucleus.

1911 Rutherford infers the nucleus as the result of the alpha-scattering experiment performed by Geiger and Marsden.

1913 Bohr constructs a theory of atomic structure based on quantum ideas.

1919 Rutherford finds the first evidence for a proton.

 

History 1920’s

1921 Chadwick and Bieler conclude that some strong force holds the nucleus together.

1923 Compton discovers the quantum (particle) nature of x rays, thus confirming photons as particles.

1924 de Broglie proposes that matter has wave properties.

1925 Pauli formulates the exclusion principle for electrons in an atom. Bothe and Geiger demonstrate that energy and mass are conserved in atomic processes.

1926 Schroedinger develops wave mechanics, which describes the behavior of quantum systems for bosons. Born gives a probability interpretation of quantum mechanics.G.N. Lewis proposes the name "photon" for a light quantum.

1927 Certain materials had been observed to emit electrons (beta decay). Since both the atom and the nucleus have discrete energy levels, it is hard to see how electrons produced in transition could have a continuous spectrum (see 1930 for an answer).

1927 Heisenberg formulates the uncertainty principle.

1928 Dirac combines quantum mechanics and special relativity to describe the electron.

 

History 1930’s

1930 There are just three fundamental particles: protons, electrons, and photons. Born, after learning of the Dirac equation, said, "Physics as we know it will be over in six months."

1930 Pauli suggests the neutrino to explain the continuous electron spectrum for β-decay.

1931 Dirac realizes that the positively-charged particles required by his equation are new objects (he calls them "positrons"). This is the first example of antiparticles.

1931 Chadwick discovers the neutron. Nuclear binding and decay become primary problems.

1933 Anderson discovers the positron.

1933-34 Fermi puts forth a theory of beta decay that introduces the weak interaction. This is the first theory to explicitly use neutrinos and particle flavor changes.

1933-34 Yukawa combines relativity and quantum theory to describe nuclear interactions by an exchange of new particles (mesons called "pions") between protons and neutrons. From the size of the nucleus, Yukawa concludes that the mass of the conjectured particles (mesons) is about 200 electron masses. Beginning of the meson theory of nuclear forces.

1937 A particle of 200 electron masses is discovered in cosmic rays. While at first physicists thought it was Yukawa's pion, it was later discovered to be the muon.

1938 Stuckelberg observes that protons and neutrons do not decay into electrons, neutrinos, muons, or their antiparticles. The stability of the proton cannot be explained in terms of energy or charge conservation; he proposes that heavy particles are independently conserved.

 

History 1940’s

1941 Moller and Pais introduce the term "nucleon" as a generic term for protons and neutrons.

1946-47 Physicists realize that the cosmic ray particle thought to be Yukawa's meson is instead a "muon," the first particle of the second generation of matter particles to be found. This discovery was completely unexpected -- Rabi comments "who ordered that?" The term "lepton" is introduced to describe objects that do not interact too strongly (electrons and muons are both leptons).

1947 A meson that interact strongly is found in cosmic rays, and is determined to be the pion.

1947 Physicists develop procedures to calculate electromagnetic properties of electrons, positrons, and photons. Introduction of Feynman diagrams.

1948 The Berkeley synchro-cyclotron produces the first artificial pions.

1949 Fermi and Yang suggest that a pion is a composite structure of a nucleon and an anti-nucleon. This idea of composite particles is quite radical.

1949 Discovery of K[math]^+[/math] via its decay.

 

Era of “Strange” Particles

 

History 1950’s

1950 The neutral pion (π[math]^0[/math]) is discovered.

1951 “V”-particles are discovered in cosmic rays. The particles were named the Λ[math]^0[/math] and the K[math]^0[/math].

1952 Discovery of particle called delta: there were four similar particles (∆[math]^{++}[/math], ∆[math]^+[/math], ∆[math]^0[/math], and ∆[math]^-[/math]).

1952 Glaser invents the bubble chamber (looking at beer). The Brookhaven Cosmotron, a 1.3 GeV accelerator, starts operation.

1953 The beginning of a "particle explosion" -- a proliferation of particles.

1953 -57 Scattering of electrons off nuclei reveals a charge density distribution inside protons, and even neutrons. Description of this electromagnetic structure of protons and neutron suggests some kind of internal structure to these objects, though they are still regarded as fundamental particles.

1954 Yang and Mills develop a new class of theories called "gauge theories."Although not realized at the time, this type of theory now forms the basis of the Standard Model.

1955 Chamberlain and Segre discover the antiproton.

1957 Schwinger writes a paper proposing unification of weak and electromagnetic interactions.

1957-59 Schwinger, Bludman, and Glashow, in separate papers,suggest that all weak interactions are mediated by charged heavy bosons, later called W[math]^+[/math] and W[math]^-[/math].

Note: Yukawa first discussed boson exchange 20 years earlier, but he proposed the pion as the mediator of the weak force.

 

History 1960’s

1961 As the number of known particles keep increasing, a mathematical classification scheme to organize the particles (the group SU(3)) helps physicists recognize patterns of particle types.

1962 Experiments verify that there are 2 distinct types of neutrinos (e and µ neutrinos). Also inferred from theoretical considerations (Lederman, Schwartz, Steinberger).

1964 Gell-Mann and Zweig tentatively put forth the idea of quarks. Glashow and Bjorken coin the term "charm" for the fourth © quark. Observation of CP violation in Kaon decay by Cronin and Fitch.

1965 Greenberg, Han, and Nambu introduce the quark property of color charge.

1967 Weinberg and Salam separately propose a theory that unifies electromagnetic and weak interactions into the electroweak interaction. Their theory requires the existence of a neutral, weakly interacting boson Z[math]^0[/math]).

1968-9 Bjorken and Feynman analyze electron scattering data in terms of a model of constituent particles inside the proton. They use the word “parton” not quark. By mid-1960’s > 50 “elementary” particles! ⇒Periodic table3 quarks introduced to “explain” the periodic table. BUT quarks were not considered to be “real” particles.

 

History 1970’s

1970 Glashow, Iliopoulos, and Maiani (GIM) recognize the critical importance of a fourth type of quark in the context of the Standard Model.

1973 First indications of weak interactions with no charge exchange (due to Z[math]^0[/math] exchange.)

1973 A quantum field theory of strong interaction is formulated (QCD)

1973 Politzer, Gross, and Wilczek discover that the color theory of the strong interaction has a special property, now called "asymptotic freedom."

1974 Richter and Ting, leading independent experiments, announce on the same day that hey discovered the same new particle bound state of charm anti-charm).

1976 Goldhaber and Pierre find the D[math]^0[/math] meson (anti-up and charm quarks).

1976 The tau lepton is discovered by Perl and collaborators at SLAC.

1977 Lederman and collaborators at Fermilab discover the b-quark.

1978 Prescott and Taylor observe Z[math]^0[/math] mediated weak interaction in the scattering of polarized electrons from deuterium which shows a violation of parity conservation, as predicted by the Standard Model, confirming the theory's prediction.

1979 Evidence for a gluon radiated by the initial quark or antiquark.

 

History 1980’s-Now

1983 Discovery of the W[math]^+[/math]and Z[math]^0[/math] using the CERN synchrotron using techniques developed by Rubbia and Van der Meer to collide protons and antiprotons.

1989 Experiments carried out in SLAC and CERN strongly suggest that there are three and only three generations of fundamental particles.

1995 Discovery of the top quark at Fermilab by the CDF and D[math]^0[/math] experiments.

1998 Observation of Neutrino oscillations by SuperK collaboration. (neutrinos have mass!)

2000-1 Observation of CP violation using B-mesons by BABAR, BELLE experiments.

2002 Solar Neutrino problem “solved”.

2002 Nobel Prize is awarded with one half jointly to: Raymond Davis Jr, and Masatoshi Koshiba, “for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos”, and the second half to Riccardo Giacconi, “for pioneering contributions to astrophysics, which have led to the discovery of cosmic X-ray sources”.

--Aram Kotzinian Dec 2003,Torino

[Riogho]

And saying the photon is the smallest energy packet..doesn't neutrinos which are smaller 'physically' , have smaller energy than a photon? do they not carry information as they are in their own respect an 'entity' or object rather?

 

lak

 

 

Neutrinos have been discovered to have mass, because the math doesn't work if they don't. That is why we are looking for something beyond the Standard model (and the fact of no gravitation)

 

Photons however, are massless.

[Fred56]

Photons however, are massless.

However, this is only 'true' when they stop moving.

Since they never do this, their rest mass is only an extrapolation, in that sense.

Since they are a quantum wave, they have energy, and this gives them momentum. Their having a zero rest mass is moot because they 'transfer' energy. This is how you are reading this at the moment (assuming you aren't obliged to listen instead, or whatever).

[Martin]

 

Photons however, are massless.

 

Riogho, thanks. You are correct according to the majority usage of the word mass. AFAIK.

 

Fred insists on repeating what is now I think a minority usage of the word. I don't know what to do. there is no physical difference only a semantic one.

 

What can we do?

 

I would say that as of the article The Concept of Mass by Lev Okun in Physics Today 1989 it is improper for anyone to say "rest mass" because it is REDUNDANT.

The mass is the inertia of the object at rest and it is incorrect to use the adjective "rest" because that suggests that there is some other kind, which there is not.

 

Okun also showed a photostat of a letter from Einstein denouncing the use of the phrase "relativistic mass". One should not say "relativistic mass" because it is confusing. One should express it as energy.

 

These issues were all discussed at length by members of the physics community circa 1989, with many letters to Physics Today etc etc.

My impression gotten from hearing from many professionals and physics grad students is that this semantic issue is settled. There are, however, a few diehard hold-outs. Rindler, I believe, may be one.

 

The Wikipedia article on mass cites Rindler, which indicates it is in the hands of what I think is the minority. I imagine the Wiki article has been a battlefield with fanatics on both sides of the linguistic divide. for my part I just want to adopt majority usage and avoid squabble about meaning of words. Swansont would probably be able to settle what is majority usage. I ccould be wrong---I've only my impressions, no official statistics

 

According to my impression, Fred is in the linguistic minority, using what amounts to his own private language.

But in my experience people that use the minority, or obsolete, mass semantics are very difficult to change. they cling to it----although it has no physics content, it is just a verbal habit. Any physical statement about the real world you can translate into Fred's language, if you are careful and consistent. And he could, if he wanted, translate any statement of his into OUR language.

 

It is just that it is very INCONVENIENT to have two different languages being used----and they confuse newcomers because they sound the same.

 

Does anyone have an idea of what to do about this?

 

However, this is only 'true' when they stop moving.

Since they never do this, their rest mass is only an extrapolation, in that sense.

Since they are a quantum wave, they have energy, and this gives them momentum. Their having a zero rest mass is moot because they 'transfer' energy. This is how you are reading this at the moment (assuming you aren't obliged to listen instead, or whatever).

 

 

Fred, it sounds like you think you are reasoning but I can see no syllogisms.

what is accomplished by putting the word TRUE in quotes?

there is no need to put the word TRANSFER in quotes because photons do indeed transfer energy

 

of course photons have momentum. so what?

this does not imply that they have mass. In the case of a photon the quantity of momentum is E/c

 

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

I find your behavior here discouraging because on the whole I think you are entertaining and original. I usually like to read your posts when i come across them.

 

But here, instead of being amusing and creative, you sound to me like a low-grade semantic deviant.

 

We should to have at least a semblance of a common language where basic words mean the same thing to everybody.

 

so please show me some evidence that majority usage has changed since the debate around 1989 or stop saying that photons have mass.

[Fred56]

So how come they have energy (momentum), if it isn´t a MASS equivalent?

Aren´t they equivalent after all, you mean Albert got it all wrong? Can you show me where he did this in his working?

Maybe just leave the m word out of the discussion altogether, like the c word (cosmology) guys do?

Photons are energy, and as a quantised packet of energy, they carry or transfer (our observation), energy as momentum (things recoil from photons), saying they have zero mass is as meaningful as saying they have zero change in amplitude (which is also true in the sense it is constant -in 2 DF). Saying they travel at the speed of light because ´thats what zero mass particles do´ perpetuates the sense of something existing that doesn´t. Energy travels at the speed of light. And it doesn´t change amplitude when it does.

 

P.S. I appear to have been accused of doing something that I am actually doing the opposite of here, I do hope you notice. Their having a zero rest mass, or being without mass, is moot (actually, completely meaningless).

[Klaynos]

Because momentum is not dependent on mass? I just can be...

[Mr Skeptic]

And this is why it is a good idea to specify rest mass or relativistic mass when talking about certain subjects, rather than just saying mass and hoping people understood what you said. More annoying, but worth it so people won't argue semantics.

 

Martin, since relativistic mass is the sum of rest mass and kinetic energy, and is used in the same equations as mass is used, I think it is fair to to write it in terms of mass or energy. Rest mass can also be specified in terms of mass or energy.

 

Personally, I think of mass and energy as the same "stuff" but with different units, with the caveat that rest mass/energy is unavailable unless you do difficult stuff like fission/fusion or annihilation. Not sure if that is a universal thought, though.