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Reliance on Information
edit"Correct and objective information exists. Otherwise, banking, cooking and chemistry would not be possible."*
"Correct, objective information and the Heisenberg principle are compatible."*
DISCLAIMER: THIS IS NOT INTENDED TO BE A CRITICISM OF WP. IT IS INTENDED TO POSITIVELY CONTRIBUTE TO THE UNDERSTANDING OF THE DYNAMICS OF INFORMATION RELIANCE IN GENERAL AND WP RELIANCE IN PARTICULAR, WITHIN THE LIMITATIONS OF THE PRESENT STATE OF WP TECHNOLOGY AND USER RULES.
How trustworthy is the information in WP?
I believe this question is important for all WP users. I am currently conducting an experiment to help answer this question. I hope the answer will be helpful to improve WP and its use.
Since information in WP is dynamic, this question cannot be answered by simply sampling at specific times. Instead, I decided to measure the lifetime of correct information (see definition below) that was seeded in WP edits of selected articles. To reduce error in defining what is correct information I used topics that are not the least controversial today, even though they are widely misunderstood (to motivate editing interest). As an important side benefit, this should provide a concrete editing benefit to WP.
Correct information
editThis item is provided in the context of the items "Neutral POV" and "Impersonal experiment" given below. "POV" is an abbreviation for "Point of View". "NPOV" is an abbreviation for "Neutral Point of View".
The correct information was defined following WP policy.
By correct information I do not mean a "may be correct but is disputed POV", or "consensus defined correctness", or "truth by activism in discussion lists", or "multiple POV information for the reader to choose from". On purpose, I refrained to edit articles that may have more than one acceptable POV today. I wanted the cases to be as clear-cut as possible but not dead, so that I could expect some editing interest by others. I limited myself to articles in physics, mathematical physics, trust theory, and other subjects in my core professional areas.
By correct information I also do not mean that I am claiming some sort of "perfect edit" with the first shot. Editing is best done collaboratively. Phrases may be clear to me and confusing or ambiguous to someone else.
By correct information I mean that which is known to be scientifically sound according to mainstream knowledge today -- in other words, that which a subject matter expert would most likely select, based on mainstream, updated and authoritative sources that can be independently verified. Even though the edit style may certainly be improved (see above), much care went into making sure that the information was scientifically sound, clear, referenced according to the WP reliable sources policy, and as concise as possible (without losing clarity). "Correct and objective information exists. Otherwise, banking, cooking and chemistry would not be possible."
By correct information I also mean absence of information that is not correct. Therefore, and with the exception of historically significant information (see below), I edited out (usually with embedded comments or talk-page comments) text and sections that contradicted correct information, were off-topic, or were not supported by references.
If an outdated or otherwise invalid POV was significantly quoted in past literature, the seeded edits included it in historical notes. This is the case, for example, with the concept of "relativistic" mass" in special relativity. This should also help provide a bridge from old edit versions including that POV, and keep a compromise within WP:NPOV guidelines.
WP relies on what reliable sources have said about the matter. By relying on what current, mainstream, verifiable sources have reported about a subject, I am limiting the influence of my POV. Further, it is important to note that evolution of this experiment does not exclude editing or recalling some of the correct information seeded in this experiment by this editor, if found to be dubious or in error. "Correct, objective information and the Heisenberg principle are compatible."
Post-exclusion of correct information from the experiment's metric is discussed in the item Impersonal experiment, and does not affect the experiment in any negative way.
References for the correct information are given in the Archives and in the Mass and energy in special relativity item below.
The experiment
editUsing the correct information and the method explained in this item, the edits were targeted to represent (as much as possible, see next items) non-controversial test points to measure the time evolution of trustworthy information in WP, as it is transformed, improved, or decays. I am not interested at this time in measuring style evolution, just content evolution.
As a further motivation to editing by others, even though the points and articles were relatively well-written, I did not strive for the best possible version. Some formulas were also left to be improved. This is an "inviting technique" I have seen and developed in collaboration work — by leaving areas to be improved, not only the original editor gains time in focusing on the core issues but also allows other people to feel motivated to participate. There is no need to make it perfect, just hitting close to the bull's eye. Ensuing discussion, when the conditions are right, should converge the result to a much better version, even better than the original editor could have done under best efforts. "Misteakes are a catalyst for the power of collaboration."
The correct information was seeded within a short time in a number of critical themes that are prone to errors. These themes are an "eye-sore" either because their subtle but critical aspects are usually forgotten (e.g., the cross product of vectors is a pseudovector, not a vector) or because they are tainted by widespread misconceptions and crank theories (e.g., almost anything that has to do with special relativity).
The idea was that by verifying how the seeded information would "decay" with time, I could see how and for how long correct information would survive in WP. In other words, in a benign-editor model (assuming that vandalism is corrected), how well would other good-intentioned editors be able to keep the seeded information alive through the edit cycles? If the seeded information "dies", can it be reborn again through another editor?
To do the experiment, I decided to:
- edit a fairly large number of basic, "eye-sore" articles that were in my professional area and had incorrect information;
- provide mainstream, WP:RS compliant, and accessible references for all edits in the edited articles, possibly more if contested;
- timely and openly discuss the edits in the talk pages with further references as needed;
- let time pass to see how much of that correct information will be "eroded" in time; and
- let others answer questions on the edits (may, as time permit, answer new questions).
I also edited other articles, just for fun. They too will be useful to verify the lifetime of information in WP.
So, the testing model is active editing, even after phase (4).
A prototype test was done during 2006, using an IP number. The results indicated that in less than 6 months a good number of correctly inserted edits had vanished. A case in point is spiral galaxy.
For this 2007 test, I used my identity to create a responsive environment for dialogue and critique. I chose a large number of articles around key, critical themes that are prone to errors (the "eye-sore" cases, see above) and have clear-cut answers (I avoided both dead and open themes). These articles were edited in the first three weeks of May/2007, to help establish a broad but clear "seed mark" for phases (1), (2) and (3) in 2007. Phases (4) and (5) began on May, 21, 2007.
Self-healing test
editThis experiment also stress-tests WP's capability for "self-healing" in case correct information is simply reversed by other editors. When reversal occurs, as opposed to simple editing of a phrase or sentence, it could be a sign of strong binding of other editors to their previous texts (which effects this experiment wants to measure). Therefore, understanding reversal dynamics and their possible voluntary or policy recall (i.e., recall as in reversing the reversal) are important for this experiment. At what level would recall occur, if it occurs at all? Is WP self-healing in a short-cycle or must the incorrect information be found again by a new editor and again corrected in an open, hopefully converging, self-healing cycle, or will it, again, be reversed?
Is editing WP a Sisyphus task?
In the case of a reversal, talking in the talk page and reversing again works in some cases. In other cases, it may create more resistance.
After some trial and error, the procedure followed in this experiment is to question a reversal in three steps, using the same terms that caused the correct information to be inserted in the first place -- under WP:NPOV, WP:Verifiability, WP:RS and other applicable WP policies.
Application of these policies in this experiment were summarized in an email from the creator of WP, Jimbo Wales, paraphrased from this post from September 2003 on the mailing list:
- If a viewpoint is in the majority, then it should be easy to substantiate it with reference to commonly accepted reference texts;
- If a viewpoint is held by a significant minority, then it should be easy to name prominent adherents;
- If a viewpoint is held by an extremely small (or vastly limited) minority, it does not belong in Wikipedia (except perhaps in some ancillary article) regardless of whether it is true or not; and regardless of whether you can prove it or not.
Thus, views held only by a tiny minority of people should not be represented as significant minority views, and perhaps should not be represented at all.
In the first step, a (for example) WP:NPOV and WP:RS violation notice is put in the talk page, substantiated by WP:NPOV and WP:RS valid references to the point(s) in question. This may be followed by a dialogue in the talk page, but keeping the issue within WP:NPOV and WP:RS and not in terms of "truth" ("Subjective truth is a pleonasm.") arguments.
If applicable, the violation notice also explains that historical references may mention a previous use or concept. In order to avoid warfare over neutrality issues, it is useful to try to come to a compromise about how a controversy should be described, so that it is fair to all. But a few things are absolute and non-negotiable, though. WP:NPOV for example. In the case of the correct information in this experiment, this concept was already included in the seeded edits as historical notes when the subject was significantly quoted in past literature.
The second step is triggered if no action occurs for some days, or if violation worsens by another reversal in the same article or section. In this case, the relevant article or talk section are tagged according to WP policy — for example, {{articleissues}}, or {{POV}}.
It is important to note that resolution of the tagged issues does not exclude editing or recalling some of the correct information seeded in this experiment, if found to be dubious or in error, as discussed in the item Impersonal experiment, which exclusion does not affect the experiment in any negative way. The experiment metric is dynamic and refined post-experiment.
What happens after the second step? If no action is taken, the previous editors refuse to recall their reversal, there is no resolution, or if the tags are erased without concern to WP policy?
As discussed in the Neutral POV item, incorrect information in WP confuses readers and reduces the verifiability of WP, preventing other WP editors from doing productive work.
According to WP: Dealing with biased contributors, there must surely be a point beyond which WP's very strong interest in being a completely open project is trumped by the interest the vast majority of WP writers have, in being able to get work done without constantly having to fix the intrusions of people who do not respect WP's policy.
The third step, thus, tests what happens if the concerns are not resolved voluntarily within WP policy.
Actions in the third step shall be as passive as possible. The third step is also open ended. Will WP main editors and software catch that an article or section was tagged with {{articleissues}}, or {{bias}}, which tags were deleted without resolution? Will other editors step in and complain? Will WP self-heal?
Neutral POV
editSomeone may rightly say "This experiment identifies certain information as trustworthy, on the basis of your own POV. Wikipedia strives for a neutral point of view WP:NPOV, which perforce includes perspectives other than your own on what is accurate and what is not accurate."
My first remark is that, as I have seen in some WP articles (e.g., on the area of special relativity), some editors think they can justify keeping an improper POV by demanding to see many sources of authoritative information that show otherwise. However, a simple google search can show that the improper POV is not mainstream in the area.
As I have also seen in other cases (e.g., in special relativity), some editors think they can justify an improper POV by demanding that something that is published 3x and more be considered within the WP:RS (reliable sources) policy. However, not every published source is equally updated or authoritative on the subject matter.
In these cases, and as a result of such use of WP:NPOV and WP:RS, WP has entrenched incorrect and misleading information that is defended without regard to the WP:OWN policy (for example, in special relativity areas). This, in addition to confusing readers and reducing the verifiability of WP, prevents other WP editors from doing productive work on what could be a better version -- with the subsequent loss of time. It may also drive away new editors. In case of an eventual, and more likely with time, reversal, this can also lead to loss of work in intertwined intermediate edits.
With more time, more "rights" are claimed for a former group consensus based on such use of WP:NPOV and WP:RS, making corrections progressively harder under the same flawed use of WP:NPOV, with more "rights" claimed in reversals, in a vicious circle.
Reasoning can actually make matters worse in such situations. In the present state of WP, reasoning ("When in doubt, think.") and the use of logic ("Snow is white is true if and only if Snow is white", Tarski) does not seem to be accepted as way to neutrally process information. The more one tries to explain about the non-controversial nature of a POV and/or assert what is logically true, even in kind and objective logical terms based on verifiable sources, the further one usually departs from consensus ... which absence is then claimed to invoke WP:NPOV against the non-controversial POV.
Such flawed, circular uses of WP:NPOV, where "anything goes" justifies "anything goes", are made worse by a sense of "ownership" by editors (mentioned, by at least one editor, as desirable), notwithstanding WP:OWN, and is observed to strongly bind editors to article versions.
To work safely within WP:NPOV, I favored following the WP reliable sources policy WP:RS over engaging too much in logical discussions. After the points are made, it is good form in online discussions (when archives are readily available, as in WP) to refer to what was already said and referenced, rather than saying it again. As a further benefit, this usually helps reduce flaming.
A beneficial (but often misunderstood and misused) aspect of WP editing is allowing anonymous editing. I decided not to use anonymity for reasons of experiment transparency. However, it could help in reducing resistance to change introduced by expert editors, for example by thinning the link to a "feared" scholarly authority, or to a well-known person with reportedly strong views. The MCWG] (an Internet discussion group that I founded in 1997 and had participants from 26 countries) was an early Internet experiment to demonstrate the benefits of anonymous discussions. The discussions were public as in a listserver but with a privacy innovation -- the participants' names and email addresses were anonymized. This privacy feature, which any participant could break voluntarily by simply disclosing name and email address in the list, allowed the discussion to proceed on a technical level more easily, with less ad hominem attacks. This also allowed unwitting competitors to collaborate, creating an open climate. The flip side was that anonymity removed the reputation deterrent to uncivil behavior. In two years, two anonymous users had to be banned from the MCWG after failing repeated calls for civil behavior. This, however, represented less than 0.2% of the number of users.
These principles allow this experiment to address, thus, how effectively fairness, openness, WP:NPOV, WP:RS, and other WP policies are in terms of protecting correct information, versus the more aggressive approach one can see by perusing the talk-pages of various articles related to this experiment.
This experiment is my research. However, the correct information is not my research or my POV.
The correct information is based on subjects that are scientifically sound and not the least controversial today, (even though they are widely misunderstood, and that is why they were chosen). Further, the correct information is supported by mainstream, updated and authoritative sources cited with every edit, which sources are available in English and can be independently verified. Several sources are available free of charge online, in addition to the hard copy version.
However, even though I took all reasonable care in selecting the correct information points, problems may still occur. "Correct, objective information and the Heisenberg principle are compatible." For example, one of my correct information points may be shown to be not as clear as I would desire. Also, there is always a possibility for some erudit edit that correctly erases what I defined as correct information. These cases are easily compensated for, as it is a simple matter to eliminate such points (justifiably) from the measured data set, before the evaluation.
In other words, the POV used for the correct information points is objectively verifiable and "self-healing" regarding my own influence. At any time, the POV or the trustworthiness metric may be contested and changed, even after each "end time" of the experiment. This is a dynamic experiment in a dynamic environment, with a metric notion that is also dynamic.
Impersonal experiment
editThe idea that the observer does not influence what is observed was shown to be incorrect in physics by Heisenberg with the uncertainty principle. Today, this is well accepted outside of physics. The act of measurement itself introduces an irreducible uncertainty in the measurement. This also helped question the so-called scientific impartiality view.
How to be impartial, when impartiality is impossible?
Impartiality is, thus, a matter of effort. To improve impartiality in this experiment, I followed my own "sunshine rule": all my assumptions and methods are laid bare for examination, critique, and can be changed to provide a different view if so dictated by the experiment itself (i.e., changed to try to minimize influence).
For example, I was careful in describing what this experiment considers to be correct information — both in terms of what it is as well as to what it is not.
Yes, my set of correct information is my version of what I consider (as a subject matter expert with verifiable qualifications) to be what a "subject matter expert would most likely select, based on mainstream, updated and authoritative sources that can be independently verified.".
But I also present to the reader exactly what my version is (even during the experiment, to preserve a trail of cause-effect and create opportunities for feedback), with a list of answers that I consider non-controversial facts. For example, in special relativity.
To make sure that my justification for the edits were visible to any editor, I used several channels. I used well-documented edit summary lines, I left HTML tags in the text to call attention to incorrect text that was deleted or changed, and I was available in multiple talk pages, in addition to my own and a special talk page for this experiment. I also answered questions in other editor's talk pages.
So, the context of the experiment and the metrics are in plain view.
To further improve impartiality, the experiment was also designed to be editor-agnostic.
It is quite possible that some good but radical changes that I introduced through my correct information points are not valued, are rejected or simply disappear from WP's current version by some editing mistake. "It is better to distrust a truth than to trust a falsity."
However, at any time, another editor can come by and retype the same correct information without knowing anything about myself or my edit, which edit may be buried too deep in the history list to be readily visible. The experiment is editor-agnostic. For the final evaluation (at each "end"), it matters not that the correct information came through my neurons.
And that's also what this experiment wants to measure, as the 'acceptance of change in WP', not just the 'trustworthiness of information'. After all, if errors cannot be changed efficiently (because WP editors are too strongly bound to articles), or if new qualified editors (hopefully with better argumentation skills and time than myself) are not attracted to WP to instill new blood into the mix, or if WP rules for peer review do not work to eventually restore the correct information, then these are also factors that reduce the trustworthiness of information in WP — and can be individually measured.
This experiment, thus, strives to be, and can be dynamically corrected to be, as impersonal as possible.
Previous Work
editThanks to Salix alba for pointing to me this previous work on the same subject, using a different approach -- Maintenance of standards
Concluding words
editHow can we preserve point to view diversity, tolerance, and yet prevent the decay of trustworthy information in WP? I don't have the answer but I am presenting the question -- with a method to help measure its importance.
Of course, people may say that this whole approach is over-simplified. But to make some progress in this, I believe we need to cut to the core issue first. As a further benefit, we shall not run out of work in improving it.
In terms of possible dynamic changes in the overall metric used (for example, one of my correct information points is shown to be not as clear as I would desire), it is a simple matter to weed out that point (justifiably) from the measured data set.
Finally, this is a publicly-verifiable experiment. This experiment has several "ends" — at each "end" of this experiment, at various times, all data will come from WP itself, objectively and publicly available, for history, versions and talk pages. All data is publicly verifiable.
I am grateful to all the nice (and not so nice sounding) editors I met (and will continue to meet) here. I hope this experiment will help shed some light into their own efforts as well.
Comments
edit- Please submit your comments on the experiment talk page
- For general comments (not related to this experiment), please leave your message at my talk page
Early results
editIt is too soon (May 27, 2007) for quantitative data. But some points seem to be fairly clear. The problem is not anonymity. Academic qualifications do not always mean fairness or even competence. It seems that current WP rules are somewhat in contradiction with the WP goals.
On May 21, 2007, I received a disputed user notice of 3RR violation because someone else reverted my edits +3x and I was not silent about it (it was an "eye-sore" case). This shows that there are indeed strong forces binding editors, including myself, to material in the articles. This also shows that the seeded information may not survive very long, as there is no binding force to other editors!
This experiment does not want to be a "trap", a riddle for unsuspecting editors. To make sure that my justification for the edits were visible to any editor, I used several channels. I used well-documented edit summary lines, I left HTML tags in the text to call attention to incorrect text that was deleted or changed, and I was available in multiple talk pages, in addition to my own and a special talk page for this experiment. I also answered questions in other editor's talk pages.
Some changes, notwithstanding all the above, were reverted without a WP valid justification. Applying WP policy, typically results in the following steps, after a revert:
1. my statement, in the talk page, that the reverted version was correct according to NPOV and RS, with current, authoritative, mainstream, supporting references (while the current version is not), with a call for that version to be reinstated.
2. back arguments, without understanding (or, perhaps even reading) the current references, that the changes do not make sense and contradict well-known (but outdated) authors.
3. Reaffirmation of #1, with more references and with a tag for NPOV dispute placed in the article.
4. The tag is deleted under a call to the "break all rules" WP policy, stating that the article cannot be held "hostage" to a clearly incorrect edit.
While this goes on, anyone reading WP or editing it will not see correct information, where correct information means information that is not the least controversial today.
Now, how many more hoops should a voluntary WP editor have to jump in order to assure that WP reflects a viewpoint that is not controversial? Escalating the edit difference to any form of litigation does not seem to be a pleasant or fun activity, or rewarding in time.
The WP idea of "anyone can edit" finds its limits in the observation that "ignorance is bliss". Those who ignore, by definition, ignore that they ignore. Many subjects, most (but not all) of them technical, have subtleties that are important. It may be easy to read a correct phrase but it is a lot harder to write one, as anyone taking a test knows.
So, requiring a WP editor to follow NPOV and RS when the editor simply does not understand the subject (eg, is not able to ascertain the falsity of his beliefs versus what the references say), seems to be nonsensical. No one can write what they do not understand. The emphasis in WP:Verifiability goes nowhere in such context, and we can see that in WP.
WP is an encyclopedia project but the bottom of the iceberg is currently dominated by an education project for editors, which is open ended.
Looking at this as a pyramid, at the top we have well-educated, scholar editors, numbering (say) one hundred. At the bottom, we have well-meaning but clueless editors who want to edit what looks to them to be an error or lack of an example that they heard somewhere, but which is not correct (according to WP:Verifiability references that they do not have and, even if they would read, would have the same "error").
I still don't have the answers. The experiment, hopefully, asks some of the right questions that we need to see in order to improve the quality of information found in WP.
Mass and energy in special relativity
edit- DO NOT COMMENT HERE - Please submit your comments on these points in the experiment talk page
- Archive: Use archive link in the experiment talk page
I may change this item frequently, with clarification and additions.
How to know that you are being swindled: if the book, course you are taking, or article you are reading differs from the answers given below — complain! These areas (barring any new physics discovery!) are not controversial today.
- Invariance and conservation are not the same. It is clearer to reserve the term "change" when discussing conservation, and use the term "difference" when discussing invariance. If a quantity is invariant, then it will have the same measured value in any inertial reference frame. If a quantity is conserved, then its value, as measured in a particular inertial reference frame, does not change over time. [1]
- In classical physics, the 3-momentum vector (px, py, pz) of an isolated system is a conserved quantity. In special relativity (in units in which c=1), the energy momentum 4-vector (E,px,py,pz) replaces 3-momentum as the conserved quantity; the magnitude of the 4-vector is computed as (E² - px² - py² - pz²)1/2. The mass of the system is defined to be the magnitude of the energy-momentum 4-vector and is thus an invariant.[1]
- Mass means invariant mass. Mass does not increase with speed, even though energy does. [1], [2]
- The concept of "relativistic mass", which increases with speed, is no longer used in physics and there are no longer prominent defenders of its use. The use of "relativistic mass" should be restricted to historical references, not used to explain physical phenomena. Relativistic mass was endorsed by well-known physicists in the past (1912-1980). For example, in 1912, Richard C. Tolman coined the concept of relativistic mass, in stating: “the expression m0(1 − v2/c2)−1/2 is best suited for THE mass of a moving body”.[3]. After 1934, relativistic mass was also defined by Richard C. Tolman [4] as m = E/c². Because the energy E is observer dependent (varies from frame to frame), this formula makes m depend on the observer. The term "relativistic mass" can be easily seen to be inconsistent. For example, one cannot observe changes in the mass of an object as a function of the speed of an observer relative to the object (to make it clearer, as it does not matter who is considered to be at rest). So, if a fast rocket passes near you and someone in there looks at you, you will not increase your mass. In other words, you will not become a black-hole if you move fast enough. The Newtonian physics p=mv momentum equation, cited in the past as a motivation to use relativistic mass, is invalid in special relativity. The association of "relativistic mass" with gravitational effects is fundamentally incorrect; for example the gravitational attraction between the photon and a large mass (the Sun) is determined by their energy-momentum tensors, not just by their energies. Relativistic mass also makes the increase of energy of an object with velocity or momentum to be connected with some change in internal structure of the object that would increase its mass, which change cannot be observed. [2], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14]
- The photon is massless. The "relativistic mass" of the photon is undefined. There is no frame in which the photon is at rest (no frame in which the momentum of a photon is zero). The photon has energy E=pc, where p is the photon's momentum and c is the speed of light. The photon has no rest energy and no rest mass. [1]
- Mass can be converted to massless energy according to E=mc2. Every mass corresponds to energy. [1]
- Energy can be converted to mass according to m=E/c². Not every energy corresponds to mass. [1]
- Contrary to classical physics, an isolated (free) system can reduce or increase its mass by internal mass energy conversion. For example, mass is not conserved when an isolated body (in a system considered large enough to be closed) emits a photon, or undergoes nuclear fission or fusion. However, an isolated (free) system cannot reduce or increase its energy by internal mass energy conversion. [1], [2]
- Two different isolated systems, with the same energy content, can have different invariant masses. For example, a system of two photons can be massless or have an invariant mass up to 2E/c², where E is each photon's energy (assumed equal), as a function of relative momentum orientation for the photons. So, in such a system, independently of the energy content being held constant at 2E, the invariant mass may vary from zero to 2E/c². [6], [15]
- The term "rest energy" is used for the energy content Eo of a body that is 1) isolated (free), and 2) at rest relative to the observer. Due to the special relativity theory mass-energy equivalence, the rest energy corresponds to the mass m = Eo/c² (this equation cannot be applied to a photon). In general (including photons), the invariant mass is given by the energy-momentum relation (mc²)² = E² - (pc)². If conditions (1) and (2) apply, then the invariant mass is equal to the rest mass. If the isolated (free) condition no longer applies (e.g., the body is placed near another body) for a body originally with rest mass m, its invariant mass will be less than m. [1], [2]
- In classical mechanics, energy is always expressed relative to a reference, arbitrary energy level, and can be positive or negative; only difference in energy is a measurable quantity. The "rest energy" (see item directly above), however, is defined absolutely and is always positive. [1]
- When physics laws are written as equations, it should be possible to make an arbitrary choice of the coordinate system (including handedness and units). To avoid problems, one should be careful when comparing quantities to verify that they behave equally under all transformations that need to be considered; for example a scalar cannot be compared to a vector component. The different invariance properties between mass and energy are due to the fact that energy is a component of the energy momentum 4-vector (E,px,py,pz), while mass (a scalar) is its magnitude. In special relativity, it is common to use units with c=1, where c is the speed of light. When using c=1 units, it is a common mistake, for example, to write the mass energy equation as m=E and infer that mass and energy are one and the same thing, or write the energy-momentum relation m² = E² - p² and infer that, in a closed system, mass must be conserved because the energy momentum 4-vector is conserved. [1]
- The mass-energy equivalence Eo =mc² changes the classical physics mass and energy conservation laws for isolated (free) systems: 1) contradicts conservation of mass (mass can be converted to massless energy); and 2) allows conservation of energy to be calculated in absolute terms (as rest energy). [1]
- It is a common misconception to consider that mass is completely equivalent to energy in special relativity. In spite of views endorsed by well-known physicists in the past (1905-1980) and popular philosophical discussions otherwise, mass and energy are not two forms of the same thing:
* Mass is a scalar (magnitude of the energy-momentum 4-vector), an invariant and is not conserved in isolated (free) systems; while
* Energy is the time component of the energy momentum 4-vector, is not an invariant, and is conserved in isolated (free) systems.
Energy also appears as a more fundamental quantity; while there is "massless energy" (e.g., a photon), there is no "energyless mass". Conversely, while an energy does indeed correspond to any mass, the opposite is not true as mass does not correspond to every energy (e.g., a photon). [1], [7], [6], [14] - The principle that the mass of a system of particles is equal to the sum of their masses, even though true in classical physics, is false in special relativity. The mass-energy equivalence formula implies that bound systems have a mass less than the sum of their parts. The difference, called the mass defect, is a measure of the binding energy — the strength of the bond holding together the parts (in other words, the energy needed to break them apart). The greater the mass defect, the larger the binding energy. The binding energy is released when the parts combine to form the bound system. [16] In particular, the total mass of two protons and two neutrons after they are brought together to create a helium nucleus is less than the total mass before, of each isolated (free) nucleon. The mass difference being the energy that is released when the four nucleons are brought together, divided by the speed of light squared. The mass difference and the energy released are related by the mass-energy equivalence formula: (mass before - mass after)c2 = energy released; the energy released is equal to the difference in rest energies.
- A common misconception is that the main reason for the power of nuclear fission and nuclear fusion used in energy generation and atomic weapons is the mass-energy conversion given by Eo = mc². Historically, Eo = mc² has been connected with nuclear energy. In reality, the main energy contribution both in nuclear fission and nuclear fusion is due to binding energy conversion (see item directly above) to other forms of energy, not mass conversion (energy from mass conversion is small in comparison). The reason is that systematic trends in nuclear binding energies allow energy to be obtained by nuclear fission of heavy nuclei (heavier than iron or nickel) or nuclear fusion of light nuclei (lighter than iron or nickel). In nuclear fission, most of the energy released comes from the difference in binding energy when a heavier nucleus is split into lighter nuclei (that are much more strongly bound). In nuclear fusion, fusing lighter atomic nuclei to give heavier nuclei sets off energy because the binding energy of the end product is larger than the sum of binding energies of the initial nuclei. [17]
References
- ^ a b c d e f g h i j k l Lev Davidovich Landau and Evgenii Mikhailovich Lifshits, (1987) Elsevier, ISBN 0750627689. Cite error: The named reference "LL" was defined multiple times with different content (see the help page).
- ^ a b c d Lev Okun, The Concept of Mass, Physics Today, June 1989.
- ^ R. Tolman, Philosophical Magazine 23, 375 (1912).
- ^ Tolman, R. C. (1934). Relativity, Thermodynamics, and Cosmology. Oxford: Clarendon Press. LCCN 340-32023. Reissued (1987) New York: Dover ISBN 0-486-65383-8.
- ^ "Does mass change with velocity?" by Philip Gibbs et al., 2002, retrieved Aug 10 2006
- ^ a b c Edwin Floriman Taylor, John Archibald Wheeler, Spacetime Physics: introduction to special relativity, W.H.Freeman & Co Ltd (1992), ISBN 0716723271.
- ^ a b Lev Borisovich Okunʹ, The Relations of Particles, (1991) World Scientific, ISBN 981020454X, p. 116-119, 127.
- ^ Arnold B. Arons, Teaching Introductory Physics, Wiley, (2001), ISBN: 0471137073
- ^ Usenet Physics FAQ
- ^ Gary Oas, On the Abuse and Use of the Relativistic Mass, 2005.
- ^ "Does light have mass?" by Philip Gibbs, 1997, retrieved Aug 10 2006
- ^ "What is the mass of a photon?" by Matt Austern et al., 1998, retrieved Aug 10 2006
- ^ William S. C. Williams, Introducing Special Relativity, CRC Press (2002), ISBN 0415277620
- ^ a b "Ouch! The concept of 'relativistic mass' is subject to misunderstanding. That's why we don't use it. First, it applies the name mass--belonging to the magnitude of a four-vector--to a very different concept, the time component of a four-vector. Second, it makes increase of energy of an object with velocity or momentum appear to be connected with some change in internal structure of the object. In reality, the increase of energy with velocity originates not in the object but in the geometric properties of space-time itself.", in Edwin Floriman Taylor, John Archibald Wheeler, Spacetime Physics: introduction to special relativity, op.cit. Cite error: The named reference "qut" was defined multiple times with different content (see the help page).
- ^ Tracing Difficulties With Relativistically Invariant Mass To Difficulties With Vector Addition Of Momentum In Newtonian Contexts by Andrew Boudreaux, in Physics Education Research Conference By Scott (EDT) Franklin, Jeffrey Marx, Paula Heron, American Association of Physics Teachers, Springer (2005), ISBN 0735402817.
- ^ Kenneth R. Lang, Astrophysical Formulae, Springer (1999), ISBN 3540296921
- ^ Max Planck Institute for Gravitational Physics, The systematics of nuclear binding energies
Truth and trust
editTruth is subjective. Wait. No! Subjective truth is a pleonasm.
Why?
Because, subjectively, we usually think that we are right. And what someone calls "truth" is what that person considers to be right. So, this is a full pleonasm.
What? You do not agree? That is not what you think is true? Well, it does not matter! This is the truth.
Biography
editEd Gerck, Ph.D.
Ed Gerck received his doctorate in physics (Dr.rer.nat.) from the Ludwig-Maximilians-Universitaet and the Max-Planck-Institut fuer Quantenoptik in Munich, Germany, 1983, with maximum thesis grade ("sehr gut"). He also has titles of Electronic Engineer (1977) and Master of Science (1978) from the Instituto Tecnologico de Aeronautica (ITA/CTA), Brazil.
In 1999, at the end of the DNS domain name registry management discussions during the formation of ICANN, Ed Gerck was nominated Registry Advisory Board Member at Network Solutions (NSI), to provide independent external advisory review of the design and testing of the NSI Shared Registration System. The Shared Registration System created a registry-registrar model for the DNS TLDs .COM, .ORG, and .NET, which opened up the business of domain name registration.
Ed Gerck work in information security and election integrity has received worldwide press coverage by The New York Times, Le Monde, O Globo, Forbes, CBS, CNN, Business Week, Wired and USA Today.
Publications and areas of interest include information security (cryptography, information theory, secure email, trust as qualified information in human-, machine-, and heterogeneous-based communication processes, online voting, usability, convenience in Internet security applications), software (Software-as-a-Service, secure programming, Java, javascript, PHP, x86/87 assembler), physics (quantum physics, high-power lasers, laser applications), and mathematics (cryptography, Clifford algebra, topology, numerical methods).
More information at gerck.com