timo

1) The sub- and superscripts in TeX must be enclosed with curly parentheses, i.e. 3^{x+1}, not 3^x+1. Only exception is when only a single character is super- or subscripted, i.e. x_2 correctly renders as [math]x_2[/math]. For a beginner it's probably best just to always write the curly parentheses, since they are never wrong. 2) The correct \frac command is \frac{a}{b}, where the term in the first parentheses is the nominator, the one in the 2nd parentheses the denominator. 3) You can check your result yourself by just plugging it into the original equation, i.e. use your calculator to verify whether [math]3^{0.62\ldots+1} \stackrel ?= 6[/math]. 4) Your result for b) was correct the first time, already. If your teacher complained about the path you took to the solution: I have no clue why he complained, so I cannot tell you if he'd like this method more. 5) I think you're putting equation signs where none belong. Why should [math]3^{x+1} = 6\log_6 6[/math] ? EDIT: Wait, I think I understand the problem; it's simply a parsing problem. Add newlines (preferably) or commas between the individual equations so that one can tell where they end and where the next begins.

That's what I also thought. But Wikipedia disagrees with that. From Wikipedia's article about the Earth Core:

"Energy must come from somewhere" is your interpretation of "total energy is constant" (not a bad interpretation, but I'm a bit picky here because you're asking about processes where everyday intuition may break down). That means that the mass of the particle that beta-decayed (times c-squared) must equal the sum of a) the mass of the object after it decayed, b) the mass of the electron that is produced, c) the kinetic energy of the object after decayed, d) the kinetic energy of the electron, e) the kinetic energy of the neutrino that is also produced. All of these addends are positive, so to make this an equation, the mass of the object after it decayed must be smaller than its mass before the decay. You might interpret this as the energy coming from the mass of the decaying particle (which becomes smaller).

To answer your 2nd question first, there are two ways: 1) The full editor has a button for sub- and superscripts (two buttons left of the smiley-selector button). 2) You could enclose your math statements with [ math] [ /math] tags. Those will trigger the Latex mode (there is a mini Latex tutorial on this forum if you want to know how to use that). I did that for the part of your post I quoted, but it's probably overkill for your purpose, if you don't know Latex already. To answer your math question: surely you learned about the logarithm by now? The question looks like one where you shall learn how to use the logarithm. Use the logarithm! For question 2: Why do you think x=-2.5 is wrong? Vastor gets the same result, and it looks pretty okay to me, too.

I don't know much (read: I know pretty much nothing) about the earth magnetic field. But I thought that's roughly the mainstream view. So how does your idea differ from the ideas that scientists have?

I'm not sure that I understood your question, CharonY. The hypothesis that has been tested was "the standard model predicts this curve correctly". This hypothesis is routinely performed on collider data, on a variety of curves. And in one these tests the deviation of the data from standard model predictions (more precisely: predictions of computer simulations of the standard model) and the experimental data was large (compared to the estimated error bars, not compared to the signal being tested). That is certainly worth of mentioning, and even publishing, since it is the particle physicist's job to look into such deviations in detail. Still, if you perform several thousand tests and one of them fail with "if it's a random deviation, then it's chance of appearance would be only 1:3700", then it is not very likely to be a scientific breakthrough (but "possibly", especially if you want to sell newspapers).

I'm not really sure if you're serious or sarcastic. I found the whole story somewhat embarrassing, since for several reasons it was very likely that the bump is just a random bump in the first place. Think about it: the likeliness of the bump just being random fluctuations was given with something like 1:4000. So, ... imagine an experiment with a few thousand physicists working on it and analyzing the data as extensively as possible: how surprising is it that you find a deviation from the average that has a likelihood of only 1:4000? Exactly. I'm not sure how widely known the bump in the data became world-wide. In Germany it was picked up by Spiegel Online, the largest German online newspaper, and sold as "physicists find possible evidence for a fifth fundamental force of nature" and "possibly the most important finding in physics since decades" (to the defense of the Tevatron people, this is really not what they claimed in their publication).

When I run out of space, I send a mail to our computer admin and ask him for more. EDIT: Now that I think of it: last time he mentioned something that there might be an end to the space, soon. That guy is an oracle!

From a more basic perspective: the Schwarzschild solution, including the Schwarzschild radius as the limit of a Black Hole, is defined for the massive object not moving and not rotating (and a few other condition that are not relevant at the moment). There is no reason to assume that your inherent assumptions about the conditions when a moving object forms a black hole are true, and the solution to your problem is "the moving object doesn't become a black hole".

It has. That's what I meant by I merely considered the statement "the sign of E in [math]m_1 + m_2 = M + E/c^2[/math] depends on the value of the masses [math]m_1, m_2, M[/math]" so trivial that I don't think it was rktpro's actual question.

The obvious answer is that it has to do with the masses of the reactants and the product. But you probably wanted to know if and how one can predict the masses. There is no working ground-up method to calculate the masses of nuclei, I think; even the calculation of a proton mass from quantum-chromodynamics (QCD) is numerical and with a few sophisticated approximations, I think. I am pretty sure loads of approximate methods exist (the theory guys have to spend their time on something, after all). The most famous, possibly oldest, and the one that is routinely taught to physics students, is the Bethe-Weizsäcker formula, which should be relatively easy to understand and apply if you bother to work through the individual terms.

I find that a strange question given the rather obvious answer: to get the guy in question (i.e. you) into re-expressing their point/issue/... in a clear, coherent, understandable, and ideally even sensible form.

Speed is measured relative to something that is defined as "at rest"; usually a physical object. For example, the speed of a car is often measured relative to the road, which is defined at rest (note that in some cases it may be more suitable to measure the speed of a car relative to that of another car; when determining how long it takes the cars to overtake another, for example). This statement has nothing to do with the first part of your sentence. This is because the first part is highly questionable; without a context it is somewhere between content-free and wrong (or does it make any sense to you?). Do you know how mathematicians capture lions? They build a cage, lock themselves in it, and declare "this is outside". Point is: you can define a lot of things if you really push it - and are willing to sacrifice sensibility. One usually assumes that there is no sensible "absolute rest". "Everything is relative" does not follow from velocity being relative (and it's very far from the viewpoint of modern physics, in case that matters).

You should explain a bit more what you are talking about. "Leaks at the LHC were to raise awareness" is a completely meaningless sentence for me. And why Carlo Rubbia and Simon van der Meer, Nobel prize laureates for discovery of the W- and Z-Boson according to Wikipedia, should get the Nobel Prize for finding Supersymmetry or the Higgs Boson is not clear to me either.

Nope. The pair of charged W bosons is perhaps the most prominent example against your idea. Apart from the semantic problem what you mean by annihilation (would the reaction of electron+postion to muon+anti-muon be an "annihilation"? If so, why would about electron+electron to muon+muon be not?): No. For instance, the reaction electron+positron to 2electron + 2positron is possible. Considering that gravitons have the tendency to interact preciously little with anything (compared to other particle physics effects), I'd bet on "preciously little" squared There is an addend that appears in the equations for the gravitational field, which is usually considered to be non-zero. If you insist on interpreting this term as a physical object rather than just an addend in the equation, then it can be considered as some unknown physical object contributing to the energy-stress-momentum tensor. I am not aware of any reason to do so, other than that an addend which has no physical interpretation in a physical equation is a bit weird. Hence, this addend is given a generic name (and since you want your scientific publication to be cited, you give it a catchy name that catches the readers' interest: dark energy ). The problem is, if I remember that correctly, that the pressure contribution of your "physical object of unknown composition" to the total pressure is negative, which is somewhat weird. I am not sure if vacuum energy, whatever that may be in detail, contributes negative pressure. It doesn't. The electromagnetic force is usually considered to be the cause that I do not fall through the floor. So it is a counter force to gravity, too. That doesn't say that the photon has similar "quantum characteristic" (again: slightly depends on whatever "quantum characteristics" may actually be in detail) as the graviton - or does it?

There is no big trick and essentially you were pretty close to the solution already, but then went around and rearranged back to where you came from. In your line [math]2^x * 8 = 2^x + 56[/math] try substracting [math]2^x[/math] on both sides, instead of dividing both sides by 8. It's not the most elegant way, but it is at least your solution for the most part, then.

I think Capn should simply fix the bug that eats the backslashes.

Perhaps I should clarify that when considering it a good measure of impact on the scientific community I had the average mid- to end-career scientist in mind (hey, you even gave examples of people who are long dead); and I was also not considering cases where grants or positions are given out (where human evaluation is indicated), but a sketch for defining a measure (in the the sense of a rule that applies a number to an object), that is half-ways appropriate.

I can't see [math]\mathcal D (\mathcal O)[/math] appearing in the first two links, which are identical; neither by scanning over them, nor by searching through the source code of the Wikipedia page. I would probably not understand the other article, so I didn't bother looking there. Please try to avoid wasting other people's time by being inaccurate.

My advisor of my diploma thesis once told me that in experimental high-energy physics, the relevant measure is usually the number of talks given (invited ones probably being the most relevant), not the number of publications (remember that some hep papers have O(100) authors). I can well imagine the number of invited talks to be a reasonable measure. "Awards" may be another, but the value of awards certainly fluctuate more than the values of publications in standard journals. Plus, you'd probably define a measure that is non-zero only for those who are already famous and influential to a degree that makes a measure unnecessary/useless. In practice, the most important criterion in my experience is the opinion that colleagues have of the respective scientist - which is of course not a measure in the mathematical sense. I don't think that the impact factor of the journals you publish in matters that much. Sure, if you apply for some EU grant, then you'd better have a Nature publication somewhere on your list. But other than that, I don't think impact factor counts as long as you publish in the standard journals for your field, and not some esoteric "we publish everything" ones. Why would that be more than one cite? I don't know the working habit in math, but I never bothered writing a paper just to point out an obvious error in other publications; pointing it out via a mail to the author seems like the more sensible option. I find it hard to imagine that someone would knowingly publish erroneous material and want to attract a lot of attention to this error. Being asked to write a review paper is quite an honor; no-names are not invited to this. All three are beyond the level where they'd be judged by their citation count. In my field, some things are common knowledge within the field (but not necessarily outside of it), and the respective publications (from the seventieth) still get cited, despite the authors already having won prestigious prizes and being the big names in the field. My personal opinion is that citation count isn't that bad as a measure of impact. I also consider the related h-index as a reasonable measure for a scientist's relative influence on the field (note that this statement implies that by these measures someone with only a single super-well-cited publication has more impact on the field that someone with several average-cited ones, but that the latter is more influential; I see no contradiction there). Of course, mathematicians may not like these measures much because they are pulling the short straw. But one shouldn't compare citation counts between different fields, and I don't think that anyone really does.

I'd expect that most string and string-like models actually aim to implement at least one Higgs Boson.

I think that the value and necessity of an M.Sc may depend on country and perhaps also field. From a mini-test: I looked at 5 PhD position announcements on spires (high energy physics). 2/5 did not explicitly mention any required qualifications, 2/5 mentioned a Masters as requirement (link 1 ,link 2), 1/5 did mention a B.Sc. (link). In Germany, the M.Sc is considered as a dropout degree by many, particularly by the students themselves, who are afraid that their education is worthless if they don't get at least a Master's degree. I know of no physics B.Sc that did not continue their studies with a Master's course, which is considered the relevant qualification for a PhD position, here. It would be cool if goku gave some feedback how it actually went, but seeing goku's last activity was over a year ago I doubt that will happen.

I just wanted to highlight it. It's a variation of what I said, so I do agree with it. I'd not go as far as to use make it a strict rule "always say 'we'", but the intent is similar to mine: don't sell something as being exclusively your work which in reality is the product of collaborative work (to whatever degree). Again, this is something I tend to agree with. My current official boss is a good example of that: she tends to ask a lot of question, even in-depth ones, when she's got the feeling that she's not fully understood what's being told. That's not necessarily a sign of disagreement of rejection, but more-so one of attempting to understand a point of view that is new and potentially interesting. So I agree in the sense that one should take questions, even questions that raise doubts about the validity of your work, as a sign of interest. But I have experienced comments on my ideas which I find hard to categorize anything else than being from a personal point of view (those comments were outside of the formal talk environment, admittedly). So I'd not make a general rule out "never take comments personally". Still, for a talk not taking comments personally is probably a good attitude because "this guy probably has some private problem with my work" is a conclusion that's better left for the resume of a talk, not for the talk itself. Remember: your audience is composed of scientist who are well capable of making their own judgment about your work and the concerns raised against it. @ajb: While those "that's a novel idea, I'd like to understand it"-comments are very frequent and an important part of potential feedback, I don't think that's what Marat had in mind. Some topics in science simply are the way that there's a divide in the community, and that some people believe that some approach is valid, while others do not. An example from my field is whether a computer simulation has to treat each individual atom as a single entity, or if one can "coarse grain" the simulation and represent a certain number of atoms by a single blob. Since the average speaker presenting some result, say in this case from a coarse grained simulation, does not have the expertise to comment on this (especially not against a real expert who already took his stance on the issue for whatever reason), all that's left is admitting "of course, you have to believe X" (with X being "coarse grained simulations appropriately representing reality" in this case).

A few obvious, and perhaps a few less obvious ones: Be polite. There's no gain to give a talk in the line of "those idiots [cite here] assumed [whatever]. As I will show, this is a completely stupid assumption". In other words: try to offend the least amount of people possible. Be more passive. The experts you talk to are no idiots, so there's no need to teach them how groundbreaking your idea is. So replace "My research has revealed a fundamental flaw in the currently accepted theories which proves the underlying assumptions completely wrong" with something like "in [field], [assumption] is usually made. However, we investigated this assumptions and found that it might not be justified". Don't be too fond of yourself. No "revealed by my superior intellect". (ok, that was a really obvious one). Related: You should consider if you should really present it as your individual research. Usually, the advisor's share is at least half of the game, at least on the intellectual level (the boring work is of course done by the student). This is also the impression that most of the audience will have, anyways. After my last conference talk, one of the many interesting feedbacks I got was: "very interesting research. I consider inviting your advisor to give a talk about it in our group seminar". While the problem mentioned by Marat is one that will appear rather frequent in various forms, it's often not really problematic. In almost any field and with almost any results, some inherent assumptions have to be made. To stay with the example: there is no problem with being honest and admitting that it's not a proof in the traditional sense, and that if one strictly does not accept computer proofs, then this is not a proof. That's really no big deal; most people in the audience are likely to accept computer proofs, or at least take them as what is usually called "an indication for X". Or to be a bit more cynic: scientists are very willing to accept an extended definition of a "proof" if it serves their current interest, e.g. when they want to publish work that foots on the four-color theorem to be correct.

I don't even know what the terms "globalist", "resisting defining culture in terms of national differences", and "anationalist globalism" are supposed to mean ("anationalist" isn't even recognized by my spell checker, but "a nationalist globalism" wouldn't make sense to me, either). My statement is a simple observation, not political/social/ethical/discriminative/philosophical/whatever mantra.