BenTheMan

I'm going to guess between 850 and 900, very cautiously. Maybe I'll get a paper or two out by December

Martin--- I wouldn't imagine that the papers are evenly distributed through the year. I would imagine that there is a surge in publications from August to October, as people who have been working (and attending conferences) all summer get their work out. The first six months of the year is generally eaten up with teaching, I would guess. After rereading your post more carefully, I see that I am thouroughly wrong!

It depends on the basis:)

Ahh yes. maybe you've been talking to other moderators around the internet. I'm only a ``blackheart'' if you're a crackpot, and I generally take much more time than I should in responding to honest questions (cf a few posts ago), EVEN to crackpots. It is only when a crackpot refuses to answer my questions or dismisses my questions altogther that my heart becomes TRULY black. I absolutely hate people who think that THEIR theory explains problems that the most brilliant people in the world work their whole lives just to understand. This is beyond irreverant to me, and I will let them know (often with great vigor) when I find a flaw in their argument. (PS---To whom it concerns...If you are a crackpot, then you should study Lorentz Invariance. 9 times out of 10, this is what is wrong with your idea.)

someguy--- have a look at this vid: http://www.tenthdimension.com/medialinks.php. Maybe it will clear up some of the misconceptions about dimensions and such.

God no. You saw how good my pedagogical thread on topology was:) In physics we have this process called ``dimensional regularization''. Basically, you take an integral that has terrible UV behavior (i.e. logarithmic or worse divergences as energy goes to infinity) and write it as an integral in a different number of dimensions---[math]4 - \epsilon[/math]. Then you evaluate it, take the limit as [math]\epsilon[/math] goes to zero, and you're left with a finite piece and an infinite piece. You throw the infinite piece away (effectively) and keep the finite piece, which can be used (quite successfuly) to predict experiments. This is very much how I view math. There's some I understand and some I don't...I only keep the piece that's easy to understand because it's all I need anyway. Talk to Jim: http://www.scienceforums.net/forum/showthread.php?t=27168

Xerxes--- Not at all. I do have a habit of stepping on mathematical definitions (as many physicsts do), and mathematicians always seem to hate that. For example, one of the post docs I am working with was lamenting about how to describe representation to his mother. I told him that I explained it to my mother using dogs. We all have ideas of what dogs are, and what they look like. But when I draw one on a piece of paper, my dog will ostensibly look different from your dog. Sure they have some of the same characteristics, but they are certainly different. Just like my representaiton of Dirac matrices look different from yours---that's ok, they still DO the same thing, they still ACT on the same space, they just LOOK different. He wasn't so amused. Either way, thank you for clearing up some of my misconceptions.

someguy--- These things are quite difficult to picture. I am a bit surprised that you aren't asking about 11 dimensions! Either way, the way I think about dimensions is coordinates---if you only need one coordinate, then it is one dimensional. I think you may have misunderstood me a bit. What I am talking about is something called a ``world-volume''. The easiest example is a point, which is zero dimensional---no length, no depth, no height...just a dot. If we let that dot move, it moves along a one dimensional line, called its world-line. In other words, if you plotted the point's position versus time, you would have a line. Also notice that one coordinate is no longer enough to describe the point---you have to know where it is in time too. The same with a string. Suppose you have a one dimensional string. You can put one coordinate on the string, so you know where you are along the string. But this is not longer good enough---you must also know WHEN you are...so you need two coordinates---one along the string, and one time coordinate.

Xerxes--- Unless I am mistaken, 1 dimension = 1 coordinate. No, thank you. I am not a mathematician, so I probably wouldn't get very much out of it. I will look these words up in my copy of Nakahara if I ever need to use them rigorously. Thank you for clearing this up. I had imagined that kinks and cusps break one of the rules of a manifold, specifically that it is not everywhere smooth and differentiable. Again, I am no mathematician. Personally, I find that when explaining things like this to laymen, mathematical rigor is a pretty useless thing. I can understand soapboxes, I've a few of my own, so thank you for the good definition. Again, rigor. Most laypeople that I've known imagine a sphere as three dimensional (which some people tell me is a 3-ball), NOT two dimensional. I won't quibble over definitions, and if you think that you can answer Hypercube's question in a better way, I invite you to do just that.

This is what originally made me join an internet discussion forum. I found a guy who didn't believe in quarks! Ok, maybe you have something intelligent to say, but when I asked him how he explained confinement he didn't know! So you want to get rid of quarks, AND you have no acceptable alternative theory other than ``well, it just seems too complicated''. This is the problem. People who dismiss modern physics out of hand and people who worship Einstein as a god... Not only are they ignorant, they convince other people to be ignorant, too. And then those people go out and vote and raise ignorant childeren. The problem with these websites is that people don't think about the responses. They only read the original posts, become convinced that GR is wrong, and then leave a comment like ``I've always thought something like this must be true...'' End of story. Someone who WANTS to understand nature isn't the problem---they will participate in discussions and try to understand. But a casual observer won't invest that much time. Scientists seem to have a real problem with Intelligent Design, and rightly so. But what I don't understand is why such crackpottery is tolerated in a self-proclaimed ``Science'' forum. Because if evolution is ``just a theory'', then so is GR, and so is Quantum Mechanics, and so is QCD. Suppose hypercube had asked a question like ``how do we know that the earth is 4 billion years old'', and my response had been ``Look at the uranium isotope ratios. And if so-and-so says something about the Earth being 6000 years old, they are an idiot and don't listen to them.'' Would the moderators have admonished me and threated me with a ban? Would I have been called a ``physics vigilante''?

Now that we've thouroughly addressed how bad of a person I am, how about my beautiful explanation of dimension?

Fair enough. It just seems like people are eager to embrace Loop Quantum Gravity, despite the fact that they don't know very much about it. I am sure that Smolin, at one time, felt the same way about String Theory. The link to the thread is on the front page, and so it looks (at least to me) like it is an active thing. Perhaps moving the link is a good idea? It's quite clear that nobody read (or nobody wanted to talk about) the book, just a bunch of ``Oh yeah I want to read that book too''-type comments. This I know well. My girlfriend is studying now for her Step 3 (?)---major exam at the end of the third year in med school. And she lives in Texas

http://cosmicvariance.com/2006/12/07/guest-blogger-joe-polchinski-on-the-string-debates/ Broken link. Now I am embarassed. I will assume that this is why my link wasn't posted---apologies for the accusations.

I've also noticed that, aparently, this book has been ``book of the month'' for seven months (since Novemeber). Methinks that this is just a backhanded endorsement, but I'm probably wrong. I'm wrong a lot.

Am I alone in noticing that ``The Trouble with Physics'' is still the book of the month? Is the ``book of the month'' intended to incite discussion, or is it something less academic? For one, I can't join the discussion (probably because of post count), and two, it seems that there is no real discussion there anyway because aparently either no one has read it or no one understands it. If this is the case, then why is it the ``book of the month''? Below is a copy of a private message I sent to blike with a comment for the thread (for some reason I can't participate). Despite the fact that this message was sent several weeks ago, and the link specifically rebuts the points in the book, my link wasn't posted. So it goes, I guess.

Sayonara--- The problem with these internet discussion fora is that credibility is determined in an ad hoc manner. Farsight (and other internet crackpots) can only confuse people who don't know any better. If you'd like me to, I can link to Farsight's posts and let you decide if he knows what he is talking about. Barring that, I will continue to warn people that he is an idiot, in threads where he is likely to comment. If you really want to, you can give me warnings or infractions, or go around edting my posts.

This is where those who know very little about string theory do one (or both) of two things: 1.) Pimp their own ideas about ``quantum reality'', or 2.) Preform intellectual fellatio on Lee Smolin and ``The Trouble with Physics''. Let us make wagers about merlin. My money is on 1 AND 2. (Apologies, of course merlin, if you are an actual physicist studying LQG or Euclidean Quantum Gravity.) What, exactly, does this question mean? One cannot ``look'' at a string. Well, if string theory is right, I take that back. You're looking at strings right now---they look like photons:) Evidence that strings actually exist may be hard to come by, and if string theory is ever proven, it may be a whole bunch of circumstancial evidence that eventually convinces us that string theory has to be right. For example, if we discover a tower of Kaluza Klein gravitons, as predicted by string theory, we would be relatively convinced that we were right. However, as in all of physics, we can only be convinced that we are right inasmuch as we are confident that we have imagined all of the other possibilities. And it might be a process of elimination---we may end up trying everything else, and finding out that quantum gravity is ONLY consistent if we quantize things as strings. This is, of course, barring a catastrophic breakdown of the strings research programme, or a fantastic breakthrough in the LQG or EQG research.

Think of a dimension as a coordinate. Think of a circle, with no inside, of constant radius. Exactly one coordinate defines a place on the circle. A circle can be deformed if you like, and whatever shape you end up with (so long as you don't break the circle, or put any kinks in it) will be isomorphic (big word, I know---I think it's the right one to use!) to a circle. The other one dimensional topology (another big word) is a line segment. Now, any one dimensional object with no kinks or cusps, and which isn't closed is isomorphic to a straight line. This means that you can take your one dimensional object and straighten it out and make it a straight line. ``Isomorphic to'' means (loosely, of course) that you can take one thing and reform it (without breaking it or creating a hole in it) to something else. ``Topology'' defines (loosely, again!) the class of surfaces for which this can be done. For example, an oval has the topology of a circle, because the two are isomorphic. (ajb, who knows much more math than I do, is probably cringing because I am giving very specific examples. The field of Topology is very broad, and I only understand what I need of it. Rest assured that there is not much more that I know about this subject!) A better example is a three dimensional lump of clay. So long as it doesn't have any holes in it, a three dimensional lump of clay is isomorphic to a sphere. Now, as long as you don't break the clay (i.e. put holes into it), you can flatten it and shape it---for example, you've seen the Venus de Milo---well, she is made from a lump of clay (in a sense!), and has no holes. So the Venus de Milo is isomorphic to a sphere. But suppose your lump of clay DOES have a hole in it. Then it is isomorphic to a donut, or more specifically, a torus. Now you can take any shape with one hole in it, and turn it into a donut, or vice versa. Take Michelangelo's David. His arms touch his body in two places, so if he were made of a lump of clay, one could reshape it into a donut with TWO holes (called a Riemann surface of genus 2). Think of coordinates man! You have no problem drawing a parabola on a set of coordinate axes, right? What you are doing is drawing a one dimensional shape (the parabola) in a two dimensional plane. Dimension = coordinate. Mathematically, you have expressed a function [math]f(x) = x^2[/math] which maps a straight line (the real numbers) to a parabola. All you have really done is take something which is a straight line (the real number axis) and bent it a little bit into a parabola. So, I would say, a straight line is isomorphic to a parabola. Think of the parabola example above. A string lives in our four (plus six!) dimensions---the string itself is one dimensional, and over time, it sweeps out a two dimensional surface (just like if you take a coin and spin it fast enough, it looks like a three dimensional sphere). Hope this wasn't too confusing. Oh yeah, and if a guy called Farsight replies, ignore him. He does not understand these concepts and will mislead you. It is, of course, for you to decide.

Accepted? By who?

You just can't IMAGINE a one-dimensional thing. Aparently, however, you have no problem imagining four dimensional things...

So I'd first look at a classical dynamics book like Marion and Thornton. http://www.amazon.com/Classical-Dynamics-Particles-Systems-Thornton/dp/0534408966/ref=pd_bbs_sr_1/002-0874372-1112034?ie=UTF8&s=books&qid=1182748942&sr=8-1 You may be able to find a used copy at your local university. Once you've digested this, or while you are digesting it, check out Griffiths two books on Quantum Mechanics and Electrodynamics. You should be very careful that you really understand these three textbooks---it will make everything you do next much easier. After this, then move on to advanced stuff---once you've got these books down (maybe one-two years studying in your spare time, longer perhaps), you should look at three other books: Goldstein (Classical Mechanics), Jackson (Electrodynamics) and a Quantum book, like Sakurai or Shankar (there are several good ones). Also, you can get a copy of Griffiths Particle Physics book---this is a very good and detailed introduction. Hopefully this will give you a good start. This is typically as much as a second year grad student studies---it's enough to get you a master's degree in most universities. Take your time, and be thourough---don't shortcut anything. (trust me) Solutions to Most of the excercizes in these textbooks can be found online as well. Good luck!

Why, the higgs boson, of course!

Nah. Jesus will come back WAY before that happens.

Ekpyrotic: About ``Black Swand''---I've seen it in the book store but haven't read it. Is it worth the money? And, again, it doesn't much make sense to talk about ``densities'' of fundamental particles.

Sounds like someone has been fooling around with Eguchi, Gilkey and Hanson. (P.S.---If you haven't, then you should!!!)