Structure Definition and 1000 Threads

I am inquiring if anyone here is qualified to numerically demonstrate the solution to this equation? The equation is the Proton lifetime derived from the SU(5) Georgi-Glashow model listed in reference 1, eq. (19). SU(5) Proton lifetime: \tau_p \geq \frac{1}{\alpha_{(5)}^2} \frac{M_X^4}{m_p^5}...

Most stable structure ?? Hi Could anyone tell me which/what is the most stable structure? And Why?? Thanks a lot

This is an invited review paper by a worldclass authority, so it could be useful. http://arxiv.org/abs/0804.2258 Let there be Light: the Emergence of Structure out of the Dark Ages in the Early Universe Abraham Loeb (Harvard) 32 pages, 18 figures, an invited review for the UNESCO EOLSS...

Has anyone heard of Milo Wolff? I recently came upon www.spaceandmotion.com using StumbleUpon, and read the section of quantum theory, and the interpretation of quantum theory using spherical standing waves to describe matter seemed interesting, but I couldn't find anything on it besides that...

Hello, I have a issue which is concerned with finding the defelction and stresses in a beam. I have attached a rough figure of the beam. Please help me by giving some suggestions. thanks chaitanya

I have two Lie algebras with structure constants f^{a}_{bc} and g^{a}_{bc}, the number of generators being the same (as will become clear). Due to a particular symmetry/construct, I have that the system needs to be valid under g \to af + bg (and a similar transform for g), which leads...

This is an unusual book which uses the Scheme programming language to functionally describe the various components of classical mechanics. I would say it is at the level of a graduate mechanics course (think Goldstein), however students with a strong programming background will find it easier...

Acetyl phosphate is produced during acetate fermentation. I can't find the structure for it anywhere. The precursor in this case is Acetyl-CoA, which has the the structure H3CO-S-(Coenzyme A). And of course I know the structure of a phosphate ion. So the only question really is, does...

Hello all. I only have a few posts here so I am somewhat new to the forum. I have been reading a number of the posts though and I am favorably impressed by many of the responses. I am also somewhat new to LaTex so please forgive my mistakes with it. I am interested in learning more about the...

A lot of scientists say that fine structure constant is still a mystery..one of them was Richard Feynmann...i know fine structure constant is a dimensionless constant and there are many dimensionless constant but why this fine structure constant takes special place?can anyone tell me why this...

Homework Statement a)what property of graphite is the result of the presence of delocalized electrons? b)what is the reason for the generally low melting point of group I A metals as compared with the high melting points of metals in the center of the transition series? The Attempt at...

Dear experts - I'm writing a novel in my spare time, and would appreciate some help with a little bit of research. Some of the story is set in the distant future, where super strong materials are available. My problem is that I don’t know how to describe these super materials. I want to...

when astrophysicists study the structure and rotation of galaxies do they take into account that we are seeing the stars in it where they were at different times, we aren't seeing them where they actually are now? Say stars on the closest edge are 100,000 light years away but stars on the...

Hi again, first of all i want to thanks the replies to my previous posts. Second... I'm looking for a paper about the GaP band structure. Actually i only need the band structure tu compare it with mine but i need the reference to that paper, can you help me?? sorry for my bad english by the way...

[SOLVED] Secondary structure of protein. 1. What determines the secondary structure of a protein? 2. I do not fully understand this question, does it mean the two general types of secondary structure a-helices and b-pleated sheets. Or does it mean by how we determine them DSSP code. And...

I am asking this question because I did not get it clarified in any of the books I have read. What is the rule for having the quark structure of an antiparticle given the structure of the particle?Is it always OK to put bar on the quark symbols of the corresponding particle? Specifically,I...

Homework Statement How many atoms are there in the unit cell of graphite? 2. The attempt at a solution I know graphite is hexagonal crystal structure. hcp also know that hcp has basis of hexagonal lattice which as 2 basis atoms. is there some other info i need because the answer...

I am working this problem... http://www.fiu.edu/~saulj/Teaching/Physics2/01-Electric_Force/CrystalStructure.html I got the answer to a as 0, but don't understand b.

Homework Statement Are these two structures resonance? if not why not? Homework Equations The Attempt at a Solution I drew these resonance forms myself, but the answer book didnt' have this resonance structure in its answer and i wanted to know if this indeed is a...

Homework Statement I spent a few hours trying out this question, so I probably need help. This is a seven pin-jointed structure mounted on the wall, with the following information given: 1) S1 and S2 are wall supports, but S2 is assumed to have no friction with the wall i.e. no vertical...

Do you think that it maybe possible to categorise life by actions rather than by structure?

[SOLVED] Resonance Structure #3 Homework Statement Can't seem to figure this one out either...I think the program may have the charges messed up...usually if i post the same exact problem as the answer, it tells me that the answer is the same as the original problem...but with this...

[SOLVED] Resonance Structure Draw the lowest energy alternative http://img87.imageshack.us/my.php?image=82956480uh8.jpg I can't figure out what I am doing wrong, but I've tried everything..any help?

Does your genetic structure change as you get older? I guess it's just the levels of NFKappa and things iike that that change?

I want to know where to look for information relating to toppling. I have looked at stability of equilibrium but the real question is: If say for arguments sake, there is a column 2m high and 1/4m wide - it would be easy, if we knew the weight of the column, to establish the force required...

what would the atomic structures of atoms 117 & 119 look like and what properties would these elements have?

Homework Statement what is the difference between a steroid molecule, phopholipid, and fat molecule?Homework Equations discuss the general difference in their structuresThe Attempt at a Solutionphospholipids are asymetrical with a hydrophilic head and a hydrophobic tail and the other two are...

hi all as known, Bismuth is a semi-metal. the question is: What is the characteristic of the electronic structure of this family (Semi-metal).

Would a geometrical structure following a single set of simple rules when it tessellates that: 1) Predicts the mass ratio of the electron to the proton 2) Derives and explains the fine structure constant 3) Explains the reason for only 3 generations of matter 4) Predicts the electron...

Homework Statement I am trying to see if I understand these corrections to the hydrogen atom: To explain the fine structure correction, we go to the electrons frame of reference, in which the proton is moving with velocity v. This produces a magnetic field according to Maxwell's equations the...

Hi- We're thinking of purchasing Gaussian 03 for electronic structure calculations. I think the basic license only allows for it to be run on a single processor. Can anyone recommend a decent desktop <1500 dollars that will do a decent job at running electronic-structure? I suspect that...

Hi, I've got a question, I recently got interested in piezoelectricity. I almost no nothing about it tho. From the wiki artcile I gathered that when a force acts upon a piezoelectric material and deforms its shape, an electrical potential is created. I know that it has many applications in...

The dimensionless pure number 1/137 obtained from the bohr theory (e^2/2hc epsilon_0) is given a particular name 'The Fine Structure Constant'. What is the significance of this number? Why has this value a name?

Hello all. Back to basics again. When defining a set of geometric vectors for a vector space of n dimensions how can we define such a set without a certain amount of structure already defined upon the n dimensional space. We presumably need some concept of direction to determine linear...

Recently I read about element 137 (feynmanium / Untriseptium ), the element which would theoretically have its electrons moving faster than light (if I understood it the right way). I know that if you involve relativity in the analysis, the problem occurs in element 139, but that's kind of...

I'm a little confused about something very simple. From a chemistry perspective I am told about how many electrons fit into each type of orbital. For instance, 1s and 2s can only have two each, the 2p orbitals total 6. It is composed of the Px, Py, and Pz and only two can be in each set, while...

Everyone "knows" that the fine structure constant (alpha) is a dimensionless number, but I am troubled by the fact that the Planck unit of resistance must be one - if that is true - and that strikes me as suspicious. I wonder if anyone can shed any light on this. I present the complete...

The modern "Large-Scale Structure of Spacetime" book Ever since I started reading Hawking's classic "Large-Scale Structure of Spacetime", written in 1973, I always wished that there was a more up-to-date book on general relativity that uses the book's level of mathematical rigour. But every...

I have some questions that i am not sure...can u guys help me out ? 1. Which of the following is the best phrase to describe the modern view of membrane structure? a. Membranes are lipid-lipid bilayers. b. Membranes are lipid-lipid bilayers with associated proteins. c. Membranes are...

Hi everybody... I have a question and i hope u could help me. Consider the diamond structure as simple cubic with 8 basis atoms. obtain the first two planes contributing to x-ray reflection from the diamond structure.

Homework Statement http://img528.imageshack.us/img528/6569/tempwv3.png Homework Equations unknown The Attempt at a Solution unsufficient amount of knowledge. Originally I thought this might've been a coefficient of friction problem with K as Kinetic energy and v as velocity... but that...

First this is NOT a homework problem. I am undertaking a self-study of mathematical analysis by following Rudin's Principles of Mathematical analysis. I have done a course in analysis before but this is a high-powered review of sorts. So I'm currently on the first chapter's problem set and...

First this is NOT a homework problem. I am undertaking a self-study of mathematical analysis by following Rudin's Principles of Mathematical analysis. I have done a course in analysis before but this is a high-powered review of sorts. So I'm currently on the first chapter's problem set and...

Joao Magueijo. Cosmologist at London Imperial, and Perimeter Institute. Three introductory lectures on the CMB observation and interpretation The first talk is a light intro to the technology, the software that does the mapping, and the analysis that derives the power spectrum (what...

I need help with these two questions: 1. Electron diffraction can be used to investigate both the arrangement of atoms and the dimensions of nuclei. Explain how changing the energy of the electrons can be used to achieve this. And... 2. Uranium has atomic number 92. Two of its common...

Something I've been reflecting about: Question 1: Given any degree 5 polynomial f over the rationals, what are the conditions on the roots of f if I want its Galois group to be isomorphic to the alternating group A_5? I know that if f is an irreducible degree 5 polynomial with 3 real...

Can someone tell me how the outer shell structure is determined from the electronic structure. I know i can look this up but I'd like to know how it is derived and are there any rules I should follow so i can determine them myself?

I've been trying to figure out this paper by W. Smilga: Spin foams, causal links, and geometry-induced interactions I don't have the knowledge and background to be able to determine whether his derivation of an estimate to the fine structure constant is interesting, or just a trick. I am...

The Ashoori group is claiming to have a picture of the ACTUAL energy density. (NOT the "wavefunction" associated with the particle). Something does not add up. We should not be able to “see” the energy density of something as small as 10^-18. -------------...

I know acoustic and optical phonons can interact with one another. Also, longitudinal and transverse phonons can interact with one another. I am wondering can a longitudinal phonon in one plane act with a transverse phonon from another plane to create a third phonon? Or, do these...