Structure Definition and 1000 Threads

Does anyone believe, given new measurements from the SDSS, that we will discover a galactic wall that exceeds the size of the Sloan Great Wall? Also, what is larger than the galactic filaments connecting to form the walls? Can somebody please provide the proper topology of what the...

I have come unstuck in my coursework project, and cannot find any information/equations for the effects of shielding on wind loading in a structure (This is not an ordinary structure, it is an unsymmetrical sculpture made up of circular and Universal beams). So i would firstly like to find how...

with lewis structures, if i come to 2 separate structures that both seem right, and i want to know which is right, and i check the formal charge, and get: for one diagram 0:1:-1:1:1 and for the other 0:0:0:0:2 which is better, i guess what I am trying to ask is, is it preferable to...

Is it generally assumed that there is a smallest building block of matter? Or is it assumed that there is always a smaller particle within any particle? because i was thinking in my calc 2 class the other day... If you have, say, a water bottle on a table, and you assume that there is always...

Like the cyanate ion (NCO-), the fulminate ion (CNO-) has three resonance structures. Which is the most important contributor to the resonance hybrid? Suggest a reason fro the instability of fulminate.

I'm not familiar with Earth science, in particular ice formation in glaciers and I hope you can bear my rather stupid question: Is the change of a "normal" ice layer into glacial ice with frozen air bubbles a continuous transition or a spontaneous reaction? Someone told me that the air...

Ok, I know this question is very old, and it has probably been answered by now, but if the electron does not have an internal structure (like the proton for example), how does it maintain itself as an entity? Why does it not disintegrate? I've asked this question a couple of times before ,and...

I am having some difficulty understanding the concept of colour charge. I realize that protons and neutrons are made up of a different number of quarks, and this is how they have the charges +1 and zero. I then realized that different quarks have color charge and that in a hadron (protons...

what is this structure?? Can anyone help in the identification of this chemical / pharmaceutical structure, tIA...

As suggested by Marcus, I have read the whole paper and decided to start a discussion of Kober's paper by asking a few questions. The paper certaintly presents a very interesting view. Part of it is an extension of Heisenberg's work on unified QFT, that the mass originates from self-interaction...

Hi, I'm looking for video lectures for the classic MIT course Structure and Interpretation of Computer Programs. While MIT OCW doesn't have any videos for this course, on the internet there seems to be at least two different sets of videos claiming to be of this course. It seems that one is...

why is it so difficult for physicists to probed inside the internal structure of an electron ? You would think it would be easier to probed the inside of an electrons and get electrons crashing into each other since electrons are a lot less massive than protons and electrons are easier to...

what does the lewis structure of (IO3) look like??

if i am told to draw a lewis diagram for PCl^{+}_{4} does this mean a melocule of 1P atom and 4 Cl atoms, the whole molecule with a charge of +1 or is it 1 P atom and 4 Cl^{+} ions, giving the molecule a charge of +4 what does the lewis structure look like, is it P in the middle with Cl...

I get an error with gcc "error: two or more data types in declaration specifiers" when trying to compile something of the form: struct tag *function (...) { ...} Apparently it won't let me create functions with return values pointers to structures. I know that it's perfectly valid code, so...

Homework Statement Draw a diagram for the structure of BrCl4+. This should be a VSEPR diagram. Homework Equations N/A. The Attempt at a Solution Br has 7 valence electrons. Cl has 7 valence electrons. 7(5)=35, but we take away one electron because of the +1 positive charge. Now I have 34...

Hello all, In my research, I use DFT from time to time using SIESTA or VASP. I have spent much time reading up on the various aspects of DFT and think I have a pretty good handle on it. In order to prove this to myself, I would like to start to write my own code. I am however finding that...

A recommended lecture on the age and detailed structure of the Universe, listed in reference 1. George Smoot is a Nobel Prize in Physics laureate for his work on COBE.Primordial fluctuations simulation by Andrey Kravtsov: [/Color] Reference...

While going through some concepts in spectroscopy, i got stuck in fine structure lines. So, i need some clarifications in this topic. Now, it is known fact that fine structure lines can be explained by the concept of electron spin. Aren't these lines as a result of spin orbit interaction? Apart...

hello all

any help on how to draw the structure of CCAGAT, a hexanucleotide segment of DNA??

how would i even begin this problem: Draw the structure of te modified nucleoside 2',3'-dideoxy-3'-fluorocytidine

Homework Statement Calculate the energy and radius for each of the five lowest (n = 1,2,3,4,5) electron orbits in a Helium atom with only one electron. Enter the energy as a positive value in units of "eV" and the radius in units of "nm". Hint: The Helium nucleus has 2 protons so Z = 2 and...

I have five generators of a lie algebra, g_1,g_2,g_3,g_4,g_5 which at first glance I believe are independent, although I could be wrong. I have calculated the structure constants, i.e. \left[g_i,g_j\right]=f_{ij}^k g_k And from that I have calculated a matrix rep using...

Homework Statement I just want to know if there is a relationship between the ground state of Hydrogen which is 13.6 eV and the ground state of Helium. The problem is asking me to find the ground state of Helium, but I am not sure how to go about it. Any advice? Homework Equations...

Hi all I am new here but i have a major question, iv been told by people that this question is easy but I am just going around in circles with it and i was wondering if you could help. here is the questionAluminium cystallises in the fcc structure with a single atom basis. the lattice constant...

Homework Statement The 3s state of Na has an energy of -5.14 eV. Determine the effective nuclear charge. Homework Equations Zeffective = Z - S (not listed in textbook, found this online when trying to figure out the problem) The Attempt at a Solution Nothing in the textbook in...

Hallo all, I have been working on a little problem. I have to calculate the forces on a certain structure, but I can not seem to find the solution. I have given a picture, drawing with my attempt and the drawing of how I try to solve it. The first drawing is to find the first forces...

Homework Statement Give the structure of C8H8O3.Homework Equations IR tells us that there is an OH group and a C=O group Degree of saturation = 5 --> Benzene ring + C=O H NMR spectrum shows: Peak at ~7.8ppm integrating for 1H and is a doublet Peak at ~7.45ppm integrating for 1H and is a...

Hi there, Does anybody know how to exploit the product of structure constants of SU(N) through Kroenecker deltas? I mean \sum_a f_{abc}f_{ade} I know this for SU(2) as in this case I have the Levi-Civita symbol but in other cases I was not able to recover it in literature. Any...

If a photon of wavelength 663nm is incident on a hydrogen atom in its fourth excited state(n=5),then A.the atom doesn't absorb the photon B.the atom absorbs the photon but is not ionized C.the atom absorbs the photon and is ionized,with the electron having zero kinetic energy after ionization...

Homework Statement What are the molecular geometry structure? 1. SeO3 2. SeO2 3. SCl2 The choices are: a.linear b. square planar c. tetrahedral d. trigonal planar e. trigonal pyramidal f. V-shaped

[9] arXiv:0809.2330 [pdf, other] Title: Hydrodynamics of structure formation in the early Universe Authors: C. H. Gibson (UCSD), T. M. Nieuwenhuizen (University of Amsterdam), R. E Schild (Harvard) Comments: 6 pages 4 figures. Additional information at this http URL Subjects...

This paper makes the case for an upper mass limit of about 10 billion solar, for black holes. Their central black holes may help galaxies to form and may be important to understanding structure formation---an outstanding problem in cosmology. The mass limit is proposed tentatively and requires...

Could you be more specific? You suggest that there are methods by which dark matter can dispose of kinetic energy, but can you show a method that is purely a gravitational interaction? If dark matter particles ineract with each other non gravitationally then do you agree that the dark matter...

Structure formation is arguably the central problem in cosmology. How did the dilute gas manage to coagulate. On what timetable did stars and galaxies form? What explains the distribution of galaxy sizes and composition--clustering--the wispy cobwebby structure with its various size voids...

Hello everyone: I was looking at Wikipedia's page on chloric acid (http://en.wikipedia.org/wiki/Chloric_acid) and was wondering if the Lewis diagram there is correct. I will not link directly to it as it has a high resolution. It shows Cl with a lone pair of electrons having double bonds with...

Hi, In all the tutorials of DFT softwares I have encountered computing of the band structure for different systems by using e.g. L-Gamma-X-(U)Gamma circuits. In the texts I have read I have found about X & Gamma but what are L & (U)-Gamma? I also enountered that they have separated the...

SU(2) and SO(3) "have the same Lie algebra". While I understand that their corresponding lie algebras su(3) and so(2) have the same commutator relations \mbox{SO(3)}: \left[ \tau^i, \tau^j\right] = \iota \varepsilon_{ijk} \tau^k \mbox{SU(2)}: \left[ \frac{\sigma^i}{2}...

Hey folks, I am trying to generate the Pauli matrices and am using the following formula taken from http://en.wikipedia.org/wiki/SU(3 ) "In the adjoint representation the generators are represented by (n^2-1)×(n^2-1) matrices whose elements are defined by the structure constants"...

Hallo ... I would like to know about the effect of the effective mass on the band structre of the materails..

One of the best sources to learn about a particular subject area in a field of study is to read someone's thesis. In this thesis, in one shot, the author has covered rather well the technique of angle-resolved photoemission spectroscopy (ARPES), many-body physics, BCS superconductivity, Fermi...

Max Tegmark develop a hypothese in which physical reality is equated as being a mathematical structure, and further it is proposed that every mathematical structure itself is a reality on it's own. To look up this idea, see these threads: http://en.wikipedia.org/wiki/Ultimate_ensemble...

What do you think of the (almost ubiquitous?) structure of the week: 5 consecutive days of work and then two consecutive days of rest and then repeat? I think it is pretty good for promoting healthy lifestyles.

Hi, I have a structure AA.BB, which goes from AA.BB(1) to AA.BB(1000). I have for example a matrix "X" of size [1000x3], which I want to add to this structure, such that it becomes like this: AA.BB(1).X(1) AA.BB(2).X(1) ... AA.BB(1000).X(1) I want the same for X(2) and X(3). Can...

I have an idea I'd like to share on this forum about the structure of numbers. I don't have a question as such but am interested to get some feedback on wheather my idea makes sense or if it's been addressed before, or maybe ways to extend on my thoughts. I begin by defining the nth prime...

Hiya. I've gotten behind in physics lately. Disturbingly so, in fact. I just can't stand how little I know, so I've recently undertaken the task of educating myself using Wikipedia, but it's terribly hard. I may have misinterpreted some things, and some things don't make much sense at all, so...

Hi I am searching for the equation for the radiation probability of a gluon from a quark. I need this for an explanation of the jet structure after a Z decay. Because I heard that hard gluons are radiated with small angles to the quark. This means the energy is focused in the directions of the...

How does quantum physics describe the structure of an atom? Is it possible to take a basic measurement an atom such as the number of proton/neutrons, and calculate the rest of the dimensions/ and properties of that particular atom?

Homework Statement Ok, i have a small (optional) project, to design a load bearing structure made of matchsticks. The structure must be able to withstand the load a computer monitor (i have a 17" one). Homework Equations Now, the problem i am facing is how would the force (of gravity due to...