Are the absolute magnitude of stars relevant (calculated) with it's mass and rotational velocity? I understand that the mass of a star has a relation to it's size... regardless of this.. I need to know if mass and rotational velocity combined are used to determine anything for stars. Furthermore...
I am having difficulty with choosing a major: Physics or Electrical Engineering(Micro&Nano)...
Physics becuase every concept is like doorways to understanding life! I like be theoretical and imagining possibilties. All physics interest me so i wouldn't know what i want specifically until...
Richard Feynman once remarked during a lecture that the invention of analytical methods such as calculus allowed people to "be more stupid", in reference to solving problems. I think he was on to something with that remark.
Often when faced with a problem which requires me to set up some...
It seems that many top scientist, mathematicians, composers etc speak of the moment of insight, including Feynman and Bohm, and it seems to come down to when the brain is silent. Being clever as Feynman was, he sought to figure out if there was some mechanical process, some pattern that could...
from my reading to DFT I constructed this algorithm
V ex...>\rho ...\varphi...SCF...new\varphi>>>new\rho ...energy
what your opinion in this algorithm ... is lost to some thing ?
and i need to some one tell me is density come from wave function or from V-external ?
Hello,
I am currently working to complete requirements to transfer to the Nuclear Engineering program at Oregon State University. I do not expect to have a BS until 2015 ( I am 33 years old and have a lot of math to catch up with). Although I am incredibly interested in this field I do need...
Homework Statement
The problem is that i have heard about things like congruences of curves and geodesically equidistant hyper-surfaces, but have no idea how to use Hamilton-Jacobi theory to solve problems( especially in mechanics), or why it works. Why do we use this method to solve...
Homework Statement
Derive the equations for the velocity and acceleration vectors of a particle in polar coordinates.
2. The attempt at a solution
r = xi + yj
where x = rCos\Theta, y = rSin\Theta
r = r(Cos\Thetai + Sin\Thetaj)
v = \frac{d}{dt}r
v = \frac{d}{dt}[r(Cos\Thetai +...
I don't know much about physics. I had a passion for eastern philosophy from a fairly young age and I got into a discussion with a friend about my theories on where we come from, the energy of existence, and other such things. He asked me if I was a physics major because he had been for a time...
I have decided to do away with the template; all calculations have been done, I'm just having trouble interpreting the results.
An experiment was performed using a calorimeter and warm water. The data collected gave the following values for heat of fusion for ice, and heat of sublimation of dry...
Homework Statement
Solve the 1st order linear initial value problem.
(1+x^2)\frac{dy}{dx}\right) + 4xy = x , y(1)=\frac{1}{4}\right)
The Attempt at a Solution
Why can I get the answer solving the equation one way (below), but not they other?
Method 1:
(1+x^2)\frac{dy}{dx}\right) = -x(4y-1)...
Hi everyone.
Little bit of my background:
Im currently studying mathematics in the third year at university (or maybe you call it college in your country), and I have two more years left. I feel that I have affinity for physics and maths, and it is something I really want to master. My...
Hello.
I hope I am posting in the right section, apologies if I am not.
I need help with a situation that has arisen for a colleague of mine, he asked me for help but sadly I can't give him an answer based on fact and logic. Can you please help?
In his kitchen he has a glass panel which is...
Hi all
My book says:
"The reason that phonons on a lattice do not carry momentum is that a phonon coordinate (except for wavevector K=0) involves relative coordinates of the atoms".
I can't quite figure this statement out. I understand the words, but I cannot see why it is an...
I found a similar question here from a couple years ago, but didn't see the whole problem or a complete explination of the solution so I wanted to repost and hopefully get some insight to help with figuring this whole thing out.
Problem:
A projectile is shot from the edge of a cliff 125m...
Homework Statement
What type of motion is occurring when the slope is changing and the graph is therefore curved on a velocity time graph?
Homework Equations
v=(delta)x/(delta)t
A= (delta)v/(delta)t
The Attempt at a Solution
my thought is that when the slope is changing...
Hi,
I am doing my PhD in Informatics and especially graph theory. I came across eigen-analysis numerous times in the context of spectral graph theory.
The question:
I would like to see an *elegant geometric explanation* of the eigenvalues and eigenvectors of a Matrix A (symmetric, real...
An outstanding puzzle in Quantum Gravity is the strange coincidence that two of the most developed approaches both produce a continuum (by different means) which looks normal 4D at large scale but at micro scale the dimensionality gradually declines to around 2D. That is the micro geometry...
I've been on the fence between a physics major and an engineering major (of some sort) but I have a few problems associated with both.
First off, what is it like to be a physicist? I really don't want to sit around and crunch numbers all day and not actually do anything with all the material...
Hey guys,
I was wondering if anyone is either currently attending, or has already gone through a 3+2 program for engineering. For those that don't know what this is, it is when you study the basic math/gen ed classes at one college, then continue to study mostly engineering at another school...
TED.com, and watch "A Stroke of Insight"
I like being 1 with everything.
the easiest way that I have found to get there is through music.
most specifically, winamp 5.531/shoutcast/groovesalad
to help you understand.... go to TED.com, and watch "A Stroke of Insight"
Has anyone in this forum worked on translating findings from invertebrates to mammals? I'm wondering how successful this tends to be. How often are actual gene sequences conserved? When the genes are conserved, how often do they have the same function across systems? Or is the most valuable...
I know RF signals can be blocked using a copper screen, for instance lining the walls of a room in order to block out cell phone signals. What I'd like to find out is if it's possible to similarly block a magnetic field, something generated by an electric motor for example. Any feedback would...
Im in high school now taking AP calc AB, AP phys C mechanics, and AP chem, and the typical english/social studies classes. I am doing this cause i like math and science. My dream schedule would have been AP calc BC, AP phys C and B, AP chem, AP bio, and probably AP stats or envi sci. This is...
Hi, I'm currently a graduate level physics student taking a course in analog electronics, and I'm really stuck on the idea of transistors. I am reading "the art of electronics", and it's explanation of transistors is horrible, and aside from the fact that i know they "magically" cause a gain in...
I'm scared... please give me some insight!
Hello,
im a grade 12 high school student. I am about to take my AS level exams in math phys chem and bio and go to college. I am thinking of medicine. and i applied and got accepted at Dalhousie University at Canada. but there's somethin about the...
Hi. I just solved a homework problem. I eventually got the right answer and am only confused about why it was solved that way. This is the reason I posted it here instead of in the homework help section. All I need is a little insight into why the solution is the way it is. OK here we go...
0.99999... = 1?
I found the following proof on Wikipedia. It looks fine, but I can hardly imagine it to be right...
Another kind of proof adapts to any repeating decimal. When a fraction in decimal notation is multiplied by 10, the digits do not change but the decimal separator moves one...
The problem (From Electromagnetism by Pollack and Stump, exercise 11.34)
A stationary charge of charge e and mass m encounters a electromagnetic wave with vector potential
\vec{A}=\vec{j}f(x-ct)
where
\vec{j}
is the unit vector in the y-direction. The scalar potential is zero...
I was thinking about that question (what is energy) and I realized that I could easily understand what energy is and why it is conserved if I thought of it as the total force needed to get a mass to the position that it is in. For example:
Kinetic energy - inorder to give a mass speed you...
hey,
I was given a problem that states:
Alyssa passes by Aaron at a constant velocity of 80km/h. Aaron wanting to catch up to her hesitates for 1 second and then starts accelerating at 10km/h/s. Where does he catch up with alyssa?
OK what i have been thinking and trying out is that the...
Hope this is the correct forum for this... :rolleyes:
I ran across this today. I've begun researching what companies are doing to replace our current dry cell batteries used in electronic devices. This is the first reference I've seen of a so called nano battery. Anyone with experience here...
Greetings,
I stumbled across two question that I have no idea on how to answer them.
1) The interaction term in a scalar field theory is -\frac{\lambda}{4!} \phi^4
Why should lambda be positive? (they say look at the energy of the ground state...)
2) Write down the Feynman rules for...
Insight into "intelligence"
we call one mind intelligent and another not.
what is first of all "intelligence" ?
is intelligence one of the quality in "thinking process" ? If so , what are the
general rules/principles of "intelligent thinking".
In an experiment in physics class, a model solid-fueled rocket is fired vertically with an acceleration of 5 m/sec2 for 7 seconds. After that time, it's fuel is exhausted and it continues upwards as a free fall particle. (Take upwards to be the positive direction.)
a) What is the maximum...