Quantum Theory

Hi Wanted to know why do we use complex representation of wave functions? for example, exp(i(kx-wt)) is a standard wave function. WHat is the significance of the imaginary part of the number. If it does not exist then why do we include them in all representations/calculations? Specially wanted to clarify this from the point of view of the Schrodinger wave equation that has a real and imaginary part. Please throw light on the same. Thx/rgds Archana Bahuguna

Preliminarily, I'd like to apologize if I didn't get this posted in the right TA - It's a newbie first-post. To get to my question: I came across a webpage ( http://www.ebtx.com/ntx/ntx10.htm ), which states: How is that mechanical devices can't detect those? For starters, "red" is simply a set frequency of light. A mechanical device could take in that proportion, and match it against a set amount to determine the color quality. For sweet, it could dig in the molecular structure to see what it's makeup is, then determine what senses it would stimulate in the mouth.... I understand that some things, like the spiritual realm and emotional realms, cannot…

Hi I am a newbie to quantum mechanics. I have just joined Grad in EE (majoring in electronics). Have studies QM before but not that much in detail. Am specifically looking for good introductory as well as detailed books that cover what a schrodinger equation is all about, and how all the derivations for Particle in a box, problem of barrier potential, reflection/transmission/tunneling concepts. Was told to check out Feynman's lectures. Can you suggest any really good book in Quantum mechanics that covers this topic very well and in detail. Thanks a lot Arch

Non-string quantum gravity is already a minority research line compared with string----although it is a growing one. But even that minority is now split over the issue of the Immirzi parameter. Some of the big names in LQG, people who head institutes and guide research, where the grad students and postdocs work on LQG. Have signed on to a value of the Immirzi parameter 1/4.21 (that is, 0.23753...) calculated by Christoph Meissner in Warsaw, with the help of Jerzy Lewandowski. but Lee Smolin and a young researcher at Perimeter Institute named Olaf Dreyer say that this key number is actually 1/8.088 about 8.088... about one over that. Lee Smolin has vo…

Are there any working theories for anti-matter containment in a matter enviroment? I can't imagine containing a gas or liquid but maybe if we have a metal anti-element it can be magnetically suspended in a vacuum. I read the problem with making anti-hydrogen last for any period of time is its neutral charge as an atom, so it loses magnetic containment and reacts with the walls of the chamber. It seems we can make plenty but we can't seem to keep it around. Just aman

I heard it said somewhere that light is both a particle and a wave. Yeah, okay. I'm in eighth grade, this tells me very little So, light is a particle, because it has to be otherwise it can't travel through space. So then, why does it have wave properties? Why can't it just be a particle? (I'm sure this is probably something obvious- it needs to cover too much area for a few particles to work on it, or something.) Also, when it hits something that isn't a vaccuum, like our atmosphere, does the particle dissipate, or what? I'm assuming that's the point when it switches to waves, but why and how? Now onto the other topic- lasers. Lasers are still light, so …

http://www.thoughtware.com.au/philosophy/science/quantum.html What is it about?

how would they have measured when the electrons where instantaneously communicate with each other , that they could have been from, lets say 10 feet or 10 billion miles apart, or lets say at the other side of the universe, and still instantaneously communicating with each other.

How can I prove Newtons Laws of Motion using Shrodinger's Equation ?

In a recent college lecture, we were briefly introduced to the concept of quantum computers...... Frankly at first it all seemed out of a science fiction novel, a computer being in various states at once and the concept of a Qubit....... Could ne1 please tell me how far do we stand today in this field, and wat sort of technology has yet been achieved, becoz as far as I know there have already been some interesting algorithms written to run on q-computers

in the past 100 odd years we have developed many machines and techniques to mesure the weights of atomic , subatomic particles.....but wont the mass, weight of ALL things be continously changing??? it is for sure that all these atoms , molecules ect are continously going through collisons....and this will leed to a constant change of energy of the system and the mass of the body.....all the weights of atoms , electrons,ect are done in special conditons (vaccume,ect..) and after all this we use these constant weights in normal condition experiments...wont it make a difference...how ever samll the variation of mass,weight may be ,when viewd in a large picture will effect …

I found nothing for the above mentioned theory on the site so hopefully this thread won't be like almost all of my other ones and someone might be able to shed some more light on this. What are your thoughts on this? Is this bell telegraph able to break the speed of light?

Hi im new to the whole idea to quantum physics, and the internet wasn't a very reliable source. It's seems to me u guys know what ur talking about, and I could greatfully use the help.

as with all things, speed starts from Zero and then reaches whatever speed the energy supplied to it will allow. does the same apply to Photons? you have a torch switched off (there`s no photons being emited) then you power up and there`s light, do these photons go from Zero kms/sec to 300,000 kms/sec instantly or does it take a little time? and how do we know?

Imagine a hypothetical situation where absolute zero is indeed achieved. In this situation does theory predict all motion to cease or will motion still exsist. I ask this bcoz of the following two points (which i found to b slitely contradictary) : 1. Kinetic energy of atoms is directly proportional to temperature, hence abs 0 shud imply no motion. 2. In quantum mechanix, the heisenberg principle would not allow for such a situation however bcoz that wud mean no uncertainty in either position or momentum. Where am I going wrong ?

i know there is another thread going called 'photons' as well, but i wanted to change the subject a bit, so started a new one.... basically, i know what a photon is, and i understand everything that has been said in the other thread [photons] but what i wanna know is just all the basics, what i need is to just sit down and read an essay on photons, starting at the basics [not what it is, but how it made/interact] and then get into more details after...... so does someone know a website, or just know about photons themselves, start with the basics, ill read it, then, [or another time, if u dont have loads of time to waste typing stuff!] get into more details th…

Hi there! I was just wondering about this: In an airplane, the flight attendant usually tells you on those annoying videos that the pressure in the cabin is carefully controlled. what does that mean? Do they mean that the cabin pressure remains at normal atmospheric levels? If so, read on: When the airplane ascends to a greater altitude, your ears start to pop, since there is a change in pressure. Doesn't that mean the pressure in the cabin is NOT controlled? As if the pressure WAS controlled, your ears wouldn't pop?

Why is E1 for He+ 4 times greater than the value for E1 for Hydrgoen This info may help I am following the conditions that: The radius of the ion is inversely proportional to the charge in the nucleus The energy of a particular level is directly proportional to the charge in the nucleus The energy of a particular level is inversely proportional to the radius I also have found two equations En = [1/(n^2)] * E1 & r = (n^2 * h^2)/(4pi^2 * m * k * q^2e) this is where r = radius, n = energy level, h = planks constant, m = mass of electrons, k = 9 x 10 ^9 and qe = charge of electron

Will we ever discover the Unified Theory? Answer the poll above

What are the following changes of state called? Solid To Plasma Liquid To Plasma Gas To Plasma Plasma To Gas Plasma To Liquid Plasma To Solid I know, i know, it's all related to plasma (hence the title). I searched for it on google, but came up with nothing, so i thought i'd post it here! Edit: Some of the symbols weren't working porperly, i had to change them to 'to's!

I heard that a photon cannot be accelerated, but.. then what happens to the energy applied... does it turns back...or what... It is supposed that speed of light is a constant specified by photon.... but then again.... when the photos has its particle moment could it be acelerated... or is this the changes between particle and wave... an aceleration and desaceleration... And .... is the speed only messurable for matter?

on an atomic scale... what happens when a photon interacts with normal matter? e.g. when light bounces of the wall or anything normal...? on an atomic scale, so what happens to the photon and what happens to the atom which it hits

Are there any works on simple quantum physics? Like Quantum Physics for Dummies? Or original works?

Where did the design for atoms come from? I mean, was it always atoms, or something before it (a proto-atom, if you will)?

I can see how you can bracket an operator with a state vector and get the expectation value of the observable represented by the operator. This would be like getting a weighted average of the different eigenvalues (which are the possible measurement outcomes). What I don't understand is the meaning of multiplying an operator times a state vector. You would get the eigenvalues multiplied times the components of the vector (for each eigenstate), and I don't see what use could be made of this information. Something I understand much less is the physical meaning of multiplying two operators together. i'll appreciate your comments.