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# Talk:Quantum physics terms

## Colour

It's a scientific article, Gatecrasher... this isn't Uncyclopedia, you know. UchihaKATON! 01:24, 4 April 2008 (EDT)

## Duplication

mea culpa copy/paste instead of cut/paste. SusanG 13:17, 4 April 2008 (EDT)

Hehe, that's why we all proofread each other! human 13:52, 4 April 2008 (EDT)

## ?

"The Hamiltonian is what is usually used in quantum mechanics to describe the system - if you give the system's Hamiltonian, you have described it." I don't get this. Sterile pencil 17:45, 18 May 2009 (UTC)

It's just a mathematical operator that you apply to your system, a function just like multiply, add, or sin and cos, but slightly more complicated and usually with imaginary numbers in it. The Ĥ in the Schrodinger equation Ĥψ=Eψ is the Hamiltonian; when you apply the Hamiltonian operation to the wave function ψ (not simply multiply Ĥ by ψ), you get the wavefunction back again multiplied by a particularly energy; Eψ. The Hamiltonian has to satisfy the Schrodinger equation so produces discrete values for E for a given wave function. Ask some actual physics students to fill in the more precise and accurate details, I'm not as hot on it as I used to be. narchist 20:25, 18 May 2009 (UTC)
Basically, the phrase means that different systems, like different molecules, will have different Hamiltonians that satisfy the Schrodinger equation and thus describe the system in an accurate mathematical context. As a point, it's only possible to exactly solve one for a one electron system. I don't think it's possible to fully describe it without going deep into a level of maths that's best left to people who get the jokes in Abstruse Goose. narchist 20:32, 18 May 2009 (UTC)
Even more simply, once the Hamiltonian of a quantum mechanical system is known, Schrodinger's equation for that system can be immediately written down. Its solution describes the time evolution of the system. (If the system is adequately described by classical mechanics, then plugging the Hamiltonian into Hamilton's equations yield the equations of motion.) Nerd (talk) 01:27, 27 June 2016 (UTC)