Mortal matrix problem Updated 2025-07-16
One of the most simple to state undecidable problems.
Computable problem Updated 2025-07-16
A:
- decidable problem is to a decision problem
- like a computable problem is to a function problem
Computable number Updated 2025-07-16
Position and momentum space Updated 2025-07-16
One of the main reasons why physicists are obsessed by this topic is that position and momentum are mapped to the phase space coordinates of Hamiltonian mechanics, which appear in the matrix mechanics formulation of quantum mechanics, which offers insight into the theory, particularly when generalizing to relativistic quantum mechanics.
One way to think is: what is the definition of space space? It is a way to write the wave function such that:And then, what is the definition of momentum space? It is of course a way to write the wave function such that:
- the position operator is the multiplication by
- the momentum operator is the derivative by
- the momentum operator is the multiplication by
physics.stackexchange.com/questions/39442/intuitive-explanation-of-why-momentum-is-the-fourier-transform-variable-of-posit/39508#39508 gives the best idea intuitive idea: the Fourier transform writes a function as a (continuous) sum of plane waves, and each plane wave has a fixed momentum.
Bibliography:
Energy operator Updated 2025-07-16
Appears directly on Schrödinger equation! And in particular in the time-independent Schrödinger equation.
Angular momentum operator Updated 2025-07-16
Then you have to understand what each one of those does to the each atomic orbital:
- total angular momentum: determined by the azimuthal quantum number
- angular momentum in one direction ( by convention): determined by the magnetic quantum number
There is an uncertainty principle between the x, y and z angular momentums, we can only measure one of them with certainty at a time. Video 1. "Quantum Mechanics 7a - Angular Momentum I by ViaScience (2013)" justifies this intuitively by mentioning that this is analogous to precession: if you try to measure electrons e.g. with the Zeeman effect the precess on the other directions which you end up modifing.
Complementarity (physics) Updated 2025-07-16
CAPTCHA Updated 2025-07-16
Absorption (electromagnetic radiation) Updated 2025-07-16
Spark-gap transmitter Updated 2025-07-16
The first type of device that allowed sending Morse code without wires, as opposed to the wired electrical telegraph that previously existed.
Wireless voice transmission came about with modulation.
Transmembrane domain Updated 2025-07-16
Translation group Updated 2025-07-16
Avery-MacLeod-McCarty experiment Updated 2025-07-16
Transfection Updated 2025-07-16
Post-transcriptional modification Updated 2025-07-16
Promoter (genetics) Updated 2025-07-16
RNA polymerase Updated 2025-07-16
Operon Updated 2025-07-16
A single operon may produce multiple different transcription units depending on certain conditions, see: operon vs transcription unit.
Transcription factor Updated 2025-07-16
There are unlisted articles, also show them or only show them.