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  1. Garlic

    Landau levels: Hamiltonian with ladder operators

    Dear PF, I hope I've formulated my question understandable enough. Thank you for your time, Garli
  2. Garlic

    I Spin evolution over time

    Dear PF, As an excercise I am to find out how the expectation value of the spin operator evolves over time. There was a hint, stating that it is enough to show that $$ e^{i \frac{\phi ( \hat{n} \cdot \sigma )}{2}} \sigma_i e^{- i \frac{\phi ( \hat{n} \cdot \sigma )}{2}} = [R_{ \hat{n} }]_{ij}...
  3. Garlic

    I Question about the quantum harmonic oscillator

    Dear PF community, I am back with a question :) The solutions for the quantum harmonic oscillator can be found by solving the Schrödinger's equation with: Hψ = -hbar/2m d²/dx² ψ + ½mω²x² ψ = Eψ Solving the differential equation with ψ=C exp(-αx²/2) gives: -hbar/2m (-α + α²x²)ψ + ½mω²x²ψ = Eψ...
  4. Garlic

    Which pH Meter to buy

    Hello everyone, In a few weeks I am going to have my anorganic chemistry laboratory experiments, and I want to buy one PH-Meter. I'm looking for a model that is realible but not expensive (in the order of 20-40 bucks) I'll be happy to hear your suggestions Thanks :smile:
  5. Garlic

    Problem with a derivative

    Hello PF, 1. Homework Statement I've been having problems with the deriative of a function, although I thought I've done everything right, my solution doesn't match with the right solution. I have no clue what (or if) I've done anything wrong, or simply don't know the tricks I was supposed to...
  6. Garlic

    Problem on a question about the gravitation potential

    Hello everyone 1. Homework Statement In the solution of a question, regarding the gravitational force fields and gravitational potential when the mass is inside earth (where the height of the mass is lower than the radius of earth), the step where we take the integral of the force in order to...
  7. Garlic

    Schools The university I wanted rejected me and I'm feeling so sad...

    Hello everyone, I couldn't visit the PF lately, as I was too busy because of the my university enrollment processes. I wanted to tell this to you later when everything is complete, but.. I finished my High School (German High School in Istanbul) this year, and want to study physics in Germany...
  8. Garlic

    News Coup attempt in Turkey

    Something really bad is happenning in Turkey. I'll update when I have more informations. Both airports are closed, there are tanks everywhere. https://www.theguardian.com/world/live/2016/jul/15/turkey-coup-attempt-military-gunfire-ankara
  9. Garlic

    I Youtube video about the sound of a pulsar

    Hello PF, I found this youtube video about the sound of a pulsar, and I have been wondering if this sound is really the radio signals of a pulsar converted into sound, or something fake. Thank you Link:
  10. Garlic

    I Electron wave energies different for +½ and -½ spin?

    Hello everyone, How come the electron wave energy states are different for spin -½ and +½ values? What causes this asymmetry?
  11. Garlic

    A Why doesn't pdg baryon list show quark compositions?

    Why doesn't pdg baryons list show the quark compositions and electrical charges? For example, there is only one roper resonance entry, but there are two roper resonances with different quark compositions (although they have the same mass), why not list all the variations?
  12. Garlic

    A Strong force bremsstrahlung equivalent

    Are there strong interactional equivalents of synchrotron, bremsstrahlung and cerenkov radiation? Or for the weak/gravitational interactions? For example, will an accelerating bare quark emit gluons?
  13. Garlic

    A Possibility of a stable mesonic nucleus

    Hello everyone, If a nucleus consisting solely of mesons has enough mesons in it, will it be stable? Mesons are bosons, therefore (unlike baryons) they aren't effected by the pauli exclusion principle, so they all can acquire the lowest energy state. In theory, if there are enough mesons, the...
  14. Garlic

    A The reaction π0 + π+ -> π+ + γ

    Hello everyone, Is this reaction allowed? π0 + π+ -> π+ + γ (just a single photon) I mean the π+ contributes with the reaction not just by making it possible that two particles decay into a single photon (by changing it's momentum), but also the π0 reacts with the π+, where the...
  15. Garlic

    I Intensity of the background neutron radiation

    Hello everyone, What is the average intensity of the background neutron radiation?
  16. Garlic

    I Detecting low intensity neutron radiation

    Hello everyone, Is it practically possible to detect a neutron source with an intensity of 0.1 Bq and each neutron having nearly 10MeV energies (and differentiate it from background neutron radiation)? If that's possible, what kind of equipment can be used? Do you need extremely sensitive and...
  17. Garlic

    Why do humans like explosions so much?

    Why do humans like explosions so much, while all the other animal species I know are afraid of them? Why do we enjoy watching a firework show or a chemical demonstrarion of a violent reaction?
  18. Garlic

    Complaint Banned IP address

    Hello everyone, I'm having this issue where 70% of the time I can't reach the PF because it says my IP address has been banned. (It only happens when I'm using my mobile phone to access PF.) I searched this issue and found this 11 years old thread, where I saw that the problem has something to...
  19. Garlic

    Detecting odors of toxic substances

    How are odors of extremely toxic chemicals be detected? If the chemical doesn't contain any of the common molecules with an odor, can we analyse how it would smells like? And can we predict how a certain substance smells like? (without even analysing it) How do we know, for example, that methyl...
  20. Garlic

    Relativistic standing wave electrons?

    Quote from the wikipedia article of relativistic quantum chemistry: "... These corrections affect the electrons differently depending on the electron speed relative to the speed of light. Relativistic effects are more prominent in heavy elements because only in these elements do electrons attain...
  21. Garlic

    Which number set does log(0) belong to?

    Hello everyone, Which number set does log(0) belong to? Or does it belong to any number sets?
  22. Garlic

    Question about isomeric transition

    Hello everyone, What happens to an isotope in a metastable state which has heavy hadron components in it? Can the heavy hadrons in the nuclei decay before a gamma ray (from the isomeric transition) is emitted, or does the isomeric transition occur first, and the hadron decays after that? (If...
  23. Garlic

    Strong force on hadrons

    Hello everyone, Why does the residual strong force arise? Hadrons carry no net color charge, so why are they experiencing the strong force?
  24. Garlic

    Electron capture in fully ionised nuclei

    Hello everyone, What happens if an isotope that normally decays through EC has no electrons at all? For example how does 7Be4+ decay?
  25. Garlic

    About mu-mesic atoms

    Hello everyone, I know that electrons in heavy atoms move at relativistic speeds, resulting in heavier electrons and smaller radius. If we replace an electron in a heavy atom with a muon, the muon would move to the center (occupying the lowest energy state possible), and making the radius of the...
  26. Garlic

    I Photon mass

    Hello everyone, I know that the photon has zero rest mass and I know that otherwise the relativistic mass formula would not make sense. When I searched for an answer to the question "how can a particle have zero mass and still possess energy if E=mc^2" I got an answer saying the mass energy...
  27. Garlic

    Different stable nuclear spins for the same isotope

    Hello everyone, When I look at the isotope lists, I always see only one nuclear spin for a specific isotope. (Why) can't an isotope have different nuclear spin types that are stable? I know metastable isotopes exist, but I am asking about the stable isotopes. Can't there be a case where the...
  28. Garlic

    Superatom chemistry

    Hello everyone, I see that superatom chemistry was considered to be a big lap in chemistry, lots of news articles were made in 2008. The problem is, I can't find any scientific articles etc. , nothing else, but basic information on it. Even the wikipedia article of superatom chemistry is really...
  29. Garlic

    Photons passing through transparent material

    Transparent materials such as glass can let visible light pass through nearly undisturbed. I don't understand how photons just pass through atoms in that material. I can understand the concept of atoms not absorbing the photons in that specific wavelengths, but how can photons avoid deflection...
  30. Garlic

    Spontaneous fission

    Are there isotopes that decay only through spontaneous fission, or in other words can normally stable nuclei decay through spontaneous fission?
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