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6:53 AM
Q: Energies between valence and conduction band

peter mafaiWhen looking at pictures of direct band gaps from a crystal lettice I wondered if it really is impossible that electrons, even if its only for a short time, occupy the Energies between the band gaps ? Or is it just that these Energies between the two gaps arent solid energies ? Meaning that an el...

3 hours later…
9:59 AM
Q: Why are heat and work path functions but internal energy is a state function?

VisvI had found a statement given in my textbook which said that heat and work are path functions, but the sum of the two according to the first law is internal energy difference. How is it that two path functions add up to give a state function?

12 hours later…
9:30 PM
Q: Are constraint forces infinite?

zetzarA lot of authors claim that mechanical constraints are idealizations obtained by allowing enforcing forces to be infinite. But I either disagree or don't know what they mean. The only case where I would find it to be true is these forces were impulsive, i.e., the velocity would change abruptly th...


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