Week 15
Current and upcoming hw assignments
Ch. 14 4, 6, 9, 12, 13, 16, 19, --- Wed. April 15
Ch. 15 Assignment 5, 9, 18, (on 18 B make that sketch a plot NOT SOME HAND DRAWN THING---users choice of software). Due April 22 or thereabouts
Comments in general:
Schroedinger's equation is a wave equation.
- When the Energy is greater than potential E>V, then solutions look like
- WAVES----That is (exp(ikx))---we know how to put in the time part for each value of k
- We may be able to add many different values of k (energies) so that we get some kind of modulated wave--think Fourier series.
- The exp(ikx) can always be expressed in terms of sin, cos, or their series'sss (and includes exp(-ikx), wave either way).
- For the case with E<V we should get solutions that (YES, that is negative KE??? ).
- Exp(kappa*x). Where kappa plays a "k" like role to avoid the square root of negative which we already took out and multiplied by the existing "i" in the last oscillation solution.
- These solutions look like exponential growths or decays.
- Aside from some superposition, adding, etc _--which can always lead to arbitrarily wonky looking functions----the SOLUTIONS TO WAVE EQUATIONS WILL GENERALLY APPEARS AS EITHER OF THE TWO THINGS ABOVE (WAVES, OR GROWTH/DECAY). Sometimes there is some geometry to contend with (space is 3 dim).
- I may give other psi for exercise of normalizing---or whatever (grinding math)----but wave equations have a type of solution that you should be on the lookout for.
- Normalization must also be answered to.
- Your wavefunctions should not grow to infinity as x gets large. Boundaries exist. Boundary condiitions exist.
- Wavefunctions that become infinite and infinite number of times in a small region can also be difficult to deal with.
- Sometimes reality will really limit what math we can write out.
Future, we'll get through 13, 14, 15 (quantum intro) and a little bit more.
Exam 3, Chs. ~10-15+ Monday April 20th note the Monday
We will discuss some "additional topics" in quantum mechanics.
In the time remaining we may discuss (will continue)
Final Exam Comments: Coming ASAP
Many of these are character development drama's
In no particular order