I know calculus (ODEs, PDEs, integration over 3 dimensions, limits, W, Zeta functions, series etc) and am working on linear algebra. What it the best book to learn quantum mechanics from with mathematical derviations?
I'm really interested in quantum theory and would like to learn all that I can about it. I've followed a few tutorials and read a few books but none satisfied me completely. I'm looking for introductions for beginners which do not depend heavily on linear algebra or calculus, or which provide a soft introduction for the requisite mathematics as they go along.  What are good introductory guides to QM along these lines?
What is / how can I get a student-safe power supply for electronics projects?  I'm looking for a student-safe power supply for solder less breadboard.  I'm developing a course to teach electrical engineering to grade school students as an after-school program.  I'm wrapping up the first course and I've learned a lot, including that I need to find a safer power supply.  We're mostly using 9V batteries and connecting them to the breadboard via alligator clips.  After lots of searching, I'm realizing that I need to turn towards the expert community for guidance.  I hope that with the rise of the Makers  this question will become increasingingly relevant with time as more kids get into electronics.  Inextricably linked to this question is what is the minimum power source to use.  I've liked using 9V batteries since we can connect to them using alligator clips; but I worry that they are just a little too powerful.  I can imagine them somehow starting a fire with them.  My #1 priority is to keep the students safe.  Kids just have no concept that they can cause damage to themselves and property.  When I ask "where is that smoke coming from?" I'll get a gleeful response from the student that is seeing how many batteries he could hook together and short out.   I really need to limit the damage they can do.  I mainly don't want anyone electrocuted or anything to catch fire.  Kids will routinely attach LEDs backwards, leave them like that and then act surprised when they explode.   After safety, I want to protect the equipment.  Kids will hook up a LED backwards all the time.  After protection, I want to give the kids feedback as to what is going on.  A light that indicates power is on would be awesome.  A light or siren or circuit break that indicated a short would be awesome too.  Battery powered supplies are slightly preferred, just to keep upfront costs low and to avoid having to run outlets to each table.  Boundaries:   We are only using simple LEDs, BJT transistors, resistors and maybe a timer IC.    Similiar Questions:       References:  Course details are here:   We currently sometimes use  from the Squishy Circuits Store and/or a 9V battery with alligator clips.  Epilogue  I found it tougher than expected to find a suitable wall wart, so I'm listing what I finally found for future reference.  I'm about to test the following combination:         Epilogue 2  A year-plus in, I've decided to drop the in-line power switch since it wasn't obvious when it was 'on' vs. 'off'.  I'm instead relying upon the students to unplug the rat-tail from the supply, which is quick and easy.  Also, since I'm primarily using this for a squishy-dough project, I'm experimenting with with using two button batteries instead of a wall power. Sometimes when reading through user comments on a particular answer, some usernames that appear like user[digit] e.g user12345 are not links. Is this a known behaviour or any other thing I am not aware of? I am looking for a way to add some string to the beginning of every line (same string for every line). Not something customizable but rather something that will be easy to remember and available on every POSIX-compliant platform (and every shell as well). How come Snape and Lily have the same patronus? Why is Severus Snape's Patronus the same as Lily Potter's? Are Snape and Lily related somehow? Are Snape and Harry related? Laptop randomly waking up = Hibernate / Low Battery? Should you pick a baby up everytime it cries? My husband and i have differing opinions on this. I don't believe in the term 'spoilt'. I would be very happy if my daughter was 'spoilt' in the sense that she expects to be treated with the highest possible respect and love and affection in all her relationships.   Also it would not bother me if she think she is special and unique (that's exactly what I want her to think). Mother's face is a mirror for the baby - through the mother's reactions and attention, the child learns that she is a lovable and valuable human being.   I spend all my time with my baby when she is awake. I play games with her, I smile, and laugh, and I never ever let her cry. I rush to pick her up immediately, even if it's the middle of the night, I force myself to get up, no matter how tired I am (I admit it's hard sometimes, and I do let her cry for 10-20 seconds sometimes, but never more). A finite summation of double binomial coefficients I find the following identity and have checked on Mathematica, while I have no idea how to prove it:  $$\sum_{j=0}^n(-1)^{n-j}\binom{p+j}{j}\binom{n+\beta}{n-j}=\binom{p-\beta}{n}, \quad \beta&gt;-1, \quad p&gt;\beta-1.$$  It seems that proof by induction does not work and because of the gamma function, the transform technique does not work either. Passing data between view controllers How many non-negative integer solutions does the equation $3x + y + z = 24$ have? I have a Toshiba Satellite laptop. My charger has stopped working.  I have access to a Lenovo charger. Can I use this charger on my laptop? Bluetooth earphones work fine until sleep. After resuming from sleep however, they appear to connect for a brief moment before disconnecting. On blueman, the error given is Resource temporarily unavailable. This issue arose only after updating to 18.04 LTS.   Here's the terminal output for lsusb:  Bus 001 Device 002: ID 8087:8001 Intel Corp.  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 002 Device 004: ID 1bcf:0002 Sunplus Innovation Technology Inc.  Bus 002 Device 003: ID 04f2:b477 Chicony Electronics Co., Ltd  Bus 002 Device 002: ID 0a5c:21f1 Broadcom Corp. HP Portable Bumble Bee Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub I am just curious that the following format looks good to you or not? The preamble I used is just   \documentclass[12pt,a4paper]{article}  \usepackage{amsmath} \usepackage{amsthm} \usepackage{amssymb}   I don't feel it's so good because the first paragraph has no indent but the second does. If the first paragraph is much longer, than it's fine. But if not, it looks strange. Should I leave it, or you have suggestions for this? I need help!  I need to prove that for any $2 \le n,k$ positive integers $(n - 1)^2 \mid n^k -1$ if and only if $(n - 1) \mid k$  Thanks! Do Category Theory and/or Quantum Logic add value in physics? I know they have their adherents, but do more or less esoteric branches of mathematics such as Category Theory and/or Quantum Logic provide powerful tools for new theory development or are they just occasionally-useful presentational frameworks?  More particularly, is it worth investing the time to study these formalisms? Copying prod multi-site installation to dev multi-site installation I am attempting to upgrade my Drupal 8.9.2 multi-site installation to D9. I was hoping to work this all out on a development installation, that is located in a subdirectory of my home directory on my NameCheap Shared Hosting plan. When I first installed this installation, I did so using the tarball method from years ago. I then followed the instructions given here (). I was able to get the current running prod version converted to use composer with out an issue. Before I go and start messing with the files, and attempting to upgrade to D9 through composer on a prod installation, I wanted to copy these files over to another installation where I can use it as a sandbox. To do this I:  copied the files on my server to a new directory made clone databases for the new installation truncated all the cache tables in the cloned DB changed all the database settings in the settings files to point to the cloned databases  I've done this before without any issues, and now I seem to be getting a WSOD error on all the sites running from the new installation. The error I'm getting is  PHP Fatal error:  Uncaught Error: Class 'Drupal\Core\Cache\DatabaseBackend' not found in ~/{new installation dir}/public_html/index.php:16.  If anyone has any thoughts what's going on I am all ears. Thank you in advance Solving an Op-amp circuit The image of the circuit is shown below and it required to find \$V_0\$,  My first attempt at solving this problem is by changing the current source into a voltage source with 1-V and 2k\$\Omega\$ resistance. The fact that the inverting and non-inverting terminals aren't grounded make this problem look difficult.To the point which, I don't know how to proceed with this question or where to start. I would appreciate any help. Following some thought and another schematic from a hint suggested by Alfred, I produced a schematic representing our work.  And  my solution for the problem is below, Using node equation at nodes A and B we have, $$\frac{V_A-V_B}{1k}=-0.5 \text{mA}$$ $$\frac{V_B-(2+V_A)}{1k}=-0.5-x$$ where x is the current that is sent in the output of the op-amp. Using KCL, at the bottom node near the current source we see that the same current that goes through the op-amp also goes through the \$2\text{k}\Omega\$ resistor. Hence, we have, $$\frac{-V_A}{2k}=x$$ Replacing this in the second equation, $$\frac{V_B-(2+V_A)}{1k}=-0.5+\frac{V_A}{2k}$$ And and solving the equations yields \$V_A=-2 \text{-V}\$ and \$V_B=-1.5 \text{-V}\$ Cutting strands of wire to fit plug I am a hvac tech, but my question is I have 2awg stranded and my plug is 6awg, will it matter much if I cut some strands to fit my plug? the plug is 60amp 250vac for a piece of kitchen equipment if the matters. How to show that Klein four-group is a normal subgroup of the alternating group $A_4$ I want to show that the Klein four-group is a normal subgroup of the alternating group $A_4$.   I am using the information in , that shows explicitly $A_4$, and Klein four-group as a subgroup.  I know that there is the direct way, by definition, but is there a way that does not require actually multiplying so many permutations ? Is there a VB.NET-Like operator in C#? Proof of $1+x\leq e^x$ for all x?