Pic unrelated

Was solving some circuit problems and came across this one. It asks for the tension in V2 and current in I3. Not sure how to proceed outside of maybe joining the resistors and I feel like the solution is super simple and I'm just not seeing it, any tips on what to do?

Why don't the buildings in Vegas get corroded by desert wind, and why isn't there sand in the streets?

So /sci/, I've been wondering. What are some topics in maths/physics/cs/etc., unknown by most, but have huge ammounts of potential/theory behind them?

What's it?
https://www.youtube.com/watch?v=r8EYQBlJoo0

Is it worth it to study classical non euclidean geometry in 2 and 3 dimensions (Spherical and Hyperbolic geometry in particular) before I study more general Riemannian and semi Riemannian geometry where the curvature of the manifold in question doesn't need to be constant and in higher dimensions?

Recently, a friend of mine got a vitamin D deficiency related tumor. Needless to say, he is of Turkish descent, living in Germany. Since the problem got resolved, I spared him the lecture about how he can't survive in this hostile environment without supplements because the sun is literally racist. I tell the vitamin D run down unprompted to all my friends "of color" to save them severe medical problems. However, I avoid it if I can, since they get all defensive and offended.

This made me wonder, though, how much variability in melanin is there among indigenous European peoples?

We all know that Anglos look like pink pigs, while Nords look like ghosts, so there seems to be a difference, everyone is not just "white".

However, for the rest of Europe, it seems that there isn't much variation. For example, Hungary and Austria look as white as say Italy and Bulgaria. Wouldn't less or more sun require slightly different melanin levels?

inb4 Italians aren't white. inb4 Bulgarians aren't white. inb4 tanned picture of greek man, tan =! natural pigmentation.

I tried looking for data, but can only find studies comparing Africans to Europeans. I am not sure why we need studies to conclude that Africans are darker than Europeans but there you go.

Also whats your vitamin D schedule? I take 2000iu everyday, but don't bother getting tested.

https://www.spectator.co.uk/article/natural-immunity-is-stronger-than-vaccination-study-suggests

https://www.sciencemag.org/news/2021/08/having-sars-cov-2-once-confers-much-greater-immunity-vaccine-no-infection-parties

>About to get my Pfizer shot after pulling an all nighter
What am I in for?

perineal ectopic testis