## I’m Outta Here!

No posts for a while, as I’m off exploring Peru! Hopefully I don’t fall off a mountain or die of altitude sickness. If you’re missing me, you can check out my previous physics videos. Until next time!!

xoxo

## You Spin My Head Right Round

I’m a little late in posting about it, but I am happy to say I was not late in actually doing my studying on Friday. I was 4/4 for meeting my study schedule last week! That makes me feel like a powerful Productive Goddess. Hopefully this momentum can continue when I am back from Peru.

Speaking of momentum, that was what I studied! Well, one chapter on Rotation and one chapter on Conservation of Angular Momentum. These are mind-bending topics if you’re not familiar with them. Or maybe just for me. In any case, it all makes sense, but I find that I have to think it through very carefully. The vectors are starting to get more complicated, and the conclusions aren’t always intuitively obvious. One example that I remember vividly from my high school AP Physics class (I couldn’t help but do the math and realize that was thirteen years ago holyshit) is someone holding a spinning bicycle wheel horizontally and then tilting it upwards, resulting in an opposite rotation of the person, assuming they are on something that is free to spin.

Amazing that something so simple as a bicycle wheel operates under the same concepts that help aim the Hubble Space Telescope via massive reaction wheels.

Today’s fun “new” fact: Angular momentum is a quantized quantity. Of course, this fact is immaterial at macroscopic levels, but it is important to keep in mind! Understanding the layers of what is “actually” happening versus our useful approximations is, I think, an important part of understanding physics.

## Work, Work, Work, Work, Work

(I’m not sure why all my posts titles have ended up being from songs. Not planned! I’m not even that much of a music person.)

I got a bit of a late start today, after falling down a rabbit hole of nostalgia while going through some boxes containing stuff from my college years. I read my journal from that time and had some panic when I saw past-self complaining about the difficulty of the Heat, Sound, and Light course. How am I ever going to manage graduate level classes?! But then I remembered that I’m a physics boss and decided not to worry. I did eventually get around to my studying, and I reviewed three chapters today: Work and Energy, Conservation of Energy, and Systems of Particles and Conservation of Momentum.

Most of the concepts here are pretty straightforward, and the “shortcuts” from using scalar quantities make for some fun problem sets. I also appreciate the refresher on elastic vs. inelastic collisions because I always mix that up for some reason. Basic introduction to Einstein concepts (energy quantization and rest energy/Newtonian mechanics applicability), although without any of the fun space-time bendiness yet.

Last night I remembered that I had also planned to learn some Python coding this summer. So that’s another thing to add to the list–but it’s going on the post-Peru list, so I have some time. I’ve done some Python before, but I never stuck with it because I had no use for it. Hopefully having a more concrete motivation will help.

Today’s fun “new” fact: Because the center of mass will always lie on the line straight down from a pivot, if you hang an object from a pivot at two different points, you can find the center of mass!

## And I’m Freeeee, Free Bodying!

Today I had scheduled myself for a study session in the AM. I slept in a bit (I must say this no-alarm-clock business is divine), went for a walk, brewed up a mug of decaf coffee in my French press, and go to work. I only had two chapters today: Newton’s Laws and Applications of Newton’s Laws. Which means–heck yeah, free body diagrams!

Free body diagrams are probably loathed by most introductory physics students. In fact, I don’t recall being fond of them myself, way back when in my AP Physics course in high school. But seriously, they are SUPER cool. I love the way they simplify down problems that sound crazy complicated into something solvable. Plus they are the quintessential “spherical cow” object! Throw in a couple massless, frictionless pulleys and you’ve got yourself a party.

I have to admit that I had to read the sections on rolling friction a couple times. I know this is basic stuff, but for some reason my brain does a little fritz when I first try to picture the forces involved and I really have to break it down for myself.

Today’s fun “new” fact: The angle of repose! $\tan\theta=\mu_{s}$ This is the maximum angle that something will stay stationary due to the force of static friction. I always like nifty little things like this that are way simpler than you might think at first glance. Also it’s kind of funny that this is something I forgot given that this equation was one I learned for the pGRE like six months ago.

## It’s a New Day, It’s a New Life, It’s a New Blog!

Last night I had a dream that it was my first day of graduate school, and I had to do some sort of physics audition for the professors. One guy even wanted us to go in this closet, read a problem, write the answer on a whiteboard, and then leave, so that it was a totally blind audition. And of course I didn’t know anything! So–needless to say, I clearly have some anxiety about this upcoming phase in my life.

Given that I am also a writer, and that writing helps me to order my thoughts, I decided to cope with this anxiety by starting a blog to chronicle my time as a PhD student (to be). I anticipate that this will be a combination of written posts, like this one, as well as vlogs.

A little background: I have accepted an offer to enroll as a PhD student in the Department of Astronomy and Astrophysics at the University of Chicago, where I plan to study exoplanets. I have my Bachelors degree in Astrophysics from the United States Naval Academy–but that was a long time ago! I’m transitioning back to astrophysics from an entirely unrelated field, and I’ll be in my 30s for grad school. Eek!

Friday was my last day at my job. I now have a glorious stretch of months ahead of me before classes start in September. I intend to study, to travel, to write, to spend time with my boyfriend, to house-hunt, and to just generally enjoy myself as much as possible. My boyfriend encouraged me to take some time to relax first, but I cannot escape that pressing feeling that I will never be able to re-learn all of physics in four months, so I best get started now. In pursuit of that object, I put together a study schedule for this week. Next week, we’re going to Peru (yay!). In June, then, I plan to really start getting into it in earnest. This week is just sort of a warm-up.

Today I reviewed three chapters from my introductory physics text (I am using my old undergrad books–in this case, Tipler and Mosca Physics for Scientists and Engineers: Standard Version, 5th Edition), which is basically barely dipping my toes in. The chapters were: Systems of Measurement, Motion in One Dimension, Motion in Two and Three Dimensions. This is the sort of basic kinematic stuff that I really love. I had to stop myself from working through simple problems that I didn’t actually need to practice just because I think they’re kind of fun. Equations here that I know by heart, concepts that I didn’t really need refreshed, but it’s a solid starting point. Good to boost my confidence a little–hey, looky here, this gal still knows what a vector is! She’ll have a PhD in no time! Ha.

It feels good to be started, though. I am already excited about tomorrow!

Today’s fun “new” fact:* The candela (cd) is one of the base SI units (there are seven), for luminous intensity.

*I plan to choose one of these from the material I am studying, an interesting thing that I knew at one point but have since forgotten and it has therefore become new again!