Fiction Is My Addiction, And Since It’s Almost The Summer, I Thought I’d Share Some Ways To Get Free

What made you get into bioethics? Like, what about it captivated you enough to go to school for it?

As with all the great passions of my life–theology, every boy I’ve ever liked–it started with an argument.

The summer before my junior year of high school, I went to a summer camp where we stayed on a college campus and took mini “classes” and generally nerded it up for three weeks. You got to choose your “major”–the main class you took–but you were also assigned a random “minor”. The minors were unusual, like Hebrew or pottery or the history of war.

I was put in Bioethics. 

My teacher was a professor of philosophy from a nearby university, and I fucking loved every second of it. I loved the articles we read, I loved watching Gattaca and talking about genetic manipulation and individuality, I loved the professor and the insights he brought up (one day class was totally derailed by the question of why we refer to the soul as “my/mine/ours” what’s doing the owning there? that blew my little high school mind.)

Most of all, I loved the arguing, I loved the wordy back and forth of it–I’d been reading Stoic philosophy in Latin and ethics is endemic to theology classes, so I had a vague grasp of the territory. The rest was being quick on your feet, taking in information and then twisting it, trying to articulate vast things, poking holes in someone’s argument and defending your own. Looking back, I am dead certain I was insufferable–there were whole classes that I spent just arguing with the professor, while my classmates looked on. But I was too excited by this new toy not to…be an asshole about it, basically.

The social dimension of science has always fascinated me–I can still remember our physics teacher sitting down and explaining the reason that Aristotelian physics hung around so long was because it bolstered Catholic theology, my AP Bio teacher talking about how Rosalind Franklin’s work was ignored. So when I was reading through UChicago’s course guide, and I saw their description of the major, I was sold.

And honestly, it was a perfect choice for me. “Bioethics” is a very simplistic way to put what I studied; the major itself was the history, philosophy, and social studies of science. So it was a chance for me to just glut myself on knowledge–one quarter I would hurry from my Cancer Biology class on the science quad to Magic & Medicine in Ancient Europe in the history building. I went to lectures about the social factors influencing kidney donation, and international medicine. I wrote my BA thesis on how bioethics has failed to respond to the changing way medicine is done.

There are things I regret about my undergrad career, but my major was absolutely not one of them.

4 Legal Ways To Get Free Textbooks.

1. Open Culture:  Not a large a selection, but high quality texts. If you just want to skim a book to brush up on a course you took in ninth grade, download one of these. I have yet to be disappointed.

2. Book Boon: Provides free college-level textbooks in a PDF format. Probably the widest range of subjects on the web. The site is also pretty.

3. Flat World Knowledge: The worlds largest publisher of free and open college textbooks. Humanitie texts are particularly difficult to come by, this site has a great selection in all disciplines.

4. Textbook Revolution:  Some of the books are PDF files, others are viewable online as e-books, or some are simply web sites containing course or multimedia content.

5. Library Pirate: I’ve always had an addiction to torrent based pirating. When this site opened a few months ago, I went a little overboard. After dropping two hundred on a paperback spanish textbook, I downloaded the ebook version illegally. I also got a great Psyc text i’m obsessed with.  It will be interesting to see how this site grows- they already have a great selection. 

I made this to put on my wall for revision, but I thought it might be helpful for some of you guys too so I thought I would share it!

College Textbook Lifehacks

Okay so it’s not the beginning of a semester but whatever. While I’m thinking about it, let me, a bonafide degree holder learn you some knowledge about college textbooks so you don’t have to take out a mortgage or try to short the market just so you can have a $1,000 paperweight that you never read.

Rule #1 I don’t care what your syllabus says or what your pre-semester welcome email from your professor says or what the bookstore website says, don’t buy the book before classes begin. Show up the first day and ask the professor if the book is necessary for passing the class. Sometimes, it’s not. Sometimes the professor teaches from his or her own memory and never consults the course textbook. If this is the case, unless you just love reading textbooks or want to keep them for whatever occupation you pursue once you have your degree, don’t get the book and save yourself some money. If he or she can teach the course without a book, you can pass it without a book.

Rule # 2 If your professor’s response is yes, you absolutely do need the book, ask them how different the required issue is from previous issues. Book publishers are dirty swindlers and will release a new edition of each book every year or two. Often times the new edition has minor changes like maybe now chapter 14 is split up into two chapters or they changed a couple of the review questions. If an older edition will suffice, just like iPhones, they will be a lot cheaper than the newest edition and you have a better chance of finding an even cheaper used copy which brings me to rule 3.

Rule # 3 Don’t buy the books from your university. Like publishing companies, universities also tend to be dirty swindlers. Copy the ISBN listed for your textbook and paste that shit into a site like half.com valorebooks.com or amazon.com where you will find discounted versions of most every textbook. You could also try to torrent them off of those sketchy russian sites that are listed under that post with the “Leak college textbook PDF’s not nudes” tweet but when that doesn’t work, you go to those sites I listed. Now you have to choose what quality you want, this is important because it can affect the resale value which I’ll talk about later. Obviously the higher the quality (New, Used-Like New etc.) will give you book without creases, markings etc. but will be more expensive. If you don’t care about this (again I’ll explain why you might care in rule 4), maybe go for the rental if the rental is cheaper than purchasing a high quality book-ONLY DO THIS IF YOU DON’T CARE ABOUT RESALE AND DON’T TEND TO MARK IN YOUR BOOKS. Otherwise, the choice is yours. Now you might ask, what will I do for the two weeks it takes to ship my book? This is where making friends in class comes in handy, just ask them to borrow their book for the time being, or better yet, if you have a close friend already in the class, split the cost of the book 50/50 and share it. If neither of these options work for you, visit your professor in his or her office hours, give them some BS like “I’m so sorry professor, I think I mixed up the shipping and billing address so it’s taking forever for the book to get here boo hoo feel bad for me.” Usually, professors have no problem photocopying the first chapter of the book for you or will be a little lenient with deadlines for the whole class if you’re not the only one. This is fun because not only do you get away with not buying the book right away, but you’re a hero for your class.

Rule #4 Even though it’s the beginning of the semester, think ahead to the end of the semester. Your university is going to offer to buy back your books at the end of the semester. Do not sell them your books, I repeat DO NOT SELL THEM YOUR BOOKS. Those dirty swindlers that sold you an overpriced book a few months ago? Yeah they’re going to buy it back for $5.00 or less. I don’t care if it’s a 10 lb, 700 page biology textbook that’s still in the plastic wrap, you will get cheated. Sell them on amazon. Seller accounts are free and though you aren’t likely to get 100% of what you paid for it back, you will make much more money selling there than you would to the school. If you bought the higher quality book and kept it in decent shape, you’ll get some good beer money. If you went with the $0.99 acceptable condition book, maybe don’t try and sell it on amazon because you’ll pay more to ship it than you’ll receive profit this is why it’s important to take into consideration whether or not you think you will mark up your book. Rentals are cheaper than buying new but you can’t mark them and can’t sell them but don’t worry, there’s other places you can sell your book if you bought a crappy one. Find out if your school has a student run for sale Facebook group (hint, it probably does, especially if you’re at a large state-school), advertise your books on the page and sell them for cash to a fellow student. 

Rule #5 Sorry to say, but these rules don’t work for every course. You might have that professor that wrote their own book and makes you buy it which means you can’t find it on any third party website. When this happens, the most you can do is see if someone who has already taken the course still has their book so you can buy it from them. You can also leave a scathing review during evaluations at the end of the semester and on RateMyProfessor.com which may not do much but is good for the soul. 

Also, especially for labs and beginning language courses, you may need to buy a workbook. Used ones are hard to come by but they do exist thanks to people like me who do their assignments on a separate sheet of paper so they don’t have to mark up the textbook and can resell it later (I advise doing this). This works for language courses, I don’t know how well it works for labs since I am not a science student, if it does work-sweet and if not-I’m truly sorry.

These are my rules and I promise they work. If any one else has additional hacks that they’ve figured out I’d love to hear them! Seriously, doing these things saved me a load of money. 

This makes me sound stupid but what does a feynman diagram mean?

You don’t sound stupid! They can be pretty confusing at first, and I’m sure you’re not they only one that doesn’t fully understand them (myself included) so let’s learn how to draw Feynman diagrams!

You do not need to know any fancy-schmancy math or physics to do this!

I know a lot of people are intimidated by physics: don’t be! Today there will be no equations, just non-threatening squiggly lines. Even school children can learn how to draw Feynman diagrams. Particle physics: fun for the whole family.

For now, think of this as a game. You’ll need a piece of paper and a pen/pencil. The rules are as follows (read these carefully):

1. You can draw two kinds of lines, a straight line with an arrow or a wiggly line:

You can draw these pointing in any direction.

2. You may only connect these lines if you have two lines with arrows meeting a single wiggly line.

Note that the orientation of the arrows is important! You must have exactly one arrow going into the vertex and exactly one arrow coming out.

3. Your diagram should only contain connected pieces. That is every line must connect to at least one vertex. There shouldn’t be any disconnected part of the diagram.

In the image above, the diagram on the left is allowed while the one on the right is not since the top and bottom parts don’t connect.

4. What’s really important are the endpoints of each line, so we can get rid of excess curves. You should treat each line as a shoelace and pull each line taut to make them nice and neat. They should be as straight as possible. (But the wiggly line stays wiggly!)

That’s it! Those are the rules of the game. Any diagram you can draw that passes these rules is a valid Feynman diagram. We will call this game QED. Take some time now to draw a few diagrams. Beware of a few common pitfalls of diagrams that do not work (can you see why?):

After a while, you might notice a few patterns emerging. For example, you could count the number of external lines (one free end) versus the number of internal lines (both ends attached to a vertex).

How are the number of external lines related to the number of internal lines and vertices?

If I tell you the number of external lines with arrows point inward, can you tell me the number of external lines with arrows pointing outward? Does a similar relation hole for the number of external wiggly lines?

If you keep following the arrowed lines, is it possible to end on some internal vertex?

Did you consider diagrams that contain closed loops? If not, do your answers to the above two questions change?

I won’t answer these questions for you, at least not in this post. Take some time to really play with these diagrams. There’s a lot of intuition you can develop with this “QED” game. After a while, you’ll have a pleasantly silly-looking piece of paper and you’ll be ready to move on to the next discussion:

What does it all mean?

Now we get to some physics. Each line in rule (1) is called a particle. (Aha!) The vertex in rule (2) is called an interaction. The rules above are an outline for a theory of particles and their interactions. We called it QED, which is short for quantum electrodynamics. The lines with arrows are matter particles (“fermions”). The wiggly line is a force particle (“boson”) which, in this case, mediates electromagnetic interactions: it is the photon.

The diagrams tell a story about how a set of particles interact. We read the diagrams from left to right, so if you have up-and-down lines you should shift them a little so they slant in either direction. This left-to-right reading is important since it determines our interpretation of the diagrams. Matter particles with arrows pointing from left to right are electrons. Matter particles with arrows pointing in the other direction are positrons (antimatter!). In fact, you can think about the arrow as pointing in the direction of the flow of electric charge. As a summary, we our particle content is:

(e+ is a positron, e- is an electron, and the gamma is a photon… think of a gamma ray.)

From this we can make a few important remarks:

The interaction with a photon shown above secretly includes information about the conservation of electric charge: for every arrow coming in, there must be an arrow coming out.

But wait: we can also rotate the interaction so that it tells a different story. Here are a few examples of the different ways one can interpret the single interaction (reading from left to right):

These are to be interpreted as: (1) an electron emits a photon and keeps going, (2) a positron absorbs a photon and keeps going, (3) an electron and positron annihilate into a photon, (4) a photon spontaneously “pair produces” an electron and positron.

On the left side of a diagram we have “incoming particles,” these are the particles that are about to crash into each other to do something interesting. For example, at the LHC these ‘incoming particles’ are the quarks and gluons that live inside the accelerated protons. On the right side of a diagram we have “outgoing particles,” these are the things which are detected after an interesting interaction.

For the theory above, we can imagine an electron/positron collider like the the old LEP and SLAC facilities. In these experiments an electron and positron collide and the resulting outgoing particles are detected. In our simple QED theory, what kinds of “experimental signatures” (outgoing particle configurations) could they measure? (e.g. is it possible to have a signature of a single electron with two positrons? Are there constraints on how many photons come out?)

So we see that the external lines correspond to incoming or outgoing particles. What about the internal lines? These represent virtual particles that are never directly observed. They are created quantum mechanically and disappear quantum mechanically, serving only the purpose of allowing a given set of interactions to occur to allow the incoming particles to turn into the outgoing particles. We’ll have a lot to say about these guys in future posts. Here’s an example where we have a virtual photon mediating the interaction between an electron and a positron.

In the first diagram the electron and positron annihilate into a photon which then produces another electron-positron pair. In the second diagram an electron tosses a photon to a nearby positron (without ever touching the positron). This all meshes with the idea that force particles are just weird quantum objects which mediate forces. However, our theory treats force and matter particles on equal footing. We could draw diagrams where there are photons in the external state and electrons are virtual:

This is a process where light (the photon) and an electron bounce off each other and is called Compton scattering. Note, by the way, that I didn’t bother to slant the vertical virtual particle in the second diagram. This is because it doesn’t matter whether we interpret it as a virtual electron or a virtual positron: we can either say (1) that the electron emits a photon and then scatters off of the incoming photon, or (2) we can say that the incoming photon pair produced with the resulting positron annihilating with the electron to form an outgoing photon:

Anyway, this is the basic idea of Feynman diagrams. They allow us to write down what interactions are possible. However, you will eventually discover that there is a much more mathematical interpretation of these diagrams that produces the mathematical expressions that predict the probability of these interactions to occur, and so there is actually some rather complicated mathematics “under the hood.” But just like a work of art, it’s perfectly acceptable to appreciate these diagrams at face value as diagrams of particle interactions.  Let me close with a quick “frequently asked questions”:

What is the significance of the x and y axes?These are really spacetime diagrams that outline the “trajectory” of particles. By reading these diagrams from left to right, we interpret the x axis as time. You can think of each vertical slice as a moment in time. The y axis is roughly the space direction.

So are you telling me that the particles travel in straight lines?No, but it’s easy to mistakenly believe this if you take the diagrams too seriously. The path that particles take through actual space is determined not only by the interactions (which are captured by Feynman diagrams), but the kinematics (which is not). For example, one would still have to impose things like momentum and energy conservation. The point of the Feynman diagram is to understand the interactions along a particle’s path, not the actual trajectory of the particle in space.

Does this mean that positrons are just electrons moving backwards in time?In the early days of quantum electrodynamics this seemed to be an idea that people liked to say once in a while because it sounds neat. Diagrammatically (and in some sense mathematically) one can take this interpretation, but it doesn’t really buy you anything. Among other more technical reasons, this viewpoint is rather counterproductive because the mathematical framework of quantum field theory is built upon the idea of causality.

What does it mean that a set of incoming particles and outgoing particles can have multiple diagrams?In the examples above of two-to-two scattering I showed two different diagrams that take the in-state and produce the required out-state. In fact, there are an infinite set of such diagrams. (Can you draw a few more?) Quantum mechanically, one has to sum over all the different ways to get from the in state to the out state. This should sound familiar: it’s just the usual sum over paths in the double slit experiment that we discussed before. We’ll have plenty more to say about this, but the idea is that one has to add the mathematical expressions associated with each diagram just like we had to sum numbers associated with each path in the double slit experiment.

What is the significance of rules 3 and 4?Rule 3 says that we’re only going to care about one particular chain of interactions. We don’t care about additional particles which don’t interact or additional independent chains of interactions. Rule 4 just makes the diagrams easier to read. Occasionally we’ll have to draw curvy lines or even lines that “slide under” other lines.

Where do the rules come from?The rules that we gave above (called Feynman rules) are essentially the definition of a theory of particle physics. More completely, the rules should also include a few numbers associated with the parameters of the theory (e.g. the masses of the particles, how strongly they couple), but we won’t worry about these. Graduate students in particle physics spent much of their first year learning how to carefully extract the diagrammatic rules from mathematical expressions (and then how to use the diagrams to do more math), but the physical content of the theory is most intuitively understood by looking at the diagrams directly and ignoring the math. If you’re really curious, the expression from which one obtains the rules looks something like this (from TD Gutierrez), though that’s a deliberately “scary-looking” formulation.

You’ll develop more intuition about these diagrams and eventually get to some LHC physics, but hopefully this will get the ball rolling for you.

Fractures:

Depression: Broken bone portion pressed inward; skull fractures.

Comminuted: Bone breaks into many fragments; common in the elderly.

Simple/Closed: Clean break, bone doesn’t penetrate skin.

Compression: Crushed bone; spinal fractures.

Compound/Open: Bone penetrates skin.

Greenstick: Bone breaks incompletely; common in children.

Impacted: Broken bone ends forced into each other; results of blocking a fall.

Pathological: Results of disease and degeneration of bone tissue.

Spiral: Ragged break as a result of twisting forces; common sports injury.

[ 02.05.16 • 4/100 DAYS OF PRODUCTIVITY ] 4 days till my exams yikes D: my first exam isn’t even geography but the subject is so content heavy so I’m studying first even though I have 8 days to the exam ahhhh didn’t really bother putting a super nice set-up for the picture because meh good luck to those having their mid-years or their finals!!

My bullet journal spread this week! ✒️📓

Hey so, I decided to do another masterpost. This time on exams. Some tips for studying at the very last minute if you are like me, disclaimer: I am not in any way supporting cramming but this is just to help you through if you are left with no choice other than cramming.

Cramming

Cramming tips that actually work by @optomstudies

The night before the exam

What to do the night before an exam by @beautifullearning

The night before your exam by @tiny-personal-university-thing

The night before exam and I didn’t study guide by @renaistudying

The night before test and I haven’t started studying by @getstudyblr

Revision methods

Revision methods that actually work by @alimastudies

The 5 Best Revision Methods by @bstudies

Study tips

More unconventional study tips by @minimaliststudy

A stash of tiny study tips by @justestjarchives

College study tips that actually help by @samsstudygram

Five tips for study marathons by @booksavolonte

General study tips by @plantednotes

More study tips

My study tips by @anatomyandcappuccini

My study tips

Personal study tips

Quickfire study tips by @annabaestudying

Quick study tip by @studyspiratiom-coffee

Rare study tips by @studybllog

Scientifically proven study tips by @swankiegrades

Secret study tips I wish someone would have told me by @fearlessroadtomd

Some rare study tips by @organisedorgana

Top 5 study tips by @studyign

Weird study tip by @artemissstudies

101 study tips by @study-early

Study tips by @howtohighschool

Study tips from someone who has already been there by @haylstudies

Study tips straight from my professor by @just-refuse-to-be-stopped

Study tips that helped me get back on my feet by @sillydaisies

Study tips that aren’t bullshit by @thebitchwhomadeit

Tips for effective study by @kimtented

How I write revision summaries by @athenastudying

Ways to study for exams that are actually productive

10 mistakes when studying by @howtostudyquick

Memorising information

How to memorise information by @monetstudy

How to memorise information faster by @qxzu

Memorization tips by @aescademic

Memorization tips by @determinationandcaffeine

Memorization tips by @studyquill

Exam tips

How to cope with exams by @uk-studying

How to revise for exams by @a-pro-s-studyblr

Studying for exams by @orangeblossomstudies

Tips for doing well on your exams by @aboysstudyblr

Tips for doing well on your exams by @thepeachystudies

Exam tips by @studywithmaggie

Exam guides

Finals: study guide for the brave by @educatier

Pennyfynotes guide to exam season by @pennyfynotes

Quick guide to doing the finals by @inkskinned

Test taking tips

How I revise for exams + tests

How to study for a test by @tbhstudying

My test taking tips by @55studies

Test taking tips

Exam preparation

How to make a stress free exam plan by @marias-studyblr

How to mentally prep yourself for a test by @eruditicn

Procrastination

How to beat procrastination by @eintsein

Types of procrastination and how to deal with them by @emmastudies

Time management

Time management by @academiceve

Time management tips for busy students

Motivation

My motivation tag

Other masterposts by me

Notetaking masterpost

College advice masterpost

Apps for students masterpost

Icon credits to @rhubarbstudies

There is no end to my biology notes… But hey, being an artist helps.