Taken from Sophia Chua-Rubenfeld, daughter of the Tiger Mother
Preliminary Steps 1. Choose classes that interest you. That way studying doesn’t feel like slave labor. If you don’t want to learn, then I can’t help you. 2. Make some friends. See steps 12, 13, 23, 24. General Principles 3. Study less, but study better. 4. Avoid Autopilot Brain at all costs. 5. Vague is bad. Vague is a waste of your time. 6. Write it down. 7. Suck it up, buckle down, get it done. Plan of Attack Phase I: Class 8. Show up. Everything will make a lot more sense that way, and you will save yourself a lot of time in the long run. 9. Take notes by hand. I don’t know the science behind it, but doing anything by hand is a way of carving it into your memory. Also, if you get bored you will doodle, which is still a thousand times better than ending up on stumbleupon or something. Phase II: Study Time 10. Get out of the library. The sheer fact of being in a library doesn’t fill you with knowledge. Eight hours of Facebooking in the library is still eight hours of Facebooking. Also, people who bring food and blankets to the library and just stay there during finals week start to smell weird. Go home and bathe. You can quiz yourself while you wash your hair. 11. Do a little every day, but don’t let it be your whole day. “This afternoon, I will read a chapter of something and do half a problem set. Then, I will watch an episode of South Park and go to the gym” ALWAYS BEATS “Starting right now, I am going to read as much as I possibly can…oh wow, now it’s midnight, I’m on page five, and my room reeks of ramen and dysfunction.” 12. Give yourself incentive. There’s nothing worse than a gaping abyss of study time. If you know you’re going out in six hours, you’re more likely to get something done. 13. Allow friends to confiscate your phone when they catch you playing Angry Birds. Oh and if you think you need a break, you probably don’t. Phase III: Assignments 14. Stop highlighting. Underlining is supposed to keep you focused, but it’s actually a one-way ticket to Autopilot Brain. You zone out, look down, and suddenly you have five pages of neon green that you don’t remember reading. Write notes in the margins instead. 15. Do all your own work. You get nothing out of copying a problem set. It’s also shady. 16. Read as much as you can. No way around it. Stop trying to cheat with Sparknotes. 17. Be a smart reader, not a robot (lol). Ask yourself: What is the author trying to prove? What is the logical progression of the argument? You can usually answer these questions by reading the introduction and conclusion of every chapter. Then, pick any two examples/anecdotes and commit them to memory (write them down). They will help you reconstruct the author’s argument later on. 18. Don’t read everything, but understand everything that you read. Better to have a deep understanding of a limited amount of material, than to have a vague understanding of an entire course. Once again: Vague is bad. Vague is a waste of your time. 19. Bullet points. For essays, summarizing, everything. Phase IV: Reading Period (Review Week) 20. Once again: do not move into the library. Eat, sleep, and bathe. 21. If you don’t understand it, it will definitely be on the exam. Solution: textbooks; the internet. 22. Do all the practice problems. This one is totally tiger mom. 23. People are often contemptuous of rote learning. Newsflash: even at great intellectual bastions like Harvard, you will be required to memorize formulas, names and dates. To memorize effectively: stop reading your list over and over again. It doesn’t work. Say it out loud, write it down. Remember how you made friends? Have them quiz you, then return the favor. 24. Again with the friends: ask them to listen while you explain a difficult concept to them. This forces you to articulate your understanding. Remember, vague is bad. 25. Go for the big picture. Try to figure out where a specific concept fits into the course as a whole. This will help you tap into Big Themes – every class has Big Themes – which will streamline what you need to know. You can learn a million facts, but until you understand how they fit together, you’re missing the point. Phase V: Exam Day 26. Crush exam. Get A.
Physics exam in two days!!!
hey guys! i’ve been seeing a lot of master posts going around so I thought I’d compile some together for college students :^)
Amazon Student // 6-month free Prime trial on Amazon if you have an .EDU e-mail. Includes students deals, free shipping, streaming of thousands of content, etc. You can also get one free month here if you don’t have an .EDU e-mail
Ann Taylor // 20% off
ASOS //10% off
Banana Republic //15% off full-priced items
Club Monaco // 20% off items
Eeastern Mountain Sports // 20% full-priced in-store items
Eddoe Bauer // ask about discounts at local store
Joanns // 10% discount
Madewell //15% off in-store
Modcloth // 10% off
Sally’s Beauty Supply // sign up online for coupons
Sam’s Club // requires membership
Target // varies, mainly online
Tom’s // 10% cash back
Topshop // 10% off
Urban Outfitters // 10% off on Student Days
Adobe // 60% on Creative Cloud
Apple // various savings (You must input your school and other information. Link in name)
AT&T // 10% discount (You must input your school email address. Link in name)
Best Buy // sign up for student discounts and coupons
Das Keyboard // special pricing through website
Dell // discounts on laptops and tablets
Fujitsu // 5% on LIFEBOOK notebook and PCs. (You must call 1-800-FUJITSU for the deal)
HP // various discounts through website
Journeyed // various discounts through website
Microsoft // various discounts. (Check through your school as well to see if they have partnerships with Microsoft)
Norton // various discounts through website
Sony // up to 10% off (You must register to get the discount. Link in name)
Sprint // various discounts (Check with your provider. Link in name)
T-mobile // 10% off monthly bill (Check with your provider. Link in name)
Verizon // up to 20% off monthly bill (Link in name is to the EMPLOYEE DISCOUNTS page. Input your school email to see if you qualify.)
Chick-Fil-A // free small drink with order
Chipotle // free small drink with order
Dairy Queen // their website says they have one but I haven’t gotten a chance to go in and ask yet. Their Student Discount section is towards the bottom under local community partnerships.
Firehouse Subs // their discounts may require a partnership with the school so please ask about the discount to see if stores not near campus still offer the discount with your ID
Hard Rock Cafe // offers a student/discounted menu. Hard Rock cafes are located in Hard Rock Casinos.
Krogers // 5% discount off total order
Pizza Hut // 10-20% off (depending on store)
Sweet Tomatoes // 10% off (website says many stores but not all so please ask about it at your local store)
Subway // 10% off (again at specific locations so please ask about it at your local store)
TCBY // 15% off
Waffle House: 10% off
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29.05.17 • day 1/30
here’s the first page of my June spread and some bio notes I did today!!
will be aiming to achieve 30 days of productivity starting from today in preparation for mid-years right after June break ;-;
managed to review my bio test, watch an online holiday lecture and do up some notes today, let’s hope that I will continue being this productive!!! (۶•̀ᴗ•́)۶
how i use google drive for university - pt 1: digital notetaking by kkaitstudies
idk about you but i’ve tested a bunch of note taking methods. in my last few years of university, i was indeed lazy and rarely referred back to the professor’s slides in the course shell. i opted to read off the slides in lecture and take notes. while MS OneNote is great, i found myself enjoying Google Drive much more. so here is a quick overview of how i take notes using Google Docs.
folders are your friends
make separate folders for each of your courses. google drive even gives you the option to change the colours of the folders. in these folders, add any relevant coursework such as the syllabi, readings, and your notes document.
use one doc for notes per course
once you receive the syllabi, take some time to take note of required readings, and assignment deadlines. i have created a free template you can save to your own google drive that you can access here. fill out:
- course code & name - prof’s name, office hours, and email - date(s) for each week of class - weekly readings (tip: if you have online readings, you can link them in the doc!) - & open the document outline (view > show document outline)
you also don’t have to use all these features. T B H, i didn’t do weekly readings. a lot. oops. BUT i did always pay attention in lecture. i simply deleted the “reading notes” header every week i didn’t bother to read.
make use of early access to lecture slides, headers, etc.
some profs (bless their souls) post the slides sometime before the lecture. if you have the time, copy the lecture slides into your notes. and if they don’t…type real quick to get all the info as it’s happening (or go back to slides online after lecture to see what you missed out on). i separate lecture topics with headers, with the bullet points underneath (see above). if there is anything that the prof says during class that isn’t in the lecture slides, i will change the colour of the text to a different colour. any important concepts or testable material are highlighted.
…and that’s how i take notes! everyone is different. not all note-taking methods work for everyone. this is what worked for me in my last 2 years of uni. hopefully a similar structure works for some of y’all! also, let me know what you think and @ me if you end up using my template. have a great semester!
coming soon: [ part 2: grade tracker | part 3: gmail and gcal ]
Hey so I'm not sure if you have any resources I can use to study chemistry? Thanks in advance!
It’s actually my chemistry teacher’s website, and pretty much everyone in my school lives off the notes he posts. The notes are concise but include everything and are especially good if you’re in the UK system/doing A Levels because he tailors them to the different exam boards. Even if you’re not a UK student, it’s still a great resource because science is the same everywhere lol (and the tab that says ‘Textbook’ is more universal and not exam board specific).
Hey guys, so I’m nearing the end of my senior year, and it’s been great so far! I accomplished my academic tasks efficiently and didn’t burn myself out, and I think the main contributor to my success as a student is my organization system. This system has been refined throughout my high school years, but I think now I’ve finally found the most effective methods.
Please remember that this isn’t the only organization system you can adopt; this is just the one that works the best for me, and I hope that by sharing it with you, you’ll gain a new perspective on how to stay organized as a high school student.
The first thing I wanna talk about is my notebook system, which I briefly mentioned in my Guide to Note-Taking.
My notebook system comprises three types of notebooks: the Everything Notebook, the subject notebook, and the revision notebook.
The first stage is in-class notes. I only bring one notebook to school every day. I call it my Everything Notebook, and this is where I write down all of the notes I take in class. This way, I don’t have to lug around six notebooks where I’m only going to use a few pages in each of them that day.
At the end of the day, I would revise my notes and compare them to the syllabus so I know where we are in the learning process. I would then transfer my class notes from my Everything Notebook to my different subject notebooks. This is stage two. I also start to jazz up my notes because I use the notes in my subject notebooks to study for tests.
In addition to my class notes, I include material from my teachers’ notes that they might not have elaborated on, as well as points in the syllabus (I’m currently taking A2) that were only glazed over briefly, or not at all, in some cases. (Note: this does not mean they completely skip a chapter or topic; it’s more like they missed a few bullet points that should be in my notes but aren’t. An example would be if we’re learning about phenol reactions and the teacher forgot to mention the use of FeCl3 as a test for phenol.)
Stage three comes a little later, when exam week is just around the corner. Essentially, I rewrite and improve my notes from my five different subject notebooks into a single revision notebook or binder. (Recently, I’ve opted for a revision notebook because they’re lighter and easier to carry around.)
Because my teachers don’t always teach in the order of the syllabus, the first thing I do is organize my notes according to the syllabus. I would then fill in any other missing gaps in the material that hadn’t been filled in stage two.
When compiling material for my revision notebook, I use as many sources as possible: my own notes, my teachers’ notes, youtube videos, online sites, and my favorite, the mark scheme! I add in some answers from past papers (explanations only, so no calculations) mainly to secure marks. It’s safer to memorize definitions straight from the mark scheme than from the textbook or from handouts. I also do this to ease my memorization, especially for topics that require lengthy explanations. It’s a lot easier to remember the 6 points I need to explain the principles of NMRI than to remember everything in the four-page handout my teacher gave me.
Folders and binders are essential to organizing your papers. Some people keep a single accordion folder for all their papers, but for me it’s just too heavy to carry around all the time. The same goes for subject folders that are brought to school every day.
Instead, my binder/folder system comprises my Everything Folder and my subject binders.
The folder I carry with me to school every day is this A4 folder I got from Tokyu Hands. It has 5 pockets, one for each day of the week, so all the papers I receive on Monday will go behind the first divider, and so on.
Some people also keep blank papers in their folders; I don’t because my school has its own lined paper and graphing pads that I keep under my desk that I use if a teacher asks us to do an assignment on those papers. If I do work at home, I prefer to just use a plain A4 paper or a legal pad.
At the end of the week, I’ll sort my papers into my subject binders. Sometimes I’ll keep some papers in the folder if I think I’ll be needing it the next week. This usually only applies to worksheets because all my teachers’ notes are available on Google Classroom, so I can access them even if I don’t physically have them.
Each of these binders have sections inside them:
Physics: 1 for handouts, notes, and tests, 1 for Paper 4 (Theory), 1 for Paper 5 (Practical Planning). I included extra tabs to mark the different topics in the handouts section.
Chemistry: same as Physics.
Economics: 1 for Paper 3 (MCQ), 1 for Paper 4 (Case Study and Essay). A lot of my Economics material is online, though.
English: 1 for Paper 3 (Text and Discourse analysis), and 2 for Paper 4 (Language Topics, which includes 1 for Child Language Acquisition, 1 for World Englishes). Past papers, handouts, and notes all go under their respective topics.
Mathematics: I just keep everything together because I never revise math and just constantly do past papers.
This makes it easier for me to revise each subject because I can just take one binder with me instead of a messy folder with everything just shoved in there.
I keep a magazine file for each of my A-Level subjects (English and Mathematics are combined). All my textbooks, revision guides, and subject notebooks are kept here, so if I need to revise one subject, that’s the magazine file I’ll take out.
These magazine files prevent any small things (like my book of flashcards) from being shoved to the back of my bookshelf, or materials from different subjects from getting mixed up.
In my senior year, I mostly plan using this app called Edo Agenda. It syncs across all my devices for free and has all the features I need: a to do list to organize tasks, monthly and weekly calendars to organize events, a journal to organize notes and memos.
I used to bullet journal regularly, but it takes too much time during weekdays, so now I just bullet journal for the therapeutic effects it gives me, and I use an app for organizing tasks and events. Sometimes at the end of each week, I’ll transfer my tasks to my bullet journal and then decorate the page, but again, this is just for its therapy.
Organizing your school supplies is just as important as organizing your papers and notes. With a more organized backpack and pencil case, you won’t waste time looking for your things at the bottom of an abyss.
I don’t find it necessary to bring so much stationery to school unless I plan on making notes at school (usually during revision week).
Because we’re already in the revision term, I don’t really carry a lot of things in my everyday backpack, just the following:
Pencil case
Everything Notebook
Everything Folder
Revision notebook
Kindle
Phone
Wallet
Earphones
Calculator
Speaker
Drinking bottle
A pouch with things like a hairbrush, pads, and lip balm
And that’s all for now! I hope this post will help you organize your school life (if you haven’t already) or at least provide some useful insights on some ways to stay organized as a high school student.
hello! for your college prompts, what advice would you give the students who don't really have any outstanding achievements? the ones who didn't join any contests or have any notable experiences to write about :(
Hi, thanks for the question!
Honestly, every experience can be written as notable. It really depends on how you word your answers. Personal stories, like caring for ill siblings can be described as inspiration for students going into the medical field or school art projects, like painting self-portraits can be described as an eye-opening experience in self-reflection for students planning to study arts.
It’s really important to remember that even though high achievements and notable experiences contribute to an individual’s application, it does not necessarily make or break an individual’s profile. This might sound deceptive, but honestly play up your strengths. (You might not think you have any really good ones, but trust me they’re there!) I’d recommend doing a bit of research of your field of interest’s general responsibilities and focusing on any transferable skills that you currently possess that can be detailed in a college essay or application form. Many scholarship and college committees are looking for students willing to think outside the box, identify transferable experiences for field compatibility and show a clear interest in studying at the school of application. The experience is not the important thing, the reflection and lessons learned are what’s most important. If you show evidence of your ability to commit and work diligently, while showing clear signs of potential; schools will definitely be interested in taking you under their wing.
Hobbies can also play a key role in applications, even non-school or organization held ones. As long as you can show evidence of progress (i.e. photography, videos, maybe a participation certificate) for an activity, self-taught instruments or languages are very impressive. Other hobbies such as crafting, machinery or creative writing can also be assets! I suggest making a list of your daily activities and going from there. Sometimes activities that you may not have considered (i.e. cooking, baking, etc) can greatly contribute to an application. Here’s just a couple examples that could possibly be helpful in the formatting of this sort of writing:
Baking (Have you considered baking something for a charity event? Baking a cake or a tray of cookies can add to your application because you can include the title of charity event volunteer and contributor or that you’ve baked to support charity events.)
Blogging (Even Tumblr blogging! As long as you can show evidence of original posts with a socially acceptable theme (I’d recommend “educational (meaning anything you can learn,)” current-event or literature-based content) you can say that you enjoy writing articles in your spare time and host a blog where you contribute original content.)
Travel (Travel a lot with your family or friends? Spin this experience into a cultural exploration activity and focus heavily on personal reflections of your trip. By doing this, you can say that you have a strong interest in sociology, modern anthropology and ancient anthropology.)
It’s never too late to pick up new skills! Keep an eye out for new opportunities to expand your abilities and community involvement and who’s knows maybe you’ll even find an activity you become extremely passionate about! Here’s some other tips to show off your skills:
Use a higher variety of language in writing: This means, use a thesaurus for application writing! A higher language variety shows that a student has a higher linguistic interest. In saying this however, do not change every word in sentences or an obvious pattern such as one-change-per-sentence! Contribute where you feel you can be fancy.
Name-drop: By that meaning, cleverly mention the names of organizations and companies you’ve been involved with. Involvement refers to any sort of assistance with physical evidence. (Remember that baking example I mentioned earlier? Say that the organization in question was Free the Children - you could add Free the Children charity event volunteer and contributor to your application.) Do not call out organizations randomly but strategically - if it just so happens that the charity in question was present and involved then it doesn’t hurt to add that to your application. This shows that a student is well-connected in their communities as well as being apt at networking.
Strategic self-reflection: In detailing how you felt and what you learned, include references to any historical/current events, academic curriculum or personal interest educational content! For example:
As I explore the streets of Greece, I cannot help but appreciate cultural identities that are in constant evolution. Greece, once a centerpiece of economic power now lies in a new era; one of economic uncertainty in the shadows of the growing strength of several new power players - the United States and China.
This shows that a student has high intellectual ability, is good at problem solving and applying their knowledge where it can be used.
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.
first notes of school year, first notes for physics, and first breakdown ft. honors pre-calculus … starting junior year strong⛈
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