« first day (3301 days earlier)      last day (93 days later) » 
09:00 - 18:0018:00 - 23:00

6:02 PM
@AaronStevens Its like when a person does something thinking that his actions will have little to no effect on some other thing since he's the only one, and there are a lot many other people sharing the same opinion :)
@AaronStevens Agree with you:) Got it
@user8718165 Right, exactly. Because of this polls might not align with actual voting results
Although I will say again, I have no evidence to say whether or not that happened in 2016 or even really effected the results
@AaronStevens No worries:)
6:17 PM
It is not fun tutoring "formula hunters"
@AaronStevens I bet. For the most part, that's the total opposite of how I like to explain things. I use a lot of words and few formulas.
@Slereah either the sphere or R^n yeah
Maybe the torus
@JMac We were doing a problem where a block was initially against a compressed spring and then released. The problem was to determine the speed of the block when it came back to the unstretched length of the spring (x = 0) assuming there is kinetic friction between the block and the surface it was on
I knew it was trouble when the first thing they asked was "so which formula do we use"?
I kept trying to say "well let's think about the physics first and that should help guide us to which equations we need to use"
But at each step when I would ask and conceptual question they would throw a formula at me
@AaronStevens The equivalent in programming is cargo cult coders.
R^n is a very nice manifold to be sure but the noncompactness is hard
6:24 PM
@AaronStevens That's frustrating, and I'm not even sure if it would be an education issue, or a personal learning issue. Teachers definitely should be pushing the idea that the formulas are just tools - not the actual physics though.
"How do we determine the effect friction has on the energy of the system?" Response: "Well f = uN"
The sphere has lots of homotopy which sucks
The torus is the best of both worlds really
@JMac I think it is an education issue. I think it also has to do with how just math is taught to people in early education
"Use this equation and get the right answer"
Unfortunately, Stack Overflow has made life even easier for the cargo-culters. Some of us try to fight the trend, but there are always "helpful" people who are only too happy to feed the cargo-culters addiction.
Then it bleeds over to physics since it involves math
It is a common characteristic of "formula hunters" to also be scared of variables and plug in numbers right away
Which also takes away from understanding the physics
@PM2Ring Sounds frustrating. It also sounds like something that is hard to break if someone has been doing it for so long
Very similar to formula hunting
During this tutoring session they kept asking "can we plug numbers in now?"
6:27 PM
@RyanUnger Speaking of torus worlds... aleph.se/andart/archives/2014/02/torusearth.html
@AaronStevens And they tend to plug in pure numbers & throw the units away.
@PM2Ring Yeah that is a losing battle there.
"But putting the units every time is tedious"
Than don't plug in numbers until the end!!
@AaronStevens It's a weird one to think about. In problem solving, it's true that ultimately what you do on paper is basically "plug into formula"; but for some reason students fail to recognize that plugging in is by far the easiest and least interesting part of physics. (at least in into physics)
@JMac Yeah I have been trying to find the best way to explain it. Because I would say the goal isn't to find the correct formula to use....but really it kind of is for intro physics problems
It is a subtle shift in mentality I think
I think lately I have been saying "Let's try to use what we know about the physics of the system to guide us to the right equations to use"
@AaronStevens Yes. It'd be bad enough if it were just students doing it, but there are lots of professionals creating websites & other software that do it to.
I think students are expecting a sort of "Here is the formula for this problem on your formula sheet"
When usually we pull in equations are are really just definitions of something in a mathematical form and then use those to obtain a new equation that actually describes what we want it to
I think students want "Here is the equation for the final velocity of a block on an incline with friction hitting a spring"
Maybe if I ever professionally teach I will make a formula sheet with stuff like that on there and see who falls for it
"The block on an incline equation"
6:38 PM
It's almost a medieval pre-scientific mindset. The formula hunters & cargo cult coders just want to know the right magic incantation to use.
@PM2Ring Haha yeah. That is how physics should be taught
"Long ago, these equations cam to scientists in visions. They found when they plugged in the exact numbers they passed their midterms"
Reminds me of this question where I went back and forth (along with AFT's answer) about why us giving equations wasn't beneficial to students. They still kept insistent that giving them the formula to use wouldn't be doing the question for them. physics.meta.stackexchange.com/questions/10214/…
@JMac Is that the right link?
I mean, sure, the formulas are important. But they're an expression of the underlying model, and it's the understanding of that model that's the important thing. And when you understand the model, you can quickly figure out the relevant formulas from scratch, at least in stuff like basic mechanics.
Yeah. Giving correct formulas help solves the problem but doesn't teach any physics
6:44 PM
@AaronStevens Lmao no copied the other meta link i had open. Fixed now
It is like how some college intro math classes teach interest
My wife was in a class recently where the teacher literally said "Don't over think it. Just plug the numbers into the equation"
@AaronStevens ... yikes. That's how we wind up with formula vampires.
So they just have a bunch of equations telling them how to find payment amounts, interest, etc.
I mean I kind of understand with interest since to derive the equations you need to talk about series and stuff...and for an intro math class that might not be ideal
But then I would say just don't even "teach" that then
Just go onto something else that you might be able to teach
@JMac Ah another term haha
I am trying to get the best one
We learned about interest pretty good in high school pre-calc if I remember correctly. That lingering knowledge is basically what saved me when I had to take a university econ class.
Formula hunter, formula vampire
I mean its just application of geometric series pretty much
6:49 PM
@AaronStevens Yeah, I just stole it from the term 'help vampire'. It's basically like a specific sub-class of them.
I just like the visual of "formula hunters" as they look around their formula sheet until they see an equation that they hope will work
My highschool calc/pre-calc teacher was really good for my style. He actually explained concepts to us; but then left the rest of the period for just doing worked textbook examples. He left the answer sheet open, and would just answer anyone who came to his desk. If someone pointed out anything major, he would share it with everyone.
I'm done smashing my head against this brick wall. — JMac Oct 13 '17 at 21:46
@JMac That seems like a good style
@AaronStevens By far the best environment I had for learning. Me and my nerdy friends would just sit in the back working through problems. We got a couple weeks ahead by the end; which would have never happened if each class didn't have most of the time dedicated to self-study.
@JMac I don't know about you, but my highschool pre-calc was essentially a repeat of Algebra 2 with some additional trig stuff (and maybe limits? I am not sure). My friend and I would always finish the problems before the teacher would. One time she got so frustrated with us saying what to do before she wrote it on the board that she yelled "Be quiet! I'm the teacher!"
Also fun fact: I was a pretty good student in grade school getting all A's except in one class. I got a B in 7th grade pre-algebra.
And now I am in physics haha
8th grade is where I really started getting math for some reason. I do not remember what I was not getting in 7th grade
7:01 PM
@AaronStevens Canada was a bit weird for HS math. It was just "Math [Year]" for the basic classes; but then math 11 and 12 also offered "Math [Year] Advanced". You had to cram math 10 11 adv and 12 adv into the first two years to take pre-calc and calculus in the last two. My pre-calc/calc teacher was great, my math 10 was good, and my math 12 adv was good. My grade 11 advanced teacher was the worst.
@JMac Interesting. Yeah I don't think I really ever had any amazing math teachers until college
@RyanUnger Point is best if you're aiming for simplicity, I suppose
I'm sure I mentioned this here before; but my 11 advanced teacher marked us wrong for rounding 0.45 down to 0, instead of up to 1, because 0.05 rounds the 0.4 up to 0.5; then that rounds up....
Or the empty set
@JMac Ah yes I remember that haha
My 9th grade geometry teacher was essentially a kindergarten teacher, so she was very patient. We got away with asking obviously outlandish, irrelevant questions. This lead to a quote I still remember today of "There are no magical squirrels in this math problem."
7:03 PM
@AaronStevens Yeah, that course was rough. I almost got in trouble for yelling with the teacher. I had like 70% in that math class. I'm pretty sure I surprised that teacher near graduation when she realized I was taking calculus.
Said very calmly and "mattter-of-factly"
@JMac Yeah.... That moment when you realize most grades are pointless
Like I graduated 7 out of over 500 students in highschool in terms of grades, but I got extremely lucky with the teachers I had. Pretty much every year I ended up with the teachers who graded much easier than other teachers I could have gotten
It's just all so subjective
No reflection of actual learning
For the effort I put in, I was way too high up in grades for my school. A lot of people really didn't care, and a lot of the people who really cared were the type to struggle with the material anyways. My HS grades definitely don't say a whole lot.
My middle of the pack university grades made a lot more sense.
@JMac They were struggling in the formula forest
Those who understand the physics get a helicopter
Something I was talking to someone about recently who teaches an intro college physics class was to put on the test problems that have already been worked and ask the student to assess if the work is correct or not
So it gets the students thinking about the validity of methods, assumptions, etc.
@AaronStevens I'm not an educator; but at first glance that sounds like a really good approach.
@JMac Yeah I thought so too
7:18 PM
Have they tried it out yet, or just thinking about it?
@JMac I'm not sure. I'll have to ask them.
It might have been a way to speed up grading also. Especially if it was more of a "which step, if any, is incorrect" and then pick a letter
Since there are many exams to grade
Which isn't as good as an actual explanation answer
Idk. I think he was considering how to have good questions that are both easy to grade, assess the learning of the students, but also don't take a while to work out
And aren't just straight up conceptual questions
7:51 PM
@Slereah the problems I’m interested in aren’t really made more interesting by putting them on crazy manifolds
Q: Why does mathematics still use symbols?

LukeI am trying to learn quantum mechanics. I am also a senior programmer. As I am trying to read formulas, often I see symbols I don't know. And I am stuck. The only way to understand it is to try and research what the symbol means. But usually there is no easy way to google a single letter or even ...

Relevant post
@AaronStevens Almost seems like they are half in the other boat. They want to learn conceptually; but keep finding all the math. It's like a formula hunter is trying to teach them or something.
@JMac Haha yeah true.
I can see their point, and maybe it is just my background, but I think it is extremely easier to read through equations than programs. Even if I need to do some digging to find what the variables mean
And it's not like the variables programmers use are always very descriptive anyway
8:08 PM
Yeah same. I would take a conceptual explanation over either though.
@JMac In the example I gave in the comments, knowing what the variables of $F=ma$ are still really doesn't help you understand any physics
Which force? which mass? which acceleration?
Ah, if I am more massive then that means I can apply more force for the same acceleration
Ah, If no force is being applied to me then 0 = m*a which means I can say I have no mass if no force is acting on me
Like most things with equations, the equations don’t mean much on their own; but the concepts can be pretty vague until you formalize them with equations.
You need both
Maybe we can define a class of formula hunters called "formula poachers" that try to pull meaning out of equations before they have the concepts down
I agree with DoubleFelix and Aaron. There is a key difference between your usual programming variables and physics/mathematical variables: In code, a variable is a container or placeholder - in mathematics/physics, a variable carries specific meaning, often only valid in certain contexts and under certain assumptions etc. Using a mathematical/physical formula requires you to know/study how it came to be, what the assumptions and requirements are etc. In this study, the variables will be defined. Describing those variables in easier terms, will not relieve you from having to study the formula. — Steeven 4 mins ago
I was trying to think of something like this but I couldn't fully formulate the ideas
In code, a variable is a container or placeholder
I think that really is the key
8:32 PM
Knowing and understanding the variables in physics is more like knowing the programming language than it is knowing the programming variables. I guess I could see how it trips up coders if they tried to approach variables the same.
@JMac Yeah that is a good point.
@AaronStevens That question doesn't really fit the Q&A format, but it's a good chat discussion topic. I was going to suggest we could invite the OP here, but it's a bit quiet at the moment.
@PM2Ring I agree. I was going to VTC but QM beat me to it.
8:47 PM
Meaningful variable names work well in coding, but they're a bit unwieldy when you're trying to solve equations. It was a major advance in Western mathematics when we started doing algebra with single letters & symbols for the operators. Reading ancient maths that uses words for the variables & operators (usually Latin) is really tedious.
@PM2Ring Yeah, I agree. I would think that the reason programmers want to use more involved names is because usually programs need way more variables to store values than mathematicians/physicists need for represent relevant "things"
@PM2Ring You would think people must have been doing that out of laziness/paper saving anyways. Maybe not when they share it with others; but you would think after writing (the latin equivalent of) velocity 20x times, you would develop a personal shorthand.
But maybe I'm super biased because people now are very comfortable with variables.
It's a relatively recent innovation, dating from the end of the 16th century, according to Wikipedia.
@JMac Yep. I'm sure people would've used abbreviations, especially for private calculations, but maybe not so much in published work. Abbreviations were pretty popular in Latin.
@PM2Ring Are you familiar with methods of parameter fitting with a large-dimensional parameter space?
Well, it might not be large. Large to me haha
9:09 PM
@AaronStevens Not really. How large?
@PM2Ring 9 parameters. I am trying to fit a model to the data. It takes about 1 second to do a run through of the model to get an output that can be compared to the data. The problem is that there isn't a good way to experimentally nail down the parameters at the moment, so I have having to do some fun expeditions through parameter space
I can come to some pretty good fits, but it takes a bit of time
IIRC, one of the SO Python room owners, Andras Deak, does that sort of thing in his work (he does QM).
Ah interesting
I am essentially trying to find as many local minima as I can and see what (if any) commonalities/relations exist between parameters so I can at least learn something about the system from the model
Makes sense. But I don't know anything better than brute force. And 9 dimensional space is a bit too large for blind brute force to be a good idea. ;)
@PM2Ring Haha yeah exactly. Plus with each calculation taking about 1 second it is too slow to do some fancier forms of parameter searching that involve multiple derivatives of the cost function, etc.
9:19 PM
@AaronStevens Maybe simulated annealing could work.
@PM2Ring Yeah I have heard of that, but I completely forgot about it
"simulated annealing may be preferable to alternatives such as gradient descent."
I was literally just trying a sort of fast and lose gradient descent haha
I bet there's some fancy new Machine Learning algorithm that could do it. They have to explore some pretty large parameter spaces. But I know next to nothing about that stuff.
@PM2Ring Yeah I was considering that too... I am having to do some self-optimization as well, as I cannot spend too much time on all of this because I am trying to finish by the end of the Summer
9:53 PM
Oh wow, a mod denied my VLQ flag on this answer physics.stackexchange.com/a/514430/127931 Seemed pretty apparent to me that it was a link only answer but I guess not...
@JMac That is very odd. I would think that would count. If the link was broken the answer is useless.
I am going to flag it anyway
@AaronStevens Please do. It's also answering an extremely broad question. I don't care a whole lot; it just seems like an obvious answer that doesn't belong.
@JMac I agree. I think I VTC when it was first posted
And for some reason I did not down vote the question when I VTC haha
I'm surprised it got any up votes at all. Probably just from people thinking "Oh yeah a model of this would be cool to see"
10:15 PM
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. 'Superstring theory' is a shorthand for supersymmetric string theory because unlike bosonic string theory, it is the version of string theory that accounts for both fermions and bosons and incorporates supersymmetry to model gravity. Since the second superstring revolution, the five superstring theories are regarded as different limits of a single theory tentatively called M-theory. == Background == The deepest problem in...
Do people not realize the five superstring theories are roughly five different forms of a derivative
This needs to be investigated on hbar and written up properly
Q: Black-holes are pretentious onions. Change my mind

OnionManWhen material falls into a black-hole it just gets time-stuck near the event horizon. It can't cross the boundary so it just sorta floats above it. Now that material contributes to the mass of the black-hole, so the event horizon expands. New material falls in, gets time-stuck above the event hor...

Hurry get rid of it
09:00 - 18:0018:00 - 23:00

« first day (3301 days earlier)      last day (93 days later) »