When I solve physics problems and get confused by something changing, I have a tendency to turn it into a "static" problem by plotting out all the possible changes as if they are points, and then represent that change as a trajectory through these points.
It often give me a better idea on what is happening, since I am kinda a computer and can only possess one step at a time
(This is why I suck at dynamical systems, too many things happening at the same time)
Basically my philosophy is Change = trajectory through points in parameter space
@ACuriousMind If we have a vector field converging to a point, like if we take the "everywhere north pointing" vector field on the sphere, will the index at the zero be $(-1)^n$ because it's basically a reflection in all directions at that point
Short text version: Two ways to think about how an object changed motion when we change frames: 1. A field of fictious force act onto the object to brought its motion to the final state such that it matches the frame when we finsihed changing frames
2. The specifics of the motion is already assigned to each frame, thus changing frames means you are just flipping through this sequence of frames until you get to the desired one
OK, whenever the mouse wheel is scrolled it sends a WM_MOUSEWHEEL message to whatever window has the focus, and that message contains the amount scrolled.
@JohnRennie Thats fine. I tried asking this on the c++ chat room on stackoverflow but the didn't give me any answers. Maybe because they are not interested. :(
Thanks for the conversation, I really had to go to lunch, but judging from the comments, I suppose you are not interested in a discussion. It was very useful, anyway to see the actual point you are making here.Thanks again! — ally50 mins ago
Right, I'm about to cycle into town but ... there are thunderstorms in Chester at the moment. So if you never hear from again that probably means my bicycle tyres weren't as insulating as I had hoped.
One point I'd like to make (and I'm naming no names here) flagging posts attracts stray mods into our cosy little den here, and that's rarely a good thing. I think all the chat room members should think long and hard before raising a flag.
I said I'd name no names. My point is just that if we want this chat room to be just the way we like it then we should not be attracting outside attention to it.
@Slereah For the record I value all the regular contributors to the chat room and the room is a better place for your presence. Yes, that even includes you 0celo7.
Indeed, multiple times an abstract concept in physics is often consolidated in my physical chemistry lectures
Chemistry is THE CENTRAL SCIENCE, thus it mixes nicely with some medicine, biology, and physics (even maths and stat when you consider the epxerimental side of things)
You know a bit of everything when you do a chemistry degree
@johnR do you know anything about bohmian mechanics? I didn't really know about this deterministic formulation of QM until recently. Why isn't it more popular if it's just as accurate?
@skillpatrol That's only really true for organic chemistry (as you need to memorise a host of reagent conditions which often has no underlying explanation other than it works), for other chemistry disciplines, usually some guidlign principle will allow you to derive msot things qualitatively and in some cases quantitatively
for example, when thinking about chemical reactions, to first order you only need to know about what controls the rate of reaction, orbitals, and thermodynamics
@JohnR I guess for computational reasons, it's easier to use QM. However, for the theoretical side, it makes sense to grapple with different theories that predict the same thing, no?
but you know thermodynamics and rates equations from your physics classes. If that is hard then I will argue physics concepts is a lot of memorisation too
Biochemistry is a subset of mostly organic chemistry and some inorganic and phsyical chemsitry. That one is REALLY a lot of memorisation due to the complexity of proteins (and the myrid metabolism pathways and chemical pathways these components interact
so yes, the bio side of chemistry is heavily memorisation, but the other branches of chemistry is not so. Take physical chemsitry as an example, it is actually quite simmialr to physics
and atmospheric chemstiry you can use 5 basic rules to derive the fate of any molecuule you released into the atmosphere (to first order)
Doing a degree requires lots of memorisation whatever course you choose. I don't think physical chemistry is any worse than physics at degree level. When you start postgrad work you specialise and rapidly forget all the stuff you had to learn for your degree.
Anybody in here think of 'differential calculus' as living in 'locally-convex topological vector spaces'?
@Secret a book like McQuarrie sets up physical chemistry as an extension of quantum/statistical mechanics pretty nicely with as little memorization as possible
I agree it is a sheer nightmare trying to learn biochemistry
So much memorization it is insane, but it's so cool :p
(on pics) To me: Screw that, just tell me the main steps and the important components. The names are JUST labels, they don't matter to me other than identify them
All of them, right now trying to understand why they didn't write book 4 after book 5 as the 2nd half :p
In other words, why didn't they explain calculus as an application of 'locally-convex topological vector spaces', even in Dieudonne's treatise he does calculus in Banach spaces which Bourbaki don't even do, even though all their other books are the pinnacle of generality (ignoring categories)
In fact, the main reason why I like organic chemsitry despite the memorisation is because I like to draw mechanisms http://rowdysites.msudenver.edu/~wiederm/401chp/unit1chp/vonrichterchp/rosenblummech.gif
I am known among my peers to draw mechanisms that fly in all directions
...which kinda reiterate the point that Acuriousmind said I need to learn how to present things linearly and coherently
@JohnRennie just browsing back, I disagree with this rather strongly. I think that if the room is in a state where we have major concerns about what reasonable outsiders (mods or otherwise) will see in it, that is a problem.
Or to put it another way, we shouldn't have flag-worthy messages posted in the first place, but if they are posted, the flags are not the problem. It's the messages that are the problem.
I'm not suggesting the room should be a den of iniquity, but I sometimes feel those reasonable outsiders aren't that reasonable. I don't think this is malicious, it's just hard to judge a room when you don't know anything about it.
My main point is that if someone doesn't like a post of mine they should say so rather than flag it.
We are all basically reasonable people here, and while no-one likes being told they are wrong if you tell me I'm wrong I will listen (then disagree ;-).
@JohnRennie That I agree with. Chat flags shouldn't be cast willy-nilly, to be sure; only for situations where attempts to resolve the problem by just talking aren't working.
I guess I take issue with the reasoning that having moderators from elsewhere on the network come into the room is inherently a bad thing, to be avoided, and therefore we should hold back from flagging things that are otherwise worthy of flagging.
Having moderators from elsewhere on the network come into the room is inherently a bad thing and is to be avoided. It means we can't keep our own house in order and that reflects badly on us. We should hold back on flagging unless it's really necessary. Then we should flag.
See, that's the issue: I think the inherently bad thing is being unable to keep our own house in order. Having moderators come into the room is merely a consequence of that. It's an indicator of a bad thing, but not a bad thing itself.
