Thank you guys, but there's something I still don't get: if Hamilton's and Lagrange's mechanics dispel the notion of a force, why do we still teach Newtonian forces in fundamental physics courses? Is it because of their simplicity? Because it seems to me as if defining motion in terms of energy...
So they're only different in their practical use? There's no conceptual difference whatsoever between them?
I'm very ignorant of these issues, but I thought I heard Newton's framework was eventually proved to work only in very special circumstances. Or does that have to do with Einstein's...
Only thing I know about them is that they are alternate mechanical systems to bypass the Newtonian concept of a "force". How do they achieve this? Why haven't they replaced Newtonian mechanics, if they somehow "invalidate" it or make it less accurate, by the Occam's razor principle?
Thanks in...
1. Uhmm, I'm not sure I'd want to stop there, but I read that the road to getting a PhD is a strenuous one. So considering I can't get that far (as someone with an average intelligence and very little exposure to basic physics at a young age), I wanted to know what were the chances of finding a...
Exactly, I enjoy more the theoretical side of physics rather than the (still interesting of course, but not as much for me) applications of it. That's why I'm asking this. I wouldn't mind being a teacher or something directly related to the subject... although it's not as good of an option as...
I've read a few other threads on the site, and many say that it's hard to get a job that has to do with Physics, at least with only an undergraduate degree. Is that true? I'd like to get onto physics because I'm curious to know more about the science, but I wouldn't like to end up working as an...
Thank you guys for all the help! Forgot to get on PF after Sunday, so apologies for being so late.
The only thing that still bugs my mind has to do with what u/rootone said. How is friction to be measured? Thought the best we could do were friction coefficients. And what does it have to do with EM?
I see. So is the law of inertia an axiom then? In the sense that you start building the laws from the hunch that there's such a thing as "inertia"?
And when you say there's no evidence that contradicts the law, are you also saying there IS specific evidence that makes the first law valid? The...
So I'm trying to understand Newton's laws, and I know that friction is supposed to be the force that stops an object in movement. But I don't really understand why this is the case, as the force of friction is not something that can be perceived intuitively (unlike, for example, the force I...
I think this is what I was looking for. So the term ##\frac{1}{2} at^2## is really the area of a triangle given by the change in velocity with respect to the initial velocity.
Relating it to Doc Al's answer above (please correct me if I'm wrong), another way to look at it would be as the area...
I see. But what happens when t=2, for example? Because then the velocity at time 2 would be 4 m/s (the average over those two seconds will be 2 m/s), while the total displacement is 8 metres.
x = x0 + v0 * t + 1/2 * constant acceleration * t^2
So this is supposed to be very very simple physics, but I still feel like there's a part of this equation I don't fully understand. The first term is the initial position of the body at t=0. The second term is the initial velocity at t=0...
I had never heard of him actually, so thanks for the suggestion! I just started reading his book "Debunking Economics", though I'm already a bit skeptical of his ideas because he brags about how heterodox theories (supposedly) helped him predict the 08 crisis - a claim that sounds a bit too...
Yeah, that's exactly what I'd like to be able to do! Knowing the concepts good enough that, with enough time, I can solve problems on my own. It's funny that you mention differential equations. We covered them in multi-variable calculus, but the professor just explained the different types and...