Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Aardwolf on November 30, 2008, 04:55:02 am
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It seems to me that a lot of physics, mostly around high-school and college level) is taught as though there existed some pair of imaginary lines outside of which Newtonian physics must be replaced with quantum physics or Einsteinian relativity. I dislike this.
For one thing "relativity" is not limited to Einsteinian relativity. There is such a thing as "Newtonian relativity"--it's what everybody means when they say a space sim is Newtonian. The alternative isn't that the space sim is Einsteinian, it's that it treats velocities (and positions) as absolute. (Well, in most cases, anyway. There probably are a few space sims with Einsteinian relativity, but they don't matter, amirite?).
I wanted to finish this point but it's 5:45 am here and I'm too tired.
Instead of babbling/ranting even more, what have some of you (preferably people who know something about the subject) thought up that felt like a 'better' way of thinking about physics?
Example:
I once posited (and was almost right, in a way) that the rate of an object's movement in space-time -- that is, the derivative of <x, y, z, t> (with respect to I-don't-know-what) was constant and had a magnitude of c, the speed of light.
I also extrapolated that an object with a negative velocity on the t axis would behave like the same object with the opposite velocity, that is, <-vx, -vy, -vz, -vt> (whatever vt means), and would behave exactly like antimatter behaves.
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I actualy think the imaginary lines method is pretty good, none of our models work everywhere, and in terms of education it helps reduce the subject's intimidation factor for the newbs.
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(http://patrick.ripp.eu/images/lolcat_dude.png)
Relativity works even at the slowest speeds- only it's effect is too small for anyone to calculate it (let's say that at 100 m/s, or 360 km/h, the relativistic time factor is 1.0000000000000557, at 0.1c, or 30 000 000 m/s, the factor is 1.005037815259212, at 0.5c it's 1.1547005383792516 and at 0.9c - 2.294157338705618)
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Yes, thats why it doesn't work everywhere :P
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It seems to me that a lot of physics, mostly around high-school and college level) is taught as though there existed some pair of imaginary lines outside of which Newtonian physics must be replaced with quantum physics or Einsteinian relativity. I dislike this.
For one thing "relativity" is not limited to Einsteinian relativity. There is such a thing as "Newtonian relativity"--it's what everybody means when they say a space sim is Newtonian. The alternative isn't that the space sim is Einsteinian, it's that it treats velocities (and positions) as absolute. (Well, in most cases, anyway. There probably are a few space sims with Einsteinian relativity, but they don't matter, amirite?).
What was your question actually? Is it that there is a line when you should use Newtonian model and Relativistic model? I recall thinking that way until I realised that it would make almost all simple computations extraordinarily cumbersome without any additional accuracy.
But this is not the only imaginary limit in Physics. There are actually more real-life related things where you simply have to draw the line between which model you want to use. But for some reason college courses tend to highlight the 0.1c boundary, while it is much easier to break other models in actuality far before relativity comes to play.
Photons behave as waves when you add a whole bunch of them and a couple of assumptions, then this wave can be sampled as directional lines called rays, assuming a couple of things. Fluid dynamics would become impossible to model without these imaginary boundaries.
Care to explain your spacesim analogy a little bit better?
Sidenote: Recently I have come to loathe paraxial optics approximation, it can be useful to obtain a something-like-that answer, but it is in no way any kind of accurate solution.
Mika
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I think those lines exist, Aardwolf, simply because of the way physics is applied: at some point you just need to say 'okay, below this point we're not wasting time with the Einsteinian stuff, so let's just stick to Newton under .1c'. That line leaks over into the teaching.
But I agree that it promotes sloppy thinking.