Recent content by dwlink

I think you may have misunderstood what I meant by learning. Assuming that learning means understanding a proven "real" scientific principle - one who is speculating may learn his idea is incorrect based on the feedback of others as opposed to other learning based on speculation. Anyways...

In the context of different branches of physics F = ma could be regarded as "junk science" just as the Lorentz ether example in the community guidelines. I think the forum should make a real attempt at allowing such discussions - heck put it in a sub-forum called junk science. Sure, there...

Why no "speculative" posting Can someone please explain to me the reason why PF prohibits the discussion of unsupported scientific theories? To me, it seems as that such a rule significantly limits what one can learn based on the feedback of others through a much more diversified knowledge...

So once again, I'm trying to wrap my head around the asymmetry in the twin paradox problem. Here's my setup. The two twins start on a very massive but small planet such that they always have an unobstructed view of each other. 1. They each attach a beacon to themselves that will briefly flash...

Hard to say for a non-linear LTV in general, but if you consider the simple example of v^2 drag [Vdot = -k/2*V*abs(V)], then you can write the state matrix for a given velocity as... dVdot = -k/2(abs(V0)+V0*sign(V0))*dV For V0 > 0 dVdot = -k*V0*dV For V0 < 0 dVdot = -k*abs(V0)*dV For...

All this stuff about needed an FEM solver is garbage. A linear approximation will do very good. Solve my equations above and for typical values for the system parameters the solution will have the form A1*e^(B1*t) + A2*e^(B2*t). I really don't know why others are making this out to be so...

This will make an excellent system identification problem. You have the right equations but there are many unknown parameters. Variables Tb & Qb = Temp & Energy of Beer Tg & Qg = Temp & Energy of Glass Bottle t = time Parameters & Constants Cb, Mb, Kbg, Abg = Specific Heat, Mass...

Suppose we have a real 25 Hz signal that is sampled at 100 Hz without any anti-aliasing filters. Taking the DFT results in a series of spikes 25 Hz, 75 Hz, 125 Hz, 175 Hz etc. Now suppose the 25 Hz signal after it enters the 100 Hz system now enters a 60 Hz system. If we take the DFT now...