Recent content by Leperous

Try "Derivative[1, 0][u][0,t] == 0" instead of "D[u[0, t], r] == 0". I think the latter evaluates, and the former represents (and will evaluate if it makes certain sense) but I'm not sure.

For (4th-order) accurate time-stepping that only requires one set of initial data, try a Runge-Kutta scheme. It's easier than it looks, trust me :) Also, I don't know how Matlab array index notation works, but it looks like you're not initializing S everywhere, and what is DC2?

When particles interact, certain quantities are conserved, much like momentum in the classical (& quantum...) world. If you react a particle with its antiparticle, these quantities are exactly opposite and so sum to zero: you end up with a charge-less, baryon/lepton-number-less quantity (which I...

Have a look at the link and the corresponding "flavour quantum number" article. According to that, antiquarks have all opposite flavour numbers (five in total): electric charge is a quantity derived from two of these and a third quantity that is equal for all quarks (I didn't know that before...

L is a number multiplied by a unit. The units cancel each other out when you divide because of simple algebra* and convenience - if you asked "how many metres in 100 metres", the answer "100 metres/metres" doesn't make any sense. It's even more insane to claim it is "100 degrees". * You can and...

It's a designation based upon a collection of properties that is not just due to its electrical charge (see, for example, antiquarks). I'm not sure if it's anything more special than a name - annihilation is probably just a fancy word for the particular interaction between the two species which...

Depends how much energy the neutron has. A neutron is uncharged so it's actually quite penetrative, but when it collides with an atomic nucleus it'll create a lot of secondary radiation - kind of why neutron bombs are so destructive. See above; depends on your neutron's kinetic energy (I'd have...

I apologize for the thread necro, but seeing as this page seems to be (relatively) important, I feel it should be pointed out that the above is itself incorrect. I should know as I'm writing a PhD on neutron stars and this error is in my correction list - I'm told by several people that this is...