Lizwi

Yes, I understand the variables. Thanks, your explanation is very clear. I think I can classify PDEs now according to their linearity.

For example Is the first equation linear or non linear?

They said " Linear equation is the one in which there is no products of the dependent variable and its derivative.

Hlw. Still I failing to understand the difference between Linear, semilinear and Quasilinear pde even after reading from Google. Can anyone clarify for me please.

Okay, thanks, the Sun is too small. Is there a general Shwarzchild radius for objects to become a black whole?

Yes, as long as that point rotates interactively with the axis of a disk or that circle

1. Is there an evidence for black holes 2. Is singularity possible? 3.If the Sun becomes a blackhole, will the planet's continue to revolve as if the Sun is still present?

Why can't the Sun form a black? , because it can collapse too.

Ahhhr!, THANKS A LOT. I GET IT.

Why is s ranging from r - R to r + R, can anyone show me me which distance is r -R and which one is r+R

Does the electron change the direction as it passes through a slit?

Thanks, does that mean the pressure at the bottom of any fluid is atmospheric pressure?

Why atmospheric pressure measure at the bottom of this fluid because atm is exerted by atmosphere and the atmosphere is at the top of the fluid? I though atmospheric pressure should be measured at P0

Why is the pressure on top of this fluid elements on the right equal to p+dp

How to remove this history

Okay, it is clear now, physics is so strange

Thanks a lot, I get it

Eyshhhhhhhhh! I get what Timo is saying. This means I'm teaching incorrect staff to high school learners tha the mass cannot be destroyed or created??

How is it possible that the massless photon changes to two particles with mass, The law of conservation of mass is not obeyed because this means during pair production mass is created

How is this equation derived (The energy of the target electron during Compton scattering)

PYTHON

Can anyone show me the following here: 1) Object 2) Method 3) Attribute Thanks

Does Huygen's principle apply to the light?

I'm trying to understand the concept of "light as waves", As far as I know, "wave is a disturbance in a medium" , to me it seems like wave is not an object, but it is a phenomenon. So if light is a wave, does that mean a light is just a disturbance through medium? I'm lost