Personal homepage of Joonas Herranen

This is my simple homepage, made with Typora in Markdown, and converted to html. I have no need for a website aside for quick and dirty filesharing, at least for now. So here’s some physics.

Let’s see how Newton formulated the fundamental law of dynamics:

which states that a force $\mathbf{F}$ is equal to a change of momentum $\mathbf{p}$ in time. In constant-mass 1D systems Eq. (1) obtains of course its most familiar form

where the last equality uses the definition of scalar acceleration as the change of speed $v$ (vector form $\mathbf{v}$ is called velocity, but I digress) in time. Any and all forms of this equation may be interpreted in ways resulting the common Newtons 1st and 2nd laws of motion. All laws of motion are, in plain English:

1. In an inertial frame of reference, an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force.
2. In an inertial frame of reference, the vector sum of the forces $\mathbf{F}$ on an object is equal to the mass m of that object multiplied by the acceleration $\mathbf{a}$ of the object: $\mathbf{F} = m\mathbf{a}$ (It is assumed here that the mass m is constant – see above.)
3. When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

The first and second laws define a force, the third law states that there are are no single isolated forces (they arise from interactions). Also, one should note that vectors can be superposed, or added as vectors.

To conclude, here is a nice image of scattered intensity of a plane wave of red light by an irregular particle, contrast in logarithmic scale to show more than just the forward direction:

I guess anything but the files shared in ./files or ./pubfiles (as they can be anyones anything) under this domain can be regarded as free use, provided you know and tell where you got it. Naturally nothing of this sort extends outside this domain, you silly thing: