Genady

Did they explain/justify it? I mean, why this action leaves the numbers unchanged.

I mean, ONE third is different from TWO sixths.

Not in my case. I was an only child.

Me too. But I remember that it bothered me, because how ONE piece of pie can be EQUAL TWO pieces of pie? Sure, they weigh the same, but they are different in so many ways...

I also had my share of bad teachers. Fortunately, I had two very good math teachers. They would never say anything like that.

How is it explained to school children that or why, e.g., 2/7=4/14=...?

To me, it is 'cold' when we need to close windows, and it would be 'extremely cold' if we needed to turn on a heater. (The latter never happened.)

Yes, it is. The temperature is down to 27oC.

Do you think this derivation, has a better chance?

No problem, I thought so. I don't know this.

They did not demonstrate that (my emphasis). They demonstrated this:

Energy and momentum cannot be both conserved in such a process.

Typo? 46.3

I have assumed only that multiplication is distributive (on the step you have marked): (a-b)×c=a×c-b×c In the case above, a=1, b=2, c=-1.

If we accept that -1 and +1 are additive inverses, and if we want to keep the distributive property of multiplication, then it appears that we don't have a choice but make (-1)×(-1)=+1. Here it goes: (-1)×(-1)=(1-2)×(-1)=1×(-1)-2×(-1)=(-1)-(-1)-(-1)=(-1)+(+1)+(+1)=+1 QED

Regardless of being a root of +1, -1 is a label for the additive inverse of +1. How come we use the same label?

https://www.amazon.com/Quantum-Field-Theory-Standard-Model/dp/1107034736/?tag=pfamazon01-20

https://www.amazon.com/Gravitation-Charles-W-Misner/dp/0691177791/?tag=pfamazon01-20

I agree. For example, why i/-1 and not -i/-1?

Beyond the crash event, the geodesic will coincide with the worldline of the Sun (the red line).

What is there to consider? What does make this scenario interesting or non-trivial? It is just a graph of \(x=x(t)\) function with \(x\) and \(t\) axes flipped.

This will manifest in the shape of the wavy curve. It will be flatter farther from the Sun and steeper closer to it.

The horizontal coordinate on the graph is projection of the asteroid position on the direction of the major axis. A geodesic is a line in spacetime, i.e., in four dimensions. To illustrate it in two dimensions, one needs to take a projection.

On a scale of an asteroid orbit shown, the Sun is considered at rest relative to the orbit center.