Flat Earthers

[Husar]

I though the big crunch theory was that all matter would eventually start falling back towards the big bang's ignition point and form a great ball of matter that would form a unimaginably massive black hole which would then apparantly explode into a new universe.

That's also a theory, these theories are not like Highlanders, there can be more than one as long as we can't definitely prove that one of them is correct. There is also the one where the universe expands until everything freezes. The crunch and the freeze are terrible for our offspring though unless they can one day escape to a parallel universe (provided there even is one) before they get burnt or freeze. I know, before that we will have to get off this planet either way, it's just why bother with children if it all just ends in a few billion trillion years or so anyway?

Before posting this I would like to make a reservation:
1. I'm in no way a mathematician, so don't try to start an argument after you have read the following information.
2. I just remembered the statement about converging parallel lines and found this corroboration. If it is no corroboration (to your mind) see #1.

https://en.wikipedia.org/wiki/Line_at_infinity

In projective geometry, any pair of lines always intersects at some point, but parallel lines do not intersect in the real plane. The line at infinity is added to the real plane. This completes the plane, because now parallel lines intersect at a point which lies on the line at infinity. Also, if any pair of lines intersect at a point on the line at infinity, then the pair of lines are parallel.

I think that is more a thought construct than actually true for real parallel lines.
See this related article for reference: https://en.wikipedia.org/wiki/Projective_plane

As it says, it relates to painting, where you actually do let parallel lines cross in one point to create the illusion of three dimensions and so on. It is merely a matter of perspective though, take the following picture. You can see several lines that appear to meet in the middle if you'd draw them on and on, that appears to be the point at infinty. In reality they would not meet though if they are actually parallel, it is a matter of perspective. The guy in my last video seems to turn this into a related mistake when he paints a triangle over some light rays to "prove" that the sun is just hovering a few thousand meters above earth.
In mathematics it seems to serve some purposes that I won't research now because it would take too much time, it does not seem very relevant for the wrong "explanation" given by flat earthers though.



I will also apologize for not being good at explaining or understanding this in English, the terms are all different from the ones I learned in German so some concepts seem new at first but really aren't, or are they?