I have noticed a few interesting videos and images from various authors about various topics recently,
and I decided to share links to these interesting and easy-to-understand educational materials in one post in an aggregated way:


1)
Pythagorean theorem
about a right-angled triangle
in a geometric physical demonstration:

The sum of the areas of the two squares on the legs (a and b)
equals the area of the square on the hypotenuse (c).
a² + b² = c²

Someone has constructed a triangle with three squares,
where a lot of small balls float from one big square to two small squares, or the other way,
to show, demonstrate and prove that the area (surface) of the big square is the sum of areas (surfaces) of those two smaller squares.

Simple, illustrative, visual, clear, effective.

https://www.facebook.com/reel/538055072286680



2)
Normal / Gaussian distribution / curve
in geometrical / physical practice:

Sand, or similar powdery material, is falling onto obstacles,
going to the left or right side of each of them.

Half of decisions is to go left,
half of decisions is to go right.

Result:
Normal distribution (Gaussian curve)

Lot of small decisions with probability 0.5 : 0.5
lead to Gaussian distribution.

https://www.facebook.com/reel/965670382126217



3)
Surface crack in the Earth's crust – one part of the land moved against another.
Clear video recording:

This is not a model,
this is a nature.
Real life. Real Earth.

Author of the post which I share here recommends to see this short videorecord more times,
watching always some specific place at the landscape, to see what this movement of land does to specific places.

https://www.facebook.com/reel/1234396204878571



4)
Error of Mercator map projection:
(a typical projection of the Globe onto a 2D image, which our modern civilisation uses the most)

There are various demonstrations of the problem when everything near to poles appears to be bigger than it really is,
I have also published an article about it at this blog some time ago:
https://www.adamek.cz/blog/?blogpost=315
(sharing also someone's picture which demonstrates it)

And I have seen also another picture now,
the picture shows the same issue a bit another way:

https://www.facebook.com/informationisbeautiful/posts/pfbid0HSkfwEkJcLXLk5mSFt296FRxrm3mrEr93U35TMxxnwibvwDHEgPcGmv98P1zeGz2l



5)
Etymology (origin) of European words (nouns)
tea = Tee = herbata = arbata = ...
vs.
čaj = чай = ... [chai]

In countries, into which the tea was imported by ships, via the sea, it is something like "tea"
(yes, it was imported via sea also into England, so also into English language).

In countries, into which the tea was imported by feet and wheels, via dry roads, it is something like [chai].
Including Czech "čaj", since Czechia is in the Central Europe, far from seas.

Interesting fact is, that in Poland, which has Baltic seacoast,
the tea is "herbata" (you can see the "ta" at the end of the word; the same like in Lithuanian "arbata"),
but the teapot (tea kettle) is "czajnik" in Polish. [chainik]
As if the tea came from the sea, but device used to make it came from the continent.

https://jakubmarian.com/tea-in-european-languages-map/
https://www.facebook.com/Uyghursbookshelf/posts/pfbid02BgtyoDz1K6ae1daKTvfFju1GjaKtSqNcz5YbKZ5dDcN8PagxtEmQezi611k1ZoB6l