If Antarctica surrounded our known Earth, the distance to circumnavigate Antarctica should be longer than circumnavigating the Equator. Right?
Also why are the poles very cold, but the equator is warm?
Yes. Circumnavigating Antarctica would take waaaay longer. I can't recall the guy's name offhand, but one explorer literally just gave the fuck up when he attempted it. The sun isn't a massive far away fire ball. It's actually a small and close. Here's a model to explain the seasons. https://www.youtube.com/watch?v=Gbec8CyHf30
I don't understand the first question. As for the second, imagine a basketball whose top tilts ever so slightly towards a fire and then away from it. The equatorial parts of the ball will be closer to the fire than the bottom or top. Ergo seasons and cold poles. Don't forget, the poles also warm up during "summer". Just not so much as to melt the ice.
It works that way on the flat earth model too. Here's a good flat earth model. https://www.youtube.com/watch?v=Gbec8CyHf30
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