The Three Weeks

Could you please explain how to handle the transition from Shabbat into Tisha B’Av (when it falls on Motzaei Shabbat) regarding se’uda shlishit, Havdala, and changing clothes?

How were the Nazis able to carry out the Holocaust - something extremely complex - without a computer?

Have you ever noticed that from the Earth, the Sun and the Moon look exactly the same size? Is it just a coincidence? Maybe there's a deeper meaning to this?