Why do worshippers at the Wailing Wall in Jerusalem seem to "bob" their heads up and dowm while praying?

Good Morning! I would like to ask you a question regarding Yom Kippur. I spoke with my doctor and I told him that I get strong chest pains, headaches and other ailments when I fast. He told me that it is due to stress and I know that chest pains can be dangerous. In any event, I get these ailments before as well as during the fast. If I use the "shiurim" measurements, is this considered eating and do I get kares? If you can not answer my question, please refer me to a rov that can. Gmar Chasimah Tovah and a Gut Yor.

How can the gemara say that praying to choose the gender of a child is valid for the 1st 40 days of pregnancy (whereas after 40 days the gender is already set) when current science has established as fact that the sperm at conception already determines gender (XY or YY chromosomes)?

Why is the shema sometimes called krishma? Just a little background on this question. My daughter who goes to a Hebrew Day School for her 6th year now from Gan to 5th grade has never heard that word. I found the talmud online where a rabbi from the 20's reads and explains in English a page per 1 hour tape. I was listening to the first tape and he kept saying Krishma. I had no idea what this word meant. From what I found out on the internet it is a kind of sluring of two words. Thanks for hearing my story.

I saw a muslm clrergyman saing that they also want a state of Israel, but a strong one and bigger, with the comming of the moshiach and not with the evil-sionism. Since it seems to me like listening a Rab giving a Kosher Torah argument, is there any makor in what did he say ? In any case, what is the failure of his argument ? thank you, jatima tova.