3 questions
1 Why use 'beyond the gift of physical science' instead of 'beyond physical science'? Is it more natual?
2 She presided over family dinners cooked on Sunday afternoons for children who were now gray with age. Why use 'were'? I think there is 'now' ,so it should be 'are'
3 Like question 1, why use 'weedings and funerals that had taken place half a century earlier'? If let me write, I will write as: weedings and funerals half a century ago. Which is better and why?
Thanks in advance.

The text: At the age of eighty my mother had her last bad fall, and after that her mind wandered free through time. Some days she went to weddings and funerals that had taken place half a century ealier. On others she presided over family dinners cooked on Sunday afternoons for children who were now gray with age. Through all this she lay in bed but moved across time, traveling among the dead decades with a speed and ease beyond the gift of physical science.

Question

3 questions
1 Why use 'beyond the gift of physical science' instead of 'beyond physical science'? Is it more natual?
2 She presided over family dinners cooked on Sunday afternoons for children who were now gray with age. Why use 'were'? I think there is 'now' ,so it should be 'are'
3 Like question 1, why use 'weedings and funerals that had taken place half a century earlier'? If let me write, I will write as: weedings and funerals half a century ago. Which is better and why?
Thanks in advance.

The text: At the age of eighty my mother had her last bad fall, and after that her mind wandered free through time. Some days she went to weddings and funerals that had taken place half a century ealier. On others she presided over family dinners cooked on Sunday afternoons for children who were now gray with age. Through all this she lay in bed but moved  across time, traveling among the dead decades with a speed and ease beyond the gift of physical science.

Answer

This is just to help with the context: "In My Day", by Russell Baker  http://wenku.baidu.com/view/378d6872482fb4daa48d4b2c.html

Answer

First of all, a bit more context would help on question 1.  Without the rest of the sentence it's hard to be sure what the writer's intention was.

For question 2, "She presided" places this in the past, so from her point of view "now" is our past.  At the time she might say "the children are grey with age", but from the reader's point of view, some time later, this is all in the past, so the children "were" grey with age - at that time.

Question 3 suffers from same problem as question 1.  Without the surrounding text, it's hard to say what the writer's intention was.