"These are the generations of Noah, Noah was a righteous and wholehearted man in his generations, Noah walked with G-d."
A question is asked on this verse why is the seemingly superfluous word "in his generations" used here? Some commmentators understand this to mean that Noah would have been righteous in any generation. Other commentators are not so complimentary, they argue that Noah was righteous in his generation, but if he had been born in the time of Abraham, he would not have been considered outstanding.

How can this somewhat derogatory comment about a person, who is described as someone who "walked with G-d", be explained? What did Noah do wrong that Abraham did right?

Noah didn't try to save the lives of those around him, either by convincing them to mend their ways or by interceding on their behalf with G-d. By contrast, Abraham's life was dedicated to caring for the people around him, even to the extent that he pleaded with G-d to save Sodom and Gemorrah. This requirement to care for those around you is a common theme throughout the Torah, the mitzvah to give charity, love your neighbour as yourself, take care of the stranger amongst you.

But Noah IS described as righteous in his generation and this may indicate an even more important message. Despite what Stephen Hawking may claim, we can't travel through time and therefore the only era we have to worry about is our own. We are expected to cope with the situations of our own time which are unique to us. We have been given our unique characteristics in order to deal with these problems. Other people in other times may have overcome the problems that they faced but only YOU are able to deal with the problems and challenges that you face.

In other words we too can become righteous in our generation by meeting the challenges in our lives.