The past weighs heavily

It is difficult to get scientists to see eye to eye on anything, but one thing they all agree on is that we shall never be able to journey to the past. A oneway trip to the future might be possible: they say one day we may be able to travel through space at incredible speeds, and after a year playing cards with the other crew members, return to Earth to find our great great grandson, now senile and locked up in a home. But, never, they say, will we be able to return to the past. It simply isn’t possible. The past is unrecoverable, it’s a fatal time.