Hal Finney wrote:
> Spike Jones, <email@example.com>, writes:
> > i am searching my memory banks. there was an asimov short story
> > i read a long time ago about this. someone had invented a machine
> > that could somehow calculate the past. you could punch in the space
> > and time coordinates and the machine would give you information
> > about that 4 space. the government launched a huge effort to
> > keep the whole thing secret. the heroes struggled to get the information
> > out, so that if they were killed by government goons the world would
> > still have their gift.
> I have read that story many times over the years, most recently just a
> few months ago. I believe it may have been called "The Dead Past".
There is also "Pastwatch" by Orson Scott Card, where you could actually view the past.
The story goes that past viewing started out as a super historiography project, then became a project to send someone into the past to prevent Cristopher Columbus from discovering the New World and causing the genocide of the Native Americans. Turns out that a previous timeline had sent an expedition back to make him discover the new world, in order to prevent the vicious Aztec civilization from decimating Europe and killing millions of poor savage Europeans.