I was watching through the wormhole and they were saying if we made a time machine we can't go back in time, only back to when the machine was made.

There's one theory that we can't travel through time until someone from a different period makes like a receiving time machine. The same way you need two phones to call each other, you need two time machines.

look up Carl sagat or sagan i cant remember

Can't happen, time is a concept made by men. Time isn't saved data on a hard disk, the past is gone forever and the future did not happen yet.

actually the past is recorded, information can not be destroyed.

BOB SagEt

just to throw one more important question on top of the "time is a construct" point... time is entirely arbitrary. We have defined that we're moving forward through time as entropy increases, as spontaneous processes go... but the reverse could be true. We could be going backwards in time, only able to see the future, and the reverse about processes is true.
The math all works, as long as you have attractions instead of repulsions.
Its creepy.

Very interesting. I have heard something similar to this as well.

Recorded really? Tell me where and how it is recorded please.

Doubt it, otherwise wouldn't we have people coming back from future and telling us things to be aware of already"?