When Des visits Faraday in the past, he opens the ntoebook and the digram about real time has a triangle against the backdrop of a circle. the same diagram is on the chalkboard. the left page is blank.

When Faraday calls Des on the freighter, the same drawing is on the right page, circle with the triangle, and the left page is blank. So when Faraday makes the call to Des, his diary matches the way it was when Des first visits him.

After Eloise makes it through the maze, he goes to the black board and erases the circle in the diagram, leaving the triangle.

Then at the end, he opens the book, and two things have changed. First the note is there, which it was not when he called des earlier in the day. Second, the diagram has changed. It is now a square box with an angle running though it. the circle is gone.

So whatever Des told him, made him revise his diagram, but more significantly....

The note about Des being the constant was not there when he opened the book the first time on the island. So they changed the past!

in the encounted at Oxford, Des says "so are we going to change the future?" and Faraday says "you can't change the future." well this runs contrary to our normal way of thinking. You can change the future. but here, they don't change the future, they change the past....

whoah. my head hurts.