So humans from the future send a message to their past...?

It's a silly script. Like all of Nolan's scripts. But he's good at visuals.

They only succeeded in getting off Earth because they once found that message from the future. So humans from the future just have to take care that the message is delivered. Simple, isn't it?

They had no choice. It's a causality loop. There is no multiverse.

Okay thanks all, I don't feel so silly now. Benevolent 5th dimensional aliens I could believe - but humans from the far future who have transcended to the 5th dimension and now want to rescue their ancestors... that's a stretch too far that was unnecessary.

Because they already knew they had received such a message in the past. They needed to close the time loop.

Kind of dumb to use Morse Code though. A simple binary or hexadecimal code would have been more efficient.

It's the dumb time loop thing. They were only able to send the message because they got the message but how did they ever survive in the first place to send the message without the message? It only works if one future over overwrites another future.

Higher-dimensional perspectives: Time is not experienced linearly across all dimensions. In higher dimensions, time may be perceived differently, with the ability to view and interact with multiple timelines simultaneously.

Non-linear nature of time: The idea that time is a construct that allows for the experience of change and growth. From a non-linear perspective, all moments exist simultaneously, and our perception of time is a result of our focus and consciousness moving through these different moments.

Time as a tool for growth and exploration: The characters in "Interstellar" are using time as a means to learn, evolve, and ensure the survival of humanity. The exploration of different timelines and the interaction with past and future versions of themselves could be seen as a way to gain wisdom and make choices that align with their desired future.

The interconnectedness of events: Every moment in time is connected to all others, and the characters' actions in the past can have a ripple effect on the future. They are part of a larger tapestry of cause and effect, where small actions in the past can lead to significant changes in the future.