Yes, agree, I really enjoyed this one! I like it much better than 'Inception' (which didn't actually make sense to me). But this one does hang together logically.

It's real strong points are the spectacular visuals and complex scientific ideas woven into the plot. Certainly breaks new ground visually, visceral gripping images of space, especially of course the worm-hole and black hole, and depictions of alien planets. Physicist Kip Thorne worked with the special effects team and used high-duty computers to simulate what real worm-holes and black-holes would look them to people passing through them - apparently he actually made some scientific advances from the simulations, and is publishing actual scientific papers on them, so the depictions you see in the movie are actually scientifically accurate representations! Definitely trippy.

And geeks and science-buffs everywhere would have to love the way concepts from relatively and quantum mechanics are woven intellectually into the plot - yes, there are plot-holes (its sci-fi after all), but the plot is way more scientifically accurate than most other sci-fi movies. As to the ending, yes it's really out-there and trippy, but it's not beyond the bounds of possibility - in fact it's based on actual scientific speculations and does manage to make sense. Yes, as someone said, its most similar to 2001, but I agree, 'Interstellar' is the better movie, and has a more coherent ending.

Not so good are the characters and dialogue. Human characters are pretty one-dimensional, dialogue is often silly. Nolan movies are really based on ideas and world-building, not characters. There are two great characters though, the robots - best, most coolest robots in a sci-fi movie ever!

SPOILER WARNING - BRIEF DISCUSSION ON THE ENDING
(Stroll down only if you've seen the movie , otherwise stop reading here)

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The ending is based on the many worlds interpretation of quantum mechanics (MWI) where everything which can happen, does happen... i.e, all possible outcomes are actually realized in concrete forms in alternative universe.

A recently published new variation of this idea (Many Interacting Worlds) is a solid scientific theory said to simplify quantum mechanics (See link below).

In the theory, the many alternative universes all exist, but can only interact via a repulsive force which is an adjunct of gravity. And communication between alternative universes is what allows for the possibility of backward causality (sending information into the past)- this is because different universes are just special cases of different times.

Here's the link to a scientific explanation of the theory