Slicer has enthused in previous posts about his fascination with physics and the insights it gives us into the nature of the cosmos. He's also enthused about artistic communication. It's hard to think of a better 20th Century communicator of physics and cosmology to the layman than Carl Sagan. He makes difficult stuff seem easy, and the video coming up is one such example.
One of the principles which Slicer has explored before, c/o Frank Wilczek's book, is the notion of mathematical symmetry - finding ways to see things from a different perspective, such that we see that they are not necessarily different, but the same. This approach has been used with some success to make sense of the universe in terms of the unification of forces, and the nature/generation of particles of matter. It renders things possible which otherwise seem impossible (never mind unlikely) at first sight. It seems that one of the things which has become necessary (eg in String Theory) is to factor in many more dimensions than the 3 spatial dimensions which we experience. Back in 1884, Edwin Abbott came up with a satirical "Romance..." which lends itself to this territory.
Using Abbott's imagery, Carl Sagan explains the concept of extra dimensions extremely well in the video below. He communicates much more eloquently and artistically than Slicer but Slicer takes some consolation that he's not trapped like Sagan in a fashion timewarp!
The revelation that there are things that we can't directly experience or represent in our 3D 'world' but which can nonetheless interact with it, eg by creating a 'shadow,' is intriguing to Slicer. In an earlier post, he's highlighted some issues around the mind/the self/the person (conscious or otherwise), and whether 'you' and 'I' are real entities or just illusions, as some working in neuroscience and philosophy currently posit. Is nature 'multidimensional' in other ways? Are there other interactions going on which are not immediately apparent or necessary to our model of reality? Are there areas we can't access directly with our measuring tools? Frank Wilczek suggested that sometimes we have to run with 'hunches' before we can know. In scientific endeavours, we're always looking for falsifiable hypotheses, and it has served us extremely well to set them up and then test them. We don't like to think/believe that there are no-go areas, or boundaries to the 'knowable.' But is it reasonable that we should assume that we can always devise an experiment which will provide the answer? In order to understand the quantum world, what if the "Large Hadron Collider" really isn't that large? Instead of needing an accelerator built in a 27km tunnel, what if we actually need one the size of the solar system, or the galaxy? Sure, let's keep trying, but let's also consider the possibility that "you can't always get what you want."
Meanwhile, Slicer wonders what it would be like to slice in more than 3 dimensions... maybe he does frequently and doesn't even realise. It's certainly tempting to think that, because we seem to function in 3 spatial dimensions perfectly well, we have no need for any other interactions....