Comment by oefrha | Hacker News Reader

Comment by oefrha | Hacker News Reader

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Speaking as a former theoretical high energy physicist who has studied string theory and other BSM theories (including “extra dimensions”) quite extensively and black hole information theory to a reasonable extent, the higher dimensions talked about in any close-to-mainstream physics really has nothing to do with sci-fi “inter-dimensional travel”.

It’s quite amusing to read the sentence “Seems easier to live in a higher dimension than to break the speed of light”. The latter is well established, very precise physics, the former is a very vague, so far fictional concept with little to do with our current understanding of physics (and actually very much goes against it), yet somehow one is “easier” than another.

Of course we can’t rule anything out, including “extra dimensions” in some scifi-esque sense that’s not currently understood, but these two don’t belong in the same sentence.

(Btw, I enjoy sci-fi about traveling between alternate universes.)

The way I understand the extra "dimension" here is like me viewing a bacteria on a cover slide. To the bacteria, that 2D flat plane is all that matters. Sure, technically it is 3D, but the 3rd dimension is compressed so much it is basically nonexistent and the bacteria can't really be bothered anyway. They can't even comprehend the concept of dimensions.

But to me, I am fully in 3D. I am literally an extradimensional being to the bacteria. And I am so far above it (no pun intended) I am incomprehensible to anything that lives on that 2D slide.

Even if I assume the bacteria has some really good teachers and can build stuff (they actually do, they make biofilms that are pretty complex "superstructures"), the kind of thing they can do in their limited plane of existence is nothing compared to what a human can.

So while I don't believe anything that was released so far points conclusively to real aliens, I don't find the concept of extradimensional beings too far fetch.

I don't think your bacteria on a slide analogy makes much sense. A thin 3D space is still not 2D. A bacterium also doesn't have any comprehension or concept of anything, so of course it doesn't have a concept of 3D space.

Undetectable beings living in another part of reality we're unaware of are, of course, unfalsifiable.

From what I remembered, string theory proposed that the extra dimensions beyond the spatial and chronological ones we experience are also compactified and technically hidden from our perception. In another word, they exist just not on a scale we can appreciate. If you accept that then the 2D plane with the 3rd dimension minimized to the point of irrelevance is not so different.

And I don't really care about what the bacteria "think". The point being there exists an extradimensional relationship between me and the bacteria right here in front of me. So at least to me, it isn't so outlandish that there can be something above this 3D plane and I am simply too primitive to understand it.

Of course, there is no sufficient proof right now so I do not accept it as a real answer. It is simply analogical reasoning. Also, I would not say it is unfalsifiable. Like mentioned earlier, the extra dimensions are simply tucked away and not easy to detect. They still exist and with sufficient technology, they can be probed.

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