Well, when one enters M (matrix) theories, extra dimensions are a given. That is the only way that the math works out...

But there is plenty of indirect evidence for other reality! For example, the human eye (observation!) can only sample visible reality at about 25 to 30 frames per second. Standard movies and digital display technology are very good examples of how we can already easily fake visible reality since it is really slow when compared to what our digital technology can already achieve and do with HDTV and even much higher resolutions...

Meaning that fake or simulated visible reality can be made to look more real and detailed than most visible reality!!!

Essentially, anything that moves much faster than that will look invisble to the naked eye and when moving much slower than that, it will look static to the eye! This confirms that observable reality is only a very small micro-cosmo of all things...

Also, when things start moving faster, but still within the visible edges, then they may look foggy and misty and eventually will disapear like we cannot see the air in the athmosphere since the molecules are moving really fast, even when there is no wind...

In summary, anything that cannot be seen is "dark" by definition...

eom