#1 In M-theory, were the other dimensions, say the 4th, 5th and 6th also created by the big bang? #2 Do the other dimensions share scientific universals with us? #3 Do the other dimensions exist outside of space-time of our dimension? Because I heard in M-theory matter/energy fades in and out of existence between our dimension and other dimensions in quantum vacuum fluctuations, so wouldn't that mean our dimensions are entwined? Someone please answer these questions. It would be much appreciated. Thank you.

 

1-Yes.

2-Yes.

3-No.

You might want to try the Modern and Theoretical Physics section for a really detailed explanation.

Three dimensions plus time exist in normal space. Inside the event horizon of a black hole, only one dimension exists, that which points to the singularity. So gravity “compactified” the other dimensions. After the Big Bang, the other dimensions that M-theory requires for strings to operate remained compactified.