A round heavy yellow object, say Homer Simpson, distorts the glowing green TronGrid of Einstein's plane of spacetime until a big hole stretches through causing one bit to touch another bit and (voila) Space Bridge to the stars.
Yaaaaaaaaaaaaaaaaaaaaaaaaaaawn....
I mean we've all seen it, oh and it was funny in that Treehouse of Horrors episode of The Simpsons, you remember the one where Homer popped into 3D to show us how science and 'the mainstream media' were literally made for each other; sorta how like the Bible was 'made for schools'.
And the Big Bang isn't just an obvious 'Creationist' moment for a 'religion without a God'.
Anyway, back to 'this sheet of paper' analogy of Gravity. In the classic description, spacetime is a sheet of Graph Paper (it doesn't have to be paper, but let's call it 'paper' until it start to go 'all melto-elastic' toute de suite). Now, land a big fat round Homer onto this sheet of Graph Paper... look, this isn't working, let's call it what it is.
Math Paper.
Let's carefully place a heavy Homer onto this Math Paper and his custard-coloured bulkines will 'dent' it. If you roll a nice shiny ball-bearing along this once-planar sheet of math paper, Homer's enormity will 'distort' the path of the steel photon and 'light will bend around this so-engineered gravitational system'.
What absolute HOKUM.
1) spacetime, it's its own unique problem.
How can ANYTHING exist outside of the understood and agreed Big Bang offspring, spacetime? There's literally nothing else. It's its own sum total.
So, to introduce a multi-dimensional force onto the plane is just idiotic. There's nothing outside of The Universe(tm) - it's all there is. Right? So, the best we can do is 'tighten' the spacetime mathpaper, somehow, make it 'more locally complex' at the 'gravitational focus' but this will not effect the path of light across the plane, from our multidimensional viewpoint it's always a plane.
Oh, didn't you realise, when we're doing this mathpaper experiment, we're NOT IN OUR UNIVERSE. Now, this should ring alarm bells all round the scientific community. But it doesn't. So tied up are they in their 'this is the way it must be'ness that they completely accept and understand that you can be a Homer OUTSIDE OUR UNIVERSE and still have a gravitational affect upon our universe.
And all that bending the sheet nonsense, you know, were you to push point A on the sheet to point B on the sheet and make a bridge... you still wouldn't have what you hope for. Points A and B are implicit to their position on the spacetime mathpaper. They can't be altered. No matter what funky operations you perform on the unity of this sheet, point A will always be where point A always was. Point A can NEVER move to where point B is. Why? Well, point B is already there. Welded into the matrix.
There's no gravitational result from a super-heavy Homer function that'll allow these two immiscible points to even SWAP or TRADE PLACES. So, though you may be able to cajole these two spacially distinct planar points next to each other (from this insanely extra-dimensional viewpoint) you'll never BRIDGE THE GAP. And such a Star Gate will always have a huge concrete door you can't push past. Splat.
2) you can't just 'remove' the Homer or lift him off the plane as ideally Homer's Homerness will be 'part of the math paper' i.e. an in-built structure of the planar spacetime 'fabric' implicit in its planarity. You can't 'suddenly' lift Homer from the gravitational matrix, he's Homer, he'll always 'have' (as part of his 3-dimensional largess) properties associated with his bulk i.e. gravity. You can't leave a Homerhole in this mathpaper, that redefines THE ENTIRE UNIVERSE and that's not allowed, not even to prove a point.
So, where were we?