OK... So the pod drops through the center of the popcorn machine and into a wormhole aperture. Great, with you so far (sort of)... But the red flashy-crap, followed by a star-field, followed by being sucked into some kind of funnel/vortex/tunnel thingy doesn't work.
Through a wormhole one can travel to distant parts of the universe instantly, avoiding all the fuss of relativity. More importantly wormhole nozzles do not look like funnels. Watch Cosmos again (The Edge of Forever, Episode X). A funnel in 4D space is a sphere in 3D space.
Here's how it should have gone... The machine should have been more like the one in the book where a stationary pod is surrounded by a device that generates a pucker in spacetime to which an awaiting wormhole nozzle can attach. The wormhole itself is an invasive sphere which envelopes a local area of spacetime; the space enclosing the pod when the machine reaches full power. A passenger would see her surroundings instantly change from departure point to destination without ever experiencing a tunnel. Whatever tunnel there is that connects these two points in space exists outside our three dimensional universe and is therefore invisible to us.
Yes, Sagan used tunnels in the book. But I think he included the tunnel adventure more for entertainment than scientific value. Since the entertainment value was negligible and misleading he would have done better to leave it out.
In the book the pod is completely encased, which conveniently doesn't allow an outside observer to see anything. The popcorn machine simply leaves out any telling spacial effects (aside form a cheap fireworks display). Both of these theatrical devices serve to reinforce the assumption of the flat-earth powers-that-be that the pod went nowhere and the bitch made it up. That's drama and it's good. But it only works to a point. The book answers the doubters, but the movie does not. The movie's only rebuttal is the usual, typical, predictable appeal to faith. 'I experienced a vision of the universe, a revelation if you will, that only I was allowed to see... Trust me.'
So the term 'wormhole,' is a kind of misnomer. What's a better nomer? Oh hell, I don't know. Let me think...
How about 'Independently Spacial Relativity-not! Focusing Aperture,' or 'ISRFA' for short. No, too complicated, too abstract, and too removed from everyday life. Not to mention being far too inaccessible to the general public (from whom science funding ultimately originates, like it or not).
And besides, it lends itself to so many unflattering acronym extensions:
When generating a wormhole one connects two places that are not connected otherwise, forcing them to occupy the same location at the same time. A wormhole, therefore, can be understood as being like a screenplay... where the novel is the entrance, and the movie an exit.
But in the case of the popcorn machine, the wormhole is more akin to a digestive tract. Fillet mignon in... shit out.