…Exotic matter is a hypothetical form of matter theorized to contain unusual properties often characterized by a negative energy density, meaning it would have a negative mass or exert a repulsive gravitational force. Wormholes would require a shell of exotic matter, but just like wormholes, exotic matter has never been observed and is considered hypothetical.
“If you could somehow create that state of matter, then, according to general relativity, you could have a wormhole. But if you ask me whether that kind of matter is possible, I doubt it,”…
As of now, scientists don’t know enough about the characteristics of wormholes to confidently identify them, such as the types of situations that would create a wormhole, the properties of a wormhole, and how to detect said properties…
One key feature is that a wormhole would look like a sphere, not a hole, says Lupsasca, adding that to travel through a wormhole would be like “getting sucked into a ball and then expelled from another ball.”…
Imagine living in a two-dimensional world, like a sheet of paper. When that sheet of paper is folded over . . . these separate locations in “space-time” are joined together in much the same way a wormhole might do. Similarly, if a person were to go through a wormhole, it would change their location in both space and time.
I imagine that such a spherical wormhole could theoretically be detected by watching for light reflecting off objects despite a lack of nearby stars. For example, if we trace the path of light passing through a wormhole and reflecting off a planet back to its origin, it would look like that light is coming from empty space. Like the beam of light coming out of a recessed lighting fixture in your ceiling, it would be directional and you’d only be able to see the lightbulb if you’re standing directly under it, otherwise you can only infer the existence of the lightbulb and recessed hole in the ceiling by observing the light reflecting off the floor.
I do wonder what happens to space-time at the points between wormhole terminations. In the folded paper analogy, someone had to apply enough energy to manipulate the position of every atom in the paper as they were bending it over on itself, and at the end there would be a dramatically different shape to the paper between those two points.
Going back to the folded paper analogy again, going the long way through space-time from one wormhole termination to the the other would be like walking in a straight line away from the first wormhole terminus and eventually looping back around to the same point in space-time, which sounds a lot like what happens to straight lines inside the event horizon of a black hole.
This does not explain why it would look like a sphere. It says that it would look like a sphere, but gives no effort to explain why it is generally thought of as a tunnel, why it would actually be a sphere, or what charactistics of the physics should necessitate a sphere like structure.
Very disappointing read