Wormholes cast weird shadows that could be seen by telescopes.
Wormholes ( an instantaneous change in space-time) are for a fiction group not EUT. Such an entity is impossible by physics.
Relativity is a background independent theory meaning it never uses physical coordinates. All its tensor equations are confined to the observer's reference frame. Relativity by its very design never affects any physical entity, just the observer's reference frame whose dimensions can be curved in this mathematical exercise.
When confined by the math to the observer's reference frame anyone is free to imagine silly changes within this context, including a wormhole.
Every being exists in their now. A person can freely change their watch or calendar to change how their now is described. When travelling across a change in time zones change one usually changes their watch to match the correct local time. These changes in one's personal time are not time travel. Though the change in time was coincident with a change in location this is not a wormhole.
An object requires energy to change its physical location.
A worm hole proposes an instantaneous change in the observer's physical location and time. This instantaneous movement with no transfer of energy is simply impossible. This story is the consequence of someone believing this fiction is possible. This 'shadow' supposedly results from this (impossible) physical connection from one physical location to another even though the person supposedly moves instantaneously and not through a tunnel like in a park with water slides. The tunnel casts a shadow but there is no physical surface in space for this shadow to become visible to telescopes as claimed. This shadow is more nonsense following the nonsensical worm hole. The author apparently believes the curved space-time dimensions provide a surface like graph paper in a geometry class.
Stories like this are abysmal.
The above post resulted in this comment:
"That was one of the more coherent descriptions of the frame problem in relativity that I've heard. Its something I struggle with, and requires repetition for me to hold on to. Thank you."
thank you, BTW I posted a rant about relativity on 10/17/19, I am sorry to admit relativity really bugs me for an observer's reference frame to become the basis of cosmology.