November 24, 2022 report
A group of researchers at Sofia University has found evidence
that suggests the reason that a wormhole has never been observed is that
they appear almost identical to black holes.
In their paper published in the journal Physical Review D, , Petya Nedkova, Galin Gyulchev, Stoytcho Yazadjiev and Valentin
Delijski describe studying theoretical linear polarization from an accretion disk that would be situated around a class of static traversable wormholes and compared the findings to images of black holes.
For many years, scientists and science fiction writers have considered the theoretical possibility of a wormhole. Such an object, theory suggests, would take the form of a tunnel of sorts that connects two
different parts of the universe. Moving through the tunnel would allow
for travel to distant destinations in ways not available to spaceships
incapable of moving faster than the speed of light—by taking a shortcut.
Unfortunately, no one has ever observed a worm hole or even any physical evidence that they actually exist. Still, because the theory for their existence
is so strong, astrophysicists assume they do exist. The problem is that
we either lack the technology to see them, or we have not been looking
for them in the right way.
In this new effort, the researchers in Bulgaria suggest that the
latter is the problem. They have found evidence, via theory, that
suggests that they might be sitting out there in the night sky in plain sight, and that the reason we are not seeing them is because we are mistaking them for black holes.
The work involved studying wormhole theories and then applying
findings to the creation of simulations, with an emphasis on the
polarity of the light that would be emitted by such an object—and by
also taking account of the characteristics of an assumed disk
surrounding its mouth. They then created both direct and indirect images
to depict what a wormhole would look like and compared them to black
holes; they found them to look remarkably similar.
The researchers noted that it should be possible to tell wormholes
and black holes apart by noting subtle differences between them, such as
polarization patterns and intensities and also their radii.
More information: Valentin Deliyski et al, Polarized image of equatorial emission in horizonless spacetimes: Traversable wormholes, Physical Review D (2022). DOI: 10.1103/PhysRevD.106.104024