We know light travels across the cosmos in straight lines – or so we think.
There’s something unknown in our galaxy that is bending and distorting that light in odd ways. Scientists studying distant galaxies and other objects find patterns that just do not follow their expectations.
Those distortions occur at sizes many times larger than anything thought possible.
What could possibly be creating those distortions in the way light travels through the Milky Way?
What problem are scientists seeing across the galaxy?
Galaxies are studied using distant sources.
One such source is about four billion light-years away.
This object emits a radio signal which is received here on Earth.
However, scientists notice there’s an issue with the way the radio signal appears.
Instead of being a single, unbroken wave, the radio signal appears broken up. It also appears to disperse upward, and farther objects appear distorted and wobbly.
Light was not expected to distort at such large scales based on previous assumptions.
Instead of fading, the radio signal remains patchy and structured when scientists observe it.
That tells scientists that the distortion occurring was likely occurring much closer to where the observation occurred. Researchers had seen small signs before but didn’t understand their extent or nature.
What traits define this strange distortion?
By studying how light behaves, researchers found a link to our galaxy’s composition.
While space appears empty, our galaxy contains large amounts of ionized gas and free electrons.
They interact and move around each other at all times, creating instabilities that affect vast areas of space.
When light enters this area, it can scatter in various directions.
In certain parts of the galaxy, this occurs at much greater levels.
There is one area in particular that is known for its extreme levels of chaotic behavior. Any light passing through that area begins to act erratically.
Over time, observable patterns emerge as well. Those patterns are not random nor are they equally spaced.
This suggests something much larger is going on than what researchers initially thought.
The one remaining question was: what could be strong enough to produce consistently distorted views? Research into these effects has been documented by Center for Astrophysics | Harvard & Smithsonian.
How did scientists discover what is causing it?
For many years, astronomers believed there was some type of distortion occurring in their data.
The frequency at which this effect happened was consistent enough to become obvious. Not only did it occur consistently; it created an easily identifiable pattern.
In addition, these distortions appeared to be part of a much larger process.
However, nothing had ever been definitively proven as to what may have been causing them.
How does this hidden structure bend starlight across the galaxy?
Scientists realized that the distortion of light coming from stars is caused by turbulent materials located between stars.
This turbulent “medium” is now called the interstellar medium (ISM).
The ISM is made up of electrically charged particles and gas that is constantly moving around freely.
Within this medium, turbulence causes pockets of varying densities to exist.
Some of these pocketed areas cover distances equal to those of our solar system.
As light passes through this turbulent material, it bends and scatters instead of continuing in a straight line.
The distortion does not come from the distant star, but from turbulent fog closer to Earth.
Scientists have now visually observed repeating structures contained in the distorted light produced by the turbulent fog. The repeating structure indicates that the turbulence has a structure rather than simply acting randomly.
Understanding this “fog” could alter how scientists observe the universe and make distant cosmic objects clearer.