Darkness can "travel" faster than light speed(nature.com)
nature.com
Darkness can "travel" faster than light speed
https://www.nature.com/articles/s41586-026-10209-z
10 comments
It's a very bad press article, that says a lot of wrong things that are not in the research article.
As I explained in a reply to a sibling comment, the spot on light on a wall can "move" faster than light. Or you can have the inverse setup of a wall that is illuminated everywhere but in a dark spot, and the dark spot can "move" faster than light.
You can imagine the second example like a movie where a dark UFO moves over a light sky. There is an illusion of movement, like in a movie. But the information is not moving FTL from a part of the screen to the other, the information is moving STL from the proyector to the screen.
They measure the point where A=0 on a surface. When the singularities are far away, they behave like particles and it makes sense. In this case the point A=0 "moves" FTL, but it's as fake as the UFO in the movie. Also in some cases it's easier to do the math considering fake objects that move FTL. (just google "phase vs group velocity"). This is a well known problem/trick that is taught in a standard course in the second year of a physics degree.
It looks like the research is interesting, but the groundbreaking "darkness can “travel” faster than light" angle in the article is just nonsense.
As I explained in a reply to a sibling comment, the spot on light on a wall can "move" faster than light. Or you can have the inverse setup of a wall that is illuminated everywhere but in a dark spot, and the dark spot can "move" faster than light.
You can imagine the second example like a movie where a dark UFO moves over a light sky. There is an illusion of movement, like in a movie. But the information is not moving FTL from a part of the screen to the other, the information is moving STL from the proyector to the screen.
They measure the point where A=0 on a surface. When the singularities are far away, they behave like particles and it makes sense. In this case the point A=0 "moves" FTL, but it's as fake as the UFO in the movie. Also in some cases it's easier to do the math considering fake objects that move FTL. (just google "phase vs group velocity"). This is a well known problem/trick that is taught in a standard course in the second year of a physics degree.
It looks like the research is interesting, but the groundbreaking "darkness can “travel” faster than light" angle in the article is just nonsense.
Can someone more knowledgeable explain this better please? I have questions:
- if you can measure the 'optical singularities' travelling FTL, then surely 'information' is travelling FTL?
- does it matter (i.e. violate relativity) if something is travelling faster than light speed in some medium as long as it doesn't travel faster than light in vacuum?
- if you can measure the 'optical singularities' travelling FTL, then surely 'information' is travelling FTL?
- does it matter (i.e. violate relativity) if something is travelling faster than light speed in some medium as long as it doesn't travel faster than light in vacuum?
Good questions:
> if you can measure the 'optical singularities' travelling FTL, then surely 'information' is travelling FTL?
Information is not traveling FTL.
The canonical example is when you have a lighthouse in the middle of a huge circular wall. The light spot may move faster than light when you see it on the wall, but the info moves from the center to the wall, not along the wall.
When the singularities are far away, you can treat them like a single entity, and track the anti-peak and measure it's speed and they will move like 1/100 of the speed of light in this case.
When the singularities are very close together the anti-peak may move at a faster speed (FTL IIUC), but it's just an illusion for tracking the peak. The information moves slower than light.
> does it matter (i.e. violate relativity) if something is travelling faster than light speed in some medium as long as it doesn't travel faster than light in vacuum?
This is totally possible. It's common if you live inside the water pool of a nuclear reactor or a neutrino detector. More info in https://en.wikipedia.org/wiki/Cherenkov_radiation
> if you can measure the 'optical singularities' travelling FTL, then surely 'information' is travelling FTL?
Information is not traveling FTL.
The canonical example is when you have a lighthouse in the middle of a huge circular wall. The light spot may move faster than light when you see it on the wall, but the info moves from the center to the wall, not along the wall.
When the singularities are far away, you can treat them like a single entity, and track the anti-peak and measure it's speed and they will move like 1/100 of the speed of light in this case.
When the singularities are very close together the anti-peak may move at a faster speed (FTL IIUC), but it's just an illusion for tracking the peak. The information moves slower than light.
> does it matter (i.e. violate relativity) if something is travelling faster than light speed in some medium as long as it doesn't travel faster than light in vacuum?
This is totally possible. It's common if you live inside the water pool of a nuclear reactor or a neutrino detector. More info in https://en.wikipedia.org/wiki/Cherenkov_radiation
Something massless and devoid of information can travel faster than light
How can such a thing be detected? And without detection how can speed be measured?
How can such a thing be detected? And without detection how can speed be measured?
Not an answer, but I'm modeling it as a way to pull stability out of non stable region of space for a soliton field. The gradient the void causes allows the soliton to find a useful basin.
Easier context to recognize light does not "move", rather the energy which our visual sense perceives as light activates or reflects off countless atoms / particles in an area. Picture the popular Newton's cradle desk toy: the interior balls to not move but pass the energy from end-to-end. Light is energy passed along atomic level, distance dependent on countless material and epigenic factors.
[deleted]
In the minds of nature.com writers. /s
https://www.popularmechanics.com/science/a70885429/darkness-...