4 ms·

> If it had no interactions with anything else between its two bracketing events. > Like a discrete edge in a simple graph, it is a connection between two node

> If it had no interactions with anything else between its two bracketing events. > Like a discrete edge in a simple graph, it is a connection between two nodes, there are no dynamics in between the nodes. An edge is just a connection, not a continuous path. How do you explain redshift from the universe expanding?

Nevermark 2y ago
Perhaps space and "particles" interact? There must be some kind of interaction since photons are energy and all energy not only travels through space but warps space. Gravity responds to all energy, not just mass. But more likely their interpretation would be that this is where the importance of "relative" comes in. Relative to us the particle has been red shifted, but that is because of our viewpoint from our space-time position and conditions of reception differ from its space-time point and conditions of emission. Or the relative topology between those events. But not because of any change in the photon during its journey.
- zmgsabst 2y ago
  > Or the relative topology between those events. But the interaction is no longer simply a connection between us and the origin: the path along which the photon traveled changed our measurement. And indeed, different paths can change different portions of it, eg, if you have something like an Einstein ring where part of it passed through a dark matter filament. At the point where the entire path needs to be considered because it interacts with space while passing, I’m not sure what sense it can be described as “an edge like a graph”. That seems like a classic trajectory, ie, a continuous path.
  - Nevermark 2y ago
    Did the path between emission and reception change the photon? Or did it change our relation to the photon? A simpler case of the latter is uncontroversial: If you move quickly away from a photon emitter, you will detect red-shifted photons. Clearly, the photons didn't change, only our relation to them. Energy, like everything else, is relative and appears to have different quantities in different situations. Strange as that seems, given conservation of energy still holds. But energy, just like space-time, is not "Euclidean".
    - zmgsabst 2y ago
      > Did the path between emission and reception change the photon? Or did it change our relation to the photon? That’s irrelevant navel gazing: the operator which describes the change depends on the continuous path between. > Strange as that seems, given conservation of energy still holds. I don’t believe it does when factoring in expansion — or at least, that hasn’t been shown. https://www.youtube.com/watch?v=ZYM6HMLgIKA https://www.youtube.com/watch?v=ZYM6HMLgIKA

Nevermark 2y ago

Perhaps space and "particles" interact? There must be some kind of interaction since photons are energy and all energy not only travels through space but warps space. Gravity responds to all energy, not just mass. But more likely their interpretation would be that this is where the importance of "relative" comes in. Relative to us the particle has been red shifted, but that is because of our viewpoint from our space-time position and conditions of reception differ from its space-time point and conditions of emission. Or the relative topology between those events. But not because of any change in the photon during its journey.

zmgsabst 2y ago
> Or the relative topology between those events. But the interaction is no longer simply a connection between us and the origin: the path along which the photon traveled changed our measurement. And indeed, different paths can change different portions of it, eg, if you have something like an Einstein ring where part of it passed through a dark matter filament. At the point where the entire path needs to be considered because it interacts with space while passing, I’m not sure what sense it can be described as “an edge like a graph”. That seems like a classic trajectory, ie, a continuous path.
- Nevermark 2y ago
  Did the path between emission and reception change the photon? Or did it change our relation to the photon? A simpler case of the latter is uncontroversial: If you move quickly away from a photon emitter, you will detect red-shifted photons. Clearly, the photons didn't change, only our relation to them. Energy, like everything else, is relative and appears to have different quantities in different situations. Strange as that seems, given conservation of energy still holds. But energy, just like space-time, is not "Euclidean".
  - zmgsabst 2y ago
    > Did the path between emission and reception change the photon? Or did it change our relation to the photon? That’s irrelevant navel gazing: the operator which describes the change depends on the continuous path between. > Strange as that seems, given conservation of energy still holds. I don’t believe it does when factoring in expansion — or at least, that hasn’t been shown. https://www.youtube.com/watch?v=ZYM6HMLgIKA https://www.youtube.com/watch?v=ZYM6HMLgIKA