5 ms·

What irks me in articles like this is the term observer. Define observer. Sure, a human is an observer. But can a dog be an observer? A plasmodium? A virus bump

What irks me in articles like this is the term observer. Define observer. Sure, a human is an observer. But can a dog be an observer? A plasmodium? A virus bumping into a molecule and changing its course? Is observing shorthand for any interaction that can collapse a wave function? In that case it seems highly unlikely to me that a photon can travel billions of light years unperturbed.

goblin89 8y ago
> The relevant literature is famously contentious and obscure. I believe it will remain so until someone constructs, within the formalism of quantum mechanics, an “observer,” that is, a model entity whose states correspond to a recognizable caricature of conscious awareness … That is a formidable project, extending well-beyond what is conventionally considered physics Wilczek, 2006. Quoted in a paper[0] that I like for its thorough stab at actually specifically defining the observer. It’s a tough task indeed! [0] https://www.frontiersin.org/articles/10.3389/fpsyg.2014.00577/full https://www.frontiersin.org/articles/10.3389/fpsyg.2014.0057...
contravariant 8y ago
I prefer the quantum decoherence perspective where being 'observed' basically means interacting with a macroscopic object in a way that's similar to the notion of reaching 'thermodynamic equilibrium' in statistical physics.
- aidenn0 8y ago
  "macroscopic object" is unsatisfying though because macroscopic objects are made out of objects that are describable under QM.
  - contravariant 8y ago
    Maybe so, but that's a problem shared by both thermodynamics and quantum mechanics. Both have macroscopic objects that exhibit phenomena like temperature, friction, wave function collapse, that simply don't exist on the smaller scale. The good news is that macroscopic objects exhibit behaviours that are predictable. The bad news is that. while those behaviours are related to the behaviour of the microscopic scale, a full description of systems involving that many particles will likely remain out of our reach forever. Although I could see it happening that we might be able to simulate systems of a sufficient scale to convincingly demonstrate wave function collapse.
commentor10 8y ago
I think an observer is a quantum process interacting with another quantum process. Photons are fundamentally different from particles with mass - and they interact differently. Two photons interact like waves at the surface of an ocean - amplitudes and phases changing, for instance. But photons interact with particles with mass by either being absorbed and, later, re-emitted by the other particle or being completely absorbed and altering the particle with mass' state in some way (speed/momentum). I remember reading somewhere about a geometry which described photons' existences as fundamentally different from particles with mass. Particles with mass have lifelines that change over the course of time. Particles without mass, such as photons, don't experience time and never change themselves. Photons etch out a straight line in this geometry from fixed points to other fixed points. The fixed points represent particles with mass. (something like that)

goblin89 8y ago

> The relevant literature is famously contentious and obscure. I believe it will remain so until someone constructs, within the formalism of quantum mechanics, an “observer,” that is, a model entity whose states correspond to a recognizable caricature of conscious awareness … That is a formidable project, extending well-beyond what is conventionally considered physics Wilczek, 2006. Quoted in a paper[0] that I like for its thorough stab at actually specifically defining the observer. It’s a tough task indeed! [0] https://www.frontiersin.org/articles/10.3389/fpsyg.2014.00577/full https://www.frontiersin.org/articles/10.3389/fpsyg.2014.0057...

contravariant 8y ago

I prefer the quantum decoherence perspective where being 'observed' basically means interacting with a macroscopic object in a way that's similar to the notion of reaching 'thermodynamic equilibrium' in statistical physics.

aidenn0 8y ago
"macroscopic object" is unsatisfying though because macroscopic objects are made out of objects that are describable under QM.
- contravariant 8y ago
  Maybe so, but that's a problem shared by both thermodynamics and quantum mechanics. Both have macroscopic objects that exhibit phenomena like temperature, friction, wave function collapse, that simply don't exist on the smaller scale. The good news is that macroscopic objects exhibit behaviours that are predictable. The bad news is that. while those behaviours are related to the behaviour of the microscopic scale, a full description of systems involving that many particles will likely remain out of our reach forever. Although I could see it happening that we might be able to simulate systems of a sufficient scale to convincingly demonstrate wave function collapse.

commentor10 8y ago

I think an observer is a quantum process interacting with another quantum process. Photons are fundamentally different from particles with mass - and they interact differently. Two photons interact like waves at the surface of an ocean - amplitudes and phases changing, for instance. But photons interact with particles with mass by either being absorbed and, later, re-emitted by the other particle or being completely absorbed and altering the particle with mass' state in some way (speed/momentum). I remember reading somewhere about a geometry which described photons' existences as fundamentally different from particles with mass. Particles with mass have lifelines that change over the course of time. Particles without mass, such as photons, don't experience time and never change themselves. Photons etch out a straight line in this geometry from fixed points to other fixed points. The fixed points represent particles with mass. (something like that)