Definitions of Observers

An observer is an entity that computational reducibility to conflate many different states and treat them as the same.
A word in a language like “cat” takes many specific cats and conflates. Similar to the idea of symbolic descriptions.

Thermodynamics

Equivalences are traditional coarse graining (ultimately to the state variables, e.g. temperature, pressure)

Relativity

Equivalences are events taking place at locations that can consistently be viewed as spacelike separated
Simultaneity of events in different places in space [AKA synchronization of clocks]

Quantum mechanics

Simultaneity of events in branchial space [AKA which states of the universe are conflated, in a superposition]

[Rulial space]

Equivalence is by different description languages for the universe
Simultaneity ::
In[]:=
ArrayPlot[CellularAutomaton[73,{{1},0},80]]
Out[]=

Perceiving Space and Time

For humans:

processing speed (~ milliseconds)
size (~ meters)
environment size [ ~ km ]
speed of light
Humans try to give a sequentiality to things that happen
[ Bucketing lots of events into a spacelike surfaces ]

Perceiving a space battle

Where the distances are like the distance to the moon

Very big intelligence

Size of a planet; your processing time is short compared to light travel
Claim might be: your processing time has to be much slower than the time to get new data (or you’ll get very frustrating) [or: you’ll keep blocking waiting for data]

From the POV of a computer

Its rate of getting data about the world is slow compared to its processing speed
The computer doesn’t care where the keys are; its senses only tell it about key events [sensor data from afferent nerves going to brain]

For a sufficiently fast computer, there’s no point in having space, or for that matter reducibility

Octopus

Multibrained creature; does it synchronize its worldview? A tentacle can have mind of its own... [~ reflex arcs]

Whales

Long-distance audio communication [ for them, there is communication throughout the universe ]
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“Arrival” heptapods

Extremal principles vs. equations of motion

Human descriptions [ mechanism vs purpose ]

Mechanism: you can always run the program and find the answer [you can always make incremental progress]
Purpose: you might not be able to solve the equation [you might not be able to find anything] <assumes everything in the world is reducible>

Space as perceived by a rat in a maze

Thundercloud

It is “perceiving” electric fields ... that determines its “choice” of where the lightning goes

GR As Seen by A Dog / A Bat

Relative to our view of space, a dog would have small coordinate charts
Dog perceives time dilation
Periodic smell pulse at certain place (“smell clock”) [Doppler effect]

Relativistic aging

“Placebo mouse”
The mouse only ages to the extent the mouse thinks it should age

Photon Perception

No data comes into a photon

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Virus Perception

Would not perceive a world in which definite things happen
If there is not microscopic causal invariance [ main question: what is the processing speed of the critter relative to the branch merging time ]

How Can One Communicate with an Intelligence with a Different Physics?

Definition of “Awareness” / Self-Awareness / Consciousness

Is this related to reducibility?
Definition of “self” vs. environment is another reducibility play

Any reduced description ⇔ intentionality

Given a reduced description which coarse grains many microstates
“I want to achieve X” [X is a reduced description]
If you’re not just specifying a particular state ... you must be coarse graining in some sense.