Here's question from a non-physics mind:
If the Earth, and the galaxy we are in, is hypothetically moving away from the outer limits of known space (in one direction) and the objects in that direction are moving away from us also, and both are travelling at half the speed of light, we would never know it because the light from that distant object (s) will never reach us.
True or false?
The light not reaching us? Kind of 'shady'.
By the way - Elroch might fill you in on the adjustments for rate of passage of time - in the subject you bring up.
Why do I think so? Because I recall him doing so several years ago - while he was also conceding about 2c and about the Big Bang not being 'the universe' -
Point: you can get 'intellectual honesty' out of him.
He's generally honest in his mathematical and science positions.
And he's apparently been essentially right in everything he's said about 'solving' chess in this forum so far. No glaring errors. Yet.
It's all in the detail. My motivation is to share the somewhat subtle point that there is a difference between a genuine speed (which is always limited by the speed of light) and a quantity which has the units of speed (which does not behave as well).
I would observe that it is not uncommon in popular accounts of physics to be misleading in this way, typically in descriptions of the expansion of the Universe. Nothing ever moves faster than the speed of light relative to something else. No amount of argument about space itself expanding changes this. The reason for the erroneous inference is always adding speeds associated with velocities in incompatible frames.
My points stand. And the concession now made by him -
"That quantity increases at 2c"
Speed versus velocity? I was taught that 'velocity' could include a vector.
I never claimed that the 2c was beyond a 'magnitude'. Nor that it wasn't.
But in considering radii of increase ... to get the 2c - diametric opposites are required.
Nor did I claim that rate of change of passage of time cannot occur ... I don't know why whoever would so 'focus' ...
The diameter of an illuminated volume increases at 2c - not c.
Radius at c. Diameter at 2c. Very simple math.
And - did we hear about some discussion clubs? Somebody wanting to make it personal? Always 'in the cards' here.
Issue: only one person in the whole forum seems to believe that chess could be solved in 'five years' or less. Not I.
But that's okay. Its not personal.
And that person holding to his position has helped maintain the discussion.