Kron wrote:Discontinuous jumps faster than light are allowed by special relativity. Even particles traveling at FTL speeds (tachyons) are allowed. It's just crossing the lightspeed barrier by acceleration that's not allowed.
Not exactly, at least according to what I'm familiar with. If you have any form of information traveling FTL, then you've violated causality, as you've gone beyond the light cone. Even with wormholes, you have continuous spacetime that doesn't allow communication beyond the light cone; it's just that the light cone may now have an odd shape and overlap in unusual ways.
Tachyons are currently only hypothesized, and even if they exist, couldn't be used to carry information.
Kron wrote:Secondly, the laws of thermodynamics aren't laws. They're just stochastic rules of thumb. Indeed, the fluctuation theorem gives us a few cases where global entropy decreases instead of increases.
I realize that. But, time travel gives you a way to "sort" matter by entropy, so you can get situations where it's not a local temporary deviation, nor even a martingale process. Say you perform some localized exchange-based sort algorithm (e.g., bublesort) of matter using your chronoporter across time. Now you've ordered the state of some closed area of the universe from high entropy to low entropy. In doing so, you could extract energy out of it to fuel the sorting (depending on chronoportation costs), and it becomes a strong positive feedback loop.
If you were to run this universe infinitely many times with different random seeds, you'd still end up with the same result. That's why it'd be a violation.
Kron wrote:Also, 'smooth translation' doesn't work: not unless you yank the entire universe back along the same axis.
Doesn't it work if you assume special relativity isn't perfectly accurate? Could you have a time dilation discontinuity shaped like the function 1/x, where beyond some boundary (where x = 0), time runs in reverse for that space? (much like you can have time dilations within a gravity field, though I remember reading something recently that this may not be as consistent as previously thought)
Here are pointers to sections on some of the central points of the topic
What real life physics rules hold/are violated in the Achron universe?
*Conservation of angular momentum
*Conservation of causality
*Conservation of consistency
*Computability class of universe
*Achron is being developed so long that it can attune itself to these kind of distinctions
*Layperson tries to/understands conservation of angular momentum
derail into reading habits
mini chapter 4
*Relation of chronoportation and teleportation in "realistic" theories
*Does math obfuscate, how do the technicalities relate to the discussion? (debated)
*Space time contains operations such as rotation and relativity of frames, time gets a special treatment and thus is categorically separate (debated)
*Chapter 6 stuff
*Location of big bang
*No going past from big bang like no going north from north pole
*Reality of time
*time is illusion/made up concept to structure reality
*time is real, directionality is made up
*Time as a property of space-time, emergence
*Thinking without time
*What it takes to prove "no time" or "time"
*Management of belief systems, accepting views you do not understand
*Management of beliefs systems, using newbies to avoid indoctrination