That's certainly one view (advocated for in e.g., Petkov's Relativity and the Nature of Spacetime and Heller's The Ontology of Physical Objects: Four-Dimensional Hunks of Matter and advocated by Einstein). In such a cosmos, everything that will happen already has happened. The future isn't determined, it's non-existent. Einstein subscribed to such a "block universe" in which change is a human illusion as is past and future. I don't find such a view convincing because it is founded not upon an empirical demonstration that time and space are one, but rather that we have to treat them this way if we wish to properly order events AND keep the laws of physics the same in all (inertial) reference frames. Furthermore, it does a poor job explaining anything regarding quantum physics, as significant mathematical maneuvers are required just to transform quantum mechanics into something compatible with special relativity.We're four dimensional beings.
They don't, for a myriad of reasons. First, time in quantum mechanics is the same as in Newtonian physics: "Time in quantum mechanics is a Newtonian time, i.e., an absolute global time."Entangled particles show that there is no time involved
Macías, A., & Camacho, A. (2008). On the incompatibility between quantum theory and general relativity. Physics Letters B, 663(1), 99-102.
Second, entanglement isn't relativistic. It doesn't occur in "no-time", but involves a process that takes "no time". According to the transactional interpretation it actually takes a certain amount of time in that this interpretation explains nonlocal effects via bi-directional time (signals traveling forward AND backward in time).
Third, if you accept an ontological interpretation of spacetime, then nothing actually happens and there is never any "time". Thus when one measures system A, and system A is entangled with system B (located light-years away), the effect that measuring A has on system B isn't instantaneous. In fact, entangled states can decohere or even not exist in different reference frames, and the nature of entanglement in relativistic quantum physics remains problematic (I can provide you with references, even give you some papers, but they are rather complicated). Entanglement is fundamentally non-relativistic, and incorporating entanglement into 4D spacetime is not always possible, but when possible it is not instantaneous as it involves the world lines of the two systems or some coordinate transformation.to determine what properties of (possibly double) the systems are invariant AND correlated (i.e., remaining in violation of Bell's inequality).
There is no theory in physics more rooted in time than quantum mechanics. In classical physics, time asymmetry is generally postulated to be a side-effect of thermodynamic entropy, but the actual physical laws governing the evolution of systems are symmetric with respect to time and there is no basis in them for past vs. future. In special and general relativity, past and present are explicitly disregarded as meaningless. However, in quantum mechanics the time-evolution of the Schrödinger equation describes a state that "collapses" the evolution of any and all systems, fundamentally distinguishing between past and present.
That's because it's an illustration of time dilation, not the relativity of simultaneity. Wrong Wikipedia page.That's not the classic Einstein thought experiment
No, there isn't. There isn't enough:I'm not sure but I think there's too much going on in your example.
The light started from delta 0 and traveled straight up and down length l, giving us a time interval
But that's not what Bob observes, as he observes a different length and thus a different time interval as in the equations below:
If we solve the top equation for d and plug the result into the bottom equation we get one equation all in terms of Δt. We square it to obtain:
Δt is now related to Δt0 through an equation that tells us (thanks to the denominator) that the time interval for Bob is greater than that for Alice (Δt > Δt0)
Interestingly, the RIGHT wiki page also uses a mirror:Take out the mirror
Time dilation
That isn't why.Well yes, because like light, the speed of which is invariable for all observers, Planck time/length is defined by light therefore is invariable for all observers as well.
I don't know, it's mine. There are many like it. I have what I think is the modern Halliday & Resnick edition as I taught an abridged modern physics course not long ago. I scanned the page on time dilation for you (see attached). It includes a train and mirrors, but I don't think it is as clear as my example.What is the reference for your train example?
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