Being present is being connected to All Things.

If the many worlds interpretation of quantum mechanics is in fact true then the universe is deterministic, but we are faced with an interesting philosophical question of identity. Since all possible outcomes exist simultaneously, it's not surprising we find ourselves asking and existing as the question must be asked by those who exist, can and do ask it, wherever and whenever. However, why exactly does our life as an individual take this particular path instead of some other? For physics they're all equal. Futhermore, if time doesn't truly exist, why/how do we experience present and flow of time?

True free will cannot exist in a deterministic universe and therefore our path cannot be determined by one. If there existed no subjective experience of specific consciousness then the question would perhaps vanish. From purely physical point of view, I suppose there doesn't have to be anything special about every possible past, present and future existing simultaneously, but from the point of view of our consciousness, it's deeply mysterious. It may of course be that in some way consciousness is just an illusion and there is nothing special about this particular experience. Though, the illusion does appear to be extremely convincing.

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Occasionally one runs into discussions about the simulation argument according to which we almost certainly live in a simulation because if simulations are possible and run then there are going to be very large amounts of them. While this is certainly somewhat entertaining argument, there isn't particularly much one can deduce from it. Whether we are in a simulation or not tells us nothing about where these simulations ultimately originate from and also doesn't tell us anything about our place in the hierarchy of the simulations (for example how deep we are from the fundamental underlying universe), unless of course we can somehow acquire empirical knowledge concerning them.

Quinine in tonic water converting 405nm (violet) laser light into 450nm (blue) by fluorescence. Diluting tonic water down to a single quinine molecule should allow antibunching to be observed by a detector capable of resolving single photons on timescales less than fluorescence lifetime of 20ns. Only a single photon from a single emitter on average within fluorescence lifetime can be emitted regardless of the number of photons in the exiting laser pulse.

Also, what might be worth considering is that at least in this particular universe (or simulation) all systems whether they be simulations or not, appear to interact with their environment to some extent and it is in fact impossible to create a perfectly isolated systems. This is why for example row hammer exploit [https://en.wikipedia.org/wiki/Row_hammer] is possible. Therefore no simulation is fundamentally any different from just a weakly coupled system in the most fundamental underlying universe. In certain sense creatures living in a simulation are then nothing more than caged animals born in captivity. Not that different from what we are now (as we are also caged by at least the limits of our current physical bodies and consciousness). Of course no particular reason why this couldn't change in the end.