Random Thoughts

[Rhizomorph13]

Time travel is impossible.

The usual sci-fi motif of traveling to the past and alter events so that the time traveller isn't even born is often used as a plot device, it even has the name the Grandfather Paradox. Although that isn't why time traveling is a paradox, but a time loop between 2 states, in essence a superposition, as Minutephysics has explained in a short YouTube vid explaining why.

I think time travel isn't possible for a different reason: The Law of Conservation of Energy. This natural law seems consistent throughout nature, so with it I can assume that the combined energy and mass of the Universe is a constant - that's one of the implications of this natural law - which we even have a good general idea what that value is for the Universe; it's always the same, AFAIK. Most physicists think this value is 0, which means the mass and energy in the Universe squares out, or so it seems. We also see this in quantum foam, where particle and antiparticle are created and almost immediately annihilated from vacuum energy or some such thing.

What do you think would happen with this constant value if we, hypothetically speaking, were able to build a device that could traverse time like we travel on roads?

If this device travelled through time t0 (present) to time t1 (past/future), then the device would disappear from the Universe at t0, removing some mass and energy, and appear in the same Universe (I suppose) at t1, adding that additional mass and energy of the device. You can probably already see where I'm going with this. At both t0 and t1, there's a discrepancy of the constant energy of the Universe as per Law of Conservation of Energy, at t0 it's less than zero, while at the same time it's greater than zero at t1, for the same Universe. This is a paradox just as much as 2kg can't simultaneously be 3kg for any mass at rest.

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To add, I think the normal way we view time itself has an inherent intuitive assumption about the supposed property of time as extant of the Universe, of how there's a past, present and future. We obviously remember the past, but that's because our brains construct them in the present, not because we supposedly have some connection to the past through our memories, IOW memories can be thought analogically as recordings. We see this problem better when we ask nonsensical questions about "what happened before the Big Bang?" when time itself, supposedly, came into existence then. I'm of the position that time doesn't exist, not in the way we usually think of time anyways. I think of time as an emergent property of the Universe, not as an ontological existence.

In the documentary film, "The Langoliers" Written by notable physicist Steven King, it is demonstrated that the past is eaten by large bags with teeth and before the past is eaten it wears down in quality as time leaves it behind.