Sections

Intro

Both of my sisters are currently busy with exams, usually my younger sister hangs out with my brother while he does the dishes, but since she’s not around, we hung out as I did the dishes.

I enjoy doing the dishes, I feel like that particular chore sparks my most creative and fringe thoughts. As any older brother does, I start to talk about time travel. When you watch a lot of sci-stuff as a kid, some ideas persist and others fade over time. Time travel is something i’ve spent a fair bit of time thinking about since i saw it potrayed in the the movies all those years ago.

State.

I said to Dolu (my brother),

The universe is just one big container of data, that holds the state.

Data about everything. And when i say everything i mean EVERYTHING.

( I’ll use the word “state” alot in this article. State is the latest description of the details of something )

I also said that what we experience as the flow of time is gazillions of particles moving through space, with each particle assuming a new state continuously ( description of it’s properties in relation to other particles).

At this point i pick up a plastic bowl and beat it into a shape and say that what i just did changed the description of the plastic bowl. Some of it’s characteristics changed. It’s position changed. All sorts of stuff about it changed.

At this point, my brother is very confused.

He asked a question which made me examine my argument a little more..

If I don’t move or breathe and the plastic bowl remains where it was, how come time doesn’t freeze ?

Both the changes we can observe and the ones we cannot will affect the global state.

There are several atoms around you changing at a rate that you cannot describe or understand because it’s changing randomly, everywhere, all at once.

Every time the state changes we move forward in time, with a brand new version of the universe.

So the forwards flow of time is a by-product of the natural entropy¹ of the universe.

The thought experiment.

To shift time backwards, you have to reset the global state of aeons of data about the universe to the snapshot of it at the exact point in time you wish to travel into.

To travel back in time, you’d have to not only shift time backwards, you’d also have to merge yourself into the state and press play so that the changes can continue to occur from that snapshot onwards.

To shift time forwards, you would have to accelerate the changes and randomness and arrive at a new snapshot of the universe several trillions of iterations ahead.

All of these statements are results of thought experiments.

These explanations are not without flaw, though.

Problems

You cannot be a part of the state if you want to mutate it. If you try to meddle with state in some way (especially if you’re going backwards in time), your actions can have side effects on other pieces of the state and then it all gets tangled. This gives rise to paradoxes which is a whole sub-genre of time travel lore in itself.

If you tried to travel back in time, the act of you trying to travel back in time will be logged as a state change and be present in several trillions of universe snapshots.

This obviously leads to several unintended consequences.

Don’t mangle the state, bro.

It’s also currently beyond our limits of computation to store and keep track of the data required to travel backwards in time, at least if we’re going to attempt to do so the same way it’s depicted in time travel movies.

Just think about time as a big stack of data containing snapshots of the universe at various points in the past.

The snapshots closer to the top are probabilistic and that represents the rapidly unfolding present.

Seconds are a man-made concept that allows humans to reason about time a bit more effectively, but i wonder at what intervals snapshots are taken.

Only an entity outside of the universe can have access to this data and actually manipulate it.

In programming terms, we don’t have read-access to this data. And even if we did have read access, who’s keeping track of it ?

No one.

So yes, traveling back in time may actually break the laws of physics.

However, I don’t know enough about physics to credibly back up that claim.

Thank you for indulging me, I think time travel is such a fascinating concept.

Footnotes

1. Capacity to continue to change. ↩