Personal Science & Physics Technology

We have all the time in the world

My fascination with time travel has been with me for as long as I can recall. The very idea of being able to travel back through history and view distant events is something truly amazing and the stuff of wistful dreams.

Indeed, within Albert Einstein’s various seminal works at the turn of the last century, there is room for such ideas to not only exist, but to offer the tantalizing prospect of being achievable.

Before the age of eighteen, I’d already grappled with and come to understand the various logical paradoxes of time travel, long before any such problems had really been covered publicly or within any film I might have seen.

I’d realized that to move an object to and beyond the speed of light was clearly impractical, and that to do so would require some mechanism whereby the mass of the object would need to be removed somehow, or at least placed elsewhere for the duration for faster-than-light acceleration to become possible.

I’d learned that particles existed that had little or no mass and routinely passed through large stellar objects as if they weren’t there. So it seemed entirely logical at the time to imagine that man might one day harness this ability to shift mass and be able to move at great speed without hindrance.

Then – rather conveniently for the purposes of my novels – came along the idea of higher dimensions, which would help mitigate such ideas of offsetting mass, if only in science fiction and not scientific fact.

These ideas and others tend to swill around my head all of the time, among other things.

So whenever articles emerge discussing new ideas concerning time travel, I’m there like a moth to a flame .. only to get burnt when I’m to be told no, time travel isn’t ‘permissible’, or no, time travel isn’t ‘allowable’.

However, there is at least a debate, now. And more importantly, time travel is a serious subject for discussion, being pulled in from the fringes of science.

But why is this? Why is the topic of time travel relevant now?

Well, this is the centenary of Einstein’s Special Theory of Relativity, so it’s seemingly befitting. But there’s another need to keep a dialogue going.

The late astronomer and Pulitzer Prize-winning author Carl Sagan once said time to be: “one of those concepts that is profoundly resistant to a simple definition.”

“Time is really difficult,” said Cumrun Vafa, a Harvard string theorist. “We have not made much progress on the emergence of time. Once we make progress we will make progress on the early universe, on high energy physics and black holes.

Indeed, it seems an understanding of time is increasingly at the heart of understanding the very elemental mechanisms of the universe:

“Time is nature’s way to keep everything from happening all at once.”
~ John. A. Wheeler

Much of the recent debate regarding time travel revolves around the issue of ‘retroactive suicide’, whereby you, the protagonist in this piece, go back through time to kill your own father:

“Quantum behaviour is governed by probabilities. Before something has actually been observed, there are a number of possibilities regarding its state. But once its state has been measured those possibilities shrink to one – uncertainty is eliminated.

So, if you know the present, you cannot change it. If, for example, you know your father is alive today, the laws of the quantum universe state that there is no possibility of him being killed in the past.

It is as if, in some strange way, the present takes account of all the possible routes back into the past and, because your father is certainly alive, none of the routes back can possibly lead to his death.

“Quantum mechanics distinguishes between something that might happen and something that did happen,” Professor Dan Greenberger, of the City University of New York, US, told the BBC News website.

“If we don’t know your father is alive right now – if there is only a 90% chance that he is alive right now, then there is a chance that you can go back and kill him.

“But if you know he is alive, there is no chance you can kill him.”

In other words, even if you take a trip back in time with the specific intention of killing your father, so long as you know he is happily sitting in his chair when you leave him in the present, you can be sure that something will prevent you from murdering him in the past. It is as if it has already happened.”

While this seems sensible enough, the idea that the laws of quantum physics would somehow rise up to prevent your actions is fundamentally flawed and actually plays right into the hands of the creationists and the like, with all of the inherent baggage of free will and determinism, and every other philosophical argument to boot.

For example, if I were to lean towards the wall of my room, the wall would indeed stop me from falling onto the floor.

Now, if I take a pick-axe to the wall and set about gouging out a huge hole, then there’s no force to prevent me.

So the same can only logically be true of traveling back through time to kill your father.

The laws of physics cannot possibly know of my intentions, to do so would imply the hidden hand of some higher force or intelligent power being able to see my intentions and thus thwart my efforts.

This is clearly not the case. So in actual fact, there cannot be any force in the universe to prevent me from killing my father in the past.

However, because of the rules of causality, for every action, there is a consequence, however small or large.

At this point, the moment the life force of my father dims and then vanishes, the forces of the universe would indeed rise up and begin the process of doing whatever it is that they must do to correct the timeline.

So how exactly would this correction manifest itself?

I’m working on that.

I’ll figure it out, just give me some time…

By Wayne Smallman

Wayne is the man behind the Blah, Blah! Technology website, and the creator of the Under Cloud, a digital research assistant for journalists and academics.

7 replies on “We have all the time in the world”

I gave up trying to get my head around this about the same time I gave up trying to decide if the universe is infinite or not.

The conclusion I came to (which serves no purpose other than to stop my headaches) was that it may well be possible to go back in time but you’d be invisible and you wouldn’t be able to interact with any object, just like Al Calavicci in Quantum Leap. The flaw in this is that if you couldn’t interact with anything then surely you’d just sink through the ground.

I feel a headache coming on …

There are other problems.

For example, right now, your body is made up of a great many atoms that have probably existed since the dawn of time.

Now, if you go back in time, to any point in time regardless of how far back you travel, you’re plunging the very atoms of your body into a period where those self same atoms exists elsewhere.

What are the consequences of this?

I imagined that this would be a great problem, and a pretty dangerous one at that.

Indeed, some years later, the film Time Cop, staring Jean-Claude Van Damme Covered that very topic…

There is no violation of causality if a way could be found to ‘see’ past events, without actually visiting the past. But there is no way you can travel back in time without violating causality. Even if you are invisible, if you wish to capture any information by seeing/hearing, you are interacting with the past, and hence possibly changing history.

I remember reading about how simply observing the motion of atoms affects them.

And then I’m also reminded of an old adage: a watched kettle never boils.

How true that is.

One of the more inspirational books I read whilst at school was a fictional account of a bunch of guys who travelled back in time to hunt dinosaurs.

The idea being that they hunted down an animal moments before it’s ‘pre-determined’ death.

In one instance, as they fell the beast, a tree then falls onto the dead animal, which would have killed it anyway.

However, on one hunt, one of the guys steps off the designated path and into the silt and mud surrounding them.

On returning to the present, no only is there a very different man as President of America, but the English language itself is different, along with a great many other things.

When the man disrobes, he finds a small butterfly embedded in the sole of his mud-caked boots.

That alone was the catalyst for all of the changes.

The death of one single butterfly millions of years ago gave rise to enormous changes in the present…

Of course Wayne, there’s the possibility that this HAS ALREADY HAPPENED. Someone could have travelled back in time and we might already be living in that altered state.

My theory: If you travelled back in time to a point before you were born and killed your father, then there’s no way that you could return to your present. You’d be trapped in the past as there’s no place for you in your present.

Hi GW and thanks for posting!

“My theory: If you travelled back in time to a point before you were born and killed your father, then there’s no way that you could return to your present. You’d be trapped in the past as there’s no place for you in your present.”

Yes, that’s a distinct theory and I think I covered that above. But seeing as though I can’t be bothered to read through my own post again, I’ll give you the gold star for mentioning it and I’ll take the wooden spoon for being lazy…

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