Tag: Grandfather Paradox

Book Review: ‘Recursion’ by Blake Crouch      

We all know that our memories are to a large degree who we are. All of our loves, and hates, all of our opinions are formed from past experiences that are stored in memory. I suppose that’s why stories, real and fictional about people with amnesia are so popular. And then there’s always the idea of reliving a memory, of going back to either enjoy once again the best time of our life or perhaps to fix some mistake we made in the past.

The process of remembering something is actually a very complex mechanism involving many different parts of our brains! (Credit: Pinterest)

That last notion is the idea behind ‘Recursion’ a recent novel by Author Blake Crouch. Barry Sutton is a New York City Detective who is investigating a suicide that is linked to ‘False Memory Syndrome’ (FMS) a rare condition where a person suddenly acquires complete and detailed memories of a life they never lived, a mental jolt that causes many of them to kill themselves. Helena Smith is a neuroscientist who is trying to develop a method of recording memories in the hopes that it will lead to a treatment for Alzheimer’s disease, which her mother is beginning to suffer from.

Cover art for ‘recursion’ by Blake Crouch. (Credit: Penguin Random House)

Turns out that what Doctor Smith has invented is a time machine, a way of literally going back into a memory in order to change the past. One interesting thing about the time travel in ‘recursion’ is that making the jump requires the release of the strong hormones that accompany death. In other words you have to die in the present in order to pop back into one of your memories. And if you do change the past those people whose lives you’ve altered will suddenly acquire the memories of their original lives when time progresses to the moment when you used the time machine to pop back, that’s the FMS.

Author Blake Crouch. (Credit: Goodreads)

Now the physics of time traveling through memory in ‘Recursion’ is never really explained and the ‘Grandfather Effect’, the logical loop where you go into the past and kill your grandfather as a boy so you are never born so how can you go into the past to kill your grandfather, is barely mentioned. That said once you accept the rules of time travel in ‘Recursion’ the novel is tightly written and very well thought out.

The Grandfather paradox is a logical absurdity that stories about time travel have to deal with, although many simply choose to ignore it. (Credit: Medium)

Doctor Smith’s research is funded by one of those techno-billionaires named Marcus Slade who somehow seems to understand the full capabilities of the machine before Helena does. Slade is the first to try to exploit the possibilities of time travel but it isn’t long before the DoD gets involved and when the technical information for the machine gets hacked there are soon a dozen different entities trying to impose their preferred version of the past and reality itself begins to crack under the pressure of multiple pasts.

Have you noticed how techno-billionaires have become to stock villains of choice in Hollywood lately? I wonder how that got started? (Credit: (l to r) Salon, The Ringer, Timeslive)

I won’t go any further but the breakdown of time itself, along with Helena and Barry’s attempts to fix it are very well written. It fact the whole of ‘Recursion’ is very well thought out and composed.

In Some Time Traveler stories the problems of changing the past are integral to the story. (Credit: Ranker)
Other Time Travel stories are more about the societies that the Time Traveler encounters. (Credit: American Literature)

I do have a couple of very minor complaints. First of all the use of a techno-billionaire as the villain is becoming trite even if Blake Crouch does put a nice twist on him. Second, the novel was written around 2018 and the main action of the story, the breakdown of time occurs in 2018 so it’s already not happened! I would have placed the story at least a few years in the future, say 2028 in order to not have the problem of time making it false even as it was being published.

Despite all of the dangers of Time Travel can any SF fan say they wouldn’t like to take a ride on a Tardis? (Credit: Giant Freaking Robot)

Other than that I cannot recommend ‘Recursion’ strongly enough. This is one of the best time travel stories I’ve read, right up there with Wells’ original ‘Time Machine’ and Bradbury’s ‘The sound of Thunder’. If you like Science Fiction in general you will certainly enjoy ‘Recursion’ but if you like time travel stories you absolutely have to read it.

Is Time Travel Possible? Two Physicists from the University of Queensland think it is.

If you think about it, over the last four hundred years humanity’s growing science and technology has given us an enormous amount of control over many aspects of nature. The speed and distance we can travel has steadily increased, as has both the size and number of structures we can build. We grow more food than ever and whether we like it or not we are even changing the weather. Can you say climate change! We have discovered the very code of life itself and begun to understand how to alter and mold living things to suit our desires. We now have many ways of controlling space and material objects that would seem like magic to our ancestors of a thousand or more years ago.

Thanks to our control over Nature we have been able to build ourselves a world completely unlike anything in Nature. (Credit: Invisiverse)

But we still have virtually no control over time. Oh, we can measure it’s passing with an accuracy that, at the risk of repeating myself, is almost magical.  We can’t stop time of however, and although Einstein’s two theories of Relativity do describe how the passage of time can be slowed that slowing requires either velocities approaching the speed of light or immense gravitational fields such as those around black holes.

A modern Atomic Clock is accurate to something like one second in a billion years. Scientists can use that precision to make measurements of phenomenon that last only a billionth of a second. (Credit: WatchPro USA)

And even theoretically we can’t go backward in time. In fact many scientists have steadfastly maintained that time travel to the past is logically impossible because of something known as the grandfather paradox.

What is the grandfather paradox? Well it works like this. What if you were to travel backward in time and murder your grandfather before he fathered your own father? In that case you would never have been born and if you were never born how could you go backward in time to kill someone?

In the Grandfather Paradox the very existence of a Time Machine leads to a Logical Absurdity. (Credit: YouTube)

This idea of the dire consequences to the present of doing anything in the past has been the central idea in many Science Fiction stories like Ray Bradbury’s ‘The Sound of Thunder’ as well as movies such as ‘Back to the Future’. Many scientists feel that the logic of the grandfather paradox is so tight that traveling into the past is simply a pipe dream better left to science fiction writers.

In Ray Bradbury’s ‘The Sound of Thunder’ hunters travel into the past to hunt a T Rex. Despite their best efforts they change the past, changing their present! (Credit: Deviant Art)
In ‘Back to the Future’ the same idea is used for humour as Marty has to repair the damage he’s done to the past or he’s a goner! (Credit: Universal Pictures)

Still theoretical physicists and mathematicians looking for solutions to Einstein’s field equations occasionally came up with equations that, while physically hard to interpret seemed to include the possibility of going backward in time. Collectively these solutions are known as ‘Closed Timelike Curves’ or CTCs and where initially discovered back in 1937 by Jacob van Stockum and later extended by Kurt Gödel in 1949. Basically a CTC describes the movement of a material particle that loops endlessly through time and space in a circle. This would imply that the existence of a particle following a CTC would be extremely limited in both time and space.

Every observer exist at a single point in space-time. Since nothing in the Universe can move faster than the speed of light that observer can only be effected by events within his Past Light Cone while he can only effect events with his Future Light Cone. (Credit: Wiktionary)
Under Certain conditions however, such as near a black hole, a light cone can be tilted. Continuous tilting results in a Closed Timelike Curve. (Credit: SlideShare)

Physically it is hard to understand how any particle following a CTC could interact with other more normal particles. Such a path in Space-Time would seem to imply the possibility of events happening without causes since to the normal particle the CTC particle can appear to pop into existence without reason. At the same time to an outside observer a particle inside a CTC might appear to experience an event before its cause!

Because of such paradoxes many physicists expect, or perhaps hope that an eventual unified theory of gravity with quantum mechanics might eliminate CTCs as even being mathematically possible. Other physicists however prefer to try to make sense of these weird solutions to the field equations.

One of those physicists is Germain Tobar, a student at the School of Mathematics and Physics at the University of Queensland in Australia. With the assistance of his colleague Dr. Fabio Costa, Tobar has analyzed CTCs in such a way that he maintains opens up the possibility of time travel into the past.

Germain Tobar (r) with his advisor Dr. Fabio Costa. (Credit: News.Com.au)

But what about the grandfather paradox? What about the problem of actions in the past changing the present? Well in Tobar’s analysis what happens if you were to try to change the past then the universe would react so as to avoid the paradox, to repair the damage you have caused in other words.

I won’t go into the math. (Actually I am going through the Math, trying to remember what I learned in my course in General Relativity but I won’t impose it on you.) However, it appears to me that in Tobar’s treatment if you were to go into the past and kill your grandfather then when you returned to your present you would find yourself with a different grandfather or something equivalent. Sounds to me kind of like what Marty and Doctor Brown did to repair things in ‘Back to the Future’ except that this repairing would occur naturally, automatically.

I have to admit I have real problems with that idea. Remember, the past starts just an instant ago! What if you were to step into a time machine and go back ten minutes and murder yourself just as you’re stepping into your time machine? I’m sorry but I can’t imagine how the Universe could repair that damage, how it could change things so much so quickly in order to somehow avoid the paradox!

Maybe it would work something like this? (Credit: xkcd)

Time Travel would be the ultimate power, the ability to undo all of our mistakes, to right all of the wrongs we’ve done. Perhaps for that very reason it is the one power that will always elude us.