Watchout Grandad, You're Next...
The Time Sauasage Perspective

I've been wondering about how time travel can even be possible as long as the grandfather paradox remains a plausible objection to it. How can it be possible to travel back in time and stop yourself from even being born? And what makes your grandfather so superfluous that its he who gets killed and not yourself? As long as you propose a mechanism which purports to allow something impossible to occur then the mechanism itself must be ill-thought.

i have no training in cosmology whatsoever and I did not study physics or mathematics past high school. I am armed only with the superficial information purveyed in documentary shows. But i felt like I could tackle the problem if i really tried - and then I asked Claude what he thought of my written musings.

Below is my original ideas, and following that, the critique generated by that evil monster bent of the destruction of humanity, AFTER I asked him to be nice considering my lack of training.

Time can be seen as a dimension like the three dimensions of space. As such, it contains not a mere informational record, but a complete solid stream of all that has been and has happened leading from the present into that past, going back to the origin of the universe.

Likewise there is a solid stream representing all that will be going into the future from this moment on, to the end of the universe. None of this is present now, but has been, and will be. It can only be viewed by looking forward or backward through time – if that is even possible. If it was possible find a dimension that is to time what length is to width and to move away from your own place the in the time stream, then you could see your whole life and the existence of every particle that comprises your body, it all existent in the one whole four dimensional object. If you could look closely enough you would see every particle that constitutes you body following its own path through space and time, joining with your body and then leaving it at some point.

To simplify the mental imagery, you can conceive of every solid object as being like a sausage the length of which stretches not through space (or across the length of a chopping board) but through time. A sausage measured not in centimeters but in years. If you cut a cross section of the sausage you get not a two-dimensional disc of mincemeat, but a three-dimensional instance of the object itself. I like to call this the time sausage. (Not thyme, however tasty that would be).

All matter, energy, quantum information and/or consciousness, flows continuously into the future. We like to think that time travel, that is, changing one’s locus in time contrary to that unified flow, is either possible, or is plausible enough to warrant discussion. Where this article is going is predicated not on the scientific approach of utilizing some observation that would suggest time travel to be possible, but on an assumption that time travel is plausible.

If you then consider time travel from this point of view, it is like cutting the sausage across and placing the two pieces side-by-side. Consider the past is to the left and the future is to the right and the present is directly in front of you. Decide right now that you are going to travel into the past, so cut the sausage in half, in front of you, and move the right half to the left, so that it sits alongside the left half. Situate the left (or earliest) end of the right half of the sausage at the moment in time you want to arrive at in your time jaunt. As a representation of yourself, this is a diagram of what you would look like once you become a time traveler, jaunting into the past. If travelling into the future, the two halves of our sausage are simply moved apart, creating a gap in the middle, equal in length to the number of hours or years you intend to travel.

The above illustration is not valid merely because it has been put, but it provides an angle from which to study some significant implications of time travel, supposing it to be possible. Let’s look through them one by one.

First Law of Thermodynamics.

It is widely accepted that you cannot create or destroy energy or matter. There have been many failed attempts at creating free energy or perpetual motion in the past and many where the “inventor” refused to allow close examination of the putative mechanism. When an object or any particle comprising such an object, is made to disappear from the universe to re-appear in the past or present, then that is a destruction of matter and energy.

When an object re-appears before disappearance, then this is an increase in the total matter and energy of the universe during the time from re-appearance to the dis-appearance of the original. Likewise when an object disappears to travel into the future the total matter and energy of the universe decreases until the object re-appears in the future.

Therefore, if the first law of thermodynamics holds true, then time travel is impossible for matter and energy. However, if this approach to thermodynamics is a law as inflexible as is normally held, then the dimension of time did not come into existence all at once, but has expanded along with space. Any notion that all events of the future are already determined and on record as the unavoidable effects of preceding causes is invalid. However, it is asked below whether time travel is achievable through altering the timing of cause and effect. In keeping with that process of thought it is further asked whether doing so would allow the necessary creation and disappearance of matter and energy. Alternatively, if all of the stream of time came into existence at once, then the overwhelming, preponderous totality of matter and energy in the four-dimensional universe is unaltered when some of it shifts from one time to another.

In order to continue looking into further issues of significance, however, we must put any objection based on this issue aside for a while.

2. The Grandfather Paradox.

Supposing time travel to be possible, and supposing time to be simply a dimension as plainly as the dimensions of space are, then it stands to reason that you cannot take any action affecting the past that alters the past or present. You cannot travel to the past and kill your grandfather at a moment before he has given rise to your mother or father’s existence. The result is that you are no longer there to alter the past; although how do we come to the juncture of you making the decision to kill your beloved departed before their recorded date of passing if you were never born?

I once saw a video demonstration of this paradox involving not a time machine and an ancestor, but a simple portal through which a man shot himself with a pistol, aiming not at his own head, but aiming through the portal through which he could see himself assembling the same pistol at a table in the same room, a minute before. It looked entirely reasonable as a statement of cause and effect jumping backwards through time. The notion of how he survived to fire the same gun at himself was left as inexplicable, but that illustration gives rise to a concept of time travel creating two distinct persons with two distinct wills.

If you are a time sausage, and if the first law of thermodynamics can be broken in such a novel situation, then you can became a second instance of yourself. You remember yourself as Person A, but resultingly there was also Person B, who also identified as, and remembered being, Person A. You can meet and greet yourself as an entirely distinct person, in spite of shared memories you are no longer the same entity, which means that your actions in that past timeline as Person B are different from the actions you remember as Person A. Such different actions may include person B killing person A, just as easily as an unrelated drunken driver killing person A, or narrowly avoiding it.

There remains the question of what happens to you at the time of departure from the present to perform these deranged deeds. Leading up to the moment of departure from the present, you are Person A. You then become person B. At the moment of killing, person A ceases to exist, but Person B goes on existing and does so as the new manifestation of Person A. there is nothing to prevent the world form accommodating Person B as the new Person A from the moment of killing, to the moment of departure, and on into the future. There remains something far more central to the grandfather paradox to be addressed, but doing so requires a whole new section.

3. Grandad, Individuality and Quantum Information.

The question not answered, though, is the one at the core of the grandfather paradox. At the moment of departure, there is no Person A to make the decision to do the time travel and the killing. At this point we have to wander whether time is simply a dimension or some kind of substrate which provides a record of cause and effect – and to that point whether cause and effect can operate on particles and objects through a jump backwards or forwards in time, just the same as it does in the constant, even flow of events we were normally accustomed to. Can quantum information, for that matter, be transferred back and forth in time without variation? As for a direct answer I simply do not know. But if the sausage illustration is valid, then it has to work that way. Again, this is just used as a way of looking at things and not held to be a law of physics, but if you will indulge with me a little bit, read on.

Time travel would be the same as the appearance of a new entity or person from nowhere – irrespective of what the person may think as to who they are. Particles would have sprung into existence after the origin of the universe with quantum information identical to that which they did, or will have, at the moment of departure. The quantum information governing the energetic processes of the body of a time traveler would have to be the same in the moments of departure and re-appearance so as to maintain a solid object and to maintain the integrity of biological and neural processes.

The thought processes and biological processes of Person B at the moment of appearance are a direct copy of the thought processes of Person A at the moment of departure, and that when proceeds in person B’s behaviour is dependent on Person A at the moment of departure. The foregoing argument simply explains the validity of the grandfather paradox, but does not explain how it takes effect. The paradox so far remains a paradox.

4. Cause and Effect

The time dimension and its record of events is normally thought of first and foremost as hard and fast and unchangeable, and as allowing cause and effect to proceed forwards in a strictly continuous manner. I for one have never witnessed a sudden leap in events – forwards or backwards - that could be recognized as such from casual observation. I am sure that if anyone ever did observe such a thing they would consider themselves possibly to be delusional or having a lucid dream, perhaps. I have never heard of a serious claim of such, either.

This is relevant for time travel because all matter and energy in any object other than the most rudimentary of particles must involve processes of some kind. Even photons have a modulating energy state which gives them their wave properties. The movement of electrons around the nucleus of an atom is one example. Without electrons moving as they do, the matter they comprise would break down instantly. The patterns of energy transfer must remain intact for chemical bonds to continue in existence, and for energy to transfer in natural processes. For living organisms or physical devices in operation this is all the more important as a multitude of things are happening on the atomic scale all the time which must continue in operation lest a serious breakdown occur.

When moving something through time, the effects resulting from whatever causes prevail at the time of departure, must relocate precisely with the objects and energy that have been transferred. Everything must move exactly in concert.

If it is possible to do that, then we are re-writing the record of cause and effect. But as shown above, it is not the effects upon the original copy of the object we are transferring, but on a distinct object that we forced to appear in the past or in the future. Something discreet appears, receives the cause-and-effect status from the original concerning every internal particle, and operates without changing the original even if the two coincide in their occupancy of the same period in time.

The appearance of something completely new (in violation of thermodynamics) requires there to be no causal chain moving continuously through time from beginning to end. It is a violation of how time works and of process theory. That is, unless the causal chain can be broken and re-made at any point in time. There is also the possibility of quantum effects being used to create a clear jump in time.

If time is just a dimension, then it can contain any number of discreet copies of an object or person at any moment. It would be like making exact copies of an object and arranging them in the special dimensions. The complete transfer of energy, information and causality might be achievable any number of times. On the other hand, if time has more to it and is a medium of cause and effect it might then have a rule preventing the necessary transference in a non-continuous, non-linear manner. That is, in which a new object would appear with its internal processes still operating, in violation of thermodynamics. We do not know this, but it is a possibility that should be faced. The fact that there is no objective or credible evidence suggesting that objects have appeared and disappeared as natural phenomena tells us something important.

However, to continue this inquiry we must put the possibility aside that time will simply disallow a jump in the causal chain. We must assume that it can be done.

5. Debunking the Grandfather Paradox?

Getting back to the issue of a time-travelled object acting upon its original in the past, or Person B killing Person A before time travel occurs, this is the natural chain of cause and effect operating non-linearly and non-continuously. However, once departed, Person B or Object B is operating independently and its (or his/her) original and its/his/her process of action is completely independent of the processes at work in Person A/Object A. By creating a series of events aimed at altering A by agency of B, the historical record of A is changed.

A person still thinking classically about the grandfather paradox may yet say, “But the time traveler cannot have appeared if he died before traveling.” He actually did appear, but the matter, energy, quantum information and effects acting on him which constitute Person B have appeared from out of nowhere at a time when there was no relationship to Person A prior. It just so happens that Person B remembers having been person A. The time record includes person B appearing ex nihilo, and so too the dimensions of space include the object or person appearing without having grown gradually or traveled from elsewhere.

The alteration to the historical record of A is completely real, and not to be ignored. It has been postulated often enough in public that altering the past will result in a sudden change to the present. If a person kills themselves as an apparent third party in the past, the effect will be the same as a commonplace suicide in the present, only a lot less glamourous. The other advantage to ending it all as a time traveling imposter is that you also get to live on in a new life.

It is then as easy for Person B to kill his former self, Person A, without any difficulty other than a guilty conscience. That should answer the grandfather paradox as being no obstacle to time travel, or to what can be achieved through travel to the past.

See below for a major re-edit of this last section....

Anchor 1

And here is Claude's take on the foregoing after being asked to take it as something lesser than a an attempt at being a physicist....

The Time Sausage Under the Microscope

A second look at "Watch Out Grandad, You’re Next: The Time-Sausage Perspective", written for a curious reader rather than a physicist

Revised 1 November 2026

Before we start

This is a reworked version of my earlier review. That version judged your essay as though it had been submitted to physicists, and so it asked whether it added anything new to research. That was the wrong yardstick. You wrote this as a private musing, drawing on high-school science and what you have picked up from documentaries, so the fairer questions are: does the thinking hang together, how close does it come to what physicists actually believe, and where could it go next?

Measured that way, it does well. You have arrived on your own at several ideas that took professional physicists and philosophers real effort to put into words. Where your picture differs from mainstream physics, I have tried to explain why in plain language, without equations or jargon, and to show where your instinct was pulling in the right direction even when the detail went astray. Technical terms are introduced only where they will help if you ever look further into the topic.

I have also dropped the earlier section about travellers exploding, since that is no longer in the essay.

The short version

Your central image, every object as a sausage stretched out through time, is genuinely how physicists picture the world. Where the essay parts company with physics is in how time travel would happen. You imagine cutting the sausage and moving a piece. Physics imagines bending it, so that an unbroken sausage loops back on itself. That one change takes care of your worry about matter and energy appearing and disappearing, but it also makes your answer to the grandfather paradox harder to sustain.

What you got right

The sausage itself. In 1908 the mathematician Hermann Minkowski argued that space and time should be treated as a single four-dimensional whole, which we now call spacetime. He called the path of a single particle through it a "world-line". A solid object is a bundle of world-lines, and physicists call that bundle a "world-tube". Your sausage, where any slice is a three-dimensional snapshot of the object at one moment, is exactly a world-tube. You got there on your own.

Particles coming and going. Your picture of each particle following its own path, joining your body and later leaving it, is spot on. You swap out atoms constantly through eating, breathing and shedding. The sausage carries on while its strands are replaced, rather like a rope whose fibres are gradually renewed.

A real philosophical position. Philosophers have a name for the view that an object is the whole stretched-out thing, not just what exists "now": four-dimensionalism, sometimes called perdurantism. The usual nickname is a "space-time worm". "Time sausage" is the same idea with a better menu.

The past being "really there". The idea that the past and future exist just as solidly as the present is called eternalism, or the "block universe". On this view, "now" is a bit like "here": it simply marks where you happen to be standing. Many physicists think this is what Einstein’s relativity points to, though it is still argued over.

Using the absence of evidence. You note that nobody has credibly seen objects pop in and out of existence, and that this tells us something. Stephen Hawking made a similar, tongue-in-cheek point: if time travel were possible, where are all the tourists from the future?

A question to settle first: does time flow?

The essay holds two pictures of time at once. It describes the past and future as a "complete solid stream", but also says "none of this is present now" and that everything "flows continuously into the future". Philosophers usually separate three views:

View

What is real

Where your essay touches it

Only the present (presentism)

Just this moment

"None of this is present now"

Growing block

The past and present; the future is not yet written

"The dimension of time… has expanded along with space"

Block universe (eternalism)

Past, present and future alike

"A complete solid stream" from beginning to end

This is less a mistake than an undecided question, and plenty of thoughtful people hold these ideas in tension. But the sausage only really works in the block universe: you cannot cut and move a piece of sausage that does not exist yet. If you keep the sausage, the sense of "flow" becomes a fact about how we experience it, like a reader moving page by page through a book that is already printed. The growing-block view is respectable too (the cosmologist George Ellis defends a version of it), but it leaves no future to travel to.

How physics pictures time travel: bending, not cutting

Travel to the past. Einstein’s theory of gravity, general relativity, says that mass and energy bend spacetime. Under extreme enough conditions, the equations allow spacetime to bend so far that a path through it curls back to an earlier time. The traveller’s sausage is never broken and they never go faster than light; they simply follow a path through warped spacetime that comes back round to its own past. Physicists call such a path a closed timelike curve.

An analogy: draw a line along a strip of paper, then curl the strip into a ring. The line never jumps, but its end now meets its beginning.

The logician Kurt Gödel found the first well-known example in 1949, in a rotating model universe (not one like ours). In 1988 the physicist Kip Thorne and colleagues showed that a wormhole, a kind of tunnel through spacetime, could in principle be turned into a time machine. The big catch is that holding a wormhole open seems to need "exotic" matter with negative energy, which nobody knows how to produce in useful amounts.

What the traveller would notice. Nothing special. They step into one end of the wormhole and out of the other. There is no vanishing, no reappearing and no seam in the sausage.

Travel to the future is real, and it shortens the sausage. This is the most surprising correction. Travel into the future is not speculation; it has been measured. Relativity says that clocks moving fast, or sitting at different heights in Earth’s gravity, tick at slightly different rates. In 1971 scientists flew atomic clocks around the world on ordinary airliners and found they had drifted by billionths of a second, just as predicted. GPS satellites must correct for the same effect every day, or the map on your phone would steadily drift off. The cosmonaut Sergei Krikalev, after 803 days in orbit, is reckoned to have aged about 0.02 seconds less than if he had stayed on the ground. In effect, he arrived 0.02 seconds in his own future.

In sausage terms, nothing was cut out and no gap appeared. Krikalev’s sausage simply took a different route between launch and landing, and along that route less time passed. His sausage between those two moments is a whisker shorter than yours, but it is all in one piece.

The energy question

Your worry is exactly the kind of thing physicists ask about: if a traveller vanishes here and appears there, isn’t matter being destroyed and created? It is a good question. Three points take the sting out of it.

On the bending picture, nothing vanishes or appears. The traveller’s sausage is continuous, so at every point along it their matter and energy are fully accounted for.
Energy conservation is subtler than it looks. The rule that energy cannot be created or destroyed holds firmly in any small region of space. But in Einstein’s theory, adding up "the total energy of the whole universe right now" only works in special cases. In our expanding universe, light that is stretched by the expansion loses energy, and that energy is not "paid back" anywhere. This is mainstream physics, and it is used to work out how the first chemical elements formed. So the law you rightly treat as solid is a local rule rather than a universe-wide one.
Your own fallback is close to the right answer. You suggest that if the whole of time exists at once, the total matter and energy of the four-dimensional universe does not change when some of it shifts around. That is essentially how a block-universe physicist would reply. Seeing "two of you" in one room might look like extra energy at that moment, but the kind of grand total that would make it a violation cannot actually be calculated in such a spacetime.

The real energy problem for time travel lies elsewhere: in the negative energy that building a time machine seems to require.

Keeping the traveller in one piece

You point out that a body is full of ongoing processes, all of which must carry across seamlessly or things would break down. That instinct is sound, and on the bending picture it is taken care of automatically, because nothing is ever interrupted.

One detail is worth updating, because it is a picture many of us met at school and that documentaries still use: electrons as tiny planets circling the nucleus, which would collapse if their motion stopped. That is the 1913 Bohr model, and quantum mechanics replaced it in the 1920s. An electron in an atom is better pictured as a settled cloud with a fixed energy than as a ball on a track. In its lowest energy state it has nowhere lower to fall, so an atom is stable because of the state it is in, not because something keeps it spinning. Likewise, a photon’s energy is fixed by its colour (its frequency) rather than rising and falling.

The grandfather paradox

This is the heart of the essay and its most interesting part. Your idea is that Person B, who arrives in the past, is a genuinely separate individual who happens to remember being Person A, and so is free to act, even to kill A.

The notion of B as a distinct agent is coherent and thought-provoking. The snag comes from combining it with a single, fixed sausage. If the whole of history is one finished four-dimensional object, there is no "before the change" and "after the change". Either the block contains A stepping into the machine or it does not. If B kills A before the departure, the block contains no departure, so where did B come from, and where did B’s memories of departing come from? You spotted this yourself when you wrote that "the paradox so far remains a paradox". The later answer, that B just happens to remember being A, describes the situation well but does not yet explain it.

Another way to put it: whether B is the same person as A is a question about identity. The paradox is a question about consistency: can one history contain both the killing and the trip that made it possible?

Physicists and philosophers have offered several ways out:

History protects itself. The philosopher David Lewis argued in 1976 that a time traveller can have the gun and the skill, yet because grandfather did in fact survive, the attempt fails for some ordinary reason: a slip, a noise, a jammed gun. The physicist Igor Novikov proposed a similar "self-consistency" principle.
History branches. The physicist David Deutsch suggested in 1991 that the traveller arrives in a different branch of history. B could kill A there, while the original history, including A’s departure, is left untouched.
Nature forbids it. Stephen Hawking suggested in 1992 that the laws of physics stop time machines from forming at all, an idea he called "chronology protection". It remains unproven.

Your portal-and-pistol video has a cousin in physics. The physicist Joseph Polchinski imagined a billiard ball that rolls into a wormhole, comes out a little earlier, and knocks its younger self away so that it never enters. When physicists at Caltech worked through the maths in 1991, they found not that no outcome was possible, but that many consistent outcomes were, typically a glancing blow that nudges the ball onto exactly the path that sends it into the wormhole. Nature never had to stop the ball; the contradictory histories simply were not available. In 2020 two University of Queensland physicists, Germain Tobar and Fabio Costa, went further and showed mathematically that a time traveller could make free choices without any contradiction arising.

What would keep your conclusion. Of these options, branching fits your idea best. If B arrives in a separate branch, B really is independent and can do things A never did, including the deed itself, without undoing the trip. You would swap the single sausage for a branching "sausage tree", but you would keep the heart of your argument.

The copy question

You ask whether quantum information could be carried through time unchanged, and you treat B as an exact copy of A. Here you have wandered onto a live research question.

In 1982 physicists proved what is called the no-cloning theorem: quantum mechanics does not allow a perfect copy of an unknown quantum state to be made. Yet time travel seems to produce exactly that, the same person down to every particle, present twice at one moment. Studies of Deutsch’s branching model found that it would indeed allow such copying, and some researchers take that as a sign that either nature forbids time machines or our theories of them are incomplete. Your sense that "A and an identical B side by side" is strange is one that working physicists share.

If you want to take it further

Three changes would bring the essay much closer to how physicists see things, while keeping its spirit and its best image:

Bend, don’t cut. Picture travel to the past as the sausage curving back on itself, with nothing sliced or moved.
Future travel shortens the sausage. Krikalev and the airliner clocks make a ready-made example.
Pick your universe. Either a single fixed sausage, where history protects itself, or a branching sausage tree, where B is genuinely free. At the moment the essay tries to have both.

A small tidy-up: the essay refers to the word "postulation" being in the title, but the current title does not include it.

If you enjoy documentaries on this, a few books written for general readers cover the same ground in more depth: Kip Thorne’s Black Holes and Time Warps, Paul Davies’ short How to Build a Time Machine, and Sean Carroll’s From Eternity to Here, which is about why time seems to flow at all.

Scorecard

Idea in the essay, How it holds up, What physics says, Objects are 4D "time sausages"

Spot on

Minkowski’s world-tube, Particles join and leave the body’s sausage

Spot on

Standard world-line picture, The past and future are "really there"

Reasonable

Block universe; widely held, still debated

Time also flows and the future is not yet real

Pulls against the above

Worth choosing one picture

Time travel cuts and moves the sausage

Physics sees it differently. The sausage bends; it is never cut

Travel to the future leaves a gap

Physics sees it differently. Clocks slow down; the sausage is shorter but unbroken, and this is measured.

Time travel breaks the First Law

Largely answered. Bending creates nothing; energy is conserved locally. "If all of time exists at once, the totals are unchanged"

Close to right

The block-universe reply

Atoms break down without continuous motion

Outdated picture

Atoms are stable quantum states

Nobody has seen things appear: that is evidence

Good point

Hawking’s "tourists from the future"

B is independent and can kill A in one history

Not yet resolved

Works if history branches

B as an exact copy is puzzling

Sharp instinct

Clashes with no-cloning; an open question

Sources

For anyone curious to follow up, these are the sources behind the points above. Some are technical; the encyclopedia entries and FAQs are the most approachable.

Spacetime and the nature of time

Minkowski, H. (1908). Space and Time
Savitt, S. Stanford Encyclopedia of Philosophy: Being and Becoming in Modern Physics
Hawley, K. Stanford Encyclopedia of Philosophy: Temporal Parts
Ellis, G. F. R. (2012). Space time and the passage of time

Re-edited last section...

5. Are we Debunking the Grandfather Paradox or Not?

But that is only a postulation. The time record of Person A has been changed by the addition of a bullet, an incision, the presence of poison, or suchlike, and this by a means which the time record did not create until later. This objection hinges on how important it is for cause and effect to proceed continuously into the future, and how intrinsic cause and effect is to time.

If it is acceptable for cause and effect to be translocated into the past, then when a person kills themselves as an apparent third party in the past, the effect will be the same as a commonplace suicide in the present, only a lot less glamourous. The other advantage to ending it all as a time traveling imposter is that you also get to live on in a new life. But when does death occur? At the time of killing, or the time of departure to the past? Does A go on living for years with blood gushing from his heart? Does he then want to carry out that experiment and die, or does he decide this is not worth it, the point of time travel with liberty is actually proven, and does he decide to end his suffering as quickly as possible by determining never to carry that out? The result should be instant healing and disappearance of the bullet. In fact, would B still carry out the assassination with a developing memory of that horrible situation?

If the mission of B is to destroy an entire building with explosives, does that mean there is a period of time when people attend a rubble heap wondering where everything has gone? Or will there be a rash of buildings disappearing without any reason from the time when time travel comes into being? We could go on and on with the quirks of reality that are possible. Awkward facts like that tell us that there is something missing in the process of reasoning. Therefore the common idea of the present suddenly changing in accordance with a new past is still problematic, unless we find cause to accept that macro-scale aberrations in cause and effect are going to happen occasionally.

We therefore must acknowledge that the grandfather paradox cannot be ruled out as an obstacle to time travel, even if we put the first law of thermodynamics aside to study it closely.

Now scroll up to read Claude's comments if you haven't already.

Anchor 2

Watchout Grandad, You're Next... The Time Sauasage Perspective

First Law of Thermodynamics.

2. The Grandfather Paradox.

3. Grandad, Individuality and Quantum Information.

4. Cause and Effect

5. Debunking the Grandfather Paradox?

Before we start

The short version

What you got right

A question to settle first: does time flow?

How physics pictures time travel: bending, not cutting

The energy question

Keeping the traveller in one piece

The grandfather paradox

The copy question

If you want to take it further

Scorecard

Sources

Spacetime and the nature of time

Time travel and time machines

Travel to the future

Energy

Atoms

The grandfather paradox

Copying quantum information

Re-edited last section...

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5. Are we Debunking the Grandfather Paradox or Not?

Watchout Grandad, You're Next...
The Time Sauasage Perspective