Monthly Archives: September 2017

Logic and Reasoning

#204: When the Brakes Fail

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This is mark Joseph “young” blog entry #204, on the subject of When the Brakes Fail.

It happens all the time in movies and television shows:  someone is driving, and someone has sabotaged the car so that the brakes don’t work, and frequently, too, the accelerator gets stuck so that the car is now out of control and headed for a major accident.  I have seen it enough times that what bothers me is the number of ways of slowing or stopping a car that they don’t try.  I have not been in the kind of situation portrayed in these fictions, but I have had brake trouble and have given thought to how to address the kinds of problems so portrayed.  Maybe if those people had considered the possible solutions to the problems before they happened, they would have avoided the life-threatening accident–and perhaps if we talk about the options, you will know what to do if it happens to you.

First, let’s get a few assumptions here.  First, it is unlikely that you will completely lose your brakes without warning, and similarly unlikely that your accelerator will jam; it is thus unlikely, barring sabotage, that both will ever happen at the same time.  Second, you are very unlikely to be the sort of person whom someone would attempt to kill by sabotaging your car.  That’s not to say that no reader of mine is such a person, but it’s a very unlikely sort of way to try to kill someone, and a very small percentage of the population are actually targets of killers, and even fewer of careful conniving killers with clever assassination plans and the mechanical knowledge to so rig a vehicle.  So you should probably assume that if either of these problems ever occurs to you, it is random mechanical failure, not an assassination attempt (don’t be paranoid, and don’t panic).  If both happen together, that’s a different matter, but let’s start with the assumption that only one happens.

Brakes once failed when they got wet.  Modern brakes generally don’t.  However, the regular driving brake on most vehicles is hydraulic (except for large trucks, which use pneumatic brakes because they work better with the trailers).  That means that there is a fluid, a hydraulic oil, in the lines, and pressing the brake pedal compresses the fluid which closes the brake pad creating the friction which slows the car.  Modern anti-lock brakes have a sensing system to prevent wheel lock skidding, but otherwise work much the same.  If air gets in the line, as from a leak, this can malfunction.  For both of these conditions, wet brakes and air in the lines, the first line of defense is to “pump the brakes”, that is, to press and release repeatedly over perhaps ten to fifteen seconds.  This will help dry wet brakes; it will help compress the fluid in hydraulic lines forcing the air out of the system otherwise.

If within ten seconds this is not showing any sign of improvement, the obvious second line of defense which is almost never used in the movies is what is properly called the parking brake but often identified as the emergency brake and in some vehicles the hand brake.  In cars with a center console it is frequently there as a lever that can be pulled up; in other cars, it is often a pedal by the driver’s door.  In both cases the control is ratcheted so that when pulled or pushed it locks into place until the release is pressed or pulled or otherwise activated.  The proper intended use of this brake is to lock the car in place when parked, particularly on slopes.  However, it serves as a secondary brake in an emergency situation.  It uses the same brake pads as the hydraulic brakes (although frequently only the rear brakes), but is connected to them by a cable, not a hydraulic system, and so is effectively a secondary but more direct method of applying the brakes.

There are other ways to slow a vehicle if the brakes are not working, but first we should consider the problem of the accelerator jamming.  The problem here is generally that the engine is being given gasoline and so increasing in revolutions per minute (RPM on the tachometer if you have one), and correspondingly increasing the vehicle speed.  The obvious first answer to this, in addition to applying the brakes, is gently to drop the transmission into neutral.  (With a standard transmission this can be accomplished simply by depressing the clutch, but standard transmissions are no longer standard on most cars.)  The engine will roar as it no longer has the burden of pushing the vehicle, but you will cease accelerating and unless you are pointed down a steep slope you will begin to decelerate.

The transmission can also be used to slow the car if the brakes are not responding, by downshifting.  If you do this at too high a velocity, you are likely to destroy your transmission and/or damage your engine, but if it’s a choice between thousands of dollars of damage to the vehicle and a fatal crash, that’s probably not a difficult choice to make.  This is less likely to be helpful if your accelerator is stuck, but it is an option that might reduce your rate of acceleration.  The objective is to let the engine be a drag on the velocity, although it works considerably better with manual transmissions than with automatic ones.

If you have put the vehicle in neutral but the brakes are not working and you are headed down a slope, if possible consider getting off the road.  Roads are generally designed to be smooth and provide the right kind of friction for rolling vehicles.  Shoulders are usually rougher and will slow the vehicle more, and if the ground beyond the shoulder looks flat and level it will probably slow the vehicle more.  There is the danger of hitting a hole that will damage an axle, but this will at least stop the vehicle and cost considerably less than a transmission or an engine.

You might also consider aiming for objects that will slow your car but neither stop it completely nor flip it.  Hitting a tree at high velocity is a bad choice, but a bush will collapse under the impact and slow or possibly stop the car less abruptly.  Sideswiping a tree, if you can control the vehicle well enough to do so, will also slow the car.  New Jersey Dividers–those perhaps three foot tall concrete walls with the half-parabola curved sides that often line highways–are designed to slow a vehicle and press it back into the lane from which it is coming.  In recent years, large usually orange plastic barrels have been placed in hazard locations along highways, such as construction areas; these are generally filled with water, and as such are designed to collapse when hit, providing a less than solid impact surface.

One other method of slowing an out-of-control car should be mentioned:  shut off the ignition.  If the car is in gear, the engine will immediately become a drag on the car, and in most modern cars the fuel pump will stop providing gasoline to the cylinders.  If you have power steering, it will immediately become much more difficult–but not impossible–to control the direction of the vehicle, somewhat worse than standard manual steering.  It will not affect the parking/emergency brake, and will have only minimal effect on the operating brake.

I have also considered the option of pushing the vehicle into reverse or park.  This requires overriding safeties on the transmission (it will require you to press or maneuver something to shift out of neutral in that direction), and will probably destroy it and damage the engine, but again if you are worried about dying versus destroying your car, that’s an easy choice.

So now if the thing that probably never will happen to you does, you’ve got some ideas about how to handle it.  I would like to say that I have tested them, but I am more pleased to say that apart from pumping the brakes I have never needed to, although I have tested the idea of pushing the car into neutral while driving, so that also works.  Oh, and once when I was teaching someone how to drive I had to use the parking brake to stop the vehicle before he drove in front of a rapidly oncoming car at an intersection, so that works, too.

Elections, Law and Politics

#203: Electoral College End Run

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This is mark Joseph “young” blog entry #203, on the subject of Electoral College End Run.

A bad idea which we mentioned in passing some years ago is apparently gaining ground, thanks in large part to Hillary Clinton’s failed 2016 Presidential bid.

The idea, which we mentioned in Why We Have an Electoral College (in the page Coalition Government), is to nullify the original Constitutional intent, that the President be selected by the States as States, by having states pass a law assigning their electors to vote for whichever candidate wins the majority of the national popular vote.  Even some Democrats recognize that the current popularity of this idea is because the losing party are sore losers, and the fact that Hillary Clinton has added her voice to the chorus only underscores that sense–but as the map provided by the idea’s promoters shows, in green, eleven states have already passed the necessary legislation.

(In fairness to Hillary, sort of, she spoke out for the elimination of the Electoral College the last time the Democrats lost the Presidency in a close race.)

That legislation is designed to prevent states from being obligated until there is what they consider a consensus, that is, the legislation passed by each state specifically states that it becomes effective when, and only when, similar legislation is passed by states representing enough Electoral College votes to constitute a majority of the College, 270 votes, that is, one half of the 538 electors plus one.  At that point, whoever receives the majority of the national popular vote would, by dint of this legislation, receive at least two-hundred seventy votes and win the election.

There is a flaw in the reasoning.  Let us suppose that the total is not reached by 2020, and thus it does not impact the 2020 election; but it might be reached in 2021.  However, 2020 is a census year, and the primary reason the Constitution mandates that we have a census every ten years is to adjust the representation of each State in the House of Representatives.  Following the 2010 census New Jersey lost a seat, and there is every likelihood that some States will lose and others gain seats before 2024.  That matters because the number of electoral votes each state gets is determined by the sum of its Representatives plus its Senators, and it might well be that in 2021 the states having passed the law provide sufficient votes to cause it to be enacted, but by 2024 there would not be quite as many.  This might be unlikely, but it is not impossible–New Jersey, which has passed the law and has been shrinking proportionately, might lose another seat, and Texas and Florida, which have showed no interest in passing the law, have been growing and might gain another seat or two each.

However, that is not really the significant point here.

Some years ago a young liberal actress got in serious public relations trouble when she suggested carpet bombing all the conservative states in the central United States because they were impeding the progress that the liberals dominating the coastal states were pushing.  That is an extreme example, but the fact is that several of the big states are coastal states, and tend to be liberal–California, New York, Pennsylvania.  That means on some level we’re talking about the big states trying to take over.

California is an important example.  It tends to be liberal, but is short-changed in the Electoral College because it is short-changed in the House of Representatives:  there is a cap on the number of Representatives any state can have, and California’s population would give it quite a few more seats were it not for the cap.  Let’s face it, though:  California is a large piece of real estate with several very large population centers within it.  It could plausibly dictate law and policy for the entire country just by flexing its popular vote.

That, though, is exactly why the Constitution is designed the way it is.  When the big kids tell the little kids what to do, we call it bullying, and we look for ways to punish and control it.  The Electoral College is designed to try to keep the big states from bullying the little states.

The proposed law disenfranchises the little states.  In doing so it disenfranchises the voters in those states.  There is good reason for the states to vote for the President chosen by the majority of their own citizens, and not the majority of the citizens of every other State in the Union.

We would ask our New Jersey legislators, and those of the ten other states which have already passed such legislation, to repeal it.  It is bad law.  It is also, as one author already cited has observed, probably unconstitutional–it is an effort to end run the Constitutionally-mandated process.

If not, voters in New Jersey and elsewhere should prepare to file suit against the legislature.  The law disenfranchises the voters of this state, taking from us our constitutional right to choose the candidate of our own choice, not that of the rest of the country.

Books by the Author

#202: Verser Confrontations

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This is mark Joseph “young” blog entry #202, on the subject of Verser Confrontations.

With permission of Valdron Inc I have begun publishing my third novel, For Better or Verse, in serialized form on the web (that link will take you to the table of contents).  If you missed the first two, you can find the table of contents for the first at Verse Three, Chapter One:  The First Multiverser Novel, and that for the second at Old Verses New.  There was also a series of web log posts looking at the writing process, the decisions and choices that delivered the final product; those posts are indexed along with the chapters in the tables of contents pages.  Now as the third is posted I am again offering a set of “behind the writings” insights.  This “behind the writings” look definitely contains spoilers because it sometimes talks about what I was planning to do later in the book–although it sometimes raises ideas that were never pursued.  You might want to read the referenced chapters before reading this look at them.  Links below (the section headings) will take you to the specific individual chapters being discussed, and there are (or will soon be) links on those pages to bring you back hopefully to the same point here.

There is also a section of the site, Multiverser Novel Support Pages, in which I have begun to place materials related to the novels beginning with character papers for the major characters, hopefully giving them at different stages as they move through the books.

These were the previous mark Joseph “young” web log posts covering this book:

  1. #157:  Versers Restart (which provided this kind of insight into the first eleven chapters);
  2. #164:  Versers Proceed (which covered chapters 12 through 22);
  3. #170:  Versers Explore (which covered chapters 23 through 33);
  4. #174:  Versers Achieve (chapters 34 through 44);
  5. #180:  Versers Focus  (chapters 45 through 55);
  6. #183:  Verser Transitions (chapters 56 through 66);
  7. #186:  Worlds Change (chapters 67 through 77);
  8. #191:  Versers Travel (chapters 78 through 88);
  9. #198:  Verser Trials (89 through 99).

This picks up from there, with chapters 100 through 110.

History of the series, including the reason it started, the origins of character names and details, and many of the ideas, are in those earlier posts, and won’t be repeated here.

Chapter 100, Hastings 126

As I was dealing with the wolves, I wondered why they should trust Lauren or care about humanity.  I realized I’d already given myself a reason:  Bethany had saved the forest for them, working with the people of Wandborough.  It also occurred to me that Lauren has always called on the wolves for aid, but they have never called on her.  It seemed reasonable to suggest that pack mother Sielle would have some problem for which Lauren was the answer.  I don’t know what it is, yet, but it gives me something for Lauren to do besides repeated commando raids on vampire government officials.

When I was playing the games that became the basis for the Philadelphia stories, the wolves did come to me for help a few times; that was a much longer story, though, than I could include in the books.  (Much of this is preserved in the older Stories from the Verse site as Journals of the Architect.)

Chapter 101, Slade 82

Most of this I realized as it was unfolding–the slack and taut ropes, for instance.  I decided on the use of the sheepshank in the midst of writing, as well.  I was thinking before I started the passage that Slade didn’t know how to find the door, and the Norns idea was getting tired, but I could have them guide him by pointing him to Shella.  I remembered that Shella had been watching, and thought perhaps I could come up with some plausible reason why she knew the way when he didn’t.  However, it wasn’t until just before I wrote it that I realized that the tower was there.  Slade’s embarrassment was thus a reflection of my own on that count.

Chapter 102, Brown 86

I discovered a numbering glitch when I was writing this; I’d numbered two consecutive Brown sections 76.  I corrected it; I hope I got it all.

I awoke with the idea of the dream, and let it simmer while I took care of some other things.  I had a lot to do today, but did not want to lose this idea.  One fragment of it, the idea that marrying might be a cause of grief, I probably got from my morning reading of Jeremiah.

I also began envisioning a bit of a battle between Derek and the king’s guards in the human city.  His aerobatics practice and his training with Lauren would finally combine into something unique to him.  I’ll have to figure out how to preserve it, but I think this could go somewhere.

I also wanted him to feel the pain of losing his family now, before he lost them.  I decided he should say goodbye to his father, but not wake his mother, but simply kiss her.

Chapter 103, Hastings 127

Adam commented a day or so ago that everyone was getting married in this book.  He didn’t know that Derek wasn’t going to reach the altar (something of which I was myself only about ninety percent certain then, and still only ninety-eight percent certain now).  Yet I did observe for him that Lauren wasn’t headed that direction.  He said he knew why this was:  it was because she was already married.  Yes, that was correct, I observed, thinking back to her tension on that in the end of the second novel.  Yet at that moment I saw something I could do with Lauren’s story that would make it far better.  I would bring Phil Hastings back as a vampire.  She never did find out what had happened to him in this world, and he had married someone else.  It was not an impossible stretch.  I could do something with it, give Lauren more depth than merely killing a bunch of vampires, and stretch the story a bit to give the others time to catch up with her.  In the midst of this, it was an echo of Bethany’s confrontation with her mother centuries before.  This time it would be Bethany who told Lauren that she could not believe it was human, and that she had to recognize it for what it was and kill it.  I thus started looking for a way to carry it in that direction.  As I write this, it seems to me that I should connect Phil Hastings with the Philadelphia area leadership somehow; I’m not yet certain how, but it would explain why Lauren arrived in Philadelphia instead of Wandborough.

The name thing was not an entirely new idea; after all, Gavin had changed his name, and that had been mentioned.  I needed a way to prevent Lauren from realizing that she was about to confront the man who was this world’s equivalent of her husband, and the name was the way to do it.  The Liberty Bell/Independence Hall idea had merit, in that having it closed and slated for demolition would provide some echo of the idea that the vampire domination was a bad thing.  I thought also that The Arena might recall Rome to some readers, although I didn’t want to push it.  I created the route on the fly (I’m not completely certain where Independence Hall is relative to the waterfront, but figured it wasn’t that close, and the sports arena is near the airport, which is the south side of the city, so things are pretty well arranged).

I also decided she needed to fight her way through.  These were no longer going to be simple run-in-and-kill-the-vampire raids.  It had to look more difficult.  I also needed to help people understand why she just doesn’t blow everyone away with the disintegrator rod.

I recalled the “old times” line that had really been something of a throwaway in the first book which had echoed in the second when they were in Camelot.  Now to have Bethany say it again more soberly I thought would have some impact.

Chapter 104, Slade 83

I remembered that there was a bar on the inside of the door, and I had to provide a way to get past it.  I also remembered the D&D Viking Handbook had said something about Viking thieves not knowing anything about mechanical locks, but understanding how to jimmy barred doors, so I figured there was a way to do it.  It seemed a simple enough approach to use the metal strip, so that’s where I went.

Chapter 105, Brown 87

Most of this I felt my way through–the difference between mentally visiting a place and being there, between traveling the streets and flying above them, and the telekinetic lock picking were all things I created during the day I wrote this, although I wrote part in the morning and part in the afternoon, and so had time between to think through the end of the chapter.

Chapter 106, Hastings 128

Part of the idea was for Lauren to face the same tension Bethany had faced, to have to kill a vampire that looked like someone she loved.  I also had it in mind that this might free her from her concerns about being married to Phil, although I don’t yet know how that will work.  It only now occurs to me that this fits well with the marriage thread of the book, as well as leading to the climax of the vampire thread and the Merlin connection.

Chapter 107, Slade 84

I’d given some thought to a quick fight scene for Slade, in which a guard came through the door and he stabbed the man through the throat and tossed him off the wall; but it seemed too violent for this moment in the story, in which a quiet takeover seemed the order of the hour.  I glossed over how many men were on the wall and how they were silenced, for much the same reason.

I considered whether Odette’s dagger should find a target, and decided against it.  I had not yet decided how to verse them out of this world, but I was eager to see a scene in which Acquivar disclaimed any interest in saving Odette.

Chapter 108, Brown 88

I’d played out this scene in my mind a few times; still, there were elements that I devised as I wrote.  The guard on the door and the food cart were both created at that moment.  I had envisioned the confusion in the room, several people being brought down by arrows, and the use of telepathy to reach the ruler (whose title I never did decide).  The idea that people did not know sprites could talk seemed reasonable, particularly since elves didn’t even know they existed.  To expand that to suggest that humans didn’t know elves or gnomes existed also seemed reasonable.  The simple rule to establish peace seemed an acceptable solution to the problem, and let me move forward.  I’d imagined some agreement being reached, and then someone very like a gardener or maintenance man bursting in and “dealing with the problem” over the objections of the ruler.  It seemed to work well enough.

Chapter 109, Hastings 129

As I prepared to write this, a number of ideas connected.  One was that Lauren and Bethany would pray for someone to come; Derek was already on his way, but they couldn’t know that, and it would be a valuable story point.

Another was the idea that Lauren, as powerful as she is, finds her real strength in building teams, of bringing people together who compliment each other.  It is perhaps a theme in Lauren’s story that she almost always works with others, that she forms teams that work well.  In Philadelphia, she brought the human hunters together with the werewolves against the vampires; in the parakeet valley she worked with Joe and Bob to rescue Speckles; in Camelot a good part of her reported adventures involved questing with Sir Sagrimore, and in the end she brought the villagers together with the werewolves against the vampires.  In the futuristic post-apocalyptic world she turned an adventuring party into a university faculty that continued after she had gone.  In Wandborough she worked with Bethany against the vampires, and then in Terranova Habitat she teamed with Derek and Joe.  She was alone on the tropical island, but her task there was to practice and learn, and now that she is back in the vampire future world she is building a new team.

I had long been thinking that Derek was going to develop the ability to change between his three forms–the sprite, the human, and the mid-sized something.  As I thought about the turns ahead, I realized I could make this work much more convincingly by having Bethany use her magic to give Derek this ability.  It would also bring him to Lauren more quickly.

A lot of this chapter was written to provide the space I needed to bring in the prayer.

Chapter 110, Slade 85

The idea of Odette confessing from the battlements had been in my mind for quite a while.  What I hadn’t worked out in advance was the movement of armies to get to this position.  I glossed some of that, but I think it was credible.

At this point I had again lost my chance to kill Slade and send him to the next world; but with Derek on the way, I wasn’t ready for him anyway.  I was envisioning Slade and Shella appearing in the midst of some battle, recognizing Lauren in trouble, and coming to her aid, and that wasn’t going to happen until I managed to handle the arrival of Derek.

The idea that formed in my head at this point was that Slade was going to fight some fire elemental, an efriit of some sort.  It should be a major battle, taking at least a chapter, maybe two.  I haven’t figured out how to set it up yet, though.

This has been the tenth behind the writings look at For Better or Verse.  Assuming that there is interest, I will continue preparing and posting them every eleven chapters, that is, every three weeks.

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Temporal Anomalies/Time Travel, Time Travel Movies

#201: The Grandfather Paradox Solution

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This is mark Joseph “young” blog entry #201, on the subject of The Grandfather Paradox Solution.

Award-winning science fiction author Larry Niven.

I sent birthday greetings to a time travel fan on Facebook–one who deserves special mention, as he has provided copies of several time travel movies analyzed on our Temporal Anomalies site–and in response received a discussion of a time travel issue.  I would have said that this is addressed already on the site, but I recognize that the site has become unwieldy in some ways and it’s difficult to find, let alone absorb, it all.  I have edited his comments for space, and added links to references on the site for those who are uncertain of the terminology.

I’ve been thinking about Niven’s Law (ie the popular “if you change it in the past it stays changed even if you undo the time travel” version).

Here’s the thing–without it, it seems to me that things work by magic.  Let’s use the old example of going back and killing my grandfather as a child.

Fixed time this is just impossible….

Parallel universes, no problem….

Replacement theory is where it gets interesting (of course).  Let’s first postulate that I’m not going back to kill Granddad.  Let’s say instead that I’d discovered in talking to other people that there was some sort of childhood toy in my granddad’s house…that was extremely rare, and if I went back and got it I could sell it for a fortune in the future….Unfortunately while I’m back in the past I interrupt a burglar, he shoots at me and misses but kills my granddad who was hiding behind the couch watching this armed burglar tussle with me….

So…I haven’t erased my motivation for going back.  However, obviously if I never exist, I can’t go back, which means that I won’t interrupt the burglar, which means he won’t shoot….

But what exactly happens?  What does the burglar see?  Does he just see me vanish into thin air?  That’s what I mean–there’s no real known phenomena that would cause that.  And in fact he wouldn’t see it anyway, because the whole idea is that I could never have been there in the 1st place.

I think in reality, if time travel is possible at all…either Niven’s Law must exist or else something like Hawking’s Conjecture must be true (the one where he says that you will be physically unable to successfully perform any actions that would create a paradox…).  I find the Conjecture even less likely (it pretty much falls under your “God won’t let it happen” thing).

Mind you that doesn’t get off the hook with “uncaused causes“.  There’s no perfect answers.  It just always seemed weird to me that things could magically change just because I remove the reason for the change.

This happens to be exactly the problem that is resolved by the standard concept of the infinity loop, two histories each of which causes the other.  My reader has missed this, falling into the notion presented by other time travel stories, perhaps most notoriously the ending of The Philadelphia Experiment II, in which the death of the childless father causes the son, a moment later, to dissolve into non-existence.  The reality postulated by the theory is much less complicated.

The postulated problem suggests that when I travel to the past I accidentally cause the death of my own grandfather.  The questioner then wonders whether I flicker out of existence, but recognizes that the problem is more complicated, that in fact if I never existed I never made the trip to the past and the burglar never shot at me.  That, though, means he never killed my grandfather, and I am able to make the trip to the past.  This much the question recognizes; it then gets caught in trying to make both versions of time real simultaneously, as if the death of my grandfather means that I must immediately vanish.  This fails to grasp the significance of causal chains, which we will here review.

In all of our science, we have causal chains:  A causes B, B causes C.  If B does not happen, C does not happen, because C only happens if caused by B; similarly, B only happens if caused by A, so if we prevent A, we prevent B, and in so doing we also prevent C.  This is simple for us in most situations, because of two “rules” that have always applied to everything we have observed.  One is that causes and effects have always happened in temporal sequence, that is, A happens before B and B before C even if only infinitessimally (the hammer strikes the firing pin which compresses and ignites the gunpowder which drives the bullet out of the shell, all in a fraction of a second but that fraction divided into sequential fractions).  The other is that once a cause has brought about an effect we are unable to remove the cause.

Time travel erases both of those rules, and therein lies our confusions.

In the present circumstance, the original history has Burglar invading Grandfather’s house, observed perhaps by grandfather but otherwise unmolested.  Decades pass and Traveler learns of the valuable toy in Grandfather’s attic.  Having access to a time machine, he travels to a time when he believes he can obtain the toy without changing anything significant in history.

  • There is an issue here which is not addressed in the problem:  we do not know how Traveler became aware of the presence of the toy in the attic, but if he removes it too soon he might well break the chain of information such that he does not know about the toy.  For example, if his information about the toy comes from the estate sale records, the toy will not be listed there once he has removed it.  However, our theorist having been careful on all other points, we will assume that Traveler got the information through a source that predates his effort to steal the toy.

He arrives in the past, and interrupts Burglar, who in attempting to kill him accidentally kills Grandfather.  There are scores of steps in this causal chain, but simplifying it we have A: Traveler travels to the past; B: Traveler interferes with Burglar; and C: Burglar kills Grandfather.

However, there was a causal chain in the original history in which Grandfather sired Father who sired Traveler, who eventually left for the past.  Our logic problem recognizes that because Grandfather is now prematurely dead, Father will never be born, and Traveler in turn will never be born.  It is precisely because the original causal chain has been disrupted that Traveler is never born–there is nothing magical about that, and no one imagines that it is.  We understand completely that if you remove the cause of an effect, the effect never happens; if you kill someone’s grandfather before he has children, the grandchild is never born.

Yet exactly the same rule applies at the other end.  If Traveler is never born, he never makes the trip to the past, which means A: Traveler travels to the past never happens.  Since A is the cause of B: Traveler interferes with Burglar, B never happens, and since B never happens, C: Burglar kills grandfather, also never happens.  If it applies to the A-B-C sequence that is Grandfather sires Father, Father sires Traveler, then it also applies equally to the A-B-C sequence Traveler travels to the past, Traveler interferes with Burglar, Burglar kills Grandfather.  The removal of the cause A undoes the effects B and C.

We balk at this because what we perceive as inaction in the future is becoming a cause of a change in the past, and we feel as if whether or not the past can be changed it can only be changed by someone traveling to the past.  However, if we look at it a different way, it might become clearer.  If I know that Gary traveled to the past, leaving tomorrow, and that what he changed altered history in a disastrous way, in theory I might attempt to travel to the past and prevent him from making that mistake, but could I not just as easily act to prevent him from making the disastrous trip?  (I admit that this would cause an infinity loop, but the point is only that preventing the trip to the past will prevent the changes to the past just as surely as traveling to the past to do so would.)  At the same time, we are mistaken to think of “not traveling to the past” as inaction.  It is much more properly different action, and different action becomes a different cause that has a different effect.  Further, since the effect B which is the cause of the effect C is itself the effect of A, if A is undone–if Traveler does not go to the past–then B is also undone–Traveler does not interfere with Burglar–and C is in turn undone–Grandfather is not killed.

But we return to what it is that Burglar experiences when his stray bullet kills Grandfather, theoretically undoing the existence of Traveler.

I admit that it is plausible that this event will cause time to unravel entirely, and the universe will cease to exist.  I think, though, that this is a bit extreme, and further it seems to require that the universe “knows” that history has changed in an irreconcilable way.  I don’t think the universe can know anything of the sort–for the universe, despite the fact that someone arrived from the future and became a new cause, this is the first time through these events, and as far as the universe “knows” (if it can be said to “know” anything in any sense), this is the history that exists.  It does not “know” that the man who just died is the grandfather, and thus the necessary cause of the life, of the Traveler who incidentally caused his death.  It has to “discover” that by playing through the events which follow.

There is thus an interweaving of two histories, in a sense.  Traveler comes from a universe in which Grandfather had a child.  The history of the universe is being rewritten, event by event, cause by cause, moment by moment, but it has not been rewritten yet.  Since under replacement theory there is ultimately only one history of the universe, each moment that is created erases and replaces the moment that was the same time in the other history.  That means the cause of Traveler’s presence in the past, cause A, has not yet been erased, and so Traveler still exists in the past even while his history is being erased and rewritten.

Ultimately the moment comes when cause A needs to happen in order for effect B, in the past, to be supported.  If we had an N-jump, that would happen.  To use our example modified, there was no Burglar, Traveler successfully collected the toy and stored it in a place where he could recover it in the future, and returned to the future without significantly altering the past.  Thus as the moment of his departure approaches he is the same person planning the same trip, and at the right moment he does so, cause A creating effect B, his arrival in the past.  This creates a stable history, and we have a sort of diverging hiccough:  because traveler leaves for the past on schedule, time continues into the future based on the history Traveler created and now confirmed.

However, with Burglar in the mix, we know that Grandfather died and Traveler was never born.  That means cause A never happens, and effect B never happens–we already know what happens if no time traveler arrives from the future, because that was the original history.  Burglar passes through the house unmolested, Grandfather survives to sire Father who sires Traveler.  That results in Traveler making the trip, creating the other history.

In no history does anyone simply disappear.  In no history does something inexplicably change without cause.  The difference between the original history and the altered history is that in the altered history someone arrives from the future and introduces causes that create a different set of events leading to its own undoing, while in the original history no one arrives from the future and so events follow the undisturbed path of events to the moment when someone decides to change them.

I should note that in all of this we experience the changes at the speed of time.  There is a sense in which at the instant Grandfather dies, Traveler ceases ever to have existed–but that only happens because of the intervening causes and effects which fail to bring him to life.  We experience those events at the speed of time; using time travel we presumably could skip ahead to the outcomes in the future.  That, though, means that in some sense all of those events happen instantaneously–and as I have suggested in The Spreadsheet Illustration, it can be understood as all happening simultaneously–it is Einstein who said that time exists so that everything would not happen at once, but if the nature of time is such that time travel is possible, the reality is that everything does happen “at once”, and time exists so that we can experience the causal chains in the order in which events cause each other.  So in that sense the moment Burglar kills Grandfather, Traveler ceases to exist, but his non-existence can only be discovered by following the causal chain to the moment when he fails to arrive in the past.

I hope this clarifies the problem and the solution.  I should mention that we previously addressed the matter in relation to a supposed “multiverse” solution in web log post #81:  The Grandfather Paradox Problem just over a year ago.

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