The English translation of the title O Homem Do Futuro is given as The Man from the Future.  It obviously identifies João, who travels back twenty years and attempts to change his own history.  In the course of that altered history, he uses that phrase as the name of his investment holdings corporation--and that got me thinking.

I speak less Portuguese than Spanish, and I'm not sure my Spanish is up to Sesame Street standards--but my linguistics background informs me that prepositions are often difficult to translate, because they frequently represent a wide range of relationships which native speakers distinguish (or sometimes fail to distinguish) by context.  I also recall that many Greco-Roman languages fail to distinguish of from from consistently.  So I suspected that there was a bit of Portuguese wordplay here--and a quick run at Google Translate confirmed for me that the title could as easily be rendered The Man of the Future.  The older João clearly is the man from the future, but the younger João, informed by his elder self of the upcoming changes in the financial world, easily names himself the man of the future, and gives that name to his investment company, suggesting the prescience of his investment decisions.

So kudos for that, and some disappointment that it didn't translate well into English.

The film does something which might be unique.  We have many movies in which time travel is accomplished by a machine, and even a few in which the discovery was entirely accidental, as perhaps Primer or Source Code.  We have also had movies in which the time travel was caused by some psychic ability, notably Peggy Sue Got Married and Somewhere in Time.  To the best of my recollection, though, this is the first instance in which the two combine:  João accidentally creates a machine that propels him to the past, and his destination is determined by his thoughts and emotions.  He was thinking about Helena and the day she humiliated him, and he arrived on that day.

He does the same with his second trip, although he arrives somewhat later in the day.  Then Otávia follows him using the same machine and the same method.

It is also clear that no trip to the past is permanent; all visits are self-terminating.  What is less clear, and never stated clearly, is what causes the termination.  The implication seems to be that at the moment someone's presence in the past becomes impossible, that person ceases to be there, dissolving into the now unseen tunnel that connects future to past and returning to the moment of departure.  However, this is not an adequate explanation for the events of the film, it is not followed consistently, and there are still questions concerning what happens to such a time traveler and why.

Quite a few things happen more than once, but are only shown once, so it may help to put everything in the sequential order in which it occurs.

We'll begin with the cast of characters.

• João Henrique Nogueria, also called Zero, begins as a probably twenty-year-old college upperclassman and brilliant physics student.  More than one person has said he is going to change the world.  After graduation, he ultimately becomes a professor himself, working on a project to produce unlimited electricity, but his entire life is still controlled by his love for
• Helena, whom we meet as a college freshman, the gorgeous girl that every guy in the school wants.  She is studying physics, and wants João to tutor her, and early in the story tells him that she loves him.
• Otávia Miranda, usually called Panda, is João's best friend in college and twenty years later is still his best friend, and his co-worker in the lab.
• Sandra is a fellow student, a sort of outgoing cheerleader type who emcees the big class party after graduation.  After college she gets rich from some seemingly prescient investment decisions, buys the university, and so goes from being João's friend and defender to being his boss.
• Ricardo is interested in Helena, but in significant part because he believes she can become a supermodel and he can ride her coattails as manager if he can get her away from João.

Those are the major players.  At the future end, a student named Sushi is helping with the computers for the experiment, and back in the past at the party Ricardo wants to introduce Helena to someone always called the Spanish guy, who apparently has the connections to make her a supermodel.

We begin with the fact that João and Panda have noticed Helena, as that girl who is just impossibly unattainable for nerds like them.  Helena, though, is not all beauty; she's got some brains, is studying physics, has read some of João's work, and wants him to tutor her.  These tutoring sessions build a relationship, and she tries to persuade the insecure science geek that she is not interested in anyone but him.  She has succeeded by the night of the graduation party, November 22, 1991, by which time she is introduced as a sophomore so it's been probably over a year.  However, Ricardo is intent on becoming rich by turning her into a supermodel, and so at the party he drugs two glasses of champagne, probably with GHB, and then arranges for Helena to embarrass and disown João completely, having him doused with honey and feathers and hoisted into the air above the crowd to fly like a chicken.  Ricardo then wisks her away to Spain to become a supermodel; João becomes university faculty, and twenty years pass.

During those twenty years, Sandra becomes head of the university after becoming wealthy from some smart investments, and she is trying to support and encourage his work but he's a bit reckless and has made some enemies.  Trying to salvage his project before the university heads put someone else in charge of it, he has Panda and Sushi join him for an unauthorized experiment.  He is recording it, and asserts that to prove the technology is safe he is going to be inside the machine as it produces its power.  The computer's clock reads July 28th, 2011, at 2:53 P.M.

It does not go as planned, and instead, well, his description of the event is:

The machine created a micro black hole, perforating the structure of time and space, and opened a link to the past.

Well, I'm not sure how plausible the science is, but since nobody knows how to travel through time we usually give movies a lot of leeway on that, as long as they don't attempt to claim something completely impossible works (like flying around the earth in the direction opposite its rotation).  João dissolves into the vortex and then awakens on the floor of the basement room that was his lab, which is now an empty basement room.

It should be mentioned that one of the things Helena particularly likes about João is that he is trying to prove that love is part of the fabric of the universe.  It seems to be very much part of his relationship to space and time, because he determines, after some stupidity, that he has landed in the past, specifically on November 22nd, 1991, the day of the party that he believes ruined his life.  He decides that this is his chance to fix things, and heads for the party.

There are eventually three versions of João at this party.  We will designate the one who is just finishing college Young João, and this one who came back by accident Older João.  The third one, still to come, we will call Oldest João.

Older João does two things, one of which changes history in the short term, the other in the long term.

The short-term change is that he warns Young João that the champagne is drugged, and so Young João and Helena don't drink it but instead insist that Ricardo drink it.  This derails Ricardo's plan, and the young couple leave the party together.

The long-term change is that he gives Young João extensive information about the stock market and other financial news such as the mortgage crash.  He tells Panda to stay with João, and Panda writes down all the information Older João is delivering.  This puts Young João on an entirely different life course, such that he becomes an investment genius instead of a physicist.

Having done this, he has undone his own existence, and the movie suggests that at this point he dissolves back into the link.

However, we are given a fair amount of information about what happens over the next twenty years.  João and Helena marry, but he is incredibly jealous and does not believe she is faithful, so eventually he not only divorces her but frames her for drug smuggling, she says so that she will be kept in a women's prison where there are no men.  He marries three other women, but none of his relationships work.  All he thinks about is how to make more money.  Panda is his partner, but after almost twenty years João sues to dissolve the partnership.  Ricardo is João's lawyer, or at least his manager.  Sandra becomes a physicist who believes she has found a way to create unlimited low-cost electricity, but believes that João bought the project so he could shut it down.

It seems that at the moment Older João failed to travel to the past (because he never built the machine), Young João, now forty years old, ceases to be that person.  Oddly, though, the only thing that changes is that when João awakens in his incredibly expensive home he has all the memories of the João who just visited the past, and remembers nothing of the history that he created.

Looking at the world he has created, in which he is divorced from Helena and she is in prison, he and Panda are fighting each other in court, he has spent his money faster than he is making it, and everyone agrees that he is the world's biggest jerk, he realizes that he has to go back and prevent himself from changing history.  He persuades Panda--now a businessman--to help him set up the machine exactly the way he had done, using Sandra's parts and materials, explains to him how it works, and focuses on returning to the party.

He lands somewhere on the outskirts of whatever city that is, terrifying a couple of teenagers who saw him arrive (he is wearing a costume space suit), and rushes to the party.  This is now the one we are calling Oldest João.  He arrives too late to prevent Older João from meeting Young João, but he instead crashes their meeting.  Seeing two versions of his older self, Young João faints, leaving his Older and Oldest selves to fight with each other about what they should do.  However, Oldest João has brought Panda's gun, secures Older João, and sends Young João to sing with Helena on the stage.  Everything seems to be headed back to the original history.

However, it seems that moments after Oldest João left for the past, Panda decided he didn't want to be not rich, and decided to come back and prevent João from restoring the original history.  He leaves from the future moments after Oldest João does, and manages to locate them once Oldest João has secured Older João in the basement.  Catching Oldest João by surprise, he takes the gun, and swaps their places so that Oldest João is now secured in the basement.  Older João and Panda race back to the party to attempt to put things back on the previous track.

This time, though, Young João was not warned about the champagne, and he drinks it.  However, Helena, wary of Ricardo, delays before drinking hers, and is interrupted by the arrival of Panda and Older João, so that her drink is left untouched on the counter as they take her away.  Panda says that the mistake made the previous time was not informing Helena of what was happening, and that they have to tell her.

Meanwhile, Sandra, heartbroken from her encounter with cheating boyfriend Antonio Carlos, stumbles into the basement looking for a private place to cry, and finds Oldest João there.  He persuades her that he is indeed João, come from twenty years in the future, telling her about their lives before, and assuring her that at the concert next week she will be connected with the love of her life, Marco Aurélio.  To prove his story, he shows her his smartphone, and she makes a video of herself telling off Antonio.  He also tells her that he has finally figured out how it all fits.

We never see the next part in detail, but Oldest João proceeds to give Sandra the investment strategy that will make her rich, including buying a huge percentage of Google and selling just before the mortgage crash.  He tells her that she will ultimately buy the university with the wealth she accrues.  In short, he gives her the ability to become the incredibly wealthy woman we met in the future.  This, he says, was always part of what was supposed to happen.

She frees him, so that when Panda and Older João return with Helena and a very drugged Young João he gets the jump on them, knocks out Panda, gets the gun, and secures Older João.  He then explains the situation to Helena, and persuades her that the only way they can have a future is for her to embarrass him publicly now and reunite with him twenty years in the future.  She decides that he is worth the wait, and agrees to his plan, telling Ricardo to set up Young João as the chicken, giving him the name "Zero" (the sign was written by Oldest João), and announcing that she will be leaving with Ricardo and the Spanish guy to become a supermodel.

By the time Oldest João returns to the basement, the others are free, but he tells them they are too late, that they cannot stop the original history from occurring.  He tells Panda that the wealthy businessman Otávia Miranda now cannot exist, and at that moment Panda dissolves.  Then the two Joãos also dissolve.

We have an intervening twenty years in which all the things we know from the original history are restored:  Sandra becomes incredibly wealthy from the stock market, João becomes a professor with Panda as his lab assistant, Helena is a supermodel with Ricardo as her manager.  We don't see any of that, and we don't see João climb into the machine.  Instead we are brought to the moment after the first João climbed into the machine, when Panda and Sushi open the machine and Oldest João exits, still wearing the astronaut costume.  He explains that he has traveled to the past twice; they think he's crazy.  However, he shows them the video the young Sandra took of herself on João's cell phone--and as he does so, he also deletes all the software that runs the machine and makes time travel possible.  Next he races to the airport; he is receiving text messages from Helena who is about to board a plane to Rome, but he manages to get there in time to meet her, she fires Ricardo and goes with João as airport security drags him away for jumping the security checkpoints.

We fast-forward a year to a moment when João is being found not guilty of destroying scientific research.  It's not clear who brought the charges.  As the verdict is delivered, he kisses Helena, and turns to get a big hug from Panda.

As they leave the building, Panda is complaining that at this point they have nothing--no invention, no jobs, the ire of the scientific community, no money--and João says maybe not as a limosine pulls up to the curb and the wealthy Sandra opens the door and invites them inside.  She has used the information Oldest João gave her in the past not only to become fabulously wealthy herself, but to set up accounts for João and Panda such that they are also--well, Panda says, "You mean I'm rich?", and João answers, "Panda, you are filthy rich."

Helena says to João, "You cheated," but he shrugs and says "I deserved it."

So that's the story.  As you can see, there are a number of problems with it.

In every time travel movie, there needs to be an underlying theory of how time works.  We might disagree with the theory, but a consistent theory such as in Synchronicity is essential to a logical movie.

It is unfortunately not clear that this film has one.

It is clear that in this story it is possible to change the past; João does so twice, in multiple ways.  That eliminates fixed time from our list of possible explanations.

At some point he suggests a divergent dimensions theory, that if someone changes history that creates a matrix of alternative histories.  However, three points can be raised against this from the movie.  First, if João has created another universe and then returned to the future, he has not undone his own universe which should still be as it was, and, second, there is no logical reason for him to have replaced his divergent self, whose universe is still going.  Third, if time travel creates another universe, there is no logical reason to attempt to change it "back", because all that you can do in that instance is create yet another universe.  It seems rather that there is only one universe, only one actual history of the world, which changes.

That means we have some form of replacement theory, in which a traveler to the past can change history and the new history erases the old.  There are some inconsistencies in how that is applied in the film, but it seems a necessary conclusion.

However, there is a flaw in this.  When João realizes what must originally have happened, part of that realization is that in the original history he had been present in the past to give Sandra the information that she used to become rich.  That's a fixed time trope:  it was always the case that I appeared in the past and gave you this information, which made it possible for you to do what you did that made it possible for me to travel to the past and give you this information.  Time has always been this way, and cannot be changed.

The problem is, time can be changed, and João proceeds to change it.  So the question is, how do we get there?

The movie leads us to believe that in the original history Sandra became ludicrously wealthy through some judicious stock transactions, and bought the university.  There are three possible explanations for this.  One is the fixed time notion that in the original history João arrived in the past and gave the market information to her.  That won't work because we know that João changes history on the two trips we see him make, and therefore this is not fixed time.  The second possibility is that somehow without João's information Sandra manages to stumble into several brilliant investments making herself rich enough to buy the university.  We can exclude this, too, on the fact that in the altered history we see she is not rich, and there is no reason to think that João and Panda's investments would alter hers, so therefore she must have been acting on information she got from João in the past.  That leaves the third possibility:  the history João thinks is the original history is actually an altered history.  It came to an end sometime probably not long after the July, 2011 departure that we see, when João accidentally traveled to the past in a similar incident.

In this history, Ricardo drugged the champagne, had Helena embarrass João, and took her to Spain to become a supermodel.  João became a university professor.

The problem we have is that it must be the case that João is not obsessed with Helena.  We also have to account for how our people come to the place that begins the replacement history.

It seems that Sandra was also a physics major, and apparently also a fairly good one.  While it might seem odd that at least four of our five primary characters--João, Helena, Panda, and Sandra--are all physics majors, it is actually rather common for students in the same field to hang out together and become friends, and the larger the school is the more common this outcome is.  We know that Sandra was a physics major, because in the history in which João does not build the machine Sandra does, and she appears to be a professor at the university.

Thus it seems at least reasonably plausible that João, Panda, and Sandra are all working at the university in the physics department.  I'm also going to suggest that after Helena's actions at the party, Sandra and João become close.  We can see during the chicken scene that Sandra cares about João; without any future travelers to intervene, she is the best bet for someone to comfort him and help him get sober after having been drugged.  I'm going to bet that in a few years, working together at the university on this project, they got married, continued working together, and had a reasonably happy life.  Together they built this machine, based on a particle accelerator, which they believed was going to produce low-cost power.

In the history we see, João gets in trouble because he is a bitter abrasive recluse.  In the history we are extrapolating, though, he is none of those things, and he is partnered with the highly charismatic people-person Sandra.  His curmudgeonliness in the history we see leads him to run the first test prematurely, because they are threatening to replace him as head of the project.  Since that pressure does not exist in the original history, it will be at least a few days, possibly a few weeks, later that the experiment is run.  João does decide to prove that the system is safe by sitting inside it during the test, and he gets thrown back in time.

He goes to the day of the party.  We might ask why; this João is not obsessed with Helena, but content with Sandra.  However, earlier that day he saw the magazine cover with Helena's picture on it, and he has probably wondered what might have happened had that night been different.  Finding himself in the past, and not having the compulsion to try to win Helena back, he decides instead that it might be nice to become rich.  He decides not to give the information to himself, partly because he knows that his younger self is drugged and won't process the information well, partly because he thinks interacting with his younger self would cause too large a change in history.  So to make himself wealthy without going directly to himself, he instead goes to his wife, Sandra, and gives her the information.  He tells her that the two of them together built this machine that accidentally sent him to the past, and as long as he is back here he has decided to give her the information she needs to help fund the project.  He does not tell her that she is his future wife, as he does not want to jinx that.

Unfortunately, he does jinx that.  It was in the aftermath of the party that João and Sandra connected; that was the beginning of the relationship that became the marriage.  Instead they become good friends, but Sandra very quickly becomes rich, stops working in the physics department, and buys the university.  Without the stabilizing influence of Sandra as a wife, João becomes bitter and obsessed with Helena, and we have the version of history we see at the beginning of the movie.

It occurs to me that fans of the film may well hit me with the same objections that I got to my analysis of Somewhere in Time, in which I said that there had to be an original history in which Elise fell in love with someone else, and that she mistook Richard for that original love.  Fans want to believe that the movie has to be saying that their love transcends time, that they belonged together.  I suspect in something of the same way fans of this movie are going to say that the entire point of the film is that the love between João and Helena is forever, and that they were always meant to be together.  The altered history in which João becomes the ludicrously wealthy jerk proves that this is not so, even though his wiser self manages to fix the problem and find a way to bring them together.

From there our histories run much as we have already outlined; however, there are quite a few quirks and problems along the way.

It is difficult to say how many trips are made to the past in this film.  We see four separate departures to the future, but only two departures from the future; one character in the past merely states that he did what João said and followed him.  The other, well, we saw him depart from the future, and we saw what he did in the past, but then others came from the future and interacted with him in the past, so it seems he only made one trip to the past but he exited the past twice.  Our interest here, though, is that we saw two of the time travelers arrive in the past, and those arrivals create inconsistencies.

The first João to travel to the past, Older João, lands in the basement where the time machine eventually will be.  He is unconscious, and everything is quiet.  We don't actually see him arrive; we see him awaken moments after having arrived.

The second João to travel to the past, Oldest João, doesn't land in the basement.  He lands somewhere on the outskirts of the city.  He is fully conscious, and lands on his feet, despite the fact that something like lightning seems to be striking him from, or emanating from him in, several directions.  He also arrives later in the day.

We might adduce several differences between their departures that might impact these arrivals.  Primarily, the first João did not expect to travel to the past, and did not even know he had done so.  He landed on that day because he was thinking about Helena embarrassing him at that party.  He arrives on that day.  The other João is specifically targeting the party, specifically trying to travel through time, and so he arrives just as the party is starting.

Also, for the second João he has done this before--he was the first João.  It is not at all unreasonable to suppose that he is growing accustomed to traveling through time, and so although the first time overwhelms him and leaves him unconscious, the second time he retains his consciousness through the experience.  That we don't see the lightning the first time is simply because we did not see him arrive.  We can assume the lightning was there.

However, there seems no reasonable explanation for why he would land in the room from which he departed the first time, but across town somewhere the second.  It suggests that the control of spacial coordinates is not particularly good, and it was merely coincidence that he landed as close to his launch point as he did.  He could easily have landed in the Atlantic Ocean, or over in Spain, or on the Moon.  Perhaps that's not true; perhaps it's only true that he lands close to his point of departure.  Perhaps he only lands close to the place in his mind when he departs.  Perhaps the second time machine is less accurate than the first.  No explanation is offered, unless they just wanted to include the silliness of the time traveler in a space suit stealing a car from a couple teenagers to drive to a party at the university.

The most confusing aspects of the time travel in this movie are in the return trips.  As already noted, trips to the past are self-terminating, as a moment comes when the traveler simply dissolves back into the tunnel that brought him to the past.  There are several problems, several questions, several inconsistencies connected to those return trips, but the first of them is the question of what triggers them.

The implication is made, the first time, that Older João has undone his own existence--that is, the changes he made to history have now made it impossible that he would become the scientist who made this trip to the past and changed history.  Thus since he cannot be there, he ceases to be there.  This suggestion is then underscored later, in connection with Panda.  Oldest João informs him that Otávia the rich businessman can no longer exist because Young João is back on his original track to being a scientist instead of a gazillionaire investment tycoon, and he promptly dissolves.  Then Older João and Oldest João somehow come to the point where they can't be there, either, and they also dissolve.

The critical problem I have with these departures is that it's not at all clear to me that at that point those people cannot possibly be there.

The easy one to see is Panda.  We know that in what we are making the fourth history (the second one in the movie) Panda becomes incredibly wealthy as João's partner in Man of the Future Investments.  We also know that he got that way because Older João gave Young João a lot of information about the future of the financial world, so that Young João could buy Google and other hot ticket stocks and sell them at the right time.  Now it is clear that Older João is not giving that information to Young João, who is not going to marry Helena and become a seemingly prescient investor, and thus Panda can't get there as his partner--but that doesn't mean Panda can't become a wealthy businessman.  After all, in the history in which Older João delivered this information to Young João, it was Panda who took notes, who wrote down all the details; it was undoubtedly Panda who kept those records and launched most of those investments over the years.  The businessman Panda standing there does not need Young João to know anything; he can walk out of that room, find Young Panda, and give him all the information he needs to know to become rich without João.  It might have become less probable; it might work out differently--but his existence has not become impossible in the sense they seem to be suggesting.

The same can be said for each of the time travelers:  at the moments of their respective departures, their future existences have become less and less probable but not impossible.  Thus the trigger for their return to the future is not really viable.  In fact, we cannot be certain that any of them could not possibly exist similar enough for the purpose of the film until they in fact fail to be the same person departing from the future.

Oh, but they are at that point different persons.  Certainly they are--they are all different from the moment they encounter a time traveler.  We can be certain that Young João did not meet his older self in the original history, and therefore Older João had no memories of having met himself before when he arrives in the past.  This is reinforced further when we observe the replay of the scene in which Older João is trying to tell Young João to stay calm and trust him, and Oldest João appears, disrupting what had happened in the previous version of history.  Otávia, too, is changed when he sees Older João at the party; when the history immediately around people changes, those people change.  The argument is that those aren't relevant changes, but how does the universe know what changes are relevant?  No, the idea that someone's presence in the past has become impossible can only be maintained when we reach the moment from which they departed in the future.

It's a clever notion, but it simply doesn't work.

Although four times we see characters leave the past, we only see two of them arrive in the future, and their arrivals introduce us to a host of inconsistencies.

The first departure to the past is made by the one we are calling Older João, and the clock on the computer says that it occurs at 2:53 in the afternoon on July 28th, 2011.  We know that the traveler lands on Novemember 22, 1991, during daylight.  He leaves the world sometime that evening, after preventing Young João from becoming a laughingstock and instead setting him on the course to become incredibly wealthy.

It is evident that he arrives in the future.  We could not guess whether he is in the body he took to the past or the body that grew up in this universe, but he is dressed in the clothes of his other self and sleeping in that self's bed, so he has apparently replaced his self.  He has complete memories of the history he has erased, and no memories of the history through which his other self must have lived.

I thought at first that he must have leapt to the moment when Young João ceases to exist because he failed to travel to the past to give himself the necessary information about the future, but the clock tells us that it is 9:26 on November 22, 2011--almost four months after the original departure--and it is daylight outside, so it must be nine in the morning.  This is not a random moment, exactly--it is twenty years to the day after the party, but in the morning.  It could be twenty years to the minute after his original arrival in the past, but we don't have the means to verify that.  The immediate problems are that this moment does not make any sense, that is, there is no reason for him to appear now, and we have no explanation for why he has replaced his other self.

Arguably, when his other self failed to travel to the past, he ceased to exist and was replaced by the original version of himself.  However, that being the case his younger self ought to have ceased ever to have existed (that is, as different from his other self), and there should be no Man of the Future Investments, no marriage to and divorce from Helena, no fight with Panda--if Young João has been "unmade", then certainly everything Young João ever created has also been "unmade".  At the moment João fails to travel to the past, we should revert to the original history in which no one traveled to the past, and we have an infinity loop.

Had they done that, we would have missed a good story, so let's just acknowledge that at this point the story has become impossible, and move forward with it, because we have some more inconsistencies ahead.

Sometime after that arrival in November, 2011, João gets Panda to agree that murder-suicide is not as good a plan as attempting to restore the original past, they complete and activate the particle accelerator that this time Sandra has been building, and the character who now becomes Oldest João leaves for the past.  He also arrives on November 22, 1991, only after sunset so he has to hurry to reach the party.  Notably, he came in costume, wearing an astronaut suit.  He interferes with Older João's efforts to change Young João's life, and then Panda dissolves into the future followed by both Joãos.

The only one of those we see arrive in the future is Oldest João, but this is where we have our major inconsistencies.  He arrives inside the time machine an instant--possibly no time at all--after his original departure, that is, the departure of Older João.  That is almost four months before his own most recent departure.  Further, he is not wearing the everyday clothes worn by Older João when he was there, but the spacesuit that he wore when he departed in the future--a spacesuit which, by all logic, must already be somewhere, wherever Oldest João originally got it before leaving for the past.  There is nothing the same about the two returns.

Note, too, that in restoring the original history and arriving four months before he arrived last time, he undoes the world to which Older João returned, and so undoes his own second trip to the past.  Further, he proceeds to delete all data and operating systems for the time machine, so even if somehow Older João arrives in four months and they meet him and persuade him of what he has to do, they have no way to send him to the past.  Again we have an infinity loop.

Travel to the future does not normally create anomalies except when it is coupled with travel to the past.  In this case, both trips to the future undo themselves, and we have multiple disasters.

This also leaves us with two other questions:  what became of Older João and Panda when they left the past?  Oldest João tells Panda that this version of him never existed, but that was also true of the version of Older João who wound up replacing Young João in November 2011; why doesn't businessman Panda replace lab assistant Panda?  It is evident that this did not happen because when Oldest João returns Panda is oblivious to the possibility that anyone might have traveled to the past, even though he himself had done so.  Nor will the argument hold, that since the trip Panda made to the past has been unmade that version of him never existed and never traveled to the past--the same is clearly true of Older João when he arrives in Young João's bed.

As to Older João, we saw that when he left the past the first time he went to Young João's bed in the future.  That future no longer exists.  Where does he go?  If he doesn't make the trip back from November 2011, Oldest João ought to cease to exist; but it seems that if he arrives in 2011 he has to bump Oldest João out of the body and become the João in the future.  We know that this does not happen, because it is still Oldest João a year later in court.

So the film is completely inconsistent in what happens to those whose time in the past ends.

There is separate problem surrounding the trip Panda makes to the past.  It has to do with the moment of his departure.

To reset the coordinates, that is, to orient ourselves, we need to remember that for twenty years this Panda has been partnered with Young João, and having just lost a lawsuit trying to claim part of their joint venture and having been persuaded by Older João that murder-suicide is not the answer, he helps Older João depart for the past to fix things.  We are subsequently told that a few minutes after Older João departed, Panda decided that it would be easy to do, and followed him.

At some point João says that he has invented the "end of time machine".  His observation is that once the world has this technology, governments, corporations, movements, just about anyone who doesn't like the way the world is will be able to use the machine to change it to something preferred, and the war over controling history will prevent the existence of a future.  But that's true at the moment of his departure from November 2011:  he has gone to the past to change the past, and anything that happens after the moment he departs happens in whatever world it is that he creates.  It is reasonably certain that one of the chief characteristics of that world is that João and Panda are not wealthy businessmen but college professors; Panda the businessman cannot follow João to the past because the moment João departs for the past Panda the businessman ceases ever to have existed--twenty years of history being altered effectively in that instant, such that they were always otherwise.

The film doesn't want that to be so.  It wants the future to exist up until the instant the people in the past make it impossible.  We have already seen how shakey such a notion is, but in shorter terms if those in the past are going to make the future impossible, they have certainly done so before the future arrives, regardless of whether it took them ten seconds or ten years.  There is no moment from which businessman Panda can depart to follow João, because at the instant João leaves to change the past, the past has been changed for twenty years, and such a moment in which businessman Panda exists will never arrive.

The fact that Panda dissolves when João has prevented the creation of Man of the Future Investments, as doubtful as that is, underscores this:  the Panda who could not possibly exist at that moment even more could not have existed twenty years in the future of the world created by Oldest João.  He would not have dissolved; he simply would not have existed.

At one point João tells Helena that she knows how to fix a quantum paradox, which is what they are experiencing.  She returns the answer, by cancelling the matrix of the multiplication of variables.  They have to restore the original future.

We have two obvious problems with this.

The first is, it is evident that they do not restore the original future.  We have created a version of history which is most probably very like the original future, but the future they restore is one in which a time travel event has already altered the past such that Sandra becomes rich.  The second is, it is also evident that João takes steps to alter the future, giving Sandra the information she needs to make him and Panda rich twenty years in the future.

Of course, what he wants to do is impossible.  By traveling to the past to "fix" history he is actually increasing the number of variables.  The only way he could restore the original history would be by preventing anyone from traveling to the past at all--and in so doing, he would restore that history which ended in him traveling to the past, creating an infinity loop.  He does not mean that he intends to restore the original history.

Rather, what he means is that he intends to attempt to create a version of the future which is similar enough to the earliest version of history he remembers (and for some reason he remembers the second altered history but not the first, very little of the third, and not the original) that the differences are not going to be critical.

He is almost right.  However, the problem is that in restoring this history he creates the anomaly that no version of him is going to exist to do what he is doing, so again we have an infinity loop.

The solution simply doesn't work.

In the denoument, João says that eventually someone will make the same discovery he made.  Helena responds that hopefully they will reach the same conclusion, that it is mistake to change the past, and a mistake that people will be eager to make once the secret is known, so they need to keep it secret.

They are of course correct in this:  if something is discovered, it is ripe for discovery.  João might have been the only person in the world working in the direction he chose, and his research will never be published, but the simple fact that Sandra was working in the same direction in the version of history in which João was not demonstrates that others will get the same idea.  Further, the more time passes, the more advances are made, and the more people will begin exploring the same technology João was exploring.  Another time machine will be built.

Of course, it was to some degree João's hubris that led to the discovery of time travel.  He insisted on sitting inside the machine.  No one outside the machine was affected.  Once someone deduces that a miniature black hole is created inside the machine, no one is going to want to be inside it when it is activated.  The fact that others see this as a potential source of electrical power does not mean that anyone else will be sent to the past.  It could go undiscovered for decades, even generations--but not forever.

Unfortunately, there is no way that João, Panda, Sandra, and Helena can communicate the lesson they learned, not to change history, without revealing that the direction they were working led to the discovery they want to hide, the creation of a time machine.  Someone won't learn the lesson until too late, and then history will come to an end, just as João predicted:  it is the end-of-time machine.  Niven's Law seems to apply in a very different way here than most people expect.

O Homem Do Futuro, a.k.a. The Man From the Future, is a very clever and very enjoyable film with a lot of good insights into time and time travel.  It is unfortunately also laced with inconsistencies, impossibilities, and temporal disasters.  As a time travel story, it fails.

The idea that love must be part of the unified equation of the universe is a fascinating notion, entirely unscientific and yet from an Intelligent Design perspective perfectly plausible.  The idea that the invention of a time machine would mean the end of time is quite insightful and well demonstrated.

Overall, I recommend the film, not because it got any of the time travel aspects right, but because it presented some significant issues in temporal questions in the context of a very enjoyable story.  Kudos across the board.