The Doomsday Equation and the Second Coming

The Book of Zachariah has a prophecy about the Lord splitting the Mount of Olives in two in the last days to save Israel at the last battle. I don’t know if that is how it is going to go down, but I like the symbolism of Christ as the second Moses dividing the land to save Israel from its enemies like Moses divided the water to save Israel of old from its enemies. 

The Second Coming and the nastiness preceding it is a somewhat passe topic for more intellectual types (although certainly not for the proverbial high priests in conservative small-town branches), I suspect largely because there has been a long history of crying wolf on the subject. Ever since the early Christians people believed that the Second Coming was nigh (although, if we really appreciate deep history of our species and planet and how incredibly long it is, “coming quickly” could be a relatively long time when measured against our lifespans). We certainly have not been immune to this in our own tradition, including with Joseph Smith, who I have the sense personally thought that the Second Coming was coming sooner rather than later (although others who know more can probably chapter and verse that belief in a primary source somewhere).

Outside our tradition, it seems like every couple of years somebody figures out a clever, unique way to recalculate the numbers in Revelations that shows that the Second Coming is a few years off (as a side, for-fun project after I’m retired I’ve always wanted to do a mathematical history of end-of-the-world calculations). While the end of the world is the traditional purview of traditional, conservative religionists, recently a variety of quasi-religious, quasi-scientific, almost new agey beliefs surrounding things like Simulation Hypothesis or the Singularity have also taken on the apocalypse. One sort of interesting version of this is what is known as the Doomsday Equation (or Argument), a subject that I recently read a book about.

The Doomsday Argument is, in principle, rather simple. If we assume that the number of people who will ever live is fixed, then all things being equal it is more likely that we would find ourselves in the middle of all people who have ever lived than near the very beginning (or the very end, for that matter). For example, if we become an interplanetary species and there will be quadrillions of humans born before we die off, then it would be quite the coincidence if we happened to find ourselves at the very beginning of history (relatively speaking). On the other hand, if the Second Coming were coming tomorrow, it would likewise be very coincidental that we happen to find ourselves at the very end. The same principle has also been applied to, for example, the survivorship of institutions, companies, Broadway run times, species, and countries. For example, if we roughly assume that we are the middle case, then the United States will survive for about 250 more years. Our survival as a species depends on a lot of different parameters, but in most cases it is unlikely that we will last for more than 20,000 or so more years.

The Church, following this model, will last for about 200 more years, unless the reference case is not years, but total membership, in which case it will be somewhat different. Here is the interesting part—if we believe that the Church will last as an institution until the Second Coming, then that actually puts Doomsday at around 200 to, say, 400 more years. We can also play around with this in terms of other religious parameters. There will be about 300 more temples built, a few more million missionaries sent out, 17 more Presidents of the Church, etc.

If this sounds a little woo, you aren’t alone, and I’m not sure what I think about its validity. The Doomsday Argument is one of those relatively rare but interesting cases where you can have extremely smart people on both sides—who think the other side is completely nuts (if you want to start a brawl yell “Monte Hall problem” in a room full of mathematicians).

Still, it kind of reifies the idea of the Second Coming. I was actually a little surprised when Elder Uchtdorf gave a talk on the subject some years ago for the reasons I note above. The Second Coming is juicy as a hobby horse subject and has been abused through the ages. Still, that does not mean that it will not, in fact, happen at some point, and scripture specifically warns us against not being caught off-guard by it.

Like Richard Bushman’s point about the golden plates being unique in religion because it gave the new faith a sort of live-or-die tangibility, the Second Coming is the ultimate in religious tangibility, the point at which faith is removed from the equation (at least in terms of religious knowledge) because God will come down and be seen by all, and I suspect that that kind of concreteness, combined with the long, tragicomical histories of apocalyptics throughout history, does make some of the more highbrow religionists nervous. But one of these days that curmudgeonly high priest will, in fact, be right.

7 comments for “The Doomsday Equation and the Second Coming

  1. Jesus splits the world in these end times to bless the saints and curse the non-believers so that they too might repent. Choose wisely, especially your politcal leaders. Word has it a true saint is on the ballot for Utah Governor this year, Jesus is his running mate.

  2. The Second Coming is not the end of people being born. While we have no idea of the relative numbers, there very well may be more people born in the 1,000 years of Millenial existence than in the previous years of the earth’s existence combined. Or, in fitting with your premise, perhaps it is precisely in the middle :-)

  3. Stephen, for the history of LDS apocalypticism and how it fits into the American background, you should take a look at Chris Blythe’s Terrible Revolution – it’s excellent. Personally, I think it’s impossible to understand Christianity without apocalypticism, but it’s very easy to go overboard with it. End time speculation doesn’t seem to be constant, though. Europeans around the year 1500 were very caught up in it, but there’s not much from around 1000 AD, if I remember correctly, while calculating dates for events in Revelation starts moving slowly from mainstream to fringe around 1700 or so.

    In any case, the Doomsday Equation is an interesting argument, but I’m not really convinced that its assumptions hold at all.

  4. My problem with the “Doomsday Equation” is that its predictions change depending on when you make them and by definition are way off a lot of the time.

    Take the Nephite civilization, for example. It actually lasted about a thousand years. But if Nephi used the Doomsday Equation he’d predict it would last a few decades at most. Enos would predict about a century. King Mosiah would get it right, but that’s not because he had superior insight or data–he just was lucky enough to actually live in the middle of Nephite civilization. Logically, the people who’d benefit most from a prediction that something is going to end are the people who will experience that ending, but that’s when the equation is most wrong. The Doomsday Equation would tell Mormon Nephite civilization will last another thousand years!

    You have a similar problem when population is involved. A classical Greek philosopher could observe that if humanity were someday going to grow to billions and billions of people, then it would be quite a coincidence he finds himself at the beginning of history. And it is, but it has to happen to somebody.

    Insofar as the Doomsday Equation makes plausible predictions, it’s because how long something has lasted tells you something about the probability of it failing in a given period (i.e. the hazard rate). But it always predicts that the probability of failure “soon” is zero, and that’s clearly wrong.

  5. John: Good point re the Millenium, hadn’t thought of that.

    Jonathan Green: I had it in the back of my mind that I wanted to get to it sometime, but I never put it on my to-read list until two seconds ago.

    RLD: So I do agree that it smells a little fishy, but I think the response to your particular concern would be that while, yes, Nephi using the Doomsday Argument to predict the longevity of Nephite civilization would drastically underestimate its longevity, that the chance of drawing Nephi out of all Nephites would be commensurately small. Probabilistically a randomly drawn Nephite would be neither with Nephi nor Moroni.

  6. True, the probability of being off by 1,000 years is very small. But the probability of being off by at least 500 years is 50% (you’ll be off by more than 500 years if you’re in the first 250 years or the last 250 years, less than 500 if you’re in the middle 500 years).

    I guess it’s like any other statistical estimator: it gives good results insofar as the required assumptions are met. But “You’re in the middle of the thing’s existence” is an awfully strong assumption! And the behavior of the estimator as that assumption is violated (error = 2 * your distance from the middle) is not great.

  7. But one of these days that curmudgeonly high priest will, in fact, be right.

    I’ve actually wondered if that’s the reason the second coming hasn’t happened yet. God doesn’t want anyone to be able to say “I correctly guessed it”. So He’s waiting for a day/month/year that no one will guess.

Comments are closed.