Paradoxes and pointlessness

In his 1967 short story "Thus We Frustrate Charlemagne," writer R. A. Lafferty took one of the first looks at something that since has become a standard trope in science fiction; going back into the past and doing something that changes history.

In his hilarious take on things, some time-machine-wielding scientists pick an event in history that seems to have been a critical juncture (they chose the near-miss assassination attempt on Charlemagne in 778 C.E. that immediately preceded the Battle of Roncevaux), then send an "avatar" back in time to change what happened.  The avatar kills the guy who saved Charlemagne's life, Charlemagne himself is killed, and his consolidation of power into what would become the Holy Roman Empire never happens.

Big deal, right?  Major repercussions down throughout European history?  Well, what happens is that when the change occurs, it also changes the memories of the scientists -- how they were educated, what they knew of history.  The avatar comes back, and everything is different, but the scientists are completely unaware of what's happened -- because their history now includes the change the avatar made.

So they decide that Charlemagne's assassination must have had no effect on anything, and they pick a different historical event to change.  The avatar goes back to try again -- with the same results.

Each time the avatar returns, things have become more and more different from where they started -- and still, none of the characters inside the story can tell.  They can never, in C. S. Lewis's words, "know what might have happened;" no matter what they do, those alternate timelines remain forever outside their ability to see.

In the end, the scientists give up.  Nothing, they conclude, has any effect on the course of events, so trying to change history is a complete waste of time.

One has to wonder if Harvard astrophysicist Avi Loeb has read Lafferty's story, because Loeb just authored an article in The Debrief entitled, "The Wormhole Dilemma: Could Advanced Civilizations Use Time Travel to Rewrite History?"  Which, incidentally, is a fine example of Betteridge's Law -- "any headline phrased as a question can be answered with the word 'no.'"

Before we get into what the article says, I have to say that I'm getting a little fed up with Loeb himself.  He's something of a frequent flier on Skeptophilia and other science-based skepticism websites (such as the one run by the excellent Jason Colavito), most recently for his strident claim that meteoric debris found in the Pacific Ocean was from the wreckage of an alien spacecraft.  (tl;dr: It wasn't.)  

I know we skeptical types can be a little hard to budge sometimes, and a criticism levied against us with at least some measure of fairness is that we're so steeped in doubting that we wouldn't believe evidence if we had it.  But even so, Loeb swings so far in the opposite direction that it's become difficult to take anything he says seriously.  In the article in The Debrief, he talks about how wormholes have been shown to be mathematically consistent with what we know about physics (correct), and that Kip Thorne and Stephen Hawking demonstrated that they could theoretically be kept open long enough to allow passage of something from one point in spacetime to another (also correct).  

This would require, however, the use of something with negative mass-energy to stabilize the wormhole so it doesn't snap shut immediately.  Which is a bit of a sticking point, because there's never been any proof that such a something actually exists.

Oh, but that's no problem, Loeb says; dark energy has negative (repulsive) energy, so an advanced civilization could "excavate dark energy from the cosmic reservoir and mold it into a wormhole."  He admits that we don't know if this is possible because we still have no idea what dark energy actually is, but then goes into a long bit about how we (or well-intentioned aliens) could use such a wormhole to "fix history," starting with getting rid of Adolf Hitler and preventing the Holocaust.

A laudable goal, no doubt, but let's just hang on a moment.

[Image is in the Public Domain courtesy of artist Martin Johnson]

The idea of the altering of history potentially creating intractable paradoxes is a staple of science fiction, ever since Lafferty (and Ray Bradbury in his brilliant and devastating short story "The Sound of Thunder") brought it into the public awareness.  Besides my own novel Lock & Key, in which such a paradox wipes out all of humanity except for one dubiously lucky man who somehow escapes being erased and ends up having to fix the problem, this sort of thing seemed to happen every other week on Star Trek: The Next Generation, where one comes away with the sense that the space-time continuum is as flimsy as a wet Kleenex.  It may be that there is some sort of built-in protection in the universe for preventing paradoxes -- such as the famous example of going back in time and killing your own grandfather -- but even that point is pure speculation, because the physicists haven't shown that time travel into the past is possible, much less practical.

So Loeb's article is, honestly, a little pointless.  He looks at an idea that countless fiction writers -- including myself -- have been exploring ad nauseam since at least 1967, and adds nothing to the conversation from a scientific perspective other than saying, "Hey, maybe superpowerful aliens could do it!"  As such, what he's done is really nothing more than mental masturbation.

I know I'm coming away sounding like a killjoy, here.  It's not that this stuff isn't fun to think about; I get that part of it.  But yet another article from Loeb talking about how (1) highly-advanced alien civilizations we know nothing about about might (2) use technology that requires an unknown form of exotic matter we also know nothing about to (3) accomplish something physicists aren't even sure is possible, isn't doing anything but giving new meaning to the phrase "Okay, that's a bit far-fetched."

The whole thing put me in mind of physicist Sabine Hossenfelder's recent, rather dismal, video "Science is in Trouble, and It Worries Me."  Her contention is that science's contribution to progress in our understanding of the universe, and to improving the wellbeing of humanity, has slowed way down -- that (in her words) "most of what gets published is bullshit."  Not that what gets published is false; that's not what she means.  Just that it's pointless.  The emphasis on science being on the cutting edge, on pushing the limits of what we know, on being "disruptive" (in a good sense), has all but vanished.  Instead, the money-making model -- writing papers so you get citations so you get grants so you can write more papers, and so on and so on -- has blunted the edge of what academia accomplishes, or even can accomplish.

And I can't help but throw this fluff piece by Loeb into that same mix.  As a struggling writer who has yet to exceed a three-figure income from my writing in a given year, I have to wonder how much The Debrief paid Loeb for his article.  I shouldn't be envious of another writer, I guess; and honestly, I wouldn't be if what Loeb had written had scientific merit, or even substance.

But as is, the whole thing pisses me off.  It adds to the public perception of scientists as speculative hand-wavers, gives the credulous the impression that something is possible when it probably isn't, teaches the reader nothing most of us haven't already known for years, and puts another entirely undeserved feather in Avi Loeb's cap.

My general sense is that he was doing less harm when he was looking for an alien hiding behind every tree.

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Mysterious mountains

It's amazing how far human knowledge has come in only a hundred years.

Consider the following about the year 1924:

• This is the year we would figure out that there are other galaxies beyond the Milky Way; before this, astronomers thought the Milky Way was all there was.  They called the galaxies they knew about (such as Andromeda and the Whirlpool Galaxy) "nebulae" (Latin for "clouds") and thought they were blobs of dust within our own galaxy.  This marks the moment we realized how big the universe actually is.
• In 1924, the quantum nature of reality was still unknown; the first major papers by Heisenberg, Schrödinger, and Born would come out next year.
• It'd be another four years before the first antibiotic -- penicillin -- was discovered.
• It'd be five years before Edwin Hubble announced his discovery of red shift, which showed the universe is expanding and led to the Big Bang model of cosmology.
• We'd have another seventeen years before we'd see the first electron micrograph of a virus; before that, it was known they caused disease, but no one knew what they were or had ever seen one.
• It'd be another twenty years before DNA was shown to be the genetic material, and a good twenty years after that when Franklin, Watson, and Crick figured out its structure and the basics of how it works.
• The first papers outlining the mechanics of plate tectonics were still forty years in the future; at this point, the only one who championed the idea that the continents moved was German geologist and climatologist Alfred Wegener, who was pretty much laughed out of the field because of it (and ultimately died in 1930 on an expedition to Greenland).

It's the last one that's germane to our topic today, which is a largely-unexplained (and massive) feature of North Africa that goes to show that however far we've come, there are still plenty of things left for the scientists to explain.  It's called the Tibesti Massif, and largely lies in the far north of the country of Chad, with a bit spilling over the southern border of Libya.

It's a strange, remote, and forbidding landscape:

[Image is in the Public Domain courtesy of photographer Michael Kerling]

What's peculiar about it -- besides the fact that it looks like the "desert planet" set from Lost in Space -- is that its terrain was largely created by volcanism, despite the fact that it lies smack in the center of one of those "stable continental cratons" I talked about in my previous post.  It's got a very peculiar geology -- the basement rock is Precambrian granite, over which there's a layer of Paleozoic sandstone, but above that is a layer of basalt which is in some places three hundred meters thick.  Basalt is one of those mafic rocks I mentioned; iron-rich, silica-poor, and ordinarily associated with seafloor rift zones like Iceland and deep-mantle hotspots like Hawaii.  But over that are felsic rocks like dacite, rhyolite, and ignimbrite, which are usually found in explosive, subduction zone volcanoes like the ones in the Caribbean, Japan, and Indonesia.

What's odd about all this is that there's no mechanism known that would generate all these kinds of rocks from the same system.  The current guess is that there was a mantle hotspot that started in the late Oligocene Epoch, on the order of twenty-five million years ago, that has gradually weakened and incorporated lower-density continental rocks as the upwelling slowed, but the truth is, nobody really knows.

It's still active, too.  The Tibesti Massif is home to hot springs, mud pools, and fumaroles, some of which contain water at 80 C or above.

So we've got a volcanic region in the southern Sahara where, by conventional wisdom, there shouldn't be one, with a geology that thus far has defied explanation.  Some geologists have tried to connect it to the Cameroon Line or the East African Rift Zone, but the truth is, Africa is a much bigger place than most people think it is, and it's a very long way away from either one.  (It's about three thousand kilometers from the northernmost active volcanoes in both Cameroon and Ethiopia to the southern edge of the Tibesti Massif; that's roughly the distance between New York City and Denver, Colorado.  So connecting Tibesti to either the Cameroon Line or the East African Rift is a bit like trying to explain the geology of Long Island using processes happening in the Rocky Mountains.)

And the problem is, figuring out this geological conundrum isn't going to be easy.  It's one of the most remote and difficult-to-access places on Earth, hampered not only by the fact that there are virtually no roads but the one-two punch of extreme poverty and political instability in the country of Chad.  So even getting a scientific team in to take a look at the place is damn near impossible.  The geologists studying the region have resorted to -- I swear I'm not making this up -- using comparisons to research on the geology of volcanoes on Mars, because even that is easier than getting a team into northern Chad.

The idea that we have a spot on the Earth still so deeply mysterious, despite everything we've learned, is both astonishing and thrilling.  Here we sit, in 2024, as arrogantly confident we have a bead on the totality of knowledge as the people did back in 1924, despite the fact that history has always shown such confidence in our understanding is unfounded.  The reality is humbling, and far more exciting.  As Carl Sagan put it, "Somewhere, something amazing is waiting to be known."

I wonder what the next hundred years will bring, and if the people in 2124 will look back at us with that same sense of "how could they not have known that?"

Onward -- into the great unknown!

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