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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Crying wolf

While I understand being deeply fascinated with a specific subject, there's a point at which an interest becomes an idée fixe.  The result, especially for a scientist, is such a single-minded focus that it can cloud judgment with regards to the strength of the evidence.  We've seen that here at Skeptophilia before -- two examples that immediately come to mind are the Sasquatch-hunting geneticist Melba Ketchum and the British proponent of extraterrestrial panspermia, Chandra Wickramasinghe.  And the problem is -- for them, at least -- their obsessions have had the effect of completely destroying their credibility in the scientific community.

I can already hear the objections -- that (1) said scientific community is a hidebound, reactionary bunch of sticks-in-the-mud who resist like mad any new ideas, and (2) there are times the mavericks have been vindicated (sometimes after a long and arduous battle to get someone, anyone, to take them seriously).  The former can sometimes be true, but almost all scientists are well aware that groundbreaking ideas -- as long as they are supported by adequate evidence -- are how careers are made.  Look at the list of Nobel Prizes in the sciences in the past fifty years if you want examples.  Virtually all of them were awarded for research that expanded our scientific models dramatically (in some cases, overturned them entirely).  

As far as the second -- that sometimes the fringe-dwelling researchers who say "our entire prior understanding of the science is wrong" turn out to be correct -- okay, yeah, it happens, but if you consider the history of scientific paradigm shifts, what will jump out at you is how seldom that actually occurs.  The Copernican/Galilean/Keplerian heliocentric theory, Newton's Theory of Gravity, Maxwell's and Faraday's studies of electromagnetism, the Germ Theory of Disease, Einstein's Theories of Relativity, quantum/atomic theory, thermodynamics, Darwin's evolutionary model, Hubble and the Big Bang, the gene as the carrier of inheritance, and the plate tectonic model of Vine and Matthews. 

And that's about it, in the last five hundred years.

The point is, we're in a position now where the amount of evidence amassed to support the edifice we call science is so colossal that the "it could all be proven wrong tomorrow" objection I used to hear from my students (especially the lazy ones) is about as close to absurd as you want to get.  Sure, there will be some modifications made to science in the future.  A few -- probably very few -- will be major revisions.  But there's no reason to think that science as it stands is in any way unstable.

And people who come at it with earthshattering claims based on extremely slim evidence are almost certainly wrong.

Which brings us to Avi Loeb.

Loeb is an astrophysicist at Harvard University who has garnered significant notice (and notoriety) in the past few years from his fixation on the extrasolar source of some astronomical objects.  (By extrasolar I mean "originating from outside the Solar System.")  In 2017 he made headlines by claiming that the oddball astronomical object 'Oumuamua was not only extrasolar -- something fairly certain given its trajectory -- but that it was the remnant of a spacecraft from an intelligent extraterrestrial civilization.  Since then, his obsession with extraterrestrials visiting the Solar System has become so intense that it has drawn unfortunate comparisons with this guy:

The latest salvo from Loeb et al. is a sample of metallic beads scavenged from the floor of the Pacific Ocean near Papua New Guinea, that Loeb says are the remnants of a meteor that exploded in 2014.  So far, nothing to raise an eyebrow; meteoritic debris is cool but hardly uncommon.

But (as always) he goes one rather enormous step further, and claims that the meteor it came from was extrasolar, and the concentrations of metals in the beads indicate the object that exploded may have been an alien spacecraft.

Look, I'm as eager as the next Doctor Who aficionado to have a meet-cute with intelligent aliens.  (As long as they don't turn out to be Daleks, Sontarans, or Stenza.  I do have my boundaries.)  Hell, the way things are going down here on Earth, I might even ask to be taken on as a crew member when they leave.  But if you're asking me to believe you have bits of an alien spaceship, I'm gonna need more than a few oddball microscopic metal beads.

Extraordinary claims require extraordinary evidence, as Carl Sagan used to put it.  And this ain't it.  

At the moment, Avi Loeb is increasingly reminding me of a famous character from fiction -- The Boy Who Cried Wolf.  I have no problem with Loeb and his friends continuing to search; maybe (to quote a luminary of the field) The Truth Is Out There, and Loeb's dogged determination will eventually pay off.  But the problem is, there's a significant chance that (like The Boy in the fable) if he ever actually does find the hard evidence he's looking for, by that time he'll have exhausted people's patience to the point that everyone will have stopped paying attention.

So sorry to rain on the UFOs-and-aliens parade, but me, I don't think we've got anything here but some pieces of a curious metallic meteorite.  Worthy of study, no doubt, but as far as what it tells us about extraterrestrial intelligence, the answer seems to be: nothing whatsoever.

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