Bill DeSmedt's Blog: The Accidental Author

Dualism Redux!

Celebrating (if that's the word for it) the tenth anniversary of my technothriller Dualism, I was moved to bare the philosophical underbelly of that work on Academia.edu.

A foretaste:

Though admittedly a tough nut to crack, I’ve never been a big fan of the “interactionist” objection to Cartesian dualism (a.k.a. substance dualism) — even going so far as to design a thought experiment aimed at challenging this objection’s core assumptions.

Then, for kicks and giggles, I went and embedded said Gedankenexperiment in one of my technothrillers — the one entitled, aptly enough, Dualism.

In so doing, I guess I was being, as the saying goes, too clever by half. Because here it is, ten years on, and nobody seems to have gotten the joke hidden at its heart yet.

So, let’s take another run at this.

Triploidy Arrives!

 A medical mystery … and a threat from beyond the stars.

For Jon and Marianna Knox, the birth of their daughter Persephone marks the happiest day of their lives.

Until they learn that Persey is suffering from a rare but fatal condition called “triploidy.”

Her doctors are baffled, and with good reason — because the source of the little girl’s genetic malfunction is not of this Earth. It is just now passing the orbit of Saturn.

And it’s coming for all of us.

* * *

from the preface to Triploidy:

Shouting in the Jungle

Once upon a time, in a place not so very far, far away, there lived a man who was convinced that he knew better than the whole rest of the human race what was good for it.

That wasn’t the problem. There have always been such men, at all times and in all places.

No, the problem was, at this particular once-upon-a-time-and-place, this particular man was in a position to act on that conviction.

His name was Aleksandr Leonidovich Zaitsev, and his position was that of head of the Yevpatoria RT-70 Planetary Radar in Crimea — a facility which, boasting a parabolic dish antenna some seventy meters in diameter, ranked at the time of our telling as the third largest radio telescope in the world. More to the point, Yevpatoria was also the only installation of its size equipped, not only to receive signals from outer space, but to send them as well.

And it was this that Zaitsev intended to do. On the evening of May 24th in the penultimate year of the second millennium he pointed the Yevpatoria dish toward the heavens and transmitted the first of several so-called “Cosmic Call” messages.

Whatever their extra-literary historical significance, these messages were hardly paragons of style or substance: Basically a binary “Rosetta Stone” composed by Stephane Dumas and Yvan Dutil which proceeded from rudimentary arithmetic to higher order math and physics, supplemented with a smorgasbord of text, audio, and video from ordinary citizens around the world. If there was one worrisome feature of Dumas and Dutil’s contribution to Cosmic Call, it was that their “primer” included a representation of the nucleotides making up deoxyribonucleic acid, better known by its initialism: DNA.

Still, in the end it wasn’t the message’s form or content that mattered. Rather, it was the simple fact that, for the three hour and fifty-five minute duration of the transmission, the Yevpatoria signal increased the radio visibility of the earth by four orders of magnitude. Briefly, in its limited frequency band and along its narrow line of sight, the earth shone ten thousand times brighter than the sun.

It was, then, not without a certain cosmic irony that Zaitsev’s surname derived from “zayats” — the Russian word for “rabbit.” Because he was indeed like some foolish little rabbit hopping down a dark and dangerous bunny trail, shouting at the top of his lungs, blithely advertising his presence to whatever predators might be lurking in the surrounding jungle.

And not just his own presence — all of Earth’s as well.

Zaitsev’s target on that lovely, late-spring evening was the yellow dwarf star 16 Cygni B, one hub of a triple-star system seventy lightyears away in the northwest corner of that patch of sky named for the constellation Cygnus the Swan. Or more precisely, not the star itself, but rather its companion world. For three years prior, in 1996, 16 Cygni B had become one of the first stars to be confirmed as hosting an extrasolar planet. True, 16 Cygni Bb, as the exoplanet was designated, was a super-Jupiter, weighing in at 2.4 Jovian masses, and as such an unpromising abode for the proverbial life-as-we-know-it. Still, where there was one planet, might there not be other, smaller, more hospitable worlds, as yet undetected, circling that same distant sun?

In any case, we wouldn’t have long — on cosmic timescales, at least — to wait before finding out: Zaitsev’s signal was scheduled to traverse the seventy light years from Earth to 16 Cygni Bb and arrive there in November of 2069. Allow, say, a year for the putative inhabitants to mull a response, then another seven decades for the lightspeed return trip to Earth, and we might hope to be receiving a reply along about the year 2140.

It was the possible form such a reply might take that rendered Zaitsev’s project deeply problematic, at least in some quarters. Even the doyens of the old Search for Extra-Terrestrial Intelligence (SETI) enterprise expressed reservations when contemplating the downside risk of this new Active-SETI endeavor — this initiative to dispense with decades of passive listening in favor of actually doing something.

Those downside risks were not inconsiderable. Did we really want, the Cosmic Call critics cried out, to call attention to ourselves, when for all we knew our transmissions might be received by some real-world equivalents of H. G. Wells’ “intellects vast and cool and unsympathetic,” beings who might — out of paranoia or sheer malevolence — reply with relativistic impactors or cosmic computer viruses or interstellar laser beams that would set our sky aflame?

Zaitsev would have none of it. Dismissing the handwringing of the naysayers as “idle and pseudoscientific,” he vowed to carry on. And, given he had access to the requisite technology, how could anyone realistically hope to stop him?

In point of fact, Zaitsev was right: None of his detractors’ nightmare scenarios would come to pass.

What would come to pass instead was much, much swifter and much, much worse.

* * *

For, in another, unimaginably further removed time and place, a wise and ancient race, after eons of godlike accomplishment, had, for their own unfathomable reasons, collectively resolved to depart the plane of material existence.

But not before leaving behind, in their terrible benevolence, a parting gift.

* * *

That gift takes the form of a spherical wavefront, a globe of coherent light expanding ever outward from its point of origin, now irretrievably lost in time and space, but currently moving through one of the spiral arms of the Milky Way galaxy.

It is a wavefront with a difference, overlaid with cunningly crafted interference patterns that split a portion of its beams off from the prime vector and bent them back in a “delay line.” Of such elemental circuitry is fashioned the functional equivalents of XORs and NAND gates and the rest of the low-level instructional menagerie that make up the firmware of a standard computer.

Save that this computer’s “ware” is decidedly not “firm.” Rather, it is a gossamer, its components forged of trimeric light. That is, light endowed with an infinitesimal smidgen of mass — and hence made capable of interacting with itself — by binding triplets of its constituent photons into the bosonic equivalent of molecules.

Save also that, inspirited by architectures of superhuman subtlety, all those simple intangible piece-parts are capable of self-assembling into something no mere earthbound computer can hope to match — a photonic intelligence.

An intelligence tasked with a single purpose: to bestow the blessings of its creators’ beneficence on any and all inhabited planets within its ever-expanding ken.

Admittedly, it is not much of an intelligence. Smeared out across the surface area of a sphere already some tens of thousands of lightyears in radius and growing all the time, that which propagates outward in all directions from its long-lost source is by now a mere shadow of its original self — a photonic entity that, after a seeming eternity of attenuating dilation, boasts all the smarts of your average amoeba.

It is, in fact, just smart enough to detect, at any given point on its enormous capture surface, one of a small number of trigger events.

The least significant of such triggers is the sort of transmission represented by the Cosmic Call, still only twelve years along on its seven-decade journey to 16 Cygni Bb at the moment when it intersects the wavefront which is the entity. In and of itself, Zaitsev’s four-hour message burst might seem too transitory, too weak, and too primitive content-wise to warrant attention. But interstellar space is vast, and life-bearing bodies are few and far between. Even the least promising candidate for Transfiguration deserves, at a minimum, some consideration.

The entity marginally alters its incorporeal internal dynamics to bestow that minimum: Rippling outward from the point of intersection, the wavefront ceases to expand, begins to fold back in on itself. Refractive structures coalesce to focus light and logic on the bare-bones intellect which had first encountered the message from earth, augmenting its processing power, and with that power, its perspicacity, until at last the nascent photonic entity achieves a modicum of mindfulness.

And waits to see what would happen next.

* * *

… What would happen next was once upon this time.

Tripoidy, the third book in Bill DeSmedt’s Archon Sequence, is now available on Amazon —

Just click here.

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Tunguska Seminar 07.1

The Aleph —

By Dr. John C. (“Jack”) Adler, as told to Bill DeSmedt 

Last time, we looked at the anatomy of a black hole, what little there is of it (just mass, spin, and charge, remember?).

More particularly, we looked at its core singularity, and at how an event horizon keeps that part quarantined from the rest of the universe. And we closed with a hint that maybe that wasn’t always and everywhere the case.

What we’re talking about is called a “naked singularity” — one that isn’t decently veiled by an event horizon. And the question here is: is such a thing even possible?

A lot of physicists are really hoping it’s not. Back in the day, Stephen Hawking had declared naked singularities to be anathema. Roger Penrose went one him better: Sir Roger’s “Cosmic Censorship Conjecture” claimed that Mother Nature herself forbids a singularity from exposing itself in public.

But calling something a conjecture is really just a fancy way of saying it’s a guess (my own Vurdalak Conjecture being no exception). And Sir Roger’s guess hasn’t been doing all that well lately: Back in the early nineties, Stephen Hawking bet Kip Thorne 100 pounds and a T-shirt that nature would never allow a naked singularity to form.

By 1996 he’d paid up.

Because that was the year Matthew Choptuik, doing some supercomputer simulations at my alma mater U. Texas, Austin, found the first stellar-collapse configuration leading to full-frontal singularity. Ever since then seems like somebody comes up with a new way to do that every other year or so. It’s looking like the cosmic censors are whistling in the dark.

Still, I know where they’re coming from. As a group, physicists have got a lot riding on the proposition that the cosmos is a nice, dull, predictable place. And a naked singularity would sure stick a burr under that saddle.

Fair warning: this’ll be kind of a detour. Still, it doesn’t seem fair to keep on rattling on about how weird singularities are, and never get around to describing the weirdness itself. So, if you’ll bear with me a minute here, we’ll try to lift the hem of Mother Nature’s garment and take a peek.

To begin with, let’s imagine we’ve somehow stripped the event horizon off of our singularity, and it’s standing there in what my granddaddy’d call its bare nekkids. Well, what’s it look like?

If only I had a nickel for every time somebody’s asked me that one!

 But try thinking about it like this: The singularity’s just a point source. You wouldn’t be able to see the thing itself at all — it’d be too infinitesimally tiny. What you might see would be instantaneous cross-sections of all the world lines caught up in its vortex.

                                                         * * *

Worldlines take some explaining in their own right. Think of the path of an object through time and space, as if you could see it from outside — a God’s-eye view maybe. From hyperspace, all the moments of your life blur together into a continuous four-dimensional “tube”: It splits off from your mother the moment you’re born, and comes to an end (or maybe not) at the hour of your death. Slice through the tube anywhere along its length and you’ll get a three-dimensional cross-section — a cross-section that is you yourself at that particular moment in time.

Or think of it like a motion picture: if every instant of your life, every “now,” were a single frame in a movie, then your worldline would be the whole reel taken together, considered as a single continuous entity.

Now think of everything and everyone tracing out a worldline path through space and time like that. And imagine all those worldlines — at least the ones local to earth — getting tangled up in a black hole. Then, assuming you could gaze into that hole’s singularity, it’d be like seeing all of recent history, only with everything all jumbled together and happening at once.

Last time I taught Astrophysics for Poets 101, a lit major came up to me after class and told me how that all reminded her of a story called “The Aleph.” Turns out Jorge Luis Borges, the Argentinean fantasist, wrote this short story about a funny-looking sphere someone finds in the basement of a Buenos Aires apartment.

Now, strictly speaking, aleph is the name of the first letter of the Hebrew alphabet (which later gets itself transmuted into the Greek alpha). It’s also the designation that Georg Cantor, the creator of set theory, gave to the class of sets of transfinite numbers, starting with Aleph-Null, the (infinite) number of all integers and going on up from there.

All of which may or may not have a bearing on Borges’ Aleph, which is only about an inch across, but somehow manages to encompass everything in existence — lions and tigers and bears, and such.

Stare into this Aleph and you’d see … well, here, Jorge tells it far better than I ever could:

    I saw tigers, pistons, bisons, tides, and armies; I saw all the ants on the planet; I saw a Persian astrolabe; I saw in the drawer of a writing table (and the handwriting made me tremble) unbelievable, obscene, detailed letters…

    In that single gigantic instant I saw millions of acts both delightful and awful; not one of them amazed me more than the fact that all of them occupied the same point in space, without overlapping or transparency. What my eyes beheld was simultaneous…

    …and I felt dizzy and wept, for my eyes had seen that secret and conjectured object whose name is common to all men but which no man has looked upon — the unimaginable universe.

That’s about as good a guess as to what a naked singularity might look like as any, I’d say.

References

Jorge Luis Borges, “The Aleph,” in Jorge Luis Borges, Collected Fictions, translated by Andrew Hurley, Penguin, 1998.

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Tunguska Seminar 06 —

Beyond the Black Horizon

By Dr. John C. (“Jack”) Adler, as told to Bill DeSmedt

When we left off last time, we’d just got done scrunching several suns’ worth of mass down into a black hole. Now it’s time to take a look inside, at what’s called a “singularity.”

Calling something a singularity is just a polite way of saying it’s impossible. Whenever an equation breaks down and starts churning out meaningless results — infinities and the like — well, us astrophysicists find that real “singular.”

It turns out that Einstein’s theory of relativity suffers just that kind of breakdown when it tries to describe what goes on inside a black hole. In particular, the field equations predict that what we’ll find at the center of the hole is a dimensionless point of infinite mass, infinite density, infinity curvature, infinite what-have-you. In short, a singularity.

All this is really bad news for modern physics. And I don’t just mean the part about the tensor calculus spitting out impossibilities. No, all kinds of bad things go on in Mr. Singularity’s Neighborhood. General Relativity says that gravitation is equivalent to acceleration, you see, and that enough acceleration will do really weird stuff to time and space. So an infinite gravitational field is something physicists would just as soon not deal with.

Luckily enough, they mostly don’t have to. Because there’s a silver lining to this particular black cloud — namely, that singularities just naturally wall themselves off from the rest of the universe.

It’s called an “event horizon.” You could think of it as job security for physicists. It’s there to make sure that all the paradoxes riddling the inside of a black hole can never get out to pollute the universe at large.

Now, for something so simple, this event horizon idea seems to’ve stirred up an awful lot of confusion over the years. Sometimes you’ll hear people talk about it like it was a physical barrier or some such. There’s even a Star Trek episode (the one called “Parallax”) where the starship Voyager escapes from a black hole by scooting through a “crack” in the event horizon!

That episode won a place of honor on Lawrence’s Krauss’s top-ten list of all-time Star Trek bloopers. Because, with apologies to Captain Janeway, the whole notion is just plain silly. It’s not like an event horizon was the sort of thing that could develop a hairline fracture. In fact, it’s not a physical object of any kind, no more so than that old, familiar horizon we watch the sun set behind every day.

With one big difference: you could walk forever and never reach the horizon here on earth, whereas it’d be all too easy to reach, and cross over, the event horizon surrounding a black hole.

Because what an event horizon really is, is just the mathematically-defined dividing line (dividing sphere?) between a singularity and the rest of the universe. It’s the point — the collection of points, actually — of no return. Cross it, and there’s just no turning back. Not even for a beam of light.

Any light that falls into a black hole gets trapped there too, remember?

Why is that, exactly? After all, it’s not as if gravity, even a black hole’s unimaginable gravity, could actually slow light down. Physicists have recently learned how to do that in a laboratory, using a special state of matter called a Bose-Einstein condensate, but it never happens in nature, far as we know.

So, how does a black hole trap light?

Here’s one way to think about it: Imagine you’re trying to climb a ladder out of a really, really deep hole. Doesn’t matter if you go fast or slow; as long as you keep climbing, you can’t help but make it eventually — or so you think.

Now, it’s going to be a long climb, so you’re going to want to bring some food along and stop every now and again to have a snack. Let’s say you go up a mile, then take a Snickers break. That gives you the energy to keep going.

But what if the pull of the gravity you’re fighting against is really strong, so strong it takes more energy to lift that candy bar a mile than you’ll get back by eating it? That makes your Snickers break a losing proposition — you’d have done better to leave the food at the bottom.

Of course, even weighing in at just a few ounces, your average candy bar’s pretty heavy compared to its nutritional value. You’d be a lot better off with something you could turn completely into energy — a candy bar, say, where the ingredients label reads “chocolate, sugar, almonds, anti-matter.”

But even that anti- Snickers has still got a finite energy content. If the gravity’s strong enough and the ladder’s tall enough, you’re still going to wind up burning more energy lifting that candybar than it can ever give you back. Meaning that, at some point short of the top, you’re just plain going to run out of steam.

Even so, it’s not like gravity’s crushing you to the floor. You can still climb. You just can’t climb all the way to the top. All the gravity in the universe won’t slow light or hold it back — but it can rob it of energy. Partway out of the hole’s gravity well, it just runs out of energy and ceases to exist! And light’s pure energy, no excess baggage. If light can’t make it to the top, neither can anything else.

Or here’s another way to look at it: Like we said last time, General Relativity tells us that gravity warps spacetime. What that means is an object with enough gravity can take all the possible escape routes away from that object and bend them back on themselves. Light’s still travelling as fast as ever, but it’s doing that travelling inside a curved space, where all roads lead back to the singularity at the center.

So whatever crosses the event horizon can’t ever “talk” to anybody on the outside ever again. A careless experimenter who slips and falls into the hole can’t tell us what his instruments read. And, considering how weird things can get down at the singularity, that’s a good thing.

Other than that, though, there’s really nothing to the event horizon itself. With a large enough hole — here I’m talking millions or billions of solar masses, like the ones at the centers of galaxies — with a hole like that you could cross right over the event horizon and never notice the difference. Until you realized you couldn’t get back out again, that is. Once you’re trapped inside an event horizon, all roads lead downward, to the singularity.

Here’s maybe the place to point out, though, that not all physicists are convinced this story’s right. In particular it’s been suggested that the gravity of a supermassive object should slow time itself to a dead stop at the event horizon. That’d mean it would take an eternity or more for anything to actually fall in — all the infalling stuff would just get “stuck” at the horizon. That’s from the perspective of the outside universe, anyway. You’d tell a different tale if you were the one doing the falling — as we’ll see in a minute.

Meanwhile, precisely because nothing can get ever out, black holes as seen from the outside are really simple objects. It doesn’t matter what the matter that went into them was in its previous life: Two or three solar masses worth of used TV sets’ll do just as well as the same weight of lottery tickets or butterflies or (in the case of a supernova) stellar core material. Or anti-matter, or pure energy, even. The end result is always the same. All that the final collapse leaves behind is mass and, optionally, spin and/or electromagnetic charge.

And that’s it. As Princeton physicist John Wheeler put it: black holes have no “hair” — no other distinguishing traits. Like a prisoner-of-war refusing to give his interrogators any more thanjust  his name, rank, and serial number, a black hole will tell you its mass, spin, and charge, but nothing else.

(Well, and maybe not. Toward the end of his life, Stephen Hawking came up with some new work that threatens to upset the applecart once again. Seems quantum fluctuations at the event horizon may cause a hole to eventually regurgitate, in a “mangled” form, all the matter it’s ever swallowed. The jury’s still out on this one, but folks like Leonard Susskind are hoping it’s right, because if matter and energy and information can really be destroyed the way classical black hole theory claims, then quantum mechanics is wrong.)

But, be that as it may, even given only mass, spin, and charge to work with, black holes can still conjure up some mighty strange effects.

Like frame drag, for instance. That’s where a spinning black hole pulls space itself along behind it in the direction of its rotation. That long-predicted effect was actually observed back in 2005, by a team out of the Harvard-Smithsonian Center for Astrophysics.

Or, my personal favorite, the tides.

Because, when you get right down to it, tides are nothing but a gravitational effect. Think about it this way: the moon’s gravity pulls on every atom of the earth. But that pull varies with distance. The atoms directly beneath the moon feel it strongest because they’re the closest, so they get dragged up toward the moon, away from the bulk of the planet. Those on the opposite side of the world, the ones furthest away, are getting pulled on the least, so they get left behind, relatively speaking. The upshot is: the whole planet gets stretched a little.

Now, the solid body of the earth itself is reasonably rigid, so it stays more or less round no matter how hard it gets pulled on. But the oceans are a different story; they get stretched out into an ellipsoid, with a bulge at either end. What that gives you is two standing waves of seawater moving through the oceans at twelve-hour intervals as the earth rotates beneath them. In other words, the tides.

With me so far? Then add this: That tidal effect isn’t peculiar to earth. It happens everywhere there’s a gravitational field. And the more intensely that field’s strength changes with distance, the higher the tides become. Get in really close to a singularity and its gravity gradient can produce tidal distortions across distances measured in micrometers or less. An object would need phenomenal tensile strength to survive a fly-by. As for a human being, you can forget about it! Come in too close, and you’d be stretched out like a piece of saltwater taffy — torn limb from limb, then atom from atom. It’s a process called “spaghettification.”

Bad as all that is, we can take comfort from the fact that the event horizon is always there to shield us from even worse.

… Or is it?

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Tunguska Seminar 05

A Black Hole Primer

By Dr. John C. (“Jack”) Adler, as told to Bill DeSmedt

Last time, you’ll recall, we were saying that maybe the key to the Tunguska riddle lies in the nature of primordial black holes, like the one the Jackson-Ryan hypothesis claims slammed into the earth that morning in June 1908.

So, what is it about really tiny black holes formed at the beginning of the universe that, all evidence to the contrary, might help that claim prove out?

We’ll get there, trust me. For now, though, maybe it’s better if we back up a bit and talk about black holes in general. Begin at the beginning, so to speak.

And, for a black hole, the beginning is gravity.

Now, the thing of it is, as forces of nature go, gravity’s just not that much to write home about. Compared to, say, the strong nuclear force, it’s a gossamer — the next best thing to nothing at all. Even plain old electromagnetism’s got it beat hands down. Ever pick up a three-penny nail with a toy magnet? Then you know how even a teensy bit of electromagnetic force can overcome the gravitational pull of the whole earth.

In fact, gravity is almost inconceivably weaker than electromagnetism: about ten to the forty-second power, or a million billion billion billion billion times weaker. To make that more concrete, try the following example thought up by string theorist Brian Greene: if the power in your left arm represented the force of gravity, then in order for your right arm to equal the force of electromagnetism, your bicep would have to extend out beyond the edge of the known universe!

This enormous difference between the two most common forces of nature is a real head-scratcher — a puzzle physicists call the “hierarchy problem.” Recently it’s been suggested that, the extra dimensions featured in string theory might offer an answer of sorts. Unlike all the other forces, you see, gravity wouldn’t be confined to our four-dimensional space-time continuum, but could bleed out into the “bulk,” as the six or seven invisible extra dimensions of reality are called.

If so, then the reason gravity’s so weak in our universe is it’s got to spread itself so thin.

But, getting back on topic here: What you maybe never realized is, it’s that same enormous disparity between forces that makes it possible for a planet like earth to exist in the first place.

Because, when you get right down to it, gravity does have one thing going for it — it just keeps on adding up.

And that’s pretty unique, for a long-range force. The strong and weak nuclear forces, for instance, they’re just too short-range to amount to much over the long haul. Electromagnetism’s got the reach, all right, but it comes in opposing flavors: positive and negative, north and south. That puts a natural upper limit on how strong an electromagnetic field can get before it attracts enough opposite charges to neutralize itself. That’s easiest to see on a subatomic scale: atoms normally have the same number of negatively-charged electrons and positively-charged protons, so they net out neutral. But it’s the same story for all the things built out of atoms, including the universe as a whole.

Gravity, on the other hand, only works one way. Never cancels out, never lets go. Each small chunk you add to an object’s mass can only increase, never diminish, the power of that mass’s gravitational field. Just by an infinitesimal amount, maybe, but still that field-strength is always growing, always pulling just a little bit harder.

In the end, it’s only the fact that electromagnetism is so much stronger than gravity that allows for kind of a Mexican standoff between the two forces. Take away the mutual repulsion of negatively-charged electron shells, and all the normal solid matter we know and love — rocks, trees, dachshunds, us, the earth itself — would implode in an instant into tiny little droplets of degenerate matter, dense as the core of the sun.

But there are times and places where even electromagnetism’s not up to the job: Pack a big enough mass into any one place — we’re talking really big here: say, a planet ten times the mass of Jupiter — and the pressure at the core will exceed anything electromagnetism can stand up to. The electron shells that give macroscopic objects their structural strength just buckle. What started out as nice, solid matter dissolves into this sort of “soup” of dissociated electrons and free nuclei.

That degenerate-matter soup is the first step on the road to making a black hole. But we’re not there yet, not by a long shot. Normal matter’s still got some fight left in it.

Take that super-Jupiter we were talking about. Once gravity overcomes the structural integrity of the planet’s core, it just naturally starts to shrink. It’d keep right on shrinking, too, except compressing matter like that generates heat, and enough compression will heat the planet’s core to upwards of ten million degrees Kelvin. That’s the flashpoint: At that temperature, the free atomic nuclei are moving fast enough to overcome their mutual repulsion and start slamming into each other. The strong nuclear force takes over and thermonuclear fusion kicks in.

Fusing lighter elements into heavier ones releases energy. Massive amounts of energy. Enough energy to push back against the pull of gravity. Enough to light the heavens. Enough to warm the worlds and spark the chemical processes that lead to life, to us.

Enough to make stars.

Things can’t go on like that forever, of course. It takes fuel to keep those fires burning. Hydrogen to start with: A star spends most of its lifetime transmuting hydrogen into helium. Works out well enough: hydrogen’s the most abundant element in the universe, after all. The average star holds enough to chug along for billions of years. But sooner or later it’s got to run out. And, when it does, the squeeze starts all over again.

Once gravitational contraction kicks in again, it raises the core temperature back up to where the fire rekindles. Only now the helium “ash” itself becomes the fuel, fusing into heavier and heavier elements — carbon, lithium, oxygen, neon, silicon. All the while, though (if you can call millions of years a “while”), the star is sliding down the slope of the binding-energy curve, earning less and less from each new element-building transaction, until it bottoms out at iron.

As far as nucleosynthesis is concerned, that’s all she wrote. End of the line: Finis. You can’t wring any more watt-hours out of the process by turning iron into something else. Turning iron into any heavier element actually consumes more energy than it produces.

Which sets the stage for the final act.

At the very end there, gravity can grip hard enough that the core of the star just … collapses — collapses so fast in fact, that it rebounds. You get a gigantic explosion, a nova or supernova. The star puts out more energy in that blink of an eye than it did in a whole lifetime of steady shining. The shockwave is powerful enough to transmute elements wholesale and scatter them all across space. At its dying moment, the star seeds the universe with the building blocks of new worlds and new life.

In the aftermath, the only thing that matters is matter itself: namely, how much matter the explosion leaves behind. If what’s left over is only the mass of the sun or so, no problem: Atomic nuclei have got enough structural strength to bear that much weight. You wind up with a brown dwarf star the size of the earth, so dense that a teaspoon of its stuff weighs as much as a locomotive.

But upwards of one solar mass, things start to get interesting.

The leftovers don’t have to weigh too much more than the sun for the pressure in the interior to mash electrons and protons together. That gives you neutrons. And that triggers another collapse, into a neutron star only a few miles across. All that’s really staving off a final collapse at that point is something called the Pauli exclusion principle, which holds that two neutrons — or two matter particles of any kind, for that, uh, matter — cannot have the same position and the same velocity at the same time. That’ll make the neutrons in our neutron star tend to move away from each other, generating an outward expansion that fights back against gravity’s downward drag.

Bizarre enough in its own way, I suppose.

But the point where the relativity theorists really sit up and take notice is when the supernova “cinder” is more than three times the mass of the sun.

Because, there’s a limit to even the exclusion principle. “Chandrasekhar’s limit” it’s called, after the man who worked it out back in the nineteen-thirties. And, at its heart it relies on that old standby speed-of-light limitation, familiar from special relativity. Because, that means there’s only so fast two particles can be moving relative to one another: Once they’re moving at lightspeed, that’s it.

So, given enough gravity, even neutrons will just cave. And neutrons are the last line of defense. Once they go, the whole stellar mass collapses to what we call a singularity — a dimensionless point of infinite density, infinite space-time curvature, infinite you-name-it.

General Relativity is not just a good idea — it’s the law. And what the law says is that, at bottom, gravity is just geometry. The geometry of space-time itself.

It’s easier to picture if we lose a dimension or two. So, imagine if three-dimensional space was a two-dimensional sheet of rubber. That’d make gravity the measure of how much that rubber sheet deforms when you put a mass on it — less for a marble than for a bowling ball. Drop a planet-sized mass onto that rubber sheet and the nearby space curves in to form a gravity well steep enough for moons to roll in orbit around it. Drop in a sun, and the deformation dips deep enough to trap a family of planets in its folds.

But that same geometry is destiny. When a really massive star dies, the sink-hole around its corpse plunges infinitely deep. The well-walls wrap around and pinch shut, sealing off the remains from the rest of space-time.

Remember Alice in Wonderland, where the Cheshire Cat vanishes, leaving only its smile behind? Well, here, the matter disappears, and only the mass is left. In the process, the gravity gradient grows so steep that nothing, not even light, can escape it …

… which is why we call them black holes.

The post Tunguska Seminar 05 appeared first on Official website of Bill DeSmedt.

Tunguska Seminar 04.2

Jackson & Ryan Bite the Dust!

When we left off last time, the Jackson-Ryan hypothesis that the Tunguska impactor was a subatomic-sized primordial black hole was being buffeted from all sides.

Now, it’s important to remember that the international physics community already had their backs up over Jackson-Ryan — a knee-jerk negative reaction, maybe, to the amount of play the idea was getting in the mass media (what they call the Carl Sagan effect). So, once the Beasley-Tinsley and Burns-Greenstein-Verosub papers came out, all hell broke loose.

Mike’s memories of that time even include a memorable run-in with the Princeton professor who’d given black holes their very name — John Archibald Wheeler himself:

“A colleague there in Austin told me that John Wheeler was absolutely furious about this, and that he was fuming and foaming at the mouth over this ‘terrible idea,’ and how dare we have done such a thing? And so, a few months later, I saw him at a conference in Dallas, so he came up to me and said, ‘I’ve been hearing about this little black hole hypothesis in Siberia.’”

Rather than face any more frothing at the mouth, Mike told Wheeler about Beasley and Tinsley’s research on the missing exit-event:

“So I said to John Wheeler, ‘They did this experiment and there’s nothing there.’ And he said, ‘Oh, good!’ And then he said, ‘And now what you have to do is write all kinds of papers saying that this is completely crazy and that there’s no possibility that it’s ever correct, because if you don’t, in the future, the nuts will get hold of it and keep it going for a long time.’”

Well, Al and Mike never did get around to writing those “all kinds of papers” disavowing their original hypothesis, but decades later Al Jackson couldn’t help but look back and entertain a counterfactual:

“I’ve really wondered over all the years, if we had titled that paper differently, like ‘What is the Physical Effect of a Primordial Black Hole Hitting the Earth,’ instead of connecting it with the Tunguska Event … because we caught holy hell over proposing that it was the Tunguska Event.”

Holy hell, indeed. Before it was all over, even Carl Sagan hopped aboard the bandwagon. In the appropriately-titled “Heaven and Hell” episode of Cosmos, you’ll see Carl pointing out how “the records of atmospheric shock waves show no hint of an object booming out of the North Atlantic later that day.”[1] The no-exit-event objection, in other words.

What had started off as a debate over a new hypothesis was turning into a game of astrophysical pile-on.

Russian researchers, who sometimes seem to think like the Tunguska Event ought to be their own private preserve, routinely went ballistic at just the mention of the Jackson-Ryan hypothesis. In his book The Day the Sky Split Apart, astronomer and meteorite hunter Roy Gallant reports that our old friend Academician Nikolai V. Vasil’ev was still steamed about it two decades later, in 1992:[2]

“If Jackson and Ryan had bothered to acquaint themselves with the geophysical materials published in Russia and America before publicizing their fantastic idea, they most likely would never have proposed it. Evidently the authors, in their naiveté, supposed that in 1908 such a cataclysmic event as a black hole exploding out of the North Atlantic Ocean would have gone unnoticed. However, the population of the eastern regions of Canada, Iceland, and southern Greenland was significant. Those people published newspapers and had meteorological stations and observatories, and there were dozens of vessels in the open ocean. Furthermore, a tsunami would have been generated. Under these circumstances the event could not possibly have gone unnoticed.

“If professional scientists indulge themselves in such liberties, you can imagine how readily such science fiction notions will be eagerly and gullibly seized by the mass media … The sad results are disoriented public opinion and complications in the further study of this complex natural phenomenon.”

It wasn’t only the Russians, of course. We’ve already seen how Tom Gehrels, the principal investigator for Operation Spacewatch, went out of his way to lump Jackson and Ryan’s “mini-black hole” hypothesis in with UFO crash-landings as “nonsensical speculation” as late as the mid-nineties.[3]

But they were all beating a long-dead horse. As far as the world physics community was concerned, by the late seventies the Jackson-Ryan conjecture had already crashed, burnt, and got shoveled over with dirt. Tunguska researchers could breathe a sigh of relief and go back to fighting over meteorite this, and cometary that.

Even Al Jackson and Mike Ryan pretty much forgot about it. It sure looked like the end of the line for the primordial black hole impact theory of Tunguska. As Mike puts it:

“It died a natural death and so no one has ever said anything about it anymore.”

Not to differ with Mike, but I’d like to say something more about it.

In particular, I’d like to try and convince you, in the rest of this Soapbox Seminar series, that — be it right or wrong — the Jackson-Ryan hypothesis isn’t “naive,” or “science fiction,” or “nonsensical speculation,” or any of the other labels folks have pinned on it over the years. That — right or wrong — it’s no less scientific than any of the more widely held theories. And that, as Burns and his friends pointed out, in a situation where “all possible explanations must be seriously considered and … no explanation can be discarded merely because it has a low probability of occurring,”[4] it might just possibly be right.

But to see how it might be right, we’ve first got to take a closer look at those primordial black holes.

References

All quotes from Al Jackson and Mike Ryan are courtesy of Albert A. Jackson, IV and Michael P. Ryan, Jr., as recorded at the Johnson Space Center Amateur Astronomical Society meeting and Singularity launch party, November 2004.

[1] As repeated in Chapter IV of Carl Sagan, Cosmos, Random House, 1980.

[2] Roy A. Gallant, The Day The Sky Split Apart: Investigating a Cosmic Mystery, Atheneum, 1995.

[3] Tom Gehrels, “Collisions with Comets and Asteroids,” Scientific American, March 1996, pp. 54-59.

[4] Jack O. Burns, George Greenstein, and Kenneth L. Verosub, “The Tungus Event as a Small Black Hole: Geophysical Considerations,” Monthly Notices, Royal Astronomical Society, vol. 175 (1976), pp. 355-357.

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Tunguska Seminar 04.1

Trouble Wasn’t Long in Coming!

Last time, you’ll recall, we were taking a look at a theory thought up by a couple of good old boys named Al Jackson and Mike Ryan — a theory as to how the 1908 Tunguska Event might have been caused by the earth colliding with a tiny black hole. And we closed just at the point where, as Mike Ryan said:

“I knew we were in trouble.

“And trouble wasn’t long in coming!”

That trouble all started out at the exit — the exit event, that is.

Remember how Al Jackson and Mike Ryan predicted there’d have been an “exit event” later the same day as the impact? Here’s how they put it in their 1973 Nature article: [1]

“Because of its high velocity and because it loses only a small fraction of its energy in passing through the Earth, the black hole should very nearly follow a straight line through the Earth, entering at 30° to the horizon and leaving through the North Atlantic in the region 40°-50° N, 30°-40° W.”

Well, they did more than predict it; they went and bet the farm on it:

“This exit provides a check for the whole hypothesis. At the exit point there would be another air shock wave and an underwater shock wave and disturbance of the sea surface. Microbarograph records could be checked for an event similar to that caused by the entry shock displaced by the proper amount of time. Oceanographic and shipping records could be studied to see if any surface or underwater disturbances were observed.”

Now, don’t get me wrong: When a new theory makes empirically-testable predictions, that’s a good thing. And the crazier the theory, the more it’s got to have that kind of verification. It was this same sort of thing, for instance, that finally brought Newtonian physicists around to Einstein’s way of thinking, once a team led by Arthur Eddington team found that the precession of Mercury during the 1919 solar eclipse exacly matched the predictions of General Relativity.

Still and all, it was because of that “exit event” prediction that Mike and Al got to watch their brand-new hypothesis go down in flames not even a year after its publication.

As Mike recalls it:

“We had calculated that it would come out in the North Atlantic — if it had come out in New York City there was absolutely no possibility. And so, um, somebody had actually gone and looked at the microbarograph records for the time that it would have taken the shockwave — an exit shockwave — to get from the North Atlantic to London, and there was nothing there.”

And, most mortifying of all, it was a couple of naturalized fellow Texans that did the looking.

In August 1974, William H. Beasley and Brian A. Tinsley from the University of Texas at Dallas wrote in to Nature (the same journal that had published Mike and Al’s original Tunguska article) to say “We have examined copies of the English microbarograph records, but have been unable to find any sign of waves from the suggested exit explosion.” [2]

There was more, but what it came down to in the end, was:

“All the evidence favours the idea that the impact which caused the Tunguska catastrophe involved a body with characteristics like a cometary nucleus, rather than a black hole.”

That wasn’t all.

Even as he was writing up the original article, Mike says he’d been worried about what other detectable effects the hole might’ve had, both on impacting the earth, and while tunneling through it. In the end, he and Al went with some handwaving about how “the black hole would leave no crater or material residue” as it plunged into the earth at the impact site, and how once inside the earth “the rigidity of rock would allow no underground shock wave.” Or, as Mike tells it:

“And then we assumed that — we didn’t assume, I just wrote it down in one sentence to make sure that we didn’t have to calculate anything —  that the earth was good and solid, so this thing, once it hit the earth, would stop producing a shockwave.”

In retrospect, Mike and Al probably should have run those calculations, just for kicks and giggles.

Because somebody else sure did. Somebody else name of Jack Burns, George Greenstein, and Ken Verosub.

And what they came up with drove the final nail in the coffin. Not that their 1976 paper in the Monthly Notes of the Royal Astronomical Society didn’t start out promisingly enough: [3]

“The apparent uniqueness of this [Tunguska] event requires that all possible explanations must be seriously considered and that no explanation can be discarded merely because it has a low probability of occurring.”

So far, so good. But it all went downhill from there.

Burns, Greenstein, and Verosub started out with the power of the impact — estimated by E. L . Krinov at somewhere between ten and forty megatons — and worked backwards.

Now, back in the early seventies, before the discovery of things like Hawking radiation and black monopoles, you’d’ve had to assume that all that energy had to come from gravitational effects alone. A submicroscopic-sized black hole is way too small and way too dense to generate anything in the way of atmospheric friction, you see. The only way it’s got of releasing energy into the atmosphere is by its gravity tugging directly on the air molecules. But that’d take a powerful gravitational field for sure. According to Burns, Greenberg, and Verosub, putting out that much gravity meant the Jackson-Ryan hole would’ve had to’ve weighed in somewhere between ten quadrillion and one quintillion tons. That’s a little on the high side versus Al and Mike’s own quadrillion-ton guesstimate, but what’s an order of magnitude or three among friends?

Then Burns and company took it one step further. They figured what would happen when that same mass, that same gravitational energy touched down on earth.

According to them —

“[T]he point of entry of the hole into the Earth should be marked by a patch of melted and resolidified rock of diameter one-half to four kilometres, overlain by fused soil of comparable extent.”

Wow! A disk of fused earth and melted rock maybe three miles wide and Lord knows how thick. Bet that’d have been hard to miss!

But Burns et al. weren’t done yet. They also went and calculated the effect of the hole’s gazillion-ton mass burrowing through thousands of miles of the earth’s crust and mantle. The answer?

Well, here, let’s let Mike Ryan tell it:

“I have here a list — as old Joe McCarthy said — of twenty-five articles. One of them that was critical, of course, took the idea that the earth is not all that solid, so it’s not just going to punch a hole through the earth, and the shockwave is going to continue. And the calculation that’s in one of the articles said that it was something on the order of all of the earthquakes in one year that the earth has ever felt, at this one time, as it’s going through the earth. I think they said something like an 8.5 earthquake for every kilometer that the thing moved through the earth.”

“Several thousand simultaneous earthquakes,” each of them as big or bigger than the most powerful earthquake ever recorded, was what the article said.

Getting a sinking feeling yet? There’s more …

References

All quotes from Al Jackson and Mike Ryan are courtesy of Albert A. Jackson, IV and Michael P. Ryan, Jr., as recorded at the Johnson Space Center Amateur Astronomical Society meeting and Singularity launch party, November 2004.

[1] Albert A. Jackson, IV and Michael P. Ryan, Jr., “Was the Tungus Event due to a Black Hole?” Nature, vol. 245, September 14, 1973, pp. 88-89.

[2] William H. Beasley and Brian A. Tinsley, “Tunguska Event was not caused by a black hole,” Nature, 250 (1974), pp. 555-556, https://www.nature.com/articles/250555a0/.

[3] Jack O. Burns, George Greenstein, and Kenneth L. Verosub, “The Tungus Event as a Small Black Hole,” Monthly Notices, Royal Astronomical Society, vol. 175 (1976), pp. 355-357.

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Tunguska Seminar 03.2

… Name of Jackson and Ryan

As I was saying, Al Jackson never forgot Willy Ley’s Tunguska tales, and thirteen years later he shared them with a fellow U Texas grad student, Mike Ryan.

So it was only natural that, when Al came across Stephen Hawking’s first paper on primordial black holes, that he’d casually ask Mike: “What about the Tunguska Event being due to a primordial black hole”?

Here’s how Mike remembers that fateful meeting: — Ladies and gents, Dr. Michael P. Ryan, Jr.:

The thing is that Al has a tremendous imagination. He can see all kinds of connections in things, and very strange connections occasionally. And he would come into my office at Austin and he would say: I’ve solved this problem — I know it’s this. And so my first reaction was: let us calculate.

And we would calculate, and find out that it just didn’t work at all.

And so one day he came in and he said: I’ve solved the Tunguska problem — it’s a small black hole.

And I said: let us calculate.

So they calculated.

It was pretty easy to see how much energy would be deposited in a shock wave due to a gravitating body moving through the atmosphere faster than the speed of sound. Sure enough, about an asteroid’s worth of mass in a package the size of a molecule would do the trick.

Weighing in at a quadrillion tons or so — black holes are very massive, remember: even the tiny ones pack a big punch! — the microscopic black hole would produce all the observed Tunguska effects (bright blue “tube,” megaton-scale explosion, total devastation) from gravitational interactions alone.

Here’s Mike again:

And we calculated, and the energy that it deposited came out to be more or less all right.

So, Al and Mike could pretty much match up their calculations with the Tunguska eyewitness accounts of the impact itself. Figuring what would happen after that was trickier. Once the thing hit the earth, it should’ve kept on going. With its tiny diameter and gargantuan mass, the primordial black hole would’ve sliced through solid rock as if it wasn’t even there. In fact, it should’ve plowed straight through the earth and come rocketing up out the other side and gone sailing off into outer space again.

But …

… Not before producing the same sorts of effects at the exit as it had at the original point of impact. In fact, as Al and Mike would write in their Nature article, “This exit provides a check for the whole hypothesis.” In other words, all you had to do was look for a second set of shockwaves and earthquakes an hour or so after the first ones.

But look where? Where would the thing have come out?

The way Mike told it to me, he and Al used the best azimuth they could find, calculated the distance through the Earth for the angle of entry, then used the high-tech method of stretching a string … on a globe someone had in their office.

It’s fun to picture that: Sort of like a low-budget remake of that scene in Close Encounters of the Third Kind, where the NASA guys roll this big globe down the hall and use it to find the latitude and longitude of Devil’s Tower, Wyoming.

But it worked, gave them the answer they were looking for: The exit event would have been out in the Atlantic, northwest of the Azores. And since — as Al and Mike had claimed — “This exit provides a check for the whole hypothesis,” all you’d need to do to test the theory was just check the shipping records for end of June 1908.

By this time, spring semester was over, and Mike was packing up to spend a summer at Oxford. Before he left, he and Al talked about the Tunguska idea a couple more times, and Mike suggested they write it up:

And so I said: I can’t resist this — we’ve got to write
a paper about it. And do it real fast and send it off, just as something fun and interesting.

By June of 1973 Al had done just that: sat down and worked through the calculations again and sent them off in a letter to Mike for some final word-polishing and equation-checking. As Mike says:

So we wrote it up and sent it off, and we sent it to Nature, and strangely enough Nature accepted it, which surprised me. So, I assumed it was completely finished and nothing would ever happen.

And then all of a sudden these things like the CBS News, New York Times, London Times, Time magazine …

If Mike was surprised, Al was shocked — he was getting phone calls from Time magazine before he even found out the paper had been published. He and Mike got their fifteen minutes of fame — or maybe notoriety is a better word.

But Al does have one good memory of that brief moment in the spotlight. As he told it to me:

Stephen Hawking had come to U Texas in the fall of 1974 for that year’s Texas Relativistic Astrophysics Conference. So at the conference Al walked on up to Hawking and introduced himself. Unfortunately, this was at a time after Hawking had lost the power of speech but before he got his speech synthesizer, so he needed his graduate assistant to “translate” for him, and the translator was nowhere to be found. Anyway, Hawking seemed to recognize Al’s name, motioned him down and said something to him.

As Al remembers it:

I didn’t understand a word. He obviously knew of the paper, but I don’t know if he said “that was an interesting paper” or “what a piece of crap!” To this day I have no idea what he said!

But, if Al’s crowning moment with Stephen Hawking ended up kind of ambiguous, the reaction of the physics community at large would be anything but. And “what a piece of crap!” would be the least of it!

Or, as Mike Ryan put it:

… the CBS News, New York Times, London Times, Time magazine — and even a Sunday science comic strip had this in it with, the Sunday science comic strip showed some Siberian peasants running away and this huge explosion behind them.

And I knew we were in trouble.

And trouble wasn’t long in coming.

What kind of trouble? Well, we’ll get into that one next time.

References

All quotes from Al Jackson and Mike Ryan are courtesy of Albert A. Jackson, IV and Michael P. Ryan, Jr., as recorded at the Johnson Space Center Amateur Astronomical Society meeting and Singularity launch party, November 2004.

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Tunguska Seminar 03.1

Two Good Ol’ Boys …

Got a special treat cued up for you today, folks: the inside story of how what we’re calling the Jackson-Ryan Hypothesis came to be — as told (in part) by the men themselves: Albert A. Jackson IV and Michael P. Ryan Jr.!

* * *

It was summer of 1973, sixty-five years to the day, give or take, from the Tunguska Event itself, that two young American physicists from my old alma mater the University of Texas at Austin sent the British science journal Nature what had to be one of the crazier ideas ever submitted to that august publication (which is saying a bunch!).

Because Al Jackson and Mike Ryan came right out and asked the question—

“Was the Tungus Event due to a Black Hole?”

Meaning what? Meaning that it was a black hole that went and hit the earth back in 1908? But how could that be? How could the earth have survived that kind of a collision? Wouldn’t our favorite planet have been torn to pieces and swallowed up whole?

Nah — you’re thinking of the big black holes, two or three times the mass of the sun on up. Jackson and Ryan had something a whole lot smaller in mind.

Seems that, a couple years earlier, in 1971, Stephen Hawking had come out with the notion that real little black holes — massing “only” a trillion tons or so — could have been created in the Big Bang (we’ll see how later).

— So now, we’ve got one of these “primordial black hole” thingees plowing into the earth?

Kind of makes you wonder who thinks this stuff up, doesn’t it? Well, meet A. A. Jackson IV, Ph.D. — Al, to his friends. Al comes from a long line of Dallas Jacksons. The family goes way back in these parts, so far back that the place where the late billionaire H. L. Hunt built his mansion was named, you guessed it, Jackson Point.

Al’s an astrophysicist by trade. He taught all over the place before returning home to Texas. There he’s working for NASA, training space-shuttle pilots and helping come up with the Nemesis or “dark star” theory for the extinction of the dinosaurs. He also once snuck me into the Johnson Space Center, where I docked the Space Shuttle with the International Space Station (in simulation, of course).

Anyway, apart from his occasional clandestine activities, Al’s credits include a being a Fellow of the Lunar and Planetary Institute. And he’s written some pretty good science fiction in his time, too.

In fact, that’s what his critics say he was doing that day in the spring of 1973 when he went to his friend and fellow grad student Mike Ryan with a crazy idea.

Here, let’s let Al tell you in his own words — Ladies and Gentlemen, Dr. Albert A. Jackson, the Fourth:

I’ll give you a little bit of history as to how this all came about: When I was a graduate student at the University of Texas from 1970 to 1975 working on my PhD in physics it turns out that Mike was a post-doc and we used to talk together quite a bit. Well, we talked about many things, and I remember that what had happened was that I had read a paper by Stephen Hawking about the production of what are called primordial black holes and the possibility that substellar-sized black holes could be made in the birth of the universe.

For some reason, which I cannot exactly recall, I got to thinking about — well, so, these small black holes would be traversing the universe, the galaxy, and what if one of them encountered the earth?

So I told this to Mike. And actually the reason I remembered the Tunguska Event is a curious thing …

In other words, Al wasn’t thinking about just your ordinary, run-of-the-mill encounter between a black hole and the earth. He was already thinking specifically about the Tunguska Event. But why? — What brought Tunguska to mind?

To figure that one out, you’d have to go back thirteen years earlier, to the 1960 World Science Fiction Convention, where Al, just a college freshman at the time, ran into a living legend: science popularizer Willy Ley.

It had been Willy’s Conquest of Space book that had gotten Al interested in science in the first place. And now, here’s Al, sitting on the banquet-room floor, hanging out with one of his boyhood heroes, in the middle of the WorldCon Masquerade and Willy’s talking about an article he’s working on for Galaxy science fiction magazine. An article about someplace way off in Siberia — a place Al had never even heard of.

I was nineteen years old and at the World Science Fiction Convention in Pittsburgh Pennsylvania and I happened to be sitting on the ballroom floor during the Costume Ball and Willy Ley happened to be there — for you that don’t know, one of the most famous science writers of all time — and he told me this story: he said that he was going to write an article about the Tunguska Event that he had been following for several years. And it turns out that some Soviet engineer had written this science-fiction story in the late forties about the Tunguska Event being produced by an alien spaceship that blew its reactor trying to land on the earth.

That Soviet engineer was, of course, Aleksandr Kazantsev — author of “Explosion” and  “A Guest from the Cosmos”— who we met briefly in our first soapbox seminar. Willy then told Al about where Kazantsev’s science fiction story had gone from there:

In roughly the late fifties, two Soviet journalists who were drunk that night had known about this story and they wrote an article that what had really happened was that an alien civilization thought that they would send us a message by dropping a nuclear weapon at the Tunguska site.

To hear Willy Ley tell it, the whole Tunguska-as-Crashed-Spaceship thing had become as big in Soviet UFO circles as Roswell was becoming here.

Needless to say, that all made an impression on the nineteen-year-old. Al never forgot Willy’s Tunguska tales, and some thirteen years later they were to blossom into a scientific paper — for better or worse.

References

All quotes from Al Jackson are courtesy of Albert A. Jackson, IV, as recorded at the Johnson Space Center Amateur Astronomical Society meeting and Singularity launch party, November 2004.

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Tunguska Seminar 02.2

Cosmologically Incorrect?

By Dr. John C. (“Jack”) Adler, as told to Bill DeSmedt

We left off last time with the pronouncement of that Grand Old Man of Tunguska Studies, Academician Nikolai Vasil’ev still ringing in our ears [Vasil’ev 1992] — to wit:

Since a final resolution to the question of the Tunguska phenomenon’s nature has yet to be found, and since it must be acknowledged that the perennial attempts to interpret it within the framework of the classical paradigm have so far brought no decisive success, it seems expedient to examine and test alternative ways of explaining it.

Wise words, for my money. Trouble was, it seems like alternative explanations were just what neither side in the Great Tunguska Debate — be they pro-asteroid or pro-comet — wanted to hear.

And the reason for that isn’t quite what you’d expect.

Before I get into that, though, let me say right up front that the folks at Operation Spacewatch and elsewhere are doing good work, trying to spot the asteroids and comets that might someday clobber us — and spot them earlier enough for us to do something about it. Trying to keep us, in other words, from going the way of the dinosaurs. And they’ve been doing it with only a handful of dedicated staffers and a funding level that wouldn’t pay NASA’s electric bill for a week!

On the other hand, doing good work’s no excuse for doing, well, not-so-good science — for letting your commitment override your objectivity. And, much as it pains me to say so, I get the feeling that explains a lot of the present-day Tunguska controversy. And here I don’t mean the comet vs. asteroid part.

No, I’m talking about the maybe comet/maybe asteroid but definitely not anything else part.

Because, in some strange way, it’s become what you might call “politically incorrect” to claim that Tunguska could’ve been caused by anything other than a meteorite or a comet.

Somewhere along the way, you see, the Tunguska Event’s become a sort of poster child for a campaign to raise public awareness that there are giant space rocks cruising around out there just waiting to clobber us. Seems it kind of brings that whole notion into focus, makes it more believable.

To hear NASA’s Dave Morrison tell it [Morrison 1997], “if it hadn’t been for Tunguska, we might not be aware today that there’s an impact hazard at all.”

Well, all I can say to that is, Dave ought to get out more. Out to where, for instance, he can catch a glimpse of the crater-pocked face of the full moon on a clear night. That’d raise his impact-hazard consciousness for sure.

Or, if that’s not good enough, how about Shoemaker-Levy back in 1994? Here, a steady barrage of cometary fragments goes slamming into Jupiter over the course of a week. Kicks up an impact plume the size of the whole world — with the whole world watching. And we still don’t get it?

But, no, we’ve just gotta have Tunguska too. As long as it’s a comet or a meteorite, it’s also our planetary wake-up call. If, Lord help us, it turned out to be anything else, we’d all just hit the snooze button and go back to sleep till doomsday.

Or so the theory goes.

Think I’m kidding, don’t you? After all, these are scientists we’re talking about. The only thing that’s supposed to matter to them is, like Carl says, “the quality of the purported evidence, rigorously and skeptically scrutinized.” Not whether some theory or other looks to be plausible, or popular, or profitable, or even politically correct enough to save the world. Right?

Well, it sure doesn’t sound that way sometimes. Give a listen to what rocket scientist James Oberg has to say about the Tunguska UFO “theorists” [Oberg 1982]:

[T]o defend against such future cosmic bombs [i.e., near-earth objects which might hit us] it is first necessary to recognize them for what they are. Here the spaceship theory and the distortions, omissions, and fabrications of its proponents (both well-meaning and otherwise) remain a major obstacle, and a major danger.

The fictional science and pseudoscience of the “Tunguska spaceship” should be discredited and dismissed as quickly as possible so that we can get on with defending the earth against future “Tunguska comets.”

Now, I’ll be the first to agree that anyone who plays as fast and loose with the facts as the flying saucer crowd does deserves to be “discredited and dismissed.” But does that make them “a major obstacle, and a major danger”? C’mon, Jim — lighten up!

It’s not the words so much, it’s the tone. I don’t know about you, but that doesn’t sound like a man of science talking to me. Sounds more like a man with a cause!

A cause that tells us we’ve got to keep a lid on any alternative explanations — maybe with one of those good old arguments from authority, like the one I quoted from Operation Spacewatch’s Tom Gehrels in our first Soapbox Seminar, about how “scientists have always understood” the Tunguska Object “was a comet or asteroid.”[Gehrels 1996]

And that right there’s the problem: Anytime you start using science in the service of a cause — even the best, worthiest cause — it stops being science. Because science has already got a cause. It’s called the truth.

And the truth is that having an axe to grind doesn’t necessarily make the comet and meteorite theorists wrong. The thing of it is, it doesn’t make them right either, much as they may think it does.

It’s as if, somewhere along the way, they’d gone and lost sight of another thing that Carl Sagan said — namely, that “all assumptions must be critically examined; arguments from authority are worthless.”

We’ve been arguing from authority, makes no never mind that the authority being claimed for the argument is that of — science itself. And the real shame of it is that, over the years, all those arguments from authority, all those self-confident extrapolations from too little evidence or none at all have pretty much combined to drive any competing hypotheses off the field.

Because, like those characters in the funny papers, the meteorightists and the cometarians have always been willing always take time off from beating on one another to join hands and beat on anybody else who threatened to come along and upset their applecart with a new and different idea.

As two good ol’ boys name of Jackson and Ryan were going to find out, way back in 1973.

References

[Vasil’ev 1992] Nikolai V. Vasil’ev, “Paradoxes of the Tunguska Meteorite Problem,” Proceedings of the Higher Educational Institutes, No. 3 “Physics,“ 1992, pp. 111-117, http://www.tunguska.ru/obzor/stat/.

[Morrison 1997] As quoted in “The Day The Earth Got Hit,” Cambridge-Conference Digest, 14 November 1997, at: http://abob.libs.uga.edu/bobk/ccc/cc111497.html.

[Oberg 1982] James Oberg, UFOs and Outer Space Mysteries, Donning Press, 1982. (Chapter Seven, “Tunguska Echoes” is available at http://www.jamesoberg.com/ufo/tungus.html.)

[Gehrels 1996] Tom Gehrels, “Collisions with Comets and Asteroids,” Scientific American, March 1996, pp. 54-59.

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