The tipping point

There's a common comment from climate change deniers that I'm sick unto death of, and it usually takes the form of something like "the Earth's climate has had ups and downs in the past, and life has gone along just fine."

First, it's the pure ignorance of this attitude that gets me.  If you did ten minutes' worth of research online, you'd find that a number of these "ups and downs" coincided with mass extinctions.  Life survived, yes, but dramatic losses in biodiversity and overall population numbers hardly constitutes "getting along just fine."  (In fact, the largest mass extinction ever -- the Permian-Triassic Extinction, which wiped out an estimated 96% of marine species and 65% of terrestrial species -- was coincident with a huge spike in temperature and atmospheric carbon dioxide, thought to have been triggered by a colossal volcanic eruption.)

But second, and honestly worse, is the blithe attitude that we can continue doing whatever we want to the environment and face no consequences whatsoever.  This raises entitlement to the level of an art form; apparently, we humans occupy such an exalted niche that no matter what we do, the rest of nature is magically going to make sure we not only survive, but thrive.

Even the most diehard deniers, however, are getting some serious hints that their determination to ignore science is not working out so well.  First of all, we have the fires in the Amazon, which have reached unprecedented levels in Brazil, with 74,000 acres burned to the ground already.  The cause is twofold -- the natural dry season, and the incomprehensible policy by Brazilian president Jair Bolsonaro of recommending large-scale slash-and-burn to "encourage agriculture."  The problem is larger in scale than just South America, however.  Environmental scientist Jonathan Foley explained why in an interview with Science News:

Some computer models... show a hypothetical scenario that when we clear rainforest, it starts to almost immediately warm up and dry out the atmosphere nearby.  When we stand in a forest, it feels cool and moist.  But when you clear-cut large areas of the forest, the air right around you gets hotter and drier, and it affects even rainfall patterns.  The worry is if you start clear-cutting more of the Amazon, in theory, a tipping point could be reached where the rest of the forest dries out, too. 

If that happens, the idea is that the Amazon could flip suddenly from being a rainforest to being a dry savanna-like ecosystem.  We’re not absolutely certain about it, but even that theoretical possibility is kind of terrifying...  Globally, about 10 to 15 percent of our CO2 emissions comes from deforestation.  If this is going back up again in Brazil, that’s going to make climate change even worse.

The only amendment that needs to be made to Foley's statement is his use of the word "if" in the last sentence.

Smoke from the 2019 Amazonian wildfires [Image is in the Public Domain, courtesy of NASA]

The other piece of alarming information this week comes from some research done at Stockholm University that firmed up a link between the salinity of the North Atlantic and climate throughout the world.  The team, made up of David K. Hutchinson, Helen K. Coxall, Matt OʹRegan, Johan Nilsson, Rodrigo Caballero, and Agatha M. de Boer, were studying the Eocene-Oligocene Transition (EOT), which occurred 34 million years ago and involved a shift from a "hothouse" to "icehouse" climate.  

The authors write:

The Eocene–Oligocene transition (EOT), ~34 Ma ago, marked a major shift in global climate towards colder and drier conditions and the formation of the first Antarctic ice sheets.  A gradual decrease in CO2 is thought to be the primary driver of the transition, causing long-term cooling and increasing seasonality through the Eocene, culminating in the glaciation of Antarctica.  Deep water circulation proxies suggest that the EOT, including the preceding 1 Myr, also marked either the onset or strengthening of an Atlantic meridional overturning circulation (AMOC).

Catch that?  An event occurring the North Atlantic is the probable trigger for the formation of the Antarctic Ice Sheet, and a radical change in Earth's climate -- and, unsurprisingly, a massive extinction that wiped out 20% of the Earth's species (large mammals were the hardest hit).

What Hutchinson and his team showed is that the likely cause of this transition was the closing of a oceanic channel between the Arctic Ocean and the North Atlantic.  The Arctic Ocean at that time had very low salinity (something the team demonstrated using the species of algae that show up in the fossil record from that time and place).  As long as the channel was open, fresh water flooded into the North Atlantic, keeping the salinity of the surface water low.  When the channel closed due to tectonic movement, the salinity of the surface of the North Atlantic spiked.  Saline water is more dense than fresh water, so this surface water began to sink, kicking off the "North Atlantic Thermohaline Circulation" and (more germane to our discussion here) drawing down dissolved carbon dioxide by the metric ton.

The result: a drastic drop in temperature, Antarctica becoming an ice-covered wasteland, and a mass extinction worldwide.

How anyone can read this and not be freaking out over the spike in carbon dioxide we've seen in the last hundred years -- that appears to be the fastest carbon dioxide concentration change anywhere in the geological record -- is beyond me.  There's no doubt that there's a tipping point, as the Eocene-Oligocene Transition shows.  The only question is where that tipping point is -- and whether we've already passed it.

What's driving it all is money.  Altering our lifestyle, protecting the rain forests, and divesting ourselves from fossil fuels all require that we make sacrifices ourselves, but more importantly, that we end the chokehold the fossil fuels industry has on our elected officials.  Of course the politicians don't want anyone to understand and accept climate science, because that would mean cutting off one of their biggest sources of donations -- the petrochemical industry.

It is fitting to end with a quote from Upton Sinclair: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."  The problem is, here what we're jeopardizing is not simply someone's salary, but the long-term habitability of the Earth.

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This week's Skeptophilia book recommendation is about a subject near and dear to my heart; the possibility of intelligent extraterrestrial life.  In The Three-Body Problem, Chinese science fiction writer Cixin Liu takes an interesting angle on this question; if intelligent life were discovered in the universe -- maybe if it even gave us a visit -- how would humans react?

Liu examines the impact of finding we're not alone in the cosmos from political, social, and religious perspectives, and doesn't engage in any pollyanna-ish assumptions that we'll all be hunky-dory and ascend to the next plane of existence.  What he does think might happen, though, makes for fascinating reading, and leaves you pondering our place in the universe for days after you turn over the last page.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

The realm of the impossible

An article appeared in the July/August issue of the Skeptical Inquirer which, on first glance, you might expect me to agree with entirely.

It's entitled "Why Parapsychological Claims Cannot Be True," and is written by Arthur S. Reber and James E. Alcock, professors of psychology at (respectively) Brooklyn College and York University.  What Reber and Alcock are attempting to show is that physical law proves that claims of extrasensory perception and the like are theoretically impossible.

Reber and Alcock cite four tenets of physics that they say render parapsychological claims untenable:

1. Causality -- all effects have definite causes that preceded them.
2. Time's arrow -- the flow of time is one-directional, although its speed may vary from reference frame to reference frame.
3. Thermodynamics -- energy cannot be created or destroyed, so parapsychological claims (such as the future influencing the present) require energy transfer that breaks the First Law.
4. The inverse-square law -- the strength of a signal diminishes as a function of the square of the distance, and no such attenuation of signal strength is reported in cases of (for example) telepathy.

Certainly, these are powerful objections to many claims of parapsychology, and anyone who says (s)he has such abilities needs to have some pretty persuasive evidence backing it up.  But what I object to is that Reber and Alcock equate a claim violating science as we currently understand it with a claim being impossible even in the broadest theoretical sense.  Based on this, they say, all parapsychological claims should be dismissed out of hand.

[Image licensed under the Creative Commons, John Stephen Dwyer, PsychicBoston, CC BY-SA 3.0]

There are a number of problems with this conflation.  The first is that physics itself suggests some awfully bizarre things -- witness Saturday's post about two spaceships being in a state of superposition where both of them are destroyed and not destroyed simultaneously, an outcome that appears to be entirely consistent with what we know about quantum theory and general relativity.  Simultaneity was shown to be inconsistent between reference frames decades ago; one of the more bizarre outcomes of Einstein's discoveries is that two events that appear simultaneous in one frame might appear sequential in another, raising questions about what exactly we mean by "causality."  (And that's not even considering such loony -- but theoretically possible -- phenomena as wormholes, connecting two different bits of spacetime.)

The second problem, though, is the assumption that our understanding now is going to turn out to be true ten years (or even ten days) from now, and will apply equally well to every new discovery.  Consider one of their examples -- the inverse-square law.  It is true that many physical phenomena drop in magnitude as a function of the inverse square of the distance.  (These include light intensity, radiation, gravitational force, electromagnetic force, and sound volume.)  But it was recently discovered that gravitational waves don't decrease in intensity with the square of the distance; they decrease inversely simply with the distance.  The power of a radar signal diminishes with the distance of the source raised to the fourth power.  Up to a distance of one femtometer, the strong nuclear force doesn't vary with distance at all, and after that it drops to nearly zero.

So saying that physics demonstrates that all information transmission follows an inverse-square law simply isn't true, and even if you ignore the handful of counterexamples known, it also implies some significant hubris -- that any subsequent discoveries we make will automatically conform to what we already know.

What is at the root of this is a confusion between what is improbable and what is impossible.  I would argue that there's very little in the latter category -- even such written-in-stone laws such as the speed of light being the ultimate universal speed limit have been subject to thus-far unresolved questions (consider, for example, the Alcubierre warp drive, a solution to Einstein's field equations that appears to allow apparent hyperlight speeds).  As you move along the continuum from improbable to impossible, the demand for rigorous and high-quality evidence quite rightly increases (Carl Sagan's "ECREE" principle -- "Extraordinary Claims Require Extraordinary Evidence").  This is why it might take a lot to move me into the "true believer" column with respect to parapsychological claims, but am quite content to remain in the "undecided" column indefinitely.

As befits a good skeptic.

But no matter where you are along the continuum, you can never rule out what the next round of discoveries might uncover.  As Einstein remarked (although it may well be apocryphal) -- "A thousand experiments could never prove me right, but one could prove me wrong."

There are a good many other objections to Reber's and Alcock's argument.  One which I'll mention briefly, but which for a fuller explication you should go to the source, was outlined by Ian Wardell in his blog Philosophical Thoughts.  The gist of his rebuttal is that parapsychological claims all hinge on issues of consciousness, and we still don't have any explanation of a mechanism by which consciousness occurs -- so how can we say with confidence what its limitations are?

Again, I'm not arguing for parapsychological claims, and regular readers of Skeptophilia know all too well that I'm pretty dubious about a lot of the specific evidence these claims rest on.  But my doubt about particular bits of psi doesn't imply anything categorical about the possibility of those sorts of phenomena in general, any more than my demonstration that a purported Bigfoot femur came from a bear would mean that Bigfoot doesn't exist anywhere in time and space.

Such examples of scientific hubris always remind me of the famous quote from Lord Kelvin, one of the pre-eminent scientists of the late 19th and early 20th century, who said in 1907, "There is nothing new to be discovered in physics now.  All that remains is more and more precise measurement."  Within twenty years of that statement, Robert Millikan showed that photons exist in discrete quanta of energy; Einstein published his paper on the general theory of relativity; Louis-Victor de Broglie showed that matter has wavelike properties; Heisenberg demonstrated the bizarrely counterintuitive uncertainty principle; and Schrödinger wrote his famous wave equation governing the role of probability in quantum phenomena.

And we're still trying to figure out the fallout from all of that stuff.

So as far as Reber and Alcock go; I'm not quite the instantaneous ally you might have expected.  My general feeling is that any time you start talking about something being theoretically impossible, world without end amen, you're skating out onto some seriously thin ice.

********************************

This week's Skeptophilia book recommendation is about a subject near and dear to my heart; the possibility of intelligent extraterrestrial life.  In The Three-Body Problem, Chinese science fiction writer Cixin Liu takes an interesting angle on this question; if intelligent life were discovered in the universe -- maybe if it even gave us a visit -- how would humans react?

Liu examines the impact of finding we're not alone in the cosmos from political, social, and religious perspectives, and doesn't engage in any pollyanna-ish assumptions that we'll all be hunky-dory and ascend to the next plane of existence.  What he does think might happen, though, makes for fascinating reading, and leaves you pondering our place in the universe for days after you turn over the last page.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

Order of operations

I try not to write in Skeptophilia about topics I don't fully understand -- well, at least understand as fully as my brainpower and the available information allow.  But today I'm going to tell you about a recent paper in theoretical physics that blew my mind so completely that I had to write a post about it, even though saying "I don't completely comprehend this" is a serious understatement.

So here goes.  Just don't ask me to clarify further, because the most you'll get is the Canine Head-Tilt of Puzzlement.

The paper, which appeared last week in Nature Communications, is entitled "Bell's Theorem for Temporal Order," and was written by Magdalena Zych and Fabio Costa (of the University of Queensland), Igor Pikovski (of Harvard University), and Časlav Brukner (of the University of Vienna).  The issue the four physicists were looking at was the seeming paradox of the different way that time (specifically, temporal order) fits into general relativity and quantum theory.  In relativity, the flow of time depends on your relative speed and the distribution of mass near you; in general, the faster you're going, or the nearer you are to a massive object, the slower your clock runs.  Because reference frame is relative (thus the name of the entire theory), you don't notice this effect yourself -- to you, your clock runs just fine.  But to someone observing you at a distance, the flow of time in your frame of reference has become more sluggish.

Weird enough, but that's only the beginning.  To take the most familiar example, consider two astronauts in spacecraft zooming away from each other at a substantial fraction of the speed of light.  To astronaut A, his clock is running fine, and astronaut B's clock is slow (because he's moving away from A at a high speed).  But from B's perspective, it's A that's moving; so B thinks his own clock is accurate, and A's is the one that's running slow.

And it's not that one's right and the other is somehow being fooled.  Both of them are right -- because time is relative to your speed.

As an outcome of this (and germane to the paper I referenced), what this also means is that A and B can differ in what they perceive as the time order of two events.  Occurrences that appear simultaneous to one of the astronauts might appear sequential to the other.

With me so far?  Well, the problem that Zych et al. were investigating was that in quantum theory, there's no allowance for relativistic ordering of events.  Time's arrow is one-directional, and if event X followed Y in one reference frame, it would do so on all reference frames.

Well, that's what the physicists thought -- until this paper showed a theoretical framework that suggests otherwise.

Zych et al. proposed a thought experiment involving two spaceships, one of which is near a massive object (which, as I mentioned, warps spacetime in such a way as to slow down the passage of time).  They're engaged in a war game that requires them to fire their phasers simultaneously and immediately afterward start their engine so as to dodge the blast.  The problem is, the ship near the massive object will have a slower clock, and will not be able to fire quickly enough to escape being blasted by the other ship.

So far, weird but not that hard to understand.  What Zych et al. did was to ask a single question: what if the two ships were in a state of quantum superposition before they fired?

Superposition is one of the weirdest outcomes of quantum physics, but it's been demonstrated experimentally so many times that we have no choice but to accept that this is how the universe works.  The idea is that if a physical system could exist in two or more possible states, its actual state is an array of possibilities all existing at the same time until some measurement destroys the superposition and drops the system into one of the possible outcomes ("collapsing the wave function").  The most famous iteration of this is Schrödinger's Cat, who is both alive and dead until the box is opened.

In the case of the ships, the superposition results in quantum entanglement, where the entire system acts as a single entity (in a causal sense).  Here's how the result is described in a press release from the University of Vienna:

If a powerful agent could place a sufficiently massive object, say a planet, closer to one ship it would slow down its counting of time.  As a result, the ship farther away from the mass will fire too early for the first one to escape. 

The laws of quantum physics and gravity predict that by manipulating a quantum superposition state of the planet, the ships can end up in a superposition of either of them being destroyed...  The new work shows that the temporal order among events can exhibit superposition and entanglement – genuinely quantum features of particular importance for testing quantum theory against alternatives.

So each of the ships is in a state of both being destroyed and not being destroyed, from the standpoint of an outside observer -- until a measurement is made, which forces the system into one or the other outcome.

Note what this isn't saying; it's not implying that one of the ships was destroyed, and we simply don't know which yet.  It's implying that both ships are in an entangled state of being blasted to smithereens and not.

At the same time.

The authors write:

This entanglement enables accomplishing a task, violation of a Bell inequality, that is impossible under local classical temporal order; it means that temporal order cannot be described by any pre-defined local variables.  A classical notion of a causal structure is therefore untenable in any framework compatible with the basic principles of quantum mechanics and classical general relativity.

All of which leaves me sympathizing a great deal with Winnie-the Pooh.

So there you have it.  It turns out that the universe is a weird, weird place, where our common-sensical notions of how things work are often simply wrong.  Even though I'm far from an expert -- I run into the wall pretty fast when I try to read actual papers in physics, or (for that matter) in most scientific fields -- I find it fascinating to get a glimpse of the actual workings of the cosmos.

Even if it blows my tiny little mind.

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This week's Skeptophilia book recommendation is a must-read for anyone interested in astronomy -- Finding Our Place in the Universe by French astrophysicist Hélène Courtois.  Courtois gives us a thrilling tour of the universe on the largest scales, particularly Laniakea, the galactic supercluster to which the Milky Way belongs, and the vast and completely empty void between Laniakea and the next supercluster.  (These voids are so empty that if the Earth were at the middle of one, there would be no astronomical objects near enough or bright enough to see without a powerful telescope, and the night sky would be completely dark.)

Courtois's book is eye-opening and engaging, and (as it was just published this year) brings the reader up to date with the latest information from astronomy.  And it will give you new appreciation when you look up at night -- and realize how little of the universe you're actually seeing.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

Big bird

There's a peculiar fascination that people have with things that are oversized.  It's part of the fascination with dinosaurs, supermassive black holes, supervolcanoes, massive meteor strikes, megacyclones, and the like, with the added frisson that those can also kill you in nasty ways.

But just size can be impressive, irrespective of the likelihood of getting eaten, blown away, disintegrated, or whatnot.  Take, for example, two fossil bird species discovered last week in New Zealand.

The first is a parrot, dubbed Heracles inexpectatus, an accurate moniker given that it translates roughly to "unexpected bigass critter."  H. inexpectatus stood a meter tall, and the scientists who discovered it said that its bill was such that it could "crack open most food sources," which seems to me to be code for "that could easily include your skull."  While most parrots are fruit and seed-eaters, carnivorous parrots are not without precedent -- the kea, a large parrot species also from New Zealand, not only eats baby seabirds, it's been known to attack sheep and take bites of fat from their backs.

H. inexpectatus, being over twice as big, could have done a great deal more damage than that.  With H. inexpectatus, if Polly wants a cracker, you better fucking well give Polly a cracker or Polly will turn you into the next item on the menu.

The good thing (from our standpoint, anyhow) is that H. inexpectatus went extinct 19 million years ago.  So that's one less thing to worry about, nasty-death-wise.

Then there's the even larger penguin fossil, also from New Zealand, that was discovered by a team from Canterbury Museum in Christchurch.  This beast, dubbed Crossvallia waiparensis, stood 1.6 meters tall and weighed 80 kilograms -- in other words, outsizing a good many human beings.

[Image courtesy of the Canterbury Museum, Christchurch, New Zealand]

Being a writer of speculative fiction, this immediately put me in mind of the enormous albino penguins in H. P. Lovecraft's brilliant novella "At the Mountains of Madness," in which an expedition to Antarctica ends very, very badly for 90% of the characters.  In the story, the penguins themselves aren't dangerous (although they seem to be at first) but start acting bizarrely when something appears that is -- namely, Shoggoths, one of Lovecraft's more nightmarish creations, a blob-like shape-shifter whose favorite hobby is pulling people's limbs out of their sockets.  So even though no one is killed by an enormous penguin in the story, seeing this picture did give me a shudder.

Although Paul Scofield, senior curator of the Canterbury Museum, said, "When the Crossvallia species were alive, New Zealand and Antarctica were very different from today – Antarctica was covered in forest and both had much warmer climates."  Which is kind of the way Lovecraft described things.  So if you go to Antarctica and get dismembered by a Shoggoth, you can't say you weren't warned.

In any case, like the humongous parrot, the humongous penguins are no more.  They were around even earlier than H. inexplicatus, having reached their peak during the Paleocene Epoch, between 55 and 65 million years ago.  Generally, clement climate and plentiful food leads to animals evolving to become larger, so it's speculated that this is what was going on with MegaPenguin and SuperParrot.  Whatever the cause, though, they're pretty impressive.

So that's our cool science story for today.  Something to keep in mind when you feed the chickadees.  The little twittering feathery guys at your bird feeder may not look very impressive now, but in the past, they had some cousins that could kick your ass into the middle of next week.

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This week's Skeptophilia book recommendation is a must-read for anyone interested in astronomy -- Finding Our Place in the Universe by French astrophysicist Hélène Courtois.  Courtois gives us a thrilling tour of the universe on the largest scales, particularly Laniakea, the galactic supercluster to which the Milky Way belongs, and the vast and completely empty void between Laniakea and the next supercluster.  (These voids are so empty that if the Earth were at the middle of one, there would be no astronomical objects near enough or bright enough to see without a powerful telescope, and the night sky would be completely dark.)

Courtois's book is eye-opening and engaging, and (as it was just published this year) brings the reader up to date with the latest information from astronomy.  And it will give you new appreciation when you look up at night -- and realize how little of the universe you're actually seeing.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

Scanning the skies for life

It will come as no surprise to regular readers of Skeptophilia that one of my dearest wishes is to live long enough to see incontrovertible proof of life on another planet.

Intelligent life would just be the icing on the cake, but I'm not counting on it, especially given how rare it is down here on Earth.  And the best of all -- having the intelligent life come here so I could have a talk with it -- is so unlikely as to be impossible, given the enormous (shall we say astronomical) distances involved.

But that doesn't mean we can't find out more about the conditions that could generate life and the likelihood of it being found elsewhere, as three pieces of research last week showed.

The first, which appeared in the journal Science Advances, is called "The Origin of RNA Precursors on Exoplanets," by a team of Cambridge University astrophysicists, Paul B. Rimmer, Jianfeng Xu, Samantha J. Thompson, Ed Gillen, John D. Sutherland, and Didier Queloz.  In it, we find out that the conditions for forming RNA nucleotides -- the fundamental building blocks of RNA, one of the two carriers of genetic information (and generally thought to be the one that formed first) -- have been narrowed down to a specific range of temperatures and luminance.  The authors write:

Given that the macromolecular building blocks of life were likely produced photochemically in the presence of ultraviolet (UV) light, we identify some general constraints on which stars produce sufficient UV for this photochemistry.  We estimate how much light is needed for the UV photochemistry by experimentally measuring the rate constant for the UV chemistry (“light chemistry”, needed for prebiotic synthesis) versus the rate constants for the biomolecular reactions that happen in the absence of the UV light (“dark chemistry”).  We make these measurements for representative photochemical reactions involving and HS−.  By balancing the rates for the light and dark chemistry, we delineate the “abiogenesis zones” around stars of different stellar types based on whether their UV fluxes are sufficient for building up this macromolecular prebiotic inventory.  We find that the light chemistry is rapid enough to build up the prebiotic inventory for stars hotter than K5 (4400 K).  We show how the abiogenesis zone overlaps with the liquid water habitable zone.  Stars cooler than K5 may also drive the formation of these building blocks if they are very active.

The good news, for exobiology aficionados like myself, is that this not only homes in on what conditions are likely to produce life -- telling us where to look -- they're conditions that are relatively common in the universe.  Which further bolsters something I've said for ages, which is that life will turn out to be plentiful out there.

[Image licensed under the Creative Commons ESO/M. Kornmesser/Nick Risinger (skysurvey.org), Artist impression of the exoplanet 51 Pegasi b, CC BY 4.0]

The second, which appeared in Monthly Notices of the Royal Astronomical Society, suggests one way to detect that life at a distance.  In "Biological Fluorescence Induced by Stellar UV Flares, a New Temporal Biosignature," by Jack T. O'Malley-James and Lisa Kaltenegger (both of Cornell University), we find out that class-M stars -- of which the Sun is one -- not only have the right temperature ranges to foster planets with life, but their habit of generating solar flares could tip us off as to which planets hosted life.  The phenomenon of biofluourescence -- the absorption of high-energy light (such as ultraviolet) and its conversion into lower-energy light (visible light) -- could act as a protective mechanism during solar flares.  So when a star flares up, all we have to do is look for the flash of fluorescence that follows.

"On Earth, there are some undersea coral that use biofluorescence to render the Sun’s harmful ultraviolet radiation into harmless visible wavelengths, creating a beautiful radiance," said study co-author Lisa Kaltenegger, who is the director of the Carl Sagan Institute for Astrophysics.  "Maybe such life forms can exist on other worlds too, leaving us a telltale sign to spot them."

The coolest thing is that one of the stars being studied is Proxima Centauri -- the closest star to our Solar System.  So the technique O'Malley-James and Kaltenegger propose using could find life that is, so to speak, right next door.

As a cool followup to this paper, the following day a paper appeared in arXiv by a team of astrophysicists led by Stefan Dreizler of the Georg-August-Universität Göttingen that found not one but three planets in the "Goldilocks zone" of a relatively nearby star -- GJ1061.  One of the problems with figuring out which planets to study for signs of life is that the mass of the planet and its distance from the star aren't the only factors that matter; another, and one much harder to determine from Earth, is the stability of the orbit.  I still remember when I was a kid watching the generally-abysmal 1960s science fiction show Lost in Space, and was blown away when it was revealed that the planet the Robinson family was on was in a highly elliptical orbit -- so the seasons varied from blisteringly hot at the planet's perigee and freezing cold at its apogee.  (The way it played out in the show was, predictably, kind of silly, but it was a concept I'd never run into before, and at age six I was pretty damned impressed.)

But what Dreizler et al. found was that the three planets around GJ1061 were in stable orbits, meaning it was likely that they were relatively circular.  (Elliptical orbits cross each other and therefore increase the likelihood of collisions or gravitational slingshots slinging a planet into the star or out into space.)

So this gives us another likely candidate for biosignatures.

I'm pretty encouraged at all the effort that's being expended in this endeavor.  I vividly recall watching my favorite movie -- Contact -- for the first time, and being appalled at how astronomer Ellie Arroway had to fight to be taken seriously, not only because she was a woman in what then (and still is to some extent now) was a man's world, but because her area of research was the search for extraterrestrial life.  What more fascinating research is there, to find out if life on Earth is unique -- or if, as I contend, we're just one of a multitude of planets hosting life?

I can't imagine a more deeply resonant idea, nor one that would have as profound an effect on how we see ourselves and our place in the universe.  And if that's not worth researching, I don't know what is.

*****************************

This week's Skeptophilia book recommendation is a must-read for anyone interested in astronomy -- Finding Our Place in the Universe by French astrophysicist Hélène Courtois.  Courtois gives us a thrilling tour of the universe on the largest scales, particularly Laniakea, the galactic supercluster to which the Milky Way belongs, and the vast and completely empty void between Laniakea and the next supercluster.  (These voids are so empty that if the Earth were at the middle of one, there would be no astronomical objects near enough or bright enough to see without a powerful telescope, and the night sky would be completely dark.)

Courtois's book is eye-opening and engaging, and (as it was just published this year) brings the reader up to date with the latest information from astronomy.  And it will give you new appreciation when you look up at night -- and realize how little of the universe you're actually seeing.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

A black hole's strange glow

I think part of my enjoyment of science is that I love a good mystery.

The universe is endlessly fascinating and also endlessly complicated, and if you get into science you'll never want for new things to learn about.  You'll also be pushing the edges of what we can explain.  Some fairly simple-to-ask questions that we still haven't solved:

• Why do we dream?  It's ubiquitous amongst mammals, but its purpose is still uncertain.
• Why does space have three spatial dimensions?  There's nothing particularly special about having three dimensions, at least from what we know.  There's a conjecture that (if string theory is correct) there are eleven spatial dimensions, but if so, why are eight of them essentially undetectable?
• Is life common in the universe, or are we alone?
• Where does consciousness come from?
• What caused the Big Bang?
• What causes aging... and can it be slowed or stopped entirely?
• What causes the flow of time?  Most processes in physics are time-reversible -- they make equal sense if you watch them by running the clock backwards.  Why do we have an unshakeable sense of time's arrow only pointing one way?
• Could human cognition and personality theoretically be emulated in a machine?
• What are dark matter and dark energy?  And why can't we detect them except by their gravitational signature?

So if you like to wonder about stuff, immerse yourself in science.  I can promise you you'll never be bored.

This comes up because of some weird behavior by one of the oddest things in the universe: black holes.  You probably know that a black hole is a collapsed supergiant star, an object that is so massive that it warps space into a closed shape.  Even light can't escape (thus the name).  Around the border of a black hole is the event horizon, which is the point of no return -- when you cross it, you'll never escape, and will ultimately fall into the singularity at the center.  But you'll be dead long before then, torn to shreds by the tidal forces as you approach (a process astrophysicists have nicknamed, no lie, spaghettification.)

Black holes, though, aren't necessarily produced by the collapse of a single star.  It's thought that most galaxies have massive black holes at their center.  The Milky Way has one with the unprepossessing name Sagittarius A*, which becomes a little more impressive when you find out that it has four million times the mass of the Sun.

You might wonder how (being black) it was detected.  As matter falls into a black hole, it accelerates, and in the process emits radiation.  (Sort of an electromagnetic death scream, is how I think of it.)  Being as massive as it is, Sagittarius A* has quite a signature in the radio region of the spectrum, which is how it was first detected way back in 1931.

Sagittarius A* [Image is in the Public Domain, courtesy of NASA]

What got me thinking about this is that Sagittarius A* has been acting rather strangely of late.  Like most black holes studied, it does fluctuate in its energy output, presumably as the amount of matter falling into it varies.  But back in May of this year, its luminosity in the near-infrared region of the spectrum increased by a factor of 75...

... in a period of two hours.

"The brightness of Sgr A* varies all the time, getting brighter and fainter on the timescale of minutes to hours—it basically flickers like a candle," said study leader, UCLA astronomer Tuan Do.  "We think that something unusual might be happening this year because the black hole seems to vary in brightness more, reaching brighter levels than we've ever seen in the past...  Many astronomers are observing Sgr A* this summer.  I'm hoping we can get as much data as we can this year before the region of the sky with Sgr A* gets behind the Sun and we won't be able to observe it again until next year...  Maybe the black hole is waking up—there's a lot we don't know at this point so we need more data to understand if what we are seeing is a big change in what is feeding the black hole or this is a brief event."

Whatever it is, it certainly is intriguing.  Such a rapid and massive increase in luminosity from such an enormous object is hard even to wrap your brain around.  All of which just goes to show that even when you have a pretty good idea of how the universe works, it can turn around an astonish you.

Which, after all, is what science is all about.

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This week's Skeptophilia book recommendation is a must-read for anyone interested in astronomy -- Finding Our Place in the Universe by French astrophysicist Hélène Courtois.  Courtois gives us a thrilling tour of the universe on the largest scales, particularly Laniakea, the galactic supercluster to which the Milky Way belongs, and the vast and completely empty void between Laniakea and the next supercluster.  (These voids are so empty that if the Earth were at the middle of one, there would be no astronomical objects near enough or bright enough to see without a powerful telescope, and the night sky would be completely dark.)

Courtois's book is eye-opening and engaging, and (as it was just published this year) brings the reader up to date with the latest information from astronomy.  And it will give you new appreciation when you look up at night -- and realize how little of the universe you're actually seeing.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

It's the end of the world, if you notice

I have commented more than once about my incredulity with regards to end-of-the-world predictions.  Despite the fact that to date, they have had a 100% failure rate, people of various stripes (usually of either the ultra-religious persuasion or the woo-woo conspiracy one) continue to say that not only is the world doomed, they know exactly when, how, and why.  (If you don't believe me, take a look at the Wikipedia page for apocalyptic predictions, which have occurred so often they had to break it down by century.)

As far as why this occurs -- why repeated failure doesn't make the true believers say, "Well, I guess that claim was a bunch of bullshit, then" -- there are a variety of reasons.  One is a sort of specialized version of the backfire effect, which occurs when evidence against a claim you believe strongly leaves you believing it even more strongly.  Way back in 1954 psychologists Leon Festinger, Henry Riecken, and Stanley Schachter infiltrated a doomsday cult, and in fact Festinger was with the cult on the day they'd claimed the world was going to end.  When 11:30 PM rolled around and nothing much was happening, the leader of the cult went into seclusion.  A little after midnight she returned with the joyous news that the cult's devotion and prayers had averted the disaster, and god had decided to spare the world, solely because of their fidelity.

Hallelujah!  We better keep praying, then!

(Note bene: The whole incident, and the analysis of the phenomenon by Festinger et al., is the subject of the fascinating book When Prophecy Fails.)

Despite this, the repeated failure of an apocalyptic prophecy can cause your followers to lose faith eventually, as evangelical preacher Harold Camping found out.  So the people who believe this stuff often have to engage in some fancy footwork after the appointed day and hour arrive, and nothing happens other than the usual nonsense.

Take, for example, the much-publicized "Mayan apocalypse" on December 21, 2012 that allegedly was predicted by ancient Mayan texts (it wasn't) and was going to herald worldwide natural disasters (it didn't).  The True Believers mostly retreated in disarray when December 22 dawned, as well they should have.  My wife and I threw a "Welcoming In The Apocalypse" costume party on the evening of December 21, and I have to admit to some disappointment when the hour of midnight struck and we were all still there.  But it turns out that not all of the Mayan apocalyptoids disappeared after the prediction failed; one of them, one Nick Hinton, says actually the end of the world did happen, as advertised...

... but no one noticed.

Hinton's argument, such as it is, starts with a bit of puzzling over why you never hear people talking about the 2012 apocalypse any more.  (Apparently "it didn't happen" isn't a sufficient reason.)  Hinton finds this highly peculiar, and points out that this was the year CERN fired up the Large Hadron Collider and discovered the Higgs boson, and that this can't possibly be a coincidence.  He wonders if this event destroyed the universe and/or created a black hole, and then "sucked us in" without our being aware of it.

[Image licensed under the Creative Commons Lucas Taylor / CERN, CMS Higgs-event, CC BY-SA 3.0]

Me, I think I'd notice if I got sucked into a black hole.  They're kind of violent places, as I described yesterday in my post about Sagittarius A*.  But Hinton isn't nearly done with his explanation.  He writes:

There's the old cliché argument that "nothing has felt right" since 2012.  I agree with this... [E]ver since then the world seems to descend more and more into chaos each day.  Time even feels faster.  There's some sort of calamity happening almost daily.  Mass shootings only stay in the headlines for like 12 hours now.  Did we all die and go to Hell?...  Like I've said, I think we live in a series of simulations.  Perhaps the universe was destroyed by CERN and our collective consciousness was moved into a parallel universe next door.  It would be *almost* identical.

Of course, this is a brilliant opportunity to bring out the Mandela effect, about which I've written before.  The idea of the Mandela effect is that people remember various stuff differently (such as whether Nelson Mandela died in prison, whether it's "Looney Tunes" or "Loony Tunes" and "The Berenstein Bears" or "The Berenstain Bears," and so forth), and the reason for this is not that people's memories in general suck, but that there are alternate universes where these different versions occur and people slip back and forth between them.

All of which makes me want to take Ockham's Razor and slit my wrists with it.

What I find intriguing about Hinton's explanation is not all the stuff about CERN, though, but his arguing that the prediction didn't fail because he was wrong, but that the world ended and six-billion-plus people didn't even notice.  Having written here at Skeptophilia for almost nine years, I'm under no illusions about the general intelligence level of humanity, but for fuck's sake, we're not that unobservant.  And even if somehow CERN did create an alternate universe, why would it affect almost nothing except for things like the spelling of Saturday morning cartoon titles?

So this is taking the backfire effect and raising it to the level of performance art.  This is saying that it is more likely that the entire population of the Earth was unaware of a universe-ending catastrophe than it is that you're wrong.

Which is so hubristic that it's kind of impressive.

But I better wind this up, because I've got to prepare myself for the next end of the world, which (according to the late psychic Jeane Dixon) was going to occur in January of 2020.  Which only gives me a few months to get ready.  So many apocalypses, so little time.

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This week's Skeptophilia book recommendation is a must-read for anyone interested in astronomy -- Finding Our Place in the Universe by French astrophysicist Hélène Courtois.  Courtois gives us a thrilling tour of the universe on the largest scales, particularly Laniakea, the galactic supercluster to which the Milky Way belongs, and the vast and completely empty void between Laniakea and the next supercluster.  (These voids are so empty that if the Earth were at the middle of one, there would be no astronomical objects near enough or bright enough to see without a powerful telescope, and the night sky would be completely dark.)

Courtois's book is eye-opening and engaging, and (as it was just published this year) brings the reader up to date with the latest information from astronomy.  And it will give you new appreciation when you look up at night -- and realize how little of the universe you're actually seeing.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]