The passport

When I was a kid, the high point of school was when we got the monthly Scholastic Book Club listings.

The opportunity to pick out a handful of books to buy -- at that point, back in the early 1970s, they cost an astonishing one or two dollars each -- turned me into the proverbial kid in the candy store.  I dutifully filled out my order form, submitted it and my money to the teacher -- and a few weeks later, there'd be a delivery of a box full of books to dole out to the students.

Pure magic.

It was in a SBC sale, when I was maybe twelve, that I got a copy of Madeleine L'Engle's A Wrinkle in Time.

Afterwards, my world would never be the same again.

I completely lost myself in the adventures of Meg, Calvin, and Charles Wallace, along with their guides, the cheerful, shapeshifting Mrs. Whatsit, the classics-quoting Mrs. Who, and the mysterious and slightly intimidating Mrs. Which.  It was a glimpse into a universe the likes of which I'd never experienced before.

I was launched into a love of magical realism that is still with me today, fifty years later.  Along the way I discovered such masters as Edgar Allen Poe, H. P. Lovecraft, Guy de Maupassant, George MacDonald, and C. S. Lewis -- and later, Neil Gaiman, Terry Pratchett, Christopher Moore, and Haruki Murakami.  What I learned from them informed my imagination and writing style, inspiring my own career as an author.

My latest -- coming out September 1!

I'm not alone in the sense that reading fiction was a lifeline when I was a child.

Research out of the University of Cambridge, published this week in the journal Psychological Medicine, has found that young people who are encouraged to read for pleasure score better on cognitive tests and have overall better mental health during their teenage years than children who don't.  The study looked at over ten thousand children, and the results were unequivocal.

"Reading isn’t just a pleasurable experience," said study co-author Barbara Sahakian.  "It’s widely accepted that it inspires thinking and creativity, increases empathy and reduces stress.  But on top of this, we found significant evidence that it’s linked to important developmental factors in children, improving their cognition, mental health, and brain structure, which are cornerstones for future learning and well-being."

I can also say that in my case, it was a welcome escape from a home situation that was -- to put it mildly -- non-ideal.  Knowing I could leave behind the unpleasantness I was immersed in daily, and tesser to the stars with Meg Murry and her friends, was a gateway to a world where I could forget my troubles, at least for a little while.

I shudder to think what my mental health would have been like if I hadn't had that magic door to escape through.

It's why I think equal emphasis should be given in schools to reading for comprehension and analysis, and reading for pure enjoyment.  Too much focus on the former, and the risk is convincing students that reading is a boring chore.  Yes, there's value in sharpening skills, and getting kids to think more deeply about what they read; but what we ideally want is getting them hooked -- and that only happens if they have an opportunity to explore what they want to read, whatever the genre or subject matter.

"We encourage parents to do their best to awaken the joy of reading in their children at an early age," said study co-author Jianfeng Feng.  "Done right, this will not only give them pleasure and enjoyment, but will also help their development and encourage long-term reading habits, which may also prove beneficial into adult life."

For some of them -- like myself -- it is not just beneficial, it was vital.  I still remember the thrill of getting my books from SBC, and even today I experience that same feeling when I walk into a bookstore or used book sale.  And it's what turned me into an author, now with twenty-two published books to my name.  My hope is that those books will be an inspiration to others -- perhaps providing them with a passport to other places and times, allowing them for a little while to glimpse the magic of worlds and characters beyond their own everyday experience.

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Stretching time

You know, I'm beginning to think that every time I want to write a piece about cosmology or physics, I should just write "Einstein wins again" and call it good.

One of my favorite science vloggers, theoretical physicist Sabine Hossenfelder, gives a wry nod to this every time Einstein's name comes up in her videos -- which is frequently -- giving a little sigh and a shake of the head, and saying "Yeah, that guy again."

Maybe we should just stop arguing with him.  [Image is in the Public Domain]

You may recall that a couple of weeks ago I did a post about a possible paradigm shift in cosmology that could account for the mysterious "dark energy," a property of spacetime that is causing the apparent runaway expansion of the universe.  While acknowledging that finding solid evidence for the contention is currently beyond our technical capabilities, I pointed out that it simultaneously does away with two of the most perplexing and persistent mysteries of physics -- dark energy, and the mismatch between the theoretical and experimentally-determined values of the cosmological constant.  (Calling it a "mismatch" is as ridiculous an understatement as you could get; the difference is about 120 degrees of magnitude, meaning the two values are off by a factor of 1 followed by 120 zeroes).

But this week a new study out of the University of Sydney has shown that another of Einstein's relativistic predictions about an expanding universe has been experimentally verified, so maybe -- to paraphrase Mark Twain -- rumors of the death of dark energy were great exaggerations.  A bizarre feature of the Theory of Relativity is time dilation, the fact that from the perspective of a stationary observer, the clock for a moving individual would appear to run more slowly.  This gives rise to the counterintuitive twin paradox, which I first ran into on Carl Sagan's Cosmos when I was in college.  If one of a pair of twins were to take off on a spaceship and travel for a year near the speed of light, then return to his starting point, he'd find that his twin would have aged greatly, while he only aged by a year.  To the traveler, his clocks seemed to run normally; but his stay-at-home brother would have experienced time running much faster.

As an aside -- this is the idea behind my favorite song by Queen, the poignant and heartbreaking "'39," the lyrics for which were penned by the band's lead guitarist, astrophysicist Brian May.  Give it a listen, and -- if you're like me -- have tissues handy.

In any case, the recent research looks at a weird feature of the effects of relativity on time.  The prediction is that the expansion of the universe should affect all the dimensions of spacetime -- and therefore, in the early universe, time should (from our perspective) seem to have been running more slowly.

And that's exactly what they found.  (Recall that when you're looking outward in space, you're looking backward in time.)  The trick was finding a "standard clock" -- some phenomenon whose rate is steady, predictable, and well-understood.  They used the fluctuations in emissions from quasars -- extremely distant, massive, and luminous proto-galaxies -- and found that, exactly as relativity predicts, the farther away they are (i.e. the further back in time you're looking), the more slowly these "standard clocks" are running.  The most distant ones are experiencing a flow of time that (from our perspective) is five times slower than our clocks run now.

"[E]arlier studies led people to question whether quasars are truly cosmological objects, or even if the idea of expanding space is correct," said study co-author Geraint Lewis.  "With these new data and analysis, however, we’ve been able to find the elusive tick of the quasars and they behave just as Einstein’s relativity predicts."

The bizarre thing, though, is the "from our perspective" part; just like the traveling twin, anyone back then would have thought their clocks were running just fine.  It's only when you compare different reference frames that things start getting odd.  So it's not that "our clocks are right and theirs were slow;" both of us, from our own vantage points, think time is running as usual.  Neither reference frame is right or wrong.  The passage of time is relative to your velocity with respect to another frame.

Apparently it's also relative to what the fabric of spacetime around you is doing.

I'm not well-versed enough in the intricacies of physics to know if this really is a death blow to the paradigm-shifting proposal of a flat, static universe I wrote about a couple of weeks ago, but at least to my layperson's understanding, it sure seems like it would be problematic.  So as far as the nature of dark energy and the problem of the cosmological constant mismatch, it's back to the drawing board.

Einstein wins again.

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Thus sayeth the prophecy

I have written daily on this blog for years now, and I still run into crazies that I haven't heard of before.  I guess this isn't that surprising, since humanity seems to produce an unending supply.  But given the amount of time I spend weekly perusing the world of woo-woo, it always comes as a little bit of a shock when I find a new one.

This week it was John Hogue, who a friend of mine asked about, in the context of, "Wait till you see what this loony is saying."  Hogue is a big fan of "Nostradamus," noted sixteenth century wingnut and erstwhile prophet, who achieved fame for writing literally thousands of quatrains of bizarre predictions.

[Image is in the Public Domain]

Hogue believes that just about everything you can think of was predicted by Nostradamus.  We'll start with his claim that Nostradamus predicted Saddam Hussein's rise and fall, only (because being a prophet and all, you can't just say things straight out) he called Saddam "Mabus."  How does Hogue know that Saddam is Mabus?  Let's have it in his own words:

Here, for your review are the two core quatrain prophecies about Mabus, the Third Antichrist, indexed 2 Q62 and 8 Q77 in Nostradamus’ prophetic masterpiece Les Propheties, initially published in serialized form between the years 1555 and 1560: 

2 Q62

Mabus puis tost alors mourra, viendra,
De gens & bestes vne horrible defaite:
Puis tout à coup la vengeance on verra,
Cent, main, soif, faim, quand courra la comète.

Mabus will soon die, then will come,

A horrible unraveling of people and animals,

At once one will see vengeance,

One hundred powers, thirst, famine, when the comet will pass.

8 Q77

L’antéchrist trois bien tost annichiliez,
Vingt & sept ans sang durera sa guerre:
Les hérétiques morts, captifs, exilez,
Sang corps humain eau rogie gresler terre.

The Third Antichrist very soon annihilated,

Twenty-seven years his bloody war will last.

The heretics [are] dead, captives exiled,

Blood-soaked human bodies, and a reddened, icy hail covering the earth.

Let us go through the milestones that [show] Saddam... to be candidate number one...
Being a dead candidate is the first and dubious milestone...  Saddam was hanged at the 30 December 2006...
[Saddam's name] can be found in the code name Mabus.  Saddam backwards spells maddas=mabbas=mabas.  Replace one redundant a and you get Mabus.

Or if you don't like that solution, maybe Mabus is Osama bin Laden, whom Hogue refers to as "Usama" for reasons that become obvious pretty quickly:

Usama mixed around get [sic] us maaus.  Take the b from bin Laden.  Replace the redundant a and you get Mabus.

If you take my first name, Gordon, and rearrange it, you get "drogon."  Replace the "o" with an "a," because after all there are two "o"s anyway, and you clearly don't need both of them.  You can get the "a" from the leftover one Hogue had by removing the redundant "a" in "maaus."  Then you get "dragon."  If you take my middle name (Paul) and my last name, and rearrange the letters, you get "a noble punt."

So this clearly means that a dragon is about to attack the United States, but I'm going to kick its ass.

Basically, if you take passages at random, and mess around with them, and there are no rules about how you do this, you can prove whatever you want.  Plus, all of the "prophecies" that Nostradamus wrote are vague and weird enough already, without any linguistic origami to help you out.  They make obscure historical and mythical allusions that, if you're a little creative, can be interpreted to mean damn near anything.  Here's one I picked at random (Century X, Quatrain 71):

The earth and air will freeze a very great sea,
When they will come to venerate Thursday:
That which will be, never was it so fair,
From the four parts they will come to honor it.

What does that mean?  Beats the shit out of me.  I'm guessing that you could apply it to a variety of situations, as long as you are willing to interpret it loosely and let the images stand for whatever you want them to.  Me, I think it has to do with the biblical End Times.  Oh, and that climate change is a lie, because the sea is going to freeze.  I'm sure that the Planet Nibiru and global conspiracies are involved, too.

They always are, somehow.

What I find amazing is that there are literally thousands of websites, books, and films out there that claim to give the correct interpretation of Nostradamus' wacky poetry.  Some of them take a religious bent, and try to tie them into scripture, especially the Book of Revelation; some try to link them to historical events, an especially popular one being World War II; others, even further off the deep end, try to use them to predict future catastrophes.  These last at least put the writers on safer ground, because you can't accuse someone of being wrong if they're using arcane poetry to make guesses about things that haven't happened yet.

In any case, I'm doubtful that Nostradamus knew anything about Saddam Hussein, any more than he predicted World War II, the dropping of the atomic bomb on Hiroshima, the assassination of JFK, or any of the hundreds of other things Hogue claims he forecasted.  All we have here is once again, people taking vague language and jamming it into the mold of their own preconceived notions of what it means.  About John Hogue himself, I'm reminded of the words of the Roman writer Cicero, who said, "I don't know how two augurs can look each other in the face while passing in the street without laughing out loud."

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License to hate

By now, I'm sure all of you have heard about the 6-3 decision by the United States Supreme Court in favor of a Colorado web designer who felt like it was her right to refuse service to a gay couple on the basis of her "sincerely-held religious beliefs."

What you may not have heard is that upon looking into the details of the case, investigative reporters found that:

1. ... the man, named only as "Stewart" to protect his privacy, whom the plaintiff Lorie Smith said was one half of the gay couple who asked for her services, has never attempted to hire her, and in fact had never heard of her before the case became public;
2. ... he's a web designer himself, so in his own words, "It would make zero sense to hire a web designer when I can do that for myself;"
3. ... his gay fiancé, "Mike," doesn't exist;
4. ... and Stewart himself not only is not gay, he's been happily married to a woman for fifteen years.

So the upshot of it all is that Smith is so motivated by hatred of LGBTQ+ people that she invented an imaginary grievance, lied about it repeatedly through the various tiers of the court system, and eventually got license to deny service to a gay couple who doesn't, technically, exist.

The lawyers from the virulently anti-LGBTQ+ Alliance Defending Freedom, who defended Smith, don't seem at all upset by this.  After all, they got what they wanted; a court-sanctioned right to discriminate.  Kellie Fiedorek, who represented her, responded with a verbal shrug.

"No one should have to wait to be punished by the government to challenge an unjust law," Fiedorek said.

Apparently this allows you to invent a grievance, along with imaginary adversaries, and carry it to the highest levels of the judicial system.

And win.

Smith immediately took the mic on right-wing news to crow about this being a "victory for free speech and freedom of religion."  Because, of course, the explicit outcome was to allow her to get away with discriminating against a particular group she despises.  But what baffles me is how neither the six justices who sided with Smith, nor Fiedorek and the Alliance Defending Freedom, nor Smith herself, seem to realize how quickly this could be turned around.  What's to stop a queer-owned business from putting up a sign saying "No Straight People Allowed"?  Or an atheist-owned business refusing to serve Christians?  Or a liberal-owned business stating that no Republicans are allowed on the premises?

You have to wonder what the Religious Right will think if this decision starts being used against them.

Wasn't there already a battle over this sort of thing?  And didn't the bigots lose?  [Image of the February 1960 sit-in at Woolworth's, Durham, North Carolina is in the Public Domain]

Discrimination laws are there to prevent one individual's prejudice and hatred from impinging on the rights, security, safety, or life of someone based upon their demographics -- and especially, to protect members of oppressed or marginalized groups.  And before anyone comes at me about how oppressed and marginalized Christians are, allow me to point out that an overwhelming majority of Americans -- 63% -- self-identify as Christian.  In large swaths of the country, a non-Christian has a snowball's chance in hell of being elected to public office.  And in any case -- as I pointed out earlier -- Lorie Smith's grievance was completely spun from lies.  She created a bullseye herself, pasted it on her own forehead, and then claimed she'd been unfairly targeted.

And two-thirds of the Supreme Court agreed with her.

It's not just queer people who should be worried about this.  This ruling blows a gaping hole in prior protections from discrimination, not only on the basis of gender identity and sexual orientation, but race and religion.  "The worry is that this provides a green light to any business owner that they can refuse service to any person on the basis of their identity, whether they’re gay or lesbian, or Jewish or Black, or anything, because they have an objection to those sorts of people being in their business,” said Katherine Franke, a professor at Columbia Law School.  "There was nothing in the opinion that limits it to objections to same-sex marriage."

The only thing that keeps me from despairing completely about this situation is the sense that this is the last gasp of dying ideological bigotry.  Younger people are overwhelmingly in support of full rights for LGBTQ people, including the right to marry, and against the bogus outrage of people like Lorie Smith and the Alliance Defending Freedom.  So inevitably, as the younger generation becomes an increasingly large percentage of voters, it is devoutly to be hoped that the pendulum will swing the other way and sweep away the ugly vestiges of racism, sexism, and homophobia.

In the interim, of course, a lot of damage can be done.  Queer people and our allies need to stand up and speak.  Shout, even.  Friday's decision was a travesty of justice, driven by a warped definition of freedom of speech and freedom of religion, and flies in the face of every piece of civil rights legislation back into the 1960s.

But now's not the time to give up, as tempting as it is.

We can't let the hatred and bigotry of the Lorie Smiths of the world win.

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Planetary spin cycle

I try not to spend too much time focusing on completely loony ideas here at Skeptophilia.  Wackos are, after all, a dime a dozen, and grabbing the low-hanging fruit is kind of a cheap way to run a blog.  But sometimes I run into a claim that is so earnest, so serious, and at the same time so completely bizarre that it's kind of charming.

That was my reaction when a friend and loyal reader of Skeptophilia sent me a link to a site called Bibliotecapleyades.  I have to admit that I have no idea what that means.  I know that biblioteca means "library" in Spanish, and pleyades sounds a little like "Pleiades," the star cluster that is thought among some of the astro-woo-woos to be the home of the Nordic aliens, who are tall, blond, blue-eyed, muscular, and drop-dead sexy.

Sort of Liam Hemsworth from Outer Space, is how I think of them.

Whether that's the origin of the name or not, I have no idea.  The site doesn't mention aliens, but given the rest of the content, I wouldn't be surprised if it came up at some point.

Anyhow, this particular page on Bibliotecapleyades is called "Earth Changes: Future Map of the World," and goes into how "international known [sic] and respected futurist Gordon-Michael Scallion" has a vision of how the world is going to end up.  And I do mean "vision."  His ideas aren't based on science (big shocker, there) but on his "ongoing visions concerning the Earth" that he experiences "sometimes as many as ten or more in a day, lasting from a few seconds to minutes."  But instead of seeking professional help for this condition, he started writing it all down, and put them all together into a unified, consolidated picture of what we were in for.

You really should look at the website itself, preferably after consuming a double scotch.  It's just that good.  But in case you don't want to risk valuable brain cells going through it, I present below a few highlights of what's going to happen.  Forewarned is forearmed, you know.

1. First, we're going to have a pole shift.  Scallion seems unaware that the position of the magnetic pole and the position of the rotational axis of the Earth are related but aren't the same, so he gets a little confused talking about the precession of the Earth's rotational axis (which is real enough; the Earth wobbles like a top, meaning that Polaris won't be the North Star forever) as somehow triggering a shift in the magnetic pole.  You get the impression he thinks when the poles reverse, the Earth is kind of going to fall over or something.  But he soldiers on ahead, saying that the Earth is going to be like "a washing machine that is out of balance in the spin cycle," and this is going to fling the poles about like damp socks.  Havoc will ensue.
2. Africa is going to fall apart into three separate continents.  Some waterways will open up in a kind of a "Y" shape, inundating large parts of what is now dry land.  Madagascar is going to sink into the ocean.  Don't ask me why.  The Pyramids will also end up under water, but the flipside is that before then, "there will be great archaeological discoveries."
3. The news is more positive for Antarctica, which is going to "be reborn, and become fertile land again."  In addition, the relics of the lost civilization of "Lumania" will be found when the ice all melts, and "great cities and temples will be discovered."  I'm not sure how I feel about this.  In the historical document "At the Mountains of Madness" by H. P. Lovecraft, some explorers went into Antarctica, discovered big abandoned cities and temples, and almost all of them ended up getting eaten by Shoggoths.  So we might want to be a little cautious about investigating "Lumania."
4. The tectonic plate underneath Europe is going to "collapse."  This will cause Scandinavia and Great Britain to sort of slide off the edge into the Atlantic Ocean.
5. The Middle East will be engulfed in war.  For a change.  But this one will be a "holy war with purification of the land by fire and water," whatever that means.  I hope no one tells the End Times folks about this, because they already spend enough time yammering on about stuff like this, and I really don't want to add any more grist to their mill.
6. North America also looks like it's in for a rough time.  California will split up into 150 islands, and the "west coast will recede to Nebraska, Wyoming, and Colorado."  How that will work, given that Nebraska is east of Wyoming and Colorado, I have no idea.  The Appalachians will be a long skinny island.  At least here in upstate New York it looks like I'll have beachfront property.

He then ends with a disclaimer, a little like the "this preparation is not intended to treat or cure any medical condition" thing you see on bottles of homeopathic "remedies."  He says:

[N]o event or prediction is final.  Predictions are given as probabilities.  Even at this time, consciousness can alter an event, modify changes in a particular area or at the very least help us to prepare for what is to come...  One final note, the areas of change presented in the Future Map of The World should not be taken as absolute.  They may differ from a few miles to several hundred miles depending on many variables.  In the end, Mother Nature and our own collective consciousness will have the final say.

Be that as it may, he provides us with a map of the world showing all of the new land contours.  I'd post it here, but I don't know how Gordon-Michael Scallion feels about the copyright on images he's created, so you'll just have to go take a look for yourself if you want to figure out whether it's time to pack up and move.  Here's a map of what the world looks like now, so you'll have a basis for comparison.

[Image is in the Public Domain courtesy of NASA]

Anyhow, that's our excursion into the deep end of the pool for today.  Me, I'm not concerned.  He didn't provide a timeline for all of these catastrophes in any case, so right now I'm going to worry about more pressing issues, such as how the hell we here in the U.S. ended up with a a twice-impeached, twice-indicted near-illiterate wearing orange spray tan as a serious contender for re-election as president.  Frankly, compared to that, "Lumania" doesn't really bother me much.

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Ripples in the cosmic pond

Springboarding off yesterday's post, about a mysterious flare-up of Sagittarius A* (the supermassive black hole at the center of the Milky Way galaxy), today we have an even more momentous discovery -- a background thrum of gravitational waves from supermassive black holes in orbit around each other.

Gravitational waves are created when massive objects accelerate through space.  They're actually pulsed fluctuations in the fabric of space-time that propagate out from the source at the speed of light.  The idea has been around for a long time; English mathematician Oliver Heaviside proposed them all the way back in 1893.  Once Einstein wrote his paradigm-overturning paper on relativity in 1915, Heaviside's proposal gained a solid theoretical underpinning.

The problem was detecting them.  They're tiny, especially at large distances from the source; and the converse difficulty is that if you were close enough to the source that they were obvious, they'd be big enough to tear you to shreds.  So observing from a distance is the only real option.

[Image licensed under the Creative Commons ESO/L. Calçada/M. Kornmesser, Artist’s impression of merging neutron stars, CC BY 4.0]

The result is that it took a hundred years to get direct evidence of their existence.  In 2015 the LIGO (Laser Interferometer Gravitational Wave Observatory) successfully detected the gravitational waves from the merger of two black holes.  The whirling cyclone of energy as they spun around their center of mass, then finally coalesced, caused the space around the detector to oscillate enough to trigger a shift in the interference pattern between two lasers.  The physicists had finally seen the fabric of space shudder for a moment -- and in 2017, the accomplishment won the Nobel Prize for Rainer Weiss, Kip Thorne, and Barry Barish.

Now, though, a new study at the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has found a whole different kind.  Instead of the sudden, violent, there-and-gone-again waves seen by LIGO, NANOGrav has found a background "hum" in the universe -- the stirring of spacetime because of the orbiting of supermassive black holes around each other.

The accomplishment is made even more astonishing when you find out how long the wavelengths of these waves are.  Frequency is inversely proportional to wavelength, so the "nanohertz" part of the name of the observatory might have given you a clue.  The gravitational waves detected by NANOGrav have wavelengths measured in light years.  So how in the hell do you detect a wave in which -- even traveling at the speed of light -- the trough of the wave doesn't hit you until a year after the crest?

The way they did it is as clever as it is amazing.  Just as you can see a pattern of waves if you look across the surface of a pond, the propagation of these gravitational waves should create a ripple in space that affects the path of any light that travels through them.  The scientists at NANOGrav measured the timing of the light from pulsars -- the spinning remnants of collapsed massive stars, that because of their immense mass and breakneck rotational speed flash on and off with clocklike precision.  And sure enough, as the waves passed, the contraction and expansion of the fabric of space in between caused the pulsars to seem to speed up and slow down, by exactly the amount predicted by the theory.

"The Earth is just bumping around on this sea of gravitational waves," said astrophysicist Maura McLaughlin, of West Virginia University, who was on the team that discovered the phenomenon.

It's a little overwhelming to think about, isn't it?  Millions of light years away, two enormous black holes are orbiting around a common center of gravity, and the ripples that creates in the cosmic pond flow outward at the speed of light, eventually getting here and jostling us.  Makes me feel very, very small.

Which, honestly, is not a bad thing.  It's always good to remember we're (very) tiny entities in a (very) large universe.  Maybe it'll help us not to take our day-to-day worries quite so seriously.

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The glowing death spiral

One of the things that always blows my mind about astronomy is how good we've gotten at using indirect evidence to figure out what's going on up there.

In a way, of course, it's all indirect, at least in the sense that everything we're seeing is (1) wicked far away, and (2) in the past.  I remember how weirded out I was when I first ran into the latter concept, back when I was maybe twelve years old.  My first inkling of it happened when I was out on a walk with my dad, and down the street there was a guy using a sledgehammer to pound in a fence post.  The strange thing was, I saw the hammer's head strike the post, and then, a second or two later I heard the bang of the strike.  I asked my dad why that was.

"Well," he said, after a moment's thought, "the sound takes a moment to get to your ears.  It's why we always see the lightning before we hear the thunder.  And the farther away it is, the longer the delay.  So as we get closer to the guy, the delay should get smaller."

Which, of course, it did.

After I'd had a minute to process that, I said, "But light takes time to get to your eyes, too.  A very short amount of time, but still, some time.  So does that mean you're not seeing things as they are, but as they were in the past?"

My dad agreed that must be so.

Upon learning some more physics, I found out that the Sun is far enough away from the Earth that it takes a bit over eight minutes for light to travel the distance in between.  So if the Sun suddenly vanished -- an unlikely eventuality, fortunately -- we not only wouldn't know it for eight minutes, there is no possible way to know it.  Einstein showed that information can't travel any faster than the speed of light -- it really is the ultimate speed limit.

The nearest star, Proxima Centauri, is 4.25 light years, so we're seeing it as it was 4.25 years ago, and have no way of seeing what it looks like right now.  Given that it seems to be a fairly stable star, it probably looks much the same; but the fact remains that we can't know what its current appearance is.  The most distant objects we've seen through our most powerful telescopes are some of the quasars, at thirteen billion light years distant (and thus, what they looked like thirteen billion years ago).  So what those quasars look like right now -- where they are, if they even exist any more -- is impossible to know.  We're seeing them as they looked shortly after the universe began; what they are today is anyone's guess.

Impressively far away, but at least still in our own galaxy, is Sagittarius A*, the supermassive black hole at the center of the Milky Way.  It's 26,000 light years distant.  But despite how far away it is -- and the fact that massive dust clouds lie between it and us, obscuring what light it does emit -- we've been able to find out an astonishing amount about it.

Sagittarius A*, as imaged by NASA's Chandra X-Ray Observatory (Image is in the Public Domain]

This, in fact, is why the topic comes up today -- some research out of the Université de Strasbourg that found evidence of a sudden flare-up of Sagittarius A*, around two hundred years ago.  For such a behemoth, it's been relatively quiet since its discovery in 1990.  But astrophysicist Frédéric Marin has found a cosmic glow that resulted from a brief, powerful flare of x-rays, during which Sagittarius A* was radiating a million times brighter than it is now.

The x-rays caused the clouds of dust surrounding the black hole to fluoresce; from the distance of those clouds from the event horizon of the black hole, Marin and his team determined that they must have been hit by a strong blast of x-rays about two hundred years ago.  (Keep in mind that because of the time-lag effect I described earlier, these times are all as seen from Earth; the actual flare-up occurred 26,200 years ago, or thereabouts.)

What caused the burst isn't known, but is surmised to be the sudden swallowing by the black hole of a denser blob of cosmic dust and gas.  As material goes into a death spiral toward the event horizon of a black hole, it speeds up, and electrons are stripped from atoms, leaving a whirling funnel cloud of charged particles.  These particles radiate away some of that energy in the form of x-rays -- the "smoking gun" that allows us to see black holes, which otherwise would be entirely invisible.

If you get a little nervous about such astronomical violence, there's no cause for alarm; neither Sagittarius A* nor any of its radiation blasts pose any sort of danger to us.  We'd only be in trouble if we were a great deal closer to the galactic center.

So we can just sit back and appreciate the amazing capacity the astrophysicists have for sifting through data and painting us a picture of what the universe looks like.  In this case, the last blaze of glory for a dust cloud that got sucked into a supermassive black hole 26,000 light years away.

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