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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A ripple in space-time

I find it nothing short of mind-boggling how far we've come in creating equipment with which to explore the cosmos.

The first telescope was invented in 1608, and it was so crude (mostly with respect to the clarity, resolution, and magnification of the lenses) that it accomplished little more than make the blurry bits look bigger.  For example, Galileo used it to see Saturn's rings in 1610, but to him they looked like "handles" -- it took another half-century for the telescope to improve enough to allow Christiaan Huygens to see that they were actually full rings encircling the planet.

Not long after that, Isaac Newton invented the reflecting telescope, substituting parabolic mirrors for lenses, allowing for a much shorter tube length (and thus easier alignment).  The equipment gradually grew in power and resolution, and we were able to peer farther and farther out into space with increasing clarity.

Then, a little before 1900, things exploded.

In 1887, Albert Michelson invented the interferometer, which used a property of light to analyze the motion of the Earth through space, and which led directly to Albert Einstein's Theories of Relativity.  The idea here is that you take a beam of light, split off part of it, and reflect that split part at right angles to the original beam; then you bounce both pieces back so they recombine after traveling equal distances.  At that point you should see positive interference -- the wave crests and troughs should all still be "in phase" (i.e. lined up).

[Image licensed under the Creative Commons Krishnavedala, Michelson interferometer with labels, CC BY-SA 4.0]

Michelson and his colleague Edward Morley used the interferometer to test a model that had been used to explain the wave nature of light -- the "luminiferous aether."  The idea here is that if light is a wave, something had to be waving -- just as water molecules move in a water wave, air molecules move in a sound wave, and so on.  When light goes through a vacuum, what, exactly, is waving?  Because it was impossible for people to imagine how a wave could travel through a complete vacuum, it was suggested that space wasn't a complete vacuum -- that there is some kind of stuff (the aether) filling it, and it is through this medium that light propagates in space.

Because the interferometer involved beams of light traveling at right angles, Michelson and Morley surmised that this meant they were moving at different speeds through the aether because of the Earth's motion around the Sun.  To take the simplest configuration, if you place the device so that one beam is parallel to the direction of the Earth's motion and the other perpendicular to it, the parallel one would be dragged back by the aether on the way out and propelled faster on the way back (in the fashion of a boat first moving upriver, then turning around and going downriver).  The perpendicular one, on the other hand, would be deflected slightly to the side (like a boat moving cross-current).  In that case, it was possible to calculate exactly how out of phase the two beams would be with each other by the time they recombined at the detector.  You should see an interference pattern -- the two waves would partially reinforce each other and partially cancel each other out, creating a pattern of stripes.

Interference between two separate waves, the green one moving to the right and the blue one moving to the left -- the red wave is what you'd see as the waves pass through each other, with the peaks and troughs alternately adding to and subtracting from each other. [Image licensed under the Creative Commons Lookangmany thanks to author of original simulation = Wolfgang Christian and Francisco Esquembre author of Easy Java Simulation = Francisco Esquembre, Waventerference, CC BY-SA 4.0]

In fact, they didn't see an interference pattern -- the two beams were still completely in phase when they recombined -- which proved that the luminiferous aether didn't exist, and there was no "aether drag" phenomenon as the Earth moved through space.  It left unsolved the original question -- "what's waving when light moves through a vacuum? -- until Albert Einstein added the electromagnetic theories of James Clerk Maxwell to light apparently having an invariant speed regardless of how fast you're traveling to completely upend physics with his Special Theory of Relativity.

All this is just a lead-up to looking at how far we've come since then.  Because it's a twist on the Michelson-Morley interferometer that is currently being used to test a prediction of Einstein's General Theory of Relativity -- the existence of gravitational waves.  The General Theory, you'll recall, says that space-time is like a three-dimensional fabric that can be stretched and compressed by the presence of massive objects -- that, in fact, is what gravity is, a deformation of space-time that's a little like what happens when you put a bowling ball on a trampoline.  Objects are deflected toward a massive object not because there's a literal pull being exerted, but because they're following the lines of curved space-time they're passing through (picture rolling a marble on the aforementioned trampoline and you'll get the picture -- the marble might appear to be attracted to the bowling ball, but it's just following the curves of the trampoline it's rolling on).

So the General Theory states that if you have massive objects moving at a high velocity, they should create waves in space-time that would propagate outward at the speed of light.  Those waves would be really small, unless you're talking about very large masses moving very fast -- such as two black holes orbiting each other.  Here's a rather contrived way to picture it:  Take a barbell, and attach it at the center of the bar to a powerful motor that spins it rapidly.  Lower it into a pond so that the weights are sweeping in circles across the surface.  The rippling waves created would spread out across the pond -- those are what gravitational waves of two orbiting black holes do to the fabric of space-time.

The problem is, the waves are incredibly feeble.  Gravity, although it seems powerful, is by far the weakest force; in fact, it's about 10^40 times weaker than the next strongest force (electromagnetism).  (That's a factor of 10,000,000,000,000,000,000,000,000,000,000,000,000,000, if you don't like scientific notation,)  Consider that a weak magnet can pick up a paperclip -- overcoming the gravitational pull on the clip exerted by the entire planet.

So how in the hell could you detect something that weak, from so far away?

Enter LIGO -- the Laser Interferometric Gravitational-Wave Observatories, in Livingston, Louisiana and Hanford, Washington.  The idea here is precisely the same as the Michelson-Morley interferometer I described earlier, except instead of some mysterious aether, they're looking for gravitational waves sweeping past the Earth from a billion light years away.  What General Relativity predicts is that as those waves roll past, the tube of the device that's parallel to the wave should compress a little, while the one perpendicular would be unaffected (well, it'd shrink a little in diameter, but that wouldn't affect the experiment).  Since the two laser beams would for an instant be traveling different distances, they'd momentarily go out of phase, and you'd pick up an interference pattern.

And it worked.  In 2015, gravitational waves were detected, just as Einstein predicted.  They've now been seen over ninety times.

I've said before that just about every time I talk about astrophysics, I should just write "Einstein wins again!" and call it good.  (Physicist Sabine Hossenfelder, whose wonderful YouTube channel Science Without the Gobbledygook is a must-watch, just pops a photo up on the screen of Einstein sticking his tongue out every time his name comes up, and says, "Yeah, that guy again.")  Relativity, as bizarre as some of its predictions are, has passed every single test.  And now, the physicists are using LIGO to look for another prediction of Relativity -- that as gravitational waves pass other massive objects, the waves themselves will be deflected -- just as the waves in the pond would be if there was rock protruding above the surface of the water.  That deflection should be detectable from Earth, even though it's even more feeble than the original wave.

I bet they'll find it, too.  We've come light years from the crude telescopes of the seventeenth century -- in only four hundred years, we've progressed from blurry glimpses of large objects in our own Solar System to observing the faint traces of phenomena that occurred (to borrow a phrase) long ago in a galaxy far, far away.  With the speed our equipment is improving, you have to wonder what refinements we'd see a hundred years from now -- or even a decade.

What new wonders will open up before us?  Galileo and Huygens and the rest, I think, would be thrilled to see what they started -- and where it led.

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Weighty matters

Despite all of the daily litany of depressing and/or fury-inducing news, I'm pleased to say that the scientists are still hard at work showing us more of the internal workings of the universe, giving us better insights into the nature of the cosmos even as most of the rest of us focus on the minuscule doings of one species on a tiny planet around a completely ordinary star in the edge of a spiral galaxy that is one amongst billions.

Not to denigrate my fellow humans, of course.  I rather like being human, and I'm awfully fond of the little floating green-and-blue sphere where I live.  But it's nice to know that while we focus on our petty concerns, we have people who are looking outward, not downward.

The discovery I'm referencing is the observation by LIGO (the Laser Interferometer Gravitational-wave Observatory) of the collision of two neutron stars.  Neutron stars are the phenomenally dense cores of exploded giant stars; their matter is so compressed that, in the famous comparison, one teaspoon of neutron star-stuff would weigh as much as Mount Everest.

What is stunning about this observation isn't just the thought of what it would be like to see two such dense objects collide; in fact, the collision itself is just part of what's fascinating about this event.  Other amazing features are:

• In the moments before the collision occurred, the two stars were circling their center of mass at a rate of a thousand times per second.
• The collision not only created gravitational waves and a burst of light across the spectrum, it's thought that such events are what create a lot of the heavy elements in the periodic table.  So yes: the gold in your ring was very likely formed in a cosmic cataclysm.
• It is possible that the combined mass of the two stars exceeded the mass limit for a neutron star, and after the collision the stars immediately vanished -- became a black hole.  That point isn't settled yet.

The coolest part of all of this, however, is that the light and the gravitational waves from the collision arrived at detectors at the same moment -- showing that gravitational waves do indeed travel at the speed of light, which is one of the predictions of the General Theory of Relativity.  Put simply: Einstein wins again.  

If that doesn't put relativity into the "proven beyond a shadow of a doubt" column, I don't know what would.

The result was a flurry of papers being published, including one in Astrophysical Journal Letters that had 4,500 authors from 910 different institutions -- which surely must be some kind of record.

Daniel Holz, astrophysicist at the University of Chicago, who worked on the LIGO project, said, "I can't think of a similar situation in the field of science in my lifetime, where a single event provides so many staggering insights about our universe."

So maybe it's time to take a step back from the dreary ongoing march of political news and think a little bit more about the bigger picture.  I mean, the really big picture.  The one that encompasses the entire universe in which we live.  And now, because of a cataclysmic event 130 million light years away, one piece of which we are now able to view with greater clarity and understanding.

Weighty matters

Yesterday, we looked at how apparently it's impossible for some people to believe that a 79-year-old man in poor health could die in his sleep without there being a sophisticated Black Ops conspiracy to take him out.  Today, we find out that gravitational waves, the recent discovery that vindicated Einstein's Theory of General Relativity, are a sophisticated hoax.

Why would scientists do this, you might ask?  Is it so they can fool us into giving them more grant money?  Is it to put them in contention for a Nobel Prize?  Is it just so they can sit in their labs, surrounded by flasks of brightly-colored liquids, rubbing their hands together and cackling in maniacal glee?

Well, sure.  Of course it's all that.  But there's more.  There's always more, where these people are concerned.

First, we have the claim that the gravitational wave hoax is a clever scheme to convince the gullible public that the Earth is a sphere.  You think I'm making this up?  Watch this video by someone who goes by the handle "Stinky Cash," and which lays the whole thing out plainly.  Or, if you'd prefer not to waste five minutes and thousands of innocent brain cells in your prefrontal cortex, just read the following excerpt:

Unless you were in a coma, or living under a rock, you have heard that scientists have detected gravitational waves, and have proven Einstein right once and for all.  Every single science outlet and news outlet has reported this bullshit throughout the day.  The propaganda machine is working overtime right now.  First you have Reuters and the Associated Press, they wouldn't stop reporting this during the last twenty-four hours, then you had the Washington Post, you got The Wall Street Journal, you got CNN, you got BBC News, you got Fox News, you got MSNBC.  MSNBC and Fox News, reporting the same propaganda!  It's because they're owned and operated by the same people, with the same agendas.  Don't get fooled by that whole conservative/liberal crap.  NBC News, The Telegraph, Al Jazeera, CBS News, ABC News, Discovery News, Newsweek, Gawker, Futurism, even Neil deGrasse Tyson got in on the action today!

Yes, and that's undoubtedly because Tyson is actually an astrophysicist, and knows what he's talking about.  But do go on.

The propaganda machine was in full force today, and this was solely as a reaction to the Flat Earth Movement.  It was a reaction to all of the videos up on YouTube explaining how gravity doesn't exist.

Of course it is.  Because all of the scientists I know decide what to research by looking at YouTube videos uploaded by lunatics, and designing experiments to prove them wrong.

Gravity is a theory, an unproven theory thought up by an occultist to explain away everything that doesn't make sense about living on a spinning ball.  Why you're sticking to the bottom of it and still feel upright.  Why you don't feel the spin, and why you don't fall off this magical ball.  Gravity was invented to explain away all common sense...  Even Einstein knew this relativity thing was a bunch of bullshit.

We then see a quote with Einstein's picture, and attributed to him, saying, "If the facts don't fit the theory, change the facts," which apparently there's reason to believe that either was (1) Einstein being sarcastic about scientific fraudsters, or (2) something he never said in the first place.  But you know how that goes.

But Stinky Cash is far from done yet:

These people are in serious damage control mode.  Let's look at this quote from Stephen Hawking about why gravity is so important to them.  Because every lie in the scientific community -- or I should say, the pseudoscientific community -- every lie in the community has one agenda, and this is what it comes down to:  "Because there is a law such as gravity, the universe can and will create itself from nothing."  Is the agenda becoming more clear?  All of the lies coming out of the scientific community have one agenda, and that's removing god from creation.  Gravity is the false god of this false science.

Righty-o.  Let's move on, shall we?  Because if you thought that the Flat Earthers are the only ones who have a problem with gravitational waves, you are sorely mistaken.

Next, we'll turn our attention to the folks who think that the gravitational waves announcement was a false flag, to turn our attention away from... um... wait, I'm sure it will come to me.  Um.  Something. Something big:

LIGO Detects Gravitational Waves using blind injection simulation which means it is basically a hoax or false flag...  People need to understand if they cannot make it they fake it. 100 years the best research labs could not confirm the assumption so they just fake it. 

There was a massive preparation for this with Hawkins [sic] doing special lectures and hinting he is going to get a Noble [sic] Prize (you see the narrative), its [sic] all showbiz. 

Astrophysics needs to be rescued. (I have never seen so much inferences made from so little data!) 

Then, we had the scientists themselves positing that the whole thing might be the work of an evil genius.  UCLA physicist and LIGO collaborator Alain Weinstein said the following in an interview with Gizmodo: 

An evil genius is, by definition, smarter than we are.  We cannot rule out the evil genius hypothesis because we’re not smart enough. 

We thought very hard about this, and concluded that we didn’t know how to do it.  So anyone who did do it had to be smarter than us.

Can't argue with that kind of logic.  And although I'll point out that Weinstein was making a joke, the conspiracy theorists -- who are kind of notorious for not getting humor -- will immediately go, "AHA!  The scientists have let the truth slip!  We're on to them now!"

So there you have it.  The thrilling announcement about gravitational waves a couple of weeks ago is just another in a long series of scientific hoaxes, conspiracies, and general screw-ups.  I'm disappointed, honestly.  Not in the scientists, who are doing phenomenal work, and richly deserve either a Nobel or a Noble Prize, whichever they end up winning.  I'm disappointed in the conspiracy theorists, who really need to come up with some new tropes.  Because everything can't be a false flag, you know?  Eventually something has to be the truth.  Even if it's the idea that gravity is real, and is what is holding us down to the surface of the Earth right now.  It'd have to be a pretty fucking huge false flag to distract us from that.