A whole lot of nothing

Anybody have any ideas about what this is?

I've shown a bunch of people, and I've gotten answers from an electron micrograph of a sponge to a close-up of a block of ramen to the electric circuit diagram of the Borg Cube.  But the truth is almost as astonishing:

It's a map of the fine structure of the entire known universe.

Most everyone knows that the stars are clustered into galaxies, and that there are huge spaces in between one star and the next, but far bigger ones between one galaxy and the next.  Even the original Star Trek got that right, despite their playing fast and loose with physics every episode.  (Notwithstanding Scotty's continual insistence that you canna change the laws thereof.)  There was an episode called "By Any Other Name" in which some evil aliens hijack the Enterprise so it will bring them back to their home in the Andromeda Galaxy, a trip that will take three hundred years at Warp Factor 10.  (And it's mentioned that even that is way faster than a Federation starship could ordinarily go.)

So the intergalactic spaces are so huge that they're a bit beyond our imagining.  But if you really want to have your mind blown, consider that the filaments of the above diagram are not streamers of stars but streamers of galaxies.  Billions of them.  On the scale shown above, the Milky Way and the Andromeda Galaxy are so close as to be right on top of each other.

What is kind of fascinating about this diagram -- which, by the way, is courtesy of NASA/JPL -- is not the filaments, but the spaces in between them.  These "voids" are ridiculously huge.  The best-studied is the Boötes Void, which is centered seven hundred million light years away from us.  It is so big that if the Earth were at the center of it, we wouldn't have had telescopes powerful enough to see the next nearest stars until the 1960s, and the skies every night would be a uniform pitch black.

That, my friends, is a whole lot of nothing.

What I find most mind-bending about the whole thing, and in fact what sent me down this particular (extremely deep) rabbit hole this morning, is that the location of the filaments is thought to reflect quantum fluctuations in the matter immediately after the Big Bang, when the whole universe was only a fraction of a centimeter across.  As inflation took over and the universe expanded, those tiny anisotropies -- unevenness in the composition of space -- were magnified until you have filaments which are densely filled and gaps where there is almost nothing at all, and the universe resembles a Swiss cheese made of stars.

Of course, I'm using "densely filled" in a comparative sense.  The cold vacuum of space between the Sun and Proxima Centauri, the nearest star, really doesn't have much in it.  Dust, comets, possibly a rogue planet or two.  But even this is jam-packed by comparison to the Boötes Void and the others like it, wherein it is thought there are light-years of space without so much as a single hydrogen atom.

All of which makes me feel awfully small.  Our determination to act as if what happens down here is of cosmic import is shaken substantially by looking up into the night sky.  It's smashed to smithereens by considering the scale of the largest structures in the universe, which are threads of billions of stars making up a latticework -- and between which there is nothing but eternal silence and such profound darkness that it contains not even a single star close enough to see.

I don't know about you, but that makes me want to climb back under the covers and hug my teddy bear for a while.

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

A strange attractor

We've had a sudden warm, sunny spell -- very unusual for mid-April in upstate New York, where the weather can remain chilly well into May and we've sometimes had snow on Mother's Day.  One thing you have to say for upstaters; we don't waste these opportunities when they come.  There was a steady stream of runners and cyclists on the road past my house, and as for me, I spent the day working in the front yard putting in some new raised-bed gardens.  The result was (1) some landscaping that's going to be gorgeous when it's full of flowers in a couple of months, (2) sunburned back and shoulders (not severe, fortunately, but a little redder than they should be), and (3) sore muscles.

The cloudless skies continued into yesterday evening, which brought me outside once again -- this time to enjoy a glass of wine and watch the stars.  As I sat there, the darkness deepening around me, I was once again astonished by how beautiful a clear night sky is.  It amazes me that anyone can look up into the star-spangled blackness and not be awestruck.  I looked at those hundreds of little pinpoints of light -- each one actually a blazing sun, some of them orders of magnitude bigger than our own -- and wondered, as I have so often before, which of them have planets, and which of those planets might host life.

Then, it struck me how little of the universe I'm actually seeing.  Regular readers of Skeptophilia might recall my posting this image of the Milky Way, but it's worth seeing again:

[Image licensed under the Creative Commons Pablo Carlos Budassi, Milky way map, CC BY-SA 4.0]

I know it's hard to read the text, so I encourage you to go to the site where it comes from, and spend some time zooming in on it.  In particular, find the little circle in the lower center that's labeled "Naked Eye Limit."

Every individual star you have ever seen without a telescope is inside that little circle.

Even our own galaxy is largely a mystery to us.  There's an enormous black hole at its center called Sagittarius A* ticking and purring (I can't help hearing that in Carl Sagan's memorable voice), which we know of by its x-ray and gamma ray signature; much of what else we know was either discovered in the last century using powerful telescopes, or else is inferential.

Amongst the inferential bits is one of the oddest mysteries in astrophysics; the Great Attractor.  The Great Attractor is the apparent center of gravity of the Laniakea Supercluster, a huge assemblage that contains not only the Milky Way and its nearby companions, the Andromeda Galaxy and the Magellanic Clouds, but one hundred thousand other galaxies, each containing something on the order of one hundred billion stars.  (Once again invoking Carl Sagan's voice for emphasis.)

If your mind boggles at this, so does everyone's.  Or should.  But the weirdest thing is that we have no idea what the Great Attractor actually is.  It is "inconveniently placed," as one astronomer put it (well aware that stating it that way is about as ridiculously anthropocentric as you can get).  Between us and it is the center of the Milky Way, so we can't currently see it, and won't be able to for another hundred million years, at which point the Solar System will have orbited around the galactic center and will be pointing toward whatever the Great Attractor is.  It may be a huge collection of galaxies, with enough mass to gravitationally attract everything in the region; it may be something odder.

We simply don't know.

And if that's not enough for you, it was recently discovered that the Great Attractor itself is moving toward something even bigger, the Shapley Supercluster, which is the largest gravitationally-bound structure we know of.

At that point in my musings, my glass of wine was empty, and I felt minuscule enough for one night.  Sitting there, looking up into the vastness of space, left me (as it always does) with a keen awareness of the insignificance of all of our little Earth-bound problems.  It didn't, and doesn't, bother me; being overawed by the grandeur of it all is hardly a bad thing.  It's comforting to know that as we toil through our busy little lives down here, overhead the majestic cosmos still soars, extending in every direction farther than we can see, or even imagine.

I think I'll go outside again this evening.

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

A whole lot of nothing

Anybody have any ideas about what this is?

I've shown a bunch of people, and I've gotten answers from an electron micrograph of a sponge to the electric circuit diagram of the Borg Cube.  But the truth is almost as astonishing:

It's a map of the fine structure of the entire known universe.

Most everyone knows that the stars are clustered into galaxies, and that there are huge spaces in between one star and the next, but far bigger ones between one galaxy and the next.  Even the original Star Trek got that right, despite their playing fast and loose with physics every episode.  (Notwithstanding Scotty's continual insistence that you canna change the laws thereof.)  There was an episode called "By Any Other Name" in which some evil aliens hijack the Enterprise so it will bring them back to their home in the Andromeda Galaxy, a trip that will take three hundred years at Warp Factor 10.  (And it's mentioned that even that is way faster than a Federation starship could ordinarily go.)

So the intergalactic spaces are so huge that they're a bit beyond our imagining.  But if you really want to have your mind blown, consider that the filaments of the above diagram are not streamers of stars but streamers of galaxies.  Billions of them.  On the scale shown above, the Milky Way and the Andromeda Galaxy are so close as to be right on top of each other.

What is kind of fascinating about this diagram -- which, by the way, is courtesy of NASA/JPL -- is not the filaments, but the spaces in between them.  These "voids" are ridiculously huge.  The best-studied is the Boötes Void, which is centered 700 million light years away from us.  It is so big that if the Earth were at the center of it, we wouldn't have had telescopes powerful enough to see the next nearest stars until the 1960s.

That, my friends, is a whole lot of nothing.

What I find most mind-bending about the whole thing, and in fact what sent me down this particular rabbit hole this morning, is that the location of the filaments is thought to reflect quantum fluctuations in the matter immediately after the Big Bang, when the whole universe was only a fraction of a centimeter across.  As inflation took over and the universe expanded, those tiny "anisotropies" -- unevenness in the composition of space -- were magnified until you have filaments which are densely filled and gaps where there is almost nothing at all, and the universe resembles a Swiss cheese made of stars.

Of course, I'm using "densely filled" in a comparative sense.  The cold vacuum of space between the Sun and Proxima Centauri, the nearest star, really doesn't have much in it.  Dust, comets, possibly a rogue planet or two.  But even this is jam-packed by comparison to the Boötes Void and the others like it, wherein it is thought there are light-years of space without so much as a single hydrogen atom.

All of which makes me feel awfully small.  Our determination to act as if what happens down here is of cosmic import is shaken substantially by looking up into the night sky.  It's smashed to smithereens by considering the scale of the largest structures in the universe, which are threads of billions of stars making up a latticework -- and between which there is nothing but eternal silence and such profound darkness that it contains not even a single star close enough to see.

I don't know about you, but that makes me want to climb back under the covers and hug my teddy bear for a while.

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

This week's recommendation is a classic.

When I was a junior in college, I took a class called Seminar, which had a new focus/topic each semester.  That semester's course was a survey of the Book Gödel, Escher, Bach: An Eternal Golden Braid by Douglas Hofstadter.  Hofstadter does a masterful job of tying together three disparate realms -- number theory, the art of M. C. Escher, and the contrapuntal music of J. S. Bach.

It makes for a fascinating journey.  I'll warn you that the sections in the last third of the book that are about number theory and the work of mathematician Kurt Gödel get to be some rough going, and despite my pretty solid background in math, I found them a struggle to understand in places.  But the difficulties are well worth it.  Pick up a copy of what my classmates and I came to refer to lovingly as GEB, and fasten your seatbelt for a hell of a ride.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]