The cosmic Tilt-O-Whirl

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 Ten.  (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 only 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 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.

The reason all this comes up is a paper that appeared last week in Monthly Notices of the Royal Astronomical Society about some research out of Cambridge and Oxford Universities into the structure of one of those cosmic filaments, which found that it shows some pretty peculiar properties.  The particular filament studied is "only" about 450 million light years away -- for reference, that's about two hundred times farther than the Andromeda Galaxy -- and contains just shy of three hundred galaxies.

Astronomers can now make amazingly accurate determinations of the rotational speed and direction of galaxies, despite the distances involved and the fact that galaxies are enormous enough that on a human timescale, you can't see the individual stars moving.  They use the Doppler effect -- the fact that if you're looking at a rotating galaxy (especially one that's edge-on), half the stars are moving away from us and half are moving towards us.  This means that the first bunch have their light stretched out (red-shifted) and the others have their light compressed (blue-shifted).  From the light coming from the center, you can tell what the galaxy's overall motion is with respect to us, so voilà -- you have the rotational speed and overall linear velocity.

I mean, it's not as simple as I'm making it sound in practice, but the principle is actually relatively straightforward.

And what they found is that within this filament, the individual galaxies are all rotating in approximately the same plane, and the filament as a whole is rotating -- in the same direction.

"What makes this structure exceptional is not just its size, but the combination of spin alignment and rotational motion," said co-lead author Dr. Lyla Jung, of the University of Oxford, in a press release.  "It’s like the teacups ride at a theme park.  Each galaxy is like a spinning teacup, but the whole platform -- the cosmic filament -- is rotating too.  This dual motion gives us rare insight into how galaxies gain their spin from the larger structures they live in."

It's kind of dizzying to think about, isn't it?  We're on a spinning globe, whirling in orbit around a star; the star, and its attendant planets and other oddments, are sitting in the spiral arm of a galaxy that is itself rotating at a breakneck speed; the entire "Local Group" of galaxies is spinning, too; and the Laniakea Supercluster, to which the Local Group and about a hundred thousand galaxies belongs, is zooming toward an unseen point called the "Great Attractor" about whose nature we haven't the first clue.  Now, we find that in addition to all this, each strand in the spiderweb of galaxy clusters that spans the entire cosmos is itself rotating, and has imparted that rotational direction to the galaxies within it.

I'm getting vertigo just thinking about it.

So think about this the next time you're tempted to say you're "going nowhere fast."  You're definitely going somewhere.  Really quickly.  In fact, the entire universe is kind of like a giant Tilt-O-Whirl.

Hope you don't suffer from motion sickness.

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