What are those buggers up to?

One proposed form
of Dyson swarm.

We learned efficient use of stellar energy because they blacked out this planet.  In fact, that's how we discovered them.  In a period of three days, Eros gradually disappeared from telescopes.  We sent a tug to  find out why.
--Ender's Game

Life sometimes imitates fiction.

In Orson Scott Card's popular 1985 science fiction novel, Ender's Game, Earth is threatened by a race of intelligent aliens, insect-like in appearance, who are seeking new worlds to colonize.  As the quote above suggests, the presence of the "buggers" was first evidenced by the sudden fading from view of the asteroid Eros.  We discovered that Eros had been surrounded by material that absorbed all of the sun's normally-reflected radiant energy, allowing the buggers to use that energy to power their activities on and inside the asteroid.  Eros appeared as black as starless Space as the Earth spaceships approached it.

Eros's fate came to mind as I read a brief article from Popular Mechanics about the strange behavior of "Tabby's Star," more formally known as  KIC 8462852, a star within our own Milky Way galaxy.  The star shows variations in brightness that are inexplicable under any known scientific theories.  The star was discovered in the 1890s, but has been intensely studied for the past four years by use of the Kepler space telescope.

According to a more in-depth article in Wikipedia, the star showed a dip in brightness of 15 percent in 2011 and of 22 percent in 2013.  Its overall average luminosity has dimmed by 20 percent since its discovery in 1890.

In the absence of other compelling explanations, some scientists have suggested that the dimming may result from an artificial structure or collection of satellites (a "Dyson shell" or "Dyson bubble" or "Dyson swarm") that an alien civilization may be constructing around the star, constructing it with the intent of intercepting a large amount of the star's radiant energy and using it for their own ends.  Such a project may be theoretically feasible, but far beyond our present engineering skills.

If our observations of Tabby's Star do reflect, therefore, a Dyson whatever, we would be observing the activities of a civilization far more advanced scientifically and technically than our own. 

Would such an advanced civilization be peaceful, or would it be human-like and aggressive.  Who knows?  The star is 1,480 light years from Earth.  That gives us more than 1,480 years to prepare for the encounter, in the unlikely event that our neighbors are able to travel near the speed of light, and that our puny civilization should attract their interest.

The buggers in Ender's Game, of course, had both the ability and the interest. 

It was only after Earth had totally destroyed the buggers' civilization in the greatest genocide of all time that we discovered that the buggers had mistakenly believed we were insensate animals, incapable of intelligent thought and consciousness.  They were actually far less savage killers, subjectively, than we were when we cleared the prairies of bison. 

Have fun, future generations.  No one ever said that life in the next millennia was going to be simpler than in the past.