How is it that Plait says no excess infrared means it isn't dust clouds and unlikely comets, but then he turns around and suggests Dyson sphere? One of the defining characteristics of Dyson spheres is excess infrared.
Here is a hypothesis that fits the data gathered so far: interstellar debris. It can be oddly shaped. It can block the star's light without generating excess infrared. A cloud of it passing between Earth and KIC 8462852 would produce non-periodic luminosity variations. If the debris was a light year away from Earth, the largest chunk would have a diameter of around 500 km. There would be no constraints due to orbital velocity, and no aliens.
It’s fair to ask, if NASA is getting 50% of the world’s funding and the rest of the world is going to the Moon, why is it unreasonable to expect that we would go as well? There are two possible answers. Perhaps the rest of the world has an unrealistic impression of the complexity of the problem and their own capabilities. Or, perhaps our own space agency has turned into a bureaucratic morass that is incapable of finishing large projects without spending ridiculous sums of money. For sure the former is a factor, but there is plenty of evidence that the latter dominates.
I think we are victims of the unstoppable hand of history in this case. NASA built the pyramids. They drove the golden spike. They defined the nation for all future generations. But once they were done, we could not throw the heroes out on the street, and we certainly could not let them keep the checkbook. So everything that has happened in human spaceflight since about 1970 has been one big retirement party and career transition program. It’s a colossal waste of time and money to pretend otherwise.
But hope is not lost. There are many bright and hungry people out there who can make the next giant leap given the right support structure and incentives.
"When people are least sure, they are often most dogmatic." -- John Kenneth Galbraith