At the beginning of the year I commented on a fairly well known blog about the danger of an asteroid or comet impact- specifically, I completely disagreed with the author who was trivializing the danger. There were of course several wishy-washy waffle statements in the article so he could plead not guilty but it was obvious he was portraying it all as a joke. He answered my arguments with a string of replies that were increasingly hostile and insulting until perhaps he realized that was not such a good idea and deleted the entire conversation. http://www.wired.com/2015/01/fun-flaming-death/

Two weeks later came the Chelyabinsk event. Said author column has since been discontinued but I doubt his “fun with flaming death” article had anything to do with that. Many of the so-called experts who write popular science columns are among the worst liars and deceivers in popular culture media. The almost unanimous support for NewSpace and the flexible path among this bunch of charlatans shows they do not take their profession or integrity as journalists seriously.

Speaking of impacts. We really are stupider than the dinosaurs for not taking measures to protect ourselves.

Since you “find it an entertaining scenario where the 1st generation of sleeper ships is sent out and a century or so later the 2nd generation of black hole Starships chase after them.”, I would suggest A.E. Van Vogt’s “Far Centaurus, written in the early 1940’s.

Hope you enjoy.

https://en.wikipedia.org/wiki/Black_hole_starship

Time dilation has always fascinated me because it is so rarely used in sci-fi- yet time travel backwards in time is completely worn out. So tired of it. I find it an entertaining scenario where the 1st generation of sleeper ships is sent out and a century or so later the 2nd generation of black hole Starships chase after them. But whether a conveyance can actually travel at 99+ percent of the speed of light is a matter of debate. Some people seem to think those tiniest particles that cannot be avoided would destroy any ship and we will never go faster than a few percent.

As a side note it appears a movie based on Joe Haldeman’s “The Forever War” may finally get made into a movie.

http://deadline.com/2015/04/channing-tatum-the-forever-war-movie-richard-edlund-1201418549/

My own theory is that it is difficult for people to make any decision that does not immediately benefit them. We all know subconsciously we are going to die so most of our thinking is based on getting what we can before that happens- and not much else matters. I used to be skeptical about such subconscious devices until my own participation in rescue missions came back to haunt me.

We take it for granted this world is the way it should be because it is. When someone says the chances of the Earth getting hit by a large comet or asteroid in our lifetime is “astronomically low” then we accept that as not worth any more attention. It is not “we” that say this, it is “I” that reasons I will be dead so it does not matter. And so biological life may be too stupid to survive.

But as Dr. Spudis has done here, if we had lives that stretched across geological time, an indefinite lifespan, then our reasoning would be much different. This is actually not so hard to imagine when star travel is taken into account. The present most plausible method of traveling to another solar system is the “sleeper ship.” In this scenario our bodies are frozen with a process that does not damage cells and the temperature lowered to close to absolute zero. The Starship is propelled to a few percent of the speed of light, probably with a tremendous beam of energy. After a voyage lasting several centuries or even thousands of years, upon arrival the ship slows down, probably using H-bombs, and the crew is revived. The alien solar system is explored and the Starship begins the return voyage. When the crew arrives they have aged perhaps ten years while centuries or millennia have passed on Earth. It would be a reasonable assumption for the crew that while they were frozen a cure for old age would be found.

The people on a Starship would be far more concerned about the future than we are. In some modest lab on planet Earth somewhere a dog or monkey may wake up tomorrow after being frozen- with no ill effects- and then what I just wrote will matter.