Why Interstellar Spaceflight is Hard

This was initially published in audio form as Burst 7 of the Wow! Signal. As part of the ongoing effort to tie this blog into that podcast and vice versa, we here present a slightly edited text version of the same.

This is a tutorial post, and is largely meant to bring some of our readers up to speed, since we are going to be talking about interstellar space flight more over the next months. If you have ever wondered by we can’t just get on a big rocket and fly to the stars, this is for you. If you already know why we can’t do that, then I think you might want to skip this one. 

Why Search?

In an earlier post, I argued that the current SETI program is not a silly waste of time if we want to search for ET and answer the question of whether we are alone, and I stand by that.  At the time I wrote that post, I didn't think that anyone would be interested in the why question. Of course we want to search, the only question is how, isn't it?  Maybe not for everyone.

All you have to do is to look at people like Frank Drake, Jill Tarter and Seth Shostak, who have

SETI Pioneer Frank Drake

devoted most of the careers to this topic, and you will realize that is is emotionally involving at a personal level, and not just "scientifically interesting".  It isn't purely a matter of scientific curiosity, and certainly not of ambitious scientific careering. 

Well, of course, the small number of people who study a topic are interested in it, and probably find it fascinating in some way.  What about everyone else?

So here is a question to ask yourself: if it was announced tomorrow that science knew for certain that there was another intelligent civilization in this galaxy, what would change for you?  Most adults are highly accomplished at keeping their own little worlds unperturbed.  Would the announcement of a distant ET civilization affect any major decisions you might make about your own life - your job, relationships, where you live, how many children you have, or any religious beliefs you might have?  Probably not you, but the younger generation, yes, because adolescents have left behind the comforts of childhood, and have yet to build their little worlds.  They don't mind being perturbed, and will often volunteer do some perturbing.  With announcement that we know about ET, their worlds just got much, much bigger.

Now it's not just Earthlings alone in the vast, cold universe anymore.  There are the others, possibly many others.  The universe no longer belongs solely to the astronomers, but is now alive, and belongs to everyone.

The Fermi Paradox - Part 1

This post is intended for those unfamiliar with the Fermi paradox. If you've already read a thing or two about it, I invite you to skip this one and wait until Part 2.

This is a companion post to Episode 2 of the Wow! Signal Podcast.  You can go over there and get the audio version with cool music.

For the purpose of this post, we are going to take as a given the null hypothesis about alien visitors to Earth - that this has never happened.  This is what the controversial astrophysicist Michael Hart called Fact A.

It turns out that accepting Fact A presents an interesting dilemma; first recognized by the distinguished physicist Enrico Fermi in 1950.  The unsolved problem is, that we would expect alien visitors on our planet, given a set of very reasonable assumptions. It’s really not such an extraordinary claim, after all. Assuming Fact A, this presents us with a puzzle. Either one or more assumptions have to go, or something really weird is going on.

Douglas Adams once famously wrote:

"Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

But space is also hugely old The entire history of Homo Sapiens is only about one twenty-thousandth the age of the Earth, and the age of the Earth is less than a third the age of the universe. What would seem to be likely is that at least local to our galaxy, time eventually overwhelms space with respect to galactic colonization.