Friday, January 25, 2013

Off-Topic: Against Tribalism

I'm trying to avoid rants in this blog, but this entry is pretty close to one.  In a rant, you allow the lines between reasoning and value judgments to blur, and the tendency is to offer no apologies for this. However, I would like to apologize for just that in the mostly off-topic post that follows: I'm not making much of an effort here to distinguish my emotional aversions from my evaluation of fact.

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Sunday, January 13, 2013

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.

Friday, January 4, 2013

Searching for Bracewell Probes - part 2

In the first part, we talked about some of the variables that I think could control the observables of a Bracewell Probe.  This is essentially a first, crude move toward mapping our ignorance of these hypothetical machines.  We can't know what Bracewell probes are yet, or even if they exist at all, but perhaps we can constrain or at least make some reasonable assumptions about what they could be.