But first, a few updates... I went to a Birthday BBQ for Matthew, a friend and former UPSA member. I had a really good time, met a lot of new people, had some good discussions... it was fun!
I'm looking forward to preaching next Sunday. My Grandpa is coming, and Mai Lan's visit got postponed till next week, so she'll be here too! Some of my friends from church seem pretty excited, I hope I don't disappoint them.
So, on to ET and Dark Matter!
This is an idea I had a day or two ago when I was browsing Wikipedia on Dyson Spheres. Before I get in to that, it's probably best we cover some background, so we can all start from the same point.
While talking about the possibility of alien civilizations with some of his collegues, Fermi is said to have asked "Where are they?". Theoretically, if alien civilizations do exist, presumably some of them are a good deal older than humanity... and would have time to spread, and should be all over the galaxy... and so it can be viewed as surprising that we haven't heard from them or seen evidence of their existence. There are a number of counterarguments to this, such as using different means of communication, but it is an interesting idea... that if they exist, civilizations should be spread all over the galaxy by now.
This is a scale used to classify how advanced a civilization is, developed by Kardashev in 1964. Its premise is the idea that more advanced civlizations by necessity use/have available more power. A Type I civilization is supposed to use the energy of an entire planet (we're not there yet), a Type II civilization is supposed to use the energy of an entire stare, and a type III civilization is supposed to use the energy of an entire galaxy.
A Dyson sphere is the result of a thought experiment done by Dyson, with the idea that human civilization progressively needs more and more energy... so it was his theoretical proposed solution taking advantage of an entire star's energy output. It was originally described as a collection of satellites orbiting a star... a modification of the idea is to have a series of spheres of satellites, each using a certain frequency of energy, with the next shell using a different frequency, so that, theoretically, the entire star's output could be used, leaving only background radiation slightly higher than that of space itself.
Dark matter is basically matter in the universe we can't see... there are several theories of what dark matter is composed of. It was introduced as an idea since there seemed to be far more gravity than would be predicted by the light we've observed from Earth. Black holes could make up some dark matter, and scientists theorize about different types of particles that we wouldn't be able to detect from light... basically dark matter just means matter we can't see and don't know exactly what it is, but there's supposed to be quite a lot of it.
Ok, so perhaps you can see were I've been going with this. It is possible (though it seems unlikely) that Earth is the only planet with intelligent life. If there is other intelligent life, it seems likely that it could be much older than us. Civilizations, at least based on Earth, tend to require more energy the more advanced their technology becomes. Presumably, an old enough civilization would spred, and would eventually require the energy output of many stars. If Dyson spheres are feasible, there could be large numbers of stars that are being used as energy sources, but which would be invisible to us... except the effect of their gravity would still be detectable!
I'm proposing that one possibility for at least some of the dark matter in the universe... is actually due to Dyson spheres being used to harness many stars, blocking their light from us, but still having their normal effects on gravity. And, if you want to get in touch advanced civilizations... one of the best places to look might be areas of space where there is little visible matter, but still large gravitational effects. Also, if there are any mysterious large gaps of stars in a galaxy... so basically, you should look exactly where it seems like you shouldn't, based on light.
Well, that's my idea as it stands right now. As always, you are all welcome to comment and contribute!