Aliens and intergalactic spheres of influence

Over the years, I've done a lot of posts speculating about alien civilizations. My take is generally that while extraterrestrial life may be prevalent in the universe, complex life is rare, and intelligent civilization producing life is profoundly rare. This seems evident from our own history, where simple life appears to have started as soon … Continue reading Aliens and intergalactic spheres of influence

What do alien civilizations look like from afar?

This is a pretty good description of the Kardashev Scale of civilization energy usage. https://www.youtube.com/watch?v=rhFK5_Nx9xY I initially thought the video overestimated how close we are to being a Type I civilization, but then I remembered that the whole scale is logarithmic, so maybe not. It also mentioned that we might "choose" to build a megastructure … Continue reading What do alien civilizations look like from afar?

36 civilizations in the galaxy?

A new analysis is getting some attention, one claiming to have refined the old Drake equation and produced firmer numbers, leading to this conclusion: Under the strictest set of assumptions – where, as on Earth, life forms between 4.5bn and 5.5bn years after star formation – there are likely between four and 211 civilisations in … Continue reading 36 civilizations in the galaxy?

The Q-Drive and the difficulty of interstellar exploration

I've discussed the difficulties of interstellar exploration before.  To get a spacecraft to another star within a human lifetime requires accelerating it to an appreciable percentage of c (the speed of light), say 10-20%.  In general that requires titanic amounts of energy.  (Forget about the common sci-fi scenarios of going into warp drive or jumping … Continue reading The Q-Drive and the difficulty of interstellar exploration

The real issues with colonizing space

At Nautilus, Phil Torres argues that we should think twice about colonizing space.  His reasoning appears to be that as we spread throughout the universe, we will undoubtedly diversify into different species, and that those species may come to distrust each other, and eventually try to destroy each other. Now, I've argued before that most … Continue reading The real issues with colonizing space

What’s at the edge of the universe?

Gizmodo has an interesting article that someone asked my thoughts on.  Part of their "Giz asks" series, it asks various physicists what's at the edge of the universe?  The physicists polled include Sean Carroll, Jo Dunkley, Jessie Shelton, Michael Troxel, Abigail Vieregg, and Arthur B. Kosowsky. They all give similar answers, that space isn't known … Continue reading What’s at the edge of the universe?