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
Category: Space
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
Apollo 11 and the lost space age
I was very young when Neil Armstrong and Buzz Aldrin landed on the moon in 1969, so I have no memory of the landing, and only limited memory of the Apollo program in general. I think I remember seeing some of Apollo 17 on TV in 1972, the final flight to the moon. (At the … Continue reading Apollo 11 and the lost space age
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?
Why faster than light travel is inevitably also time travel
I've always loved space opera, but when I was growing up, as I learned more about science, I discovered that a lot of the tropes in space opera are problematic. Space operas, to tell adventure stories among the stars, often have to make compromises. One of the earliest and most pervasive is FTL (faster than … Continue reading Why faster than light travel is inevitably also time travel
The difficulty of going to Mars
There's been a lot of celebration this holiday season of the fiftieth anniversary of the Apollo 8 mission, the first time humans went into (relatively) deep space and orbited another body, the moon. I'm glad to see Apollo 8 getting some recognition. It's usually overshadowed by Apollo 11, the first mission to actually land on … Continue reading The difficulty of going to Mars
SETI vs the possibility of interstellar exploration
Science News has a short article discussing a calculation someone has done showing how small the volume of space examined by SETI (Search for Extraterrestrial Intelligence) is relative the overall size of the galaxy. With no luck so far in a six-decade search for signals from aliens, you’d be forgiven for thinking, “Where is everyone?” A … Continue reading SETI vs the possibility of interstellar exploration
The extraordinary low probability of intelligent life
Marc Defant gave a TEDx talk on the improbable events that had to happen in our planet's history for us to eventually evolve, along with the implications for other intelligent life in the galaxy. http://www.youtube.com/watch?v=_nCOhrYV7eg I find a lot to agree with in Defant's remarks, although there are a couple points I'd quibble with. The … Continue reading The extraordinary low probability of intelligent life
The difficulty of interstellar travel for humans
Futurism.com has an article reviewing the results of a survey they conducted with their readers asking when the first human might leave the solar system. The leading answer was after the year 2100, which make sense given our current level of progress just getting humans back out of low Earth orbit. But I think the … Continue reading The difficulty of interstellar travel for humans
97% of the observable universe is forever unreachable
The other day, I was reading a post by Ethan Siegel on his excellent blog, Starts With a Bang, about whether it makes sense to consider the universe to be a giant brain. (The short answer is no, but read his post for the details.) Something he mentioned in the post caught my attention. But … Continue reading 97% of the observable universe is forever unreachable