It’s summer, and that means I get to read fiction. The time I spend preparing for class during the semesters prevents me from often getting to enjoy the simple luxury of a book that I’m not either teaching from or reviewing. With my grades turned in, it times time to find a good paperback. Wanting to be a properly educated geek, I turned to , a list of books that was put together by a group of science faculty here at SIUE over good food and good beer. One of the books on the list that I haven’t read is Larry Niven’s “Ring World“. While I’m only a little way’s in, I already have this feeling of “Wow, this was great science once, but that was a long time ago.” Just as astronomy text books can go out of date, science fiction books based on science can go out of date.

No significant spoilers ahead.

I’m only going to talk about one idea at this point, because I’m still reading. In Ringworld, one of the underlying plot ideas is that the dense stars at the center of the galaxy had undergone a chain reaction of nova, and the light from the nova are going to make life impossible for humans and aliens within the known star systems. At the time of its 1970 publication, astronomers didn’t know what was at the center of the galaxy.
Astronomers (not me, I wasn’t alive yet) knew it was a high-mass region, but we didn’t know how that mass was distributed. Some thought it was high density objects like white dwarfs, neutron stars, and stellar mass black holes. Others suspected a super massive black hole. It was also possible that it was a region of just a lot of normal stars. Because of the intervening dust and gas combined with the high density nature of the region, we just didn’t really have the ability to find out what was there.

In the 1990s, however, technology was employed by UCLA astronomer Andrea Ghez to take high speed images of the center of the galaxy. These images were then aligned and stacked. By taking extremely short exposures, the noise introduced by the atmosphere was overcome. By stacking the images (adding together the light from successive frames), faint objects were drawn out of the darkness. In this case, Ghez and her team have been able to make out the orbits of series of stars (7 are highlighted in the image above) as they orbit an invisible point. This points observationally indicated mass of 2.6 million times the mass of the Sun is confined into such a small area that it has to be a black hole. Nothing else can be that dense.

So, Niven’s image of a dense region of exploding stars isn’t quite as possible as people might have thought in the 1960s (when he was writing it) and the 1970s (when people starting reading it).

That problem aside, Niven mentions gamma rays from supernova almost 30 years before we had the concept of gamma ray bursts being caused by certain subsets of supernova. I know he is just taking about gamma rays in general being given off during SN, but it does raise the question how how would a star be effected if it were in the a star cluster and took the fill blast of a gamma ray burst at close range. I’m going to have to think on that for a while, but it seems that if it were close enough (defining “enough” is the part where I’m going to need to think awhile) external heating could disrupt the normal energy transport mechanism and potential cause a burst nuclear burning in places where it normally would occur. These two effects could definitely disrupt a star in a “I just can’t make ‘er go, Cap’n” kind of way, but just Scotty could always repair the Enterprise, I suspect the star would rebound as well. But again, I need to think on this some more.

Still – neat science. The book makes you think, even if it also is showing some age. I’m sure I’ll have more to say as I continue to read this book and others this summer.