Not only were the individual detectors (essentially individual pixels) in these new arrays as sensitive or more sensitive than the ones we’d been using, but an array lets you make much more sophisticated measurements. Imagine taking a photograph of something one pixel at a time as opposed to having a whole array of detectors that gives you a whole picture. The latter would clearly be a lot faster. Arrays also preserve the continuity of the pixels in intensity and the spatial relations between the pixels. The arrays give you a much better picture. Even the first arrays were a huge breakthrough.
The arrays were a major advance and the technology has just kept taking off since they were introduced. You could say it really took off, since we have now used arrays on space telescopes like Spitzer. But in any case it has gotten better and better. I’m currently involved in the James Webb Space Telescope, which when it launches will be yet another huge advance in what we can do in infrared astronomy. I worked out that the capability to do astronomy will have doubled roughly every ten months ever since I told Frank Low I was going work for Carl Fichtel on gamma rays. Moore’s law for computers is doubling in capability every two years, but infrared technology is increasing in capability a lot faster.
So we were truly in the right place at the right time. With the advent of the arrays, with all the right objects to look at, and then with the culture shift to astronomers actually appreciating this field instead of resisting it, the infrared field really took off within 15 years of its inception.
What’s phenomenal about this story is that you would think this rapid growth would have started when the field started. But it didn't. I recently reviewed the progress of infrared astronomy in the late 1920s. That’s when I realized how good the work was that was done back then. But, it didn't drive rapid growth of the field. The technical breakthrough that enabled everybody in the field to get involved and to become a really big player in astronomy waited until the early 1980s.
What happened was that astronomers who were used to using visible imaging devices, electronic or photographic, could now take infrared data that looked very familiar using infrared arrays. It took a certain level of dumb stubbornness to map things by taking one detector and painfully scanning it over every point in the field, then figuring out how to reassemble all that into a map. I think people who were used to getting their data by just taking a visible light picture and analyzing the picture were fundamentally resistant to that. There were also cultural perceptions that I’ve been referring to, about how astronomers thought this was kind of a strange field and these physicists weren’t real astronomers, that they didn’t really understand all the nuances of astronomical thought.
