The rate of scientific progress

Responsible Nanotechnology has this New Year's thought.

It stuns me to realize that less than a century ago most scientists believed that our galaxy -- the Milky Way -- was, in fact, the entire universe. Let's go back to the early 1920's...

At that time, the prevailing view of the cosmos was that the universe consists entirely of the Milky Way galaxy. Using the Hooker Telescope, Hubble identified Cepheid variables in several objects, including the Andromeda Galaxy, which at that time were known as 'nebulae' and had been assumed to lie within the Milky Way. His observations in 1922–1923 conclusively proved that these objects were much more distant than previously thought and were hence galaxies themselves, rather than constituents of the Milky Way. Announced on January 1, 1925, this discovery fundamentally changed the view of the universe.

Just 83 years ago, today. That's all.

Think about it. That means that the size of the recognized universe has expanded by billions of times in the last century. Meanwhile, of course, we've also learned much more about the inner workings of the universe -- of subatomic particles and fundamental forces -- knowledge that was nearly non-existent not long ago.

Now, if you consider how much we've learned since then, when you realize that a large proportion of what we now deem to be scientific truth is only recently discovered -- that is, within the last century -- then it has to make you wonder how much more we will learn in the next 83 years.