The great thing about the Exploratorium, is that it works at many levels. Almost everything is hands on, so you tend to run to it first and press all the buttons and make it do its tricks. Then, if you're still interested, it's fun to read about what you would have learned, had you read all this stuff beforehand. Then you mess with all the levers and pull all the chains again. It makes everyone four years old, in a good way.