@CamiCan Epcot is definitely great on a rainy day! The Land Pavillion has 3 attractions and 2 restaurants so you can easily spend a few hours there, and Universe of Energy is a 45 minute attraction. Epcot offers alot to learn, each pavillion can give you information about it's devoted topic.
Spaceship Earth- A slow dark ride that shows the history of communications through animatronic figures.
Innoventions- lots of hands on exhibits, some more for younger kids. The IBM exhibit and the House of the future are educational and interesting.
Universe of Energy- Teaches about energy in a humorous way with Ellen Degeneres. Some info may be dated but it's still a fun ride.
Mission: SPACE- Space simulator, it also has a lot of space artifacts while you wait in line and an exhibit area with space related games.
Test Track- Teaches about the automotive industry. The line has a lot of information about concepts and ideas for cars. The ride allows you to design a simulated car to see what functions gives you the most points. The ride itself is a thrill ride that goes through turns and loops and experiences cars go through when being tested for safety. The exhibit area allows you to use the car you designed to find your score and use the car for experiences like a racing game.
Imagination- Maybe not the most educational. The ride is cute and features a figment of imagination who sings about using your imagination... The movie Captain EO is dated but you may enjoy it.
The Land- Living with the Land provides a lot of interesting experiments to grow plants more efficiently such as a tomato tree. Circle of Life is a movie with the Lion King characters but features a lot of educational aspects. Soarin' is a fun ride that simulates hang gliding, not too much education there though.
The Seas ride is Finding Nemo themed, but the aquariums after have a lot to discover. They have dolphin training exhibits, manatees, divers, etc.
World Showcase has exhibits in each country with artifacts on display as well as restaurants and shopping experiences from that country. Mexico has a boat ride that passes it's restaurant themed to the Three Caballeros that's cute, but not educational. Norway also has a viking boat ride. China and Canada have 360 degree movies about their country. American Adventure is an audio animatronic show detailing American history. France has a film as well.
All of these can be educational experiences, while it' not as much as it used to be you can have fun and a lot for adults to enjoy.