How do I know what research I have already done?
I can't cross the ocean, but I can travel through seas. I want to know if I have done astronomy research or not (if it makes a difference, I am playing as Haroun al Rashid).
Best Answer
Click the research tab (detailed view). Is in the top left of the screen if I remember it right (looks like a blue Erlenmeyer flask). There you can see the techs you have, tech that can be researched, eras, dependencies, you can create queues, etc.
The researched techs are colored cream-ish.
In the screen 
you can see that agriculture was researched, while pottery etc. can be researched.
Astronomy is in Renaissance era, on the top row if I remember it right, been a while :).
Pictures about "How do I know what research I have already done?"
How do I find my current research paper?
Finding Current Research Using Free Online ResourcesHow do you know if the research is already published?
How do you know if a resource has been published?What are some ways to find your research?
Try the following research resources:How do I find the original research topic?
Overview: How To Find & Choose A Research TopicHow I became a researcher
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Jess Bailey Designs, Pavel Danilyuk, Zen Chung, Zen Chung