4 ideas
Human scientists orbiting the neutron star Dragon's Egg beam a library of human knowledge down to the cheela by laser. Because the cheela live about a million times faster, they absorb it and pass human science within roughly a day of human time, a span of many cheela generations.
Life on Earth runs on chemical bonds between electron shells. Cheela life runs on nuclear interactions in neutron-star matter, which are about a million times more energetic and faster. The speed of metabolism, thought and generational turnover follows the energy scale of the bonds a life form is built from, so a whole civilization's clock can differ from ours by a fixed physical ratio.
To a being living a million times faster, a slower species looks like static scenery. Communication across such a gap cannot be a conversation, so the faster side has to send questions in batches and plan across generations to hold a single exchange.
Any fall or any object overhead is lethal, so height and 'up' become deep dangers in their culture. Fixed physical constraints set not only anatomy but also a species' fears, architecture and intuitions about space.