What is a swiffer?

What does "emanate" mean in this sentence? The predictive signal is a steady rhythm of alpha waves emanating from the brain’s right hemisphere, which are closely associated with relaxing activities.

Jobs designed the entire workplace to maximise the chance of strangers bumping into each other, striking up conversations and learning from one another -> What does "strike up" mean?

However, to be more imaginative, says Lehrer, it’s also crucial to collaborate with people from a wide range of backgrounds because if colleagues are too socially intimate, creativity is stifled -> What does "stifle" mean?

As for predictions that the rise of the Internet would make the need for shared working space obsolete, Lehrer says research shows the opposite has occurred -> what does "obsolete" mean?

Cities, however, allow our ingenuity to grow by pulling huge numbers of different people together, who then exchange ideas -> what does "ingenuity" mean?

Creativity, it seems, thrives on serendipity -> what does "serenpidity" mean?