Readers respond to Anthony Lane's essay about Christopher Marlowe, Lauren Collins's report on Uniqlo, and Dhruv Khullar's article about A.I. and medical diagnosis. I very much enjoyed Anthony Lane's gleeful review of Stephen Greenblatt's new biography of Christopher Marlowe (Books, September 15th). Lane reminds us that Marlowe took the plot of his play "Dido, Queen of Carthage" from Virgil's Aeneid. I'm not convinced, though, that Virgil would "blench" at Marlowe's opening scene, where a lecherous Jupiter entertains Ganymede, a boy, on his knee. Have another look at the opening verses of the Aeneid (especially Book I, line 28).

The clustering and visualisation of high-dimensional data is a ubiquitous task in modern data science. Popular techniques include nonlinear dimensionality reduction methods like t-SNE or UMAP. These methods face the `scale-problem' of clustering: when dealing with the MNIST dataset, do we want to distinguish different digits or do we want to distinguish different ways of writing the digits? The answer is task dependent and depends on scale. We revisit an idea of Robinson & Pierce-Hoffman that exploits an underlying scaling symmetry in t-SNE to replace 2-dimensional with (2+1)-dimensional embeddings where the additional parameter accounts for scale. This gives rise to the t-SNE tree (short: tree-SNE). We prove that the optimal embedding depends continuously on the scaling parameter for all initial conditions outside a set of measure 0: the tree-SNE tree exists. This idea conceivably extends to other attraction-repulsion methods and is illustrated on several examples.

Of all the sectors that artificial intelligence is disrupting--finance, health care, transportation--the creative art of fiction writing seems like the least likely candidate to be impacted by A.I. But A.I. has arrived like a gift-wrapped box on the doorstep of the author community. Or do we need to worry that what's inside will put authors out of a job? It turns out that a new fiction-savvy bot is not out to take the place of the next Hemingway, Steinbeck or Atwood. Nor is it out to displace editors or other humans.

Of all the sectors that artificial intelligence is disrupting--finance, health care, transportation--the creative art of fiction writing seems like the least likely candidate to be impacted by A.I. But A.I. has arrived like a gift-wrapped box on the doorstep of the author community.