It sort of depends on the panel? It's possible even for science-y panels to go a bit more in-depth, and certainly for the more fannish panels, but it all depends on the panelists and sort of the audience. Worldcon is general audiences friendly, but the people who turn up in a panel on X are typically the people who not only are of the slightly-more-sciencey-than-average set known as Worldcon attendees, but also those who are interested in topic X and generally have some pre-knowledge, so it's possible to be more in-depth than a general-general audiences panel.