Sometimes it does show serious topics that are or have been pretty seriously researched. It'd is quite easy to filter out the entertainment or worthless talks in fact: See if math or diagrams are used.

Some talks are pie in the sky idea talks, essentially fuel for hypotheses. Filtered by talking about a serious subject but not showing math or diagrams.

And finally there are stories. Spotted by a typically "human" talk and "social" topic. Not useful.